A Text Book of Practical Botany 1 PDF

 A Text Book of Practical Botany -1 ALGAE, FUNGI, LICHENS, MICROBIOLOGY, PLANT PATHOLOGY, BRYOPHYTA, PTERIDOPHYTA, GYMNOSPERMS AND PALAEOBOTANY  DR. ASHOK M. BENDRE FORMERLY HEAD, DEPARTMENT OF BOTANY AND DR. ASHOK KUMAR F...

 A Text Book of Practical Botany -1 ALGAE, FUNGI, LICHENS, MICROBIOLOGY, PLANT PATHOLOGY, BRYOPHYTA, PTERIDOPHYTA, GYMNOSPERMS AND PALAEOBOTANY  DR. ASHOK M. BENDRE FORMERLY HEAD, DEPARTMENT OF BOTANY AND DR. ASHOK KUMAR FORMERLY, READER OF BOTANY MEERUT COLLEGE MEERUT ~ RASTOGI PUBLICATIONS 'GANGOTRI' SHIVAJI ROAD, MEERUf- 250002, INDIA  ,------------~- ------ A Text Book of Practical Botany -1 ALGAE, FUNGI, LICHENS, MICROBIOLOGY, PLANT PATHOLOGY, BRYOPHYTA, PTERIDOPHYTA, GYMNOSPERMS AND PALAEOBOTANY NEW DELHI OFFICE: 9, RANI JHANSI ROAD ( MOTIA KHAN) NEW DELHI 110055 A Text Book of Practical Botany -1 ISBN 10: 81-7133-923-9 ISBN 13: 978-81-7133-923-5 ©RESERVED All rights reserved. No part of this book (any edition/reprint) may be produced, stored in a retrieval system or transmitted in any form what so ever or by any means electronically or mechanically or by photocopying, recording or otherwise without the prior written permission of the Publisher. Infringement of copyright is a criminal offence. TITLE CODE NO. B-14 Revised Edition : 2009-2010 PUBLISHED BY RAKESH KUMAR RASTOGI FOR RASTOGI PUBLICATIONS, 'GANGOTRI' SHIVAJI ROAD, MEERUT-250 002 PHONES: 0121 - 2510688, 2515142, 2516080 FAX: 0121-2521545 email: [email protected] Website: www.rastogipublications.com PRINTED AT CAPTIAL OFFSET PRESS NEW DELHI, INDIA (JMD I 0708) Contents 1. Introduction 1-15 Preamble 1, Laboratory etiquette 1, Work plan 1, Necessary instruments 1, Microscope 1, Other laboratory provisions 4, Fixing agents and preservatives 4, Laboratory techniques 4, Record of work 11, Herbarium 12. 2. Algae 16 -69 Preamble 16, Classification 20, Chlamydomonas 21, Volvox 22, Chiarella 24, Hydrodictyon 25, Cladophora 26, Fritschiella 28, Coleochaete 29, Oedogonium 31, Zygnema 34, Chara 36, Vaucheria 40, Diatoms 43, Ectocarpus 45, Fucus 47, Sargassum 50, Batrachospermum 55, Ceramium 56, Polysiphonia 59, Oscillatoria 63, Nostoc 64, Scytonema 66, Rivularia 67, Gloeotrichia 68. 3. Fungi 70 - 130 Preamble 70, Classification 71, Plasmodiophora 74, Synchytrium 77, Saprolegnia 79, Achlya 81, Phytophthora 83, Albugo 86, Rhizopus 89, Erysiphe 92, Sphaerotheca 95, Phyllactinia 97, Aspergillus 99, Penicillium 102, Claviceps 103, Peziza 106, Ascobolus 107, Morchella 109, Ustilago 111, Puccinia 114, Agaricus 120, Polyporus 122, Alternaria 124, Cercospora 126, Colletotrichum 128. 4. Lichens 131 - 136 Ascolichens 131, Crustose lichens 131, Foliose lichens 132, Fruticose lichens 134, Basidiolichens 136. 5. Microbiology 137 - 141 To culture bacteria 137, To isolate micro-organisms from mixed culture and grow a pure culture 139, To stain and study bacteria 140, To measure bacterial cells 140, Microscopic examination of curd 141.  Contents 6. Plant Pathology 142 -166 Preamble 142, List of diseases 142, Black wart disease 143, Damping off 144, Late blight of potato 145, Green ear disease of bajra 146, Downy mildew of pea 148, White rust of crucifers 149, Powdery mildew of barley 150, Loose smut of wheat 151, Covered smut of barley 152, Whip smut of sugarcane 152, Black stem rust of wheat 153, Brown (orange) rust of wheat 154, Rust of linseed 155, Early blight of potato 156, Tikka disease of groundnuts 157, Wilt of cotton 158, Red rot of sugarcane 159, Bacterial blight of rice 160, Citrus canker 160, Tundu disease of wheat 161, Leaf curl of potato 162, Tobacco mosaic 162, Leaf curl of tabacoo 163, Leaf curl of papaya 163, Yellow vein mosaic of bhindi 164, Little leaf of brinjal 164, Root knot of vegetables 164. Important plants and their bacterial diseases 165, Important plants and their viral diseases 166. 7. Bryophyta 167 - 219 Preamble 167, Classification 169, Riccia 169, Riccia fluitans 173, Marchantia 173, Pellia 180, Porella 184, Frullania 188, Anthoceros 191, Sphagnum 196, Funaria 203, Polytrichum 208, Pogonatum 215. 8. Pteridophyta 220 - 272 Preamble 220, Distinguishing characters of taxa 220, Psilotum 223, Lycopodium 227,Selaginella 233, Equisetum 239, Adiantum 247, Nephrolepis 253,Pteridium 256, Marsilea 262, Azolla 469. 9. Gymnosperms 273 - 312 Preamble 273, Classification 273,Distinguishing characters of taxa 274, Cycas 275, Pinus 288, Ephedra 303. 10. Palaeobotany 313 - 327 Preamble 313, Classification 313, Distinguishing characters 314, Rhynia 315, Homeophyton lignieri 317, Lepidodendron 318, Calamites 320, Lyginopteris 322, Cycadeoidea 324, Williamsonia 326 Appendix 329 - 330 Fixing agents and preservatives 328, Stains 328, Mounting media 329, Recommended stains and mounting media 329. Index 331 - 332 (B-14) Introduction to Laboratory 1 Chapter Preamble Science is a systematised study based on facts and observations. It involves curiosity, inquisitiveness and unbiased analysis. Most of the scientific work is done in a laboratory. It provides an opportunity to a person with scientific frame of mind to see and study various aspects of an object under observation. Hence, a biology student too is obliged to attend laboratory work-out with utmost sincerity, honesty and inquisitiveness. Laboratory Etiquette Necessary Instruments The study of living things in laboratory requires The variety of instruments required depends upon that facilities provided are properly used. the nature of work. It has, however, been found One is expected to complete the assigned work convenient to prepare a small kit in suitable within a specified time. This requires proper containers such as a pencil box containing utilization and planning of time. One should, 1. a pair of forceps, therefore, keep busy with own work and wherever 2. two fine, long handle, dissecting needles, necessary consult the teacher alone. 3. glass droppers, Laboratory provisions should be handled with 4. good and sharp razor, utmost care. At the end of the laboratory period, 5. safety blade, working place should be left clean and in order. 6. a fme hair brush, Laboratory exercise to be performed should be 7. a pair of sharpened pencils, read in advance and one is expected to arrive to 8. pencil eraser, the class theoretically prepared. 9. a clean and soft handkerchief and Work Plan 10. practical record with cover file and spare pages, etc. 1. Listen and understand the instructions and information given by teacher-in-charge. Microscope 2. Work out or observe the materials carefully. 3. Mount to prepare slides as per requirements. It is the most indispensable instrument in a biology 4. Study the preparations or specimen carefully. laboratory, so much so that it comes to be called 5. Draw suitable diagrams in a proper sequence 'The primary instrument of the biologists'. It and label them in your practical record. helps to increase the resolv.iJlg power (property 6. Write down the observations sequentially and to distinguish objects lying very close as watch carefully if variations occur. separate bodies) of human eye which fails to 7. Get your work checked by teacher-in-charge recognise objects lying closer between 0.01 to and make necessary corrections. 0.25 mm. (B-14)  Introduction to Laboratory Fig. 1. A dissecting microscope. iris diaphragm Some common types of microscopes are listed below- '""'---mirror 1. dissecting microscope, 2. compound microscope, 3. binocular microscope, 4. phase contrast microscope and 5. electron microscope. Of these, dissecting microscope and compound Fig. 2. Compound microscope. microscopes are very commonly used by the students. At one time, it employs one ocular (eye piece) and one objective, in working position. As such, it is [I] Dissecting microscope also known as monocular-mono-objective microscope. It is used for dissection, specially during taxonomic Construction. The microscope is built around studies, embryo separation, etc. a strong basal foot and a vertical limb. The foot Construction. It consists of basal foot, a supports the vertical limb. vertical limb, stage and a lens. The basal foot is a A round, rectangular or square stage is fixed stand. The limb has an attached stage made of glass to the limb. It is provided with spnng clips to hold plate. A folded arm which can be moved vertically the slide in position. holds the lens. A mirror is attached at the base of A movable or fixed sub-stage is situated the limb. directly below the stage. It is provided with an iris Mechanical operation. 1. Move the lens and adjust diaphragm and condenser lens. Iris diaphragm is a it over the object. wheel-shaped metal disc to regulate the aperture, 2. Illuminate the object suitably by adjusting the through which light rays reach the condenser and mirror. are passed to an object. Condenser is a system of 3. Focus the object by using adjustment screw. two or more lenses under the stage which receives [II] Compound microscope parallel light rays from mirror and converge them at the level of stage. It is one of the most commonly used and by far the A movable concave mirror is fixed at the most suitable microscope in the Botany Laboratory. lowermost part of the limb to focus a converging (B-I4) Introduction to Laboratory cone of rays at the level of specimen. Whether day 2. Light is adjusted by turning the mirror towards or artificial light is used as a source, concave mirror the source of light and also by moving the converges the light if there are no condensing lenses. sub-stage up and down, as well as with the Body of the microscope is composed of a tube. help of iris diaphragm. At the upper end of the tube, is an ocular (eye 3. A prepared slide is placed on the stage. Object piece) which can be changed for lower or higher is adjusted just over the stage aperture. values of magnifications. At the lower end of this 4. The object is located and focussed with a low- tube is a revolving nose-piece with about three power objective using coarse adjustment. objectives viz. low power, high power and oil 5. If higher magnification is desired, nose-piece immersion. These magnifications range from 3.2x is turned to next higher power. Fine adjustment to lOOx. The conventional low power objective is can be used freely at this stage, while the use lOx. of coarse adjustment be avoided. Tube of the microscope is vertically movable 6. High power objective and subsequent higher with the help of coarse and fine adjustment screws powers are used only when object is properly on the limb, operated by a rack and pinion system. mounted under coverslip. Coarse adjustment moves the tube rapidly, while 7. The object should always be observed with fine adjustment screw does it gradually. both eyes open. Mechanical operation. 1. Microscope is placed in Care. 1. Before and after the use, all the lenses maximum diffuse light. Direct sunlight is and metal parts including stage should be harmful for the eyes. The northern light is most cleaned. The lenses are cleaned with tissue suitable. If light source is artificial, filter paper, muslin cloth or clean and soft (preferably blue coloured) is used. handkerchief. ,I I' 1\ ,: ii' I, 'I' , , " , Ii' , II, , 'I.: tray staining rack watch glass scissors needle eraser slide with coverslip pencil Fig. 3. Some laboratory provisions and necessary instruments.  Introduction to Laboratory 2. Microscope is kept covered when not in use. ready. These may be either square or round shaped. Proper wodden box, plastic bags, bell jars or The standard thickness of the coverslip is 0.17 mm. even a clean cloth can be used. 3. Objectives should not be ordinarily removed Fixing Agents and Preservatives from the nose-piece. The plants or plant parts, collected fresh need to be 4. Operating screws, condenser, iris diaphragm, immediately killed and subsequently preserved for a mirror and stage or stage clips should always long time. be handled carefully. For this purpose, a few chemicals are used Other Laboratory Provisions which do not cause any structural disturbance or distortion of the material. Carnoy's fluid, Formalin- Some other provisions available in the laboratory aceto-alcohol, Formalin-propiono-alcohol, Randolph's include staining rack, dropping bottles, slides, cover modified Navashin fluid and Bouin's fluid are some glasses, watch glasses, petri dishes, beakers, enamel of the common agents used. trays, wash bottles, spirit lamp, hone, strop, dusters, Plants are generally fixed immediately after etc. Some of these are described below- collection but these can also be fixed after bringing 1. Staining rack. It is mostly made of wood them to laboratory. The collected material must to hold the dropping bottles. The capacity of number always be kept completely immersed in preservatives. of bottles per rack varies. 2. Dropping bottle. The stains, chemicals, Laboratory Techniques mounting media, etc., are stored in these bottles. [I] Section cutting This glass bottle has a narrow mouth fitted with a slotted cock. Cock is provided with a beak that Sections of preserved material are cut in suitable permits the liquid to flow out in drops. planes for histological and ecological studies. Razor 3. Slides. The size of slides is mostly is suitable for cutting the sections in laboratory. 3" x I" (25 mm x 75 mm). It is about 1 mm thick. 1. Boning and stropping. Razor should be These are used to mount the material under study. sharp and free from nicks. Hence, it should be 4. Cover glasses. The cover glasses are sharpened on a hone (fine-grit stone). Oblique, mounted on the object when the preparation is fmally T.S. T.S. T.L.S. T.L.S R.L.S R.L.S. V.T.S. Fig. 4. Planes for section cutting. Introduction to Laboratory uniform and slow strokes are carefully given to the razor with edge foremost on this stone. After honing, uniform strokes are given on the strop (a smooth leather belt). The leather side of the belt is first slightly oiled and then razor is moved over. This should be done more frequently than honing, to maintain razor edge in good condition. 2. Planes. The following are a few commonly A needed planes- In case of cylindrical organs : (e.g., stems, roots, etc.). Transverse. The section is cut by passing razor's edge at right angles to the longitudinal axis. Longitudinal. The section is cut by passing razor's edge at right angles to the transverse axis. Two sections are possible in this plane. 8 (i) Radial Longitudinal section (R.L.s.) if it passes along one of the radii. (ii) Tangential Longitudinal section (T.L.s.) if section is cut along one of its tangents. In case of dorsiventral organs (e.g. leaf, thallus of liverwort, etc.), transverse section is cut. It is known as vertical transverse section (being cut in vertical plane). 3. Method. Following steps would be useful for section cutting. 1. Soft, thin and small materials are placed in pith either by piercing a hole with a needle or c by splitting it longitudinally with a blade. The Fig. 5. Method of section cutting. A. holding the material, pith used include carrot root and radish root, B. right way of holding the razor, C. holding the material and stroke of the razor. potato tubers, etc. 2. A razor must be held properly to cut the 6. More and more uniform strokes are used till section. The handle and the blade of the razor desired quality and number of sections are should be at right angles to one another. The obtained. Care is taken to keep the material handle should remain free while the index and the razor flooded with water. finger is placed on the hooked end of the 7. Sections float in water on the razor's edge. razor; 1st, 2nd and 3rd fingers pressed against These are carefully lifted by a fine camel hair the thick back edge of the razor and thumb brush and then transferred to a watch glass against the milled surface of the thick shank containing water. of blade. 8. After the section cutting is over, the razor is 3. The material or the pith with embedded tapped dry and cleaned without disturbing the material is held between the thumb and the edge. It is honed, stropped and encased. fingers of the left hand. 9. The sections which float on water in the watch 4. The material in the left hand and the razor's glass are considered to be thin. edge should form right angle. 10. These sections are lifted by a hair brush, 5. The razor is now moved quickly over the placed on a slide in a drop of water and material and the stroke is completed in one observed through microscope. A thin and action only. uniform section is selected for staining.  Introduction to Laboratory [II] Stains and staining 5. The stained material is ready for mounting. Fungi are stained in cotton blue as given The selected sections need to be stained. The stains below- help to distinguish different tissues, cells or 1. A drop of cotton blue (prepared in lactophenol) inclusions from one another by developing specific is placed on a slide. colours. Acetocarmine, Aniline blue, Crystal violet, 2. Fungal hyphae is now placed in this drop. Erythrosine, Hematoxylins, Fast green, Light green 3. The slide is run over the flame of the spirit and Safranin are some of the commonly used stains. lamp so that the stain is warmed up. 1. Specificity. Most of the stains are specific 4. The preparation is now ready for mounting. in reaction and are purposely used so that definite 3. Combinations. Commonly two or more structures or substances are stained. The following stains are employed wherever tissue differentiation are some of the stains used for staining different is found. Combination of acidic and basic dyes of structures. contrasting colours is of general use. This permits Achromatic figure Cutinised cell wall the distinction of woody tissue from non-woody Aniline blue Crystal violet tissue. The following few combinations are Erythrosine Erythrosine Fast green Safranin commonly recommended- Light green Callose 1. hematoxylin and safranin, Cellulose cell wall Aniline blue 2. safranin and fast green, Aniline blue Chitin 3. safranin and aniline blue, Delafield hematoxylin Safranin 4. safranin and crystal violet and Fast green Proteins Light green Safranin 5. crystal violet and erythrosine. Lignified cell wall Mitochondria 4. Staining procedures. There are two types Crystal violet Crystal violet of preparations-semi-permanent and permanent. The Safranin Plastids procedures differ in both the cases. These are given Suberised cell wall Crystal violet below. Safranin Iron hematoxylin CytoplasI1t Nucleus (a) For semi-permanent and temporary Aniline blue Crystal violet preparations. Certain preparations are made for Erythrosine Hematoxylin temporary use. The material is studied and the slide Fast green Safranin is then discarded. The method for staining them is Light green Chromosomes given below. Hematoxylin Safranin 1. The selected sections are transferred from 2. Single stains. Safranin or fast green is used watch glass containing water to another alone to stain filaments of algae, fungi, sections of watch glass containing principal stain bryophytes, spores of pteridophytes, pollen grains (e.g. hematoxylin, safranin or crystal violet). of gymnosperms, etc. Aniline blue or safranin is 2. The sections are allowed to remain in the stain suitable for algae. for sometime (for about 4-5 minutes). Following is the common method of staining. 3. Excess amount of stain is removed by washing 1. The material is kept in a watch glass. A few the sections repeatedly with water. (This can drops of stain are added so that the material be seen under the microscope. The stain should is immersed in the stain. be taken either by lignified or non-lignified 2. The material is allowed to remain so for a tissues. Otherwise the section should be washed few minutes and allowed to take stain. The till the stain disappears from one type of time required varies with materials. tissue). 3. After the stain is taken up, the excess of stain 4. If de staining is not achieved, sections are is washed off in water. The washing is repeated washed with acid alcohol. In this case, further till stain stops coming out. washing with water is necessary till traces of 4. In some cases, excess stain is removed by acid acid are removed. water or acid alcohol if water alone fails to 5. This is followed by transfer of sections to a do so. watch glass containing counter-stain Tntroduction to Laboratory (e.g., safranin, fast green, erythrosine). This 9. Pure xylol is the last stage of clearing. Section stain acts on the tissue more rapidly than the is now ready for mounting. principal stain. Therefore, section is kept in 10. Mounting is done in Canada balsam. this stain for short period (about a minute or two). Specific Schemes for Staining 6. Excess of stain is removed by washing stained Combinations sections with glycerine (15-20%). The section should distinctly bring out demarcation between (for temporary and semi-permanent preparations) tissue system while preserving the colour of the stain. 1. Hematoxylin 2. Safranin & fast green 7. The section is now ready for mounting. & safranin or aniline blue (b) For permanent preparations. In certain Select a section Select a section cases preparations need to be stored permanently as.j,.j, a future record. The method of preparation followed Stain with hematoxylin Stain with safranin.j, (for 4-5 minutes) is described below. Wash with water.j, 1. The section is fIrst stained with principal stain.j, Wash with water (aqueous hematoxylin, safranin or crystal Wash with ammonia water.j, violet). till stain turns blue Destain with acid alcohol 2. The section is then washed with water till no (tap water is suitable if if necessary alkaline).j, more stain dissolves and water remains.j, Wash repeatedly with water colourless..j, Wash with water 3. Section is passed through a graded series of.j, Stain with fast green or alcohol for dehydration. A watch glass is fIlled Stain with safranin aniline blue with requisite amount of alcohol, (beginning.j, (for about a minute) Wash with glycerine.j, with 30% alcohol) and the section is transferred.j, Wash with glycenne to it. This watch glass should always be.j, Mount in glycerine covered with another larger one. In order not Mount in glycerine to disturb the section, used alcohol is removed by glass dropper. All the 30% alcohol is replaced with 50% alcohol. This procedure is [III] Mounting an object repeated till 70% of alcohol grade is reached. Mounting is necessary to properly positlon an 4. At this stage, counterstain is employed object for clear view. Lactophenol, glycerine and (e.g. safranin, fast green or erythrosine prepared glycerine jelly are used for temporary mounting in 80% or 90% alcohol). while Canada balsam is used for permanent 5. This stain acts quickly and as such section is mounting. washed immediately after the requisite time is 1. Mounting media. Following are some of over. the common media. 6. Destaining is done by washing sections with (a) Canada balsam. It is a resin obtained from 90% or 100% alcohol. a conifer-Abies balsamea, most suitable for 7. The section is now transferred to absolute permanent slide preparation. The material to be alcohol to complete the dehydration. mounted should come through alcohol (dehydration) 8. Clearing now begins with 25% of xylol and xylol (clearing) series. (25 cc of xylol and 75 cc of absolute alcohol). The sections are gradually passed through xylol (b) Lactophenol. It is a mixture of equal parts series of 25%, 50%, 70%, 90% and finally of phenol crystals, lactic acid, glycerine (sometimes transferred to pure xylol. If dehydration is not two parts) and distilled water. Stains may be mixed complete, pure xylol turns white or turbid. At with this medium (e.g. cotton blue in lactophenol this stage section should be passed through used to stain ,fungi) or copper acetate is added to reverse series. preserve green colOllf of t4e pigment.  Introduction to Laboratory Specific Schemes for Staining Combinations (for permanent preparations) 1. Hematoxylin 2. Safranin & fast green & safranin 3. Crystal violet & erythrosine Select a section Aqueous safranini A (If necessary use mordant) crystal violet j, j, Stain in hematoxylin Water change, (If necessary destain until with mordant) colourless j, j, Wash in ammonia water Dehydration with or tap water 30% alcohol B j, j, Dehydration with 30% alcohol 50% alcohol j, j, 50% alcohol 70% alcohol j, j, 70% alcohol 90% alcohol j, Stain with safranin j, Stain with fast green! c erythrosine RNGIOSPERMS Destain with 70% alcohol Destain with 90% alcohol CANNA j, j, T.S.ROOT 90% alcohol Absolute alcohol j, j, INDIRA Absolute alcohol Clearing or de-alcoholizing D j, with 25% xylol Clear with 25% xylol j, Fig. 6. Method of mounting coverslip. j, 50% xylol j,. 2. Care. Following care should be taken 50% xylol j, 70% xylol during mounting- 70% xylol j, 1. Object should be mounted in the centre of the j, 90% xylol j, slide. A simple method may prove suitable for 90% xylol j, Pure xylol this purpose. Take a piece of thick and white Pure xylol j, cardboard sheet larger than the size of the j, Mount in Canada balsam slide. Place the slide over it. Draw lines along Mount in Canada balsam all the four edges. Join all the four corner (c) Glycerine. Pure glycerine diluted to 15-25% points diagonally by two lines. The point, is widely used. Semi-permanent and temporary where these two lines cross, gives the centre preparations are mounted in glycerine. of the slide. While mounting an object, place (d) Glycerine jelly. Jelly is also used for the slide over this drawn sheet and an object mounting. It is made of gelatin 1 : glycerine 7 : on the central point. water 6. 2. No air bubbles should enter the medium while Warm the gelatin for two hours by adding mounting. This results in drying of medium water. Phenol (1%) is added later. Add crystals of and preparation is spoiled. To avoid air safranin if desired. Allow the solution to cool and bubbles, touch one side of the coverslip to the settle into jelly. drop of mounting medium on the slide. Support Many other mounting media like cedar oil, the coverslip by needle and lower it gradually dammar, balsam, venetian turpentines and synthetic before finally removing it. resins are also used. 3. Use the necessary small quantity of mounting medium so that it does not flow on to the Introduction to Laboratory slide. If so, use little lesser quantity for the 7. Drain out all the macerating fluid. Wash the next preparation. The extra amount can be material repeatedly with water till all the traces soaked by touching a piece of blotting paper of acids are removed. to the edge of the coverslip. 8. The material is now stained with safranin and 4. Preparation should be clean, hence the edges destained with water. of slide and the coverslip alone should be held 9. The pulp of the material is crushed with the between the fingers. glass rod and teased by a needle so that it is 5. Labels are pasted uniformly on one side of spread over the slide. the prepared slide. It should carry the name of 10. The material is mounted in glycerine or the division or generic and specific names, the glycerine jelly. part mounted and the section's plane. At the 2. Harlow's method. The following are the bottom be written, the name of the student steps- who has prepared the slide. 1. Sliced and boiled material is treated with 3. Sealing the coverslip. Temporary chlorine water for two hours. preparations can be sealed with Canada balsam, gum, 2. It is then washed with tap water. dammar, nail polish, etc. Such a preparation is called 3. The material is now boiled in sodium sulphate a semi-permanent preparation. for about 15 minutes. Sealing is done by simply painting the edges 4. The liquid is transferred to a watch glass. of the coverslip with sealing agent in such a way 5. The material is now washed repeatedly with that the space between the slide and the coverslip water. gets filled with the agent. It will prevent the 6. It is teased with needle or crushed with glass mounting medium from drying. rod. Similarly ringing table should be used for 7. The teased material is evenly spread on the sealing the round coverslips. The use of Canada slide, stained in safranin and then mounted in balsam for ringing is more convenient. glycerine or glycerine jelly. 3. Schultze's method. The following are the [IV] Maceration steps- This is a technique of separating individual cells 1. Material is sliced and boiled in a test tube from a group or tissue by dissolution of pectic filled with water. middle lamella. There are three common methods. 2. The tube is now fIlled with concentrated nitric 1. Jeffery's method. The following are the acid, to which a few crystals of potassium steps- chlorate are added. 1. Cut the fresh or dried material into small slices 3. The test tube is heated slowly and gradually thinner than a tooth-pick. till the material is bleached white. 2. Fill the test tube with material. Boil it in water 4. The liquid is then transferred to watch glass till it settles down at the bottom indicating and drained out leaving only the material. that it is free from air. 5. The material is now washed with water. 3. Replace water with the following macerating 6. Later it is teased or crushed, till individual solution- (i) 10% Nitric acid cells appear isolated. (90 cc water + 10 cc nitric acid) [V] Peelings (ii) 10% Chromic acid (90 cc water + 10 cc chromic acid) The removal of leaf epidermis, to study the number, Mix both these acids in equal parts. arrangement, distribution and structure of stomata, 4. Heat the test tube filled with macerating fluid. is called peeling. The method consists of breaking 5. Stop heating as soon as the material becomes the leaf irregularly with a force. This easily separates soft and pulpy. a little part of the lower epidermis which remains 6. Transfer the fluid to a watch glass. protruding on the lower surface of the leaf. It is  Introduction to Laboratory pulled out so that a long ribbon or strip of lower 5. Slide is now inverted with smeared side epidennis gets removed. If lower epidennis does upward. It is now ready for staining.; It may not separate easily, a needle or forceps is inserted, also be stained immediately without inhnersing and a small part is fIrst slowly broken. This can in killing fluid. now be held in hand and considerably large strip is 2. Staining procedure. The method described pulled apart. below is called Belling's iron acetocannine method. The stripped lower epidennis is stained in The slides are stained in the following way. safranin and washed. It can be mounted in glycerine 1. A few drops of acetocannine are placed on or glycerine jelly. If permanent preparation is the smeared material or unsmeared anthers are desired, normal procedure of dehydration and kept on slide in a drop of acetocannine. After clearing is followed before mounting it in mounting a few minutes, stain is replaced with a fresh medium. drop of stain. 2. At this stage, anthers are crushed and large [VI] Smearing pieces and debris are removed. Smearing is used to study the chromosomes. The 3. Slide is gently heated over a flame, cover glass method consists of spreading the cells in a single is placed on the material and uniform pressure layer. The cells are smeared at a stage when they is applied on the material by placing blotting are in the process of cell division. This pennits the paper on the cover glass and then pressing it. study of chromosome structure and various stages of 4. Slide is immediately sealed with melted wax. cell division. Pre-requisite for such studies is the Another simple method is followed where killing of dividing tissues at a proper stage of cell anthers are smeared on the cover glass. It is then division and selection of material where cells are not inverted on the slide with a drop of acetocannine. frrmly united with one another by middle lamellae. Cover glass is sealed with slide by melted wax. Microsporocytes of Trillium spp., Lilium spp. and [VII] Squash Oenothera spp., as well as anthers of Tradescantia spp., Triticum spp. and Nicotiana spp. and root tips This technique is also useful in the study of cell of onion, Ficus, etc. fIxed at appropriate time are division especially mitosis and the chromosome widely used for smear preparations. structure. Root tips give the best results. For this 1. Technique. The following are the steps- purpose allow the onion bulbs to grow in bottle 1. Slides should be perfectly clean for preparation fIlled with water. If the lower root portion of the of smears. In order to do so these are bulb touches the water, it quickly sends forth large immersed in sulphuric acid potassium number of roots. Cut the root tips and fIx them. bichromate mixture or concentrated nitric acid 1. Place the fIxed root tip in a drop of 45% for a long time. acetic acid. 2. Slides are thoroughly washed with running 2. Place a cover glass over the tip and diffuse water and fInally dried with absolutely clean acetocannine. cloth, free from dust and lint. 3. Tap and apply uniform pressure over the cover 3. Fresh anthers dissected out from the buds are glass. placed in the centre of slide. The anthers on 4. The squash preparation is ready. the slide are crushed with scalpel or another clean slide. [VIII] Micrometry 4. Slide is now inverted over a petri dish (Measurement by means of microscope) containing killing fluid (most suitable being This is the procedure used to measure the size of Randolph modifIed Navashin fluid), in a way microscopic objects like cell, spore, pollen grain, that smeared surface comes in contact with the etc. The method consists of using a calibrated ocular fluid. It should be allowed in this position for micrometer (a glass disc with engraved scale). The about 10-15 minutes. calibration is done by comparing ocular with stage Introduction to Laboratory stage micrometer scale 1 dn = 0.01 mm 1. Thus as in above example (when objective 45x and eye piece lOx are used), each division of 1 2 3 4 5 6 7 ocular (micrometer) would measure the distance I I I I I I 14.411 ~~s 11111111111111 of 14.4/! or microns. 2. Now remove the stage micrometer and place a slide with object to be measured. 11111111111 150 3. Use oculometer (micrometer) to measure the dns width of a bacillus or diameter of a pollen Fig. 7. Matching ocular micrometer with stage micrometer. grain or a fungal spore. For example a fungal spore measures 2 divisions. micrometer (a slide bearing an engraved scale of 4. The diameter of a fungal spore would be known values). The stage micrometer is usually ruled (2 x 14.4/!) 28.8/!. into tenths and hundredths of a millimeter (scales The length, breadth, diameter, etc. of different in hundredths of an inch are also obtainable). Each structures can be measured in this way. of the 100 parts of stage micrometer scale represents 0.01 mm or 10/! (1 mm = 1000 microns or /!). Record of Work 1. Calibration of ocular micrometer. The calibration is done as follows. After the preparations are ready, these should be 1. Place the ocular micrometer inside the eye carefully observed, salient features noted and drawn piece by unscrewing the upper lens. on a practical record sheet. The following 2. The stage micrometer slide is now placed on suggestions would prove useful. the stage of the microscope and focussed to 1. Always use a sharp and pointed pencil for thin observe the scale. and uniform lines. 3. The stage micrometer scale is moved in such 2. Punched holes should be on the left hand side a way that it lies by the side of the scale of of the drawing sheet. ocular micrometer when focussed. 3. Diagrams of the entire plant or its various 4. Now compare and count the divisions on both aspects are drawn on the same page. The micrometers to fmd out the number of divisions diagrams of unrelated specimens should in no where both scales are equally opposite. case be drawn on the same page. 5. For example when 45x objective and lOx eye 4. The sequence of the diagrams should always piece are used, divisions of ocular micrometer be-external features, anatomy and then are found equal to 72 divisions of stage reproduction. micrometer. 5. For anatomical studies an outline diagram 6. CalIbrate the ocular micrometer as given below. followed by a cellular sketch of its suitable Stage micrometer scale : sector are drawn one above the other on the 100 dns = 1 mm (=100/! or microns*) same page. 1 dn =:: 0.01 mm (=10/! or microns) 6. All the parts of the diagram must be labelled. If, 50 dns (ocular micrometer) Capital letters are used for labelling. The labels = 72 dns (stage micrometer) are arranged one below the other in a row. then, 50 dns (ocular micrometer) 7. Labelling lines should never cross one another. = 0.72 mm (=720/! or microns) Beautification and shading are not required therefore, Idn (ocular micrometer) until specific effects are to be produced. = 0.14 mm (=14.4/! or microns) 8. Every diagram must have caption at its bottom 2. Measurement of objects. The following (e.g. T.s. stem). method is useful in actually determining the size of 9. Date is written in the left hand comer of the objects. An example is given below. page. *One milimeter = 1,00011. 10. Classification and name of the plant are given 11, this Greek letter is an abbreviation for micron. in the right hand comer of the sheet. -1 12 Introduction to Laboratory 11. The description is written either on the reverse side of the drawing sheet or on a new facing page. 12. During description only technical terms are used. The points of identification are added in the end. 13. Anatomical studies are described as others. A section should be described starting from epidermis to the central region; give thickness of layer (how many cells deep), shape and size of the cells constituting it. Also give in details of the structure of stele and vascular bundle. Collection Field work is one of the most essential part in the Botanical study. It permits to come across many types of plants, otherwise not seen and available in the laboratory. It is, therefore, advisable to go round Fig. 8. Collection bottles_ many localities and explore their vegetation. Organised excursions or outings, led by experienced containers. But if material (except a few algae and persons, add to the knowledge of common plants in fungi) are collected in lesser quantities a herbarium nature. sheet is prepared. Even if large quantity of such While on a collection trip, local or outstation, plants is available, one plant with fertile parts be following things are to be carried along. preserved in the form of a herbarium sheet, while 1. Containers. For packing the collected others should be packed in a container. material, preferably carry plastic unbreakable Every tube should be labelled. It is desired to containers or polyethylene bags. write the name of the specimen, place and date of 2. Preservatives. Formalin-Acetic-Alcohol collection. The place of collection and date should (FAA) or Alcohol 70% or Alcohol 90%, and/or also be written on a small piece of white card with Formalin 6%-10%. a pencil, on the spot and inserted in the container. 3. Other requirements. Scalpel, knife, blade, On return to laboratory, material is identified with forceps, pencil, paper, a hand lens, a bag or the help of standard books. A label bearing name vasculum for keeping plants or plant press with of the division and class to which the material many newspapers or blotting papers. belongs, the name of the material, date and place After collecting the plant, it should be of collection and also the name of student is pasted immediately killed and preserved or pressed to avoid on the container. All the containers should be of its rotting and dehydration. Plants are either sprinkled uniform size as far as possible. or immersed with a little of the killing agent at the spot. On return to the laboratory collected material Herbarium should be transferred to new and suitable containers with fresh preservative. The plants should be A collection of dried plant specimen, mounted on completely immersed in the preservative. sheets is known as herbarium. Freshly-picked A few plants e.g. filamentous algae, fungi, specimen are dried and pasted on mounting paper reproductive parts of bryophytes, fertile parts of of regulation-sized herbarium sheets. The purpose pteridophytes and different parts of gymnosperms, of such a collection is to study the vegetation of a if collected in large quantities, are preserved in locality and maintain its record. Introduction to Lo.boratory tightened by iron chain and screws. This is used HERBARIUM for pressing specimen after they are brought to the laboratory. Vasculum may be used in case only a small number of plants are to be brought back. 2. Collection. Collected plants are placed in the collecting sheets. The most practical size is 16;' x 23 inches; when folded 16'12 x 11 '12 inches. Old newspapers serve this purpose to an appreciable extent and a large supply should always be included in the kit. A specimen collected should represent root, stem, leaves and flowers. The plants are placed between the sheets or newspapers in such a way that relation between different organs is maintained. Herbaceous plants, 2 feet or less higher, may be collected entire. These can be bent to V or N shape whenever necessary. The most desirable is to collect a branch, about one foot high, containing leaves and flowers. In cases, where entire plant or branch MEERUT COllEGE MfERUT cannot be folded to the size of herbarium sheet, HERBARIUM only reproductive and fruiting parts and a stem with Field Book No 12- Famlty Atb""1uJ4Ceal! a few leaves are collected. Bot NIIm6 Alb'i0 Canduia. Local Name lia.fed. Rat= Delicate reproductive parts collapse even if Placellk~(.{oc.'otywh Road Notes pressed fresh. These can be pressed perfectly by Date20.1,~ applying bits of moist paper to the fresh reproductive CoIlecled by Hab,b structures and spreading them when plants are placed in the press. If parts of the herbaceous plant are Fig. 9. A typical herbarium sheet. thick and difficult to dry, split them before placing [I] Preparation of herbarium sheets on the collecting sheet. Water plants collapse if dried by usual method. 1. Equipment. On excursion, for the collection of These should be rolled up in wet paper when in the plants, several items required to be carried include- field and brought to the laboratory. On return to 1. Trowel or pick, the laboratory, these plants are placed in water and 2. Collecting can (vasculum) or field plant press, floated out on sheets of white paper. The sheets are 3. Heavy laboratory plant press, taken out of water carefully, so that the various 4. Blotting papers or newspapers, parts do not cohere. The white sheets are placed in 5. Collecting sheets, the blotting paper and then dried as usual. 6. Mounting sheets, After specimen has been collected and placed 7. Gum, gummed tape, labels, notebook, pen and in collecting sheet, it is kept in plant press. This pencil, etc. collecting sheet be placed in between blotting papers, Trowel or pick is used to dig out the plant as one on either side. a whole, wherever possible. A light-weight field While on collection it is important to note date, press is most practical. It is made by taking two locality, habitat, height, method of branching, colour pieces of plyboard or heavy binder's board of of reproductive parts, common name, etc. This 12" x 17" size. These are held together by two should be noted separately in a field-book. pieces of heavy cord or straps tied or buckled 3. Pressing. The collecting sheets should be together and press can be carried over the shoulders. transferred to a heavy laboratory press. It must be A heavy plant press carries sheets of size at least remembered that specimen would acquire the same 11'12 x 17 inches. It is made of iron and tied and shape, as on collecting sheet, after pressing. The  Introduction to Laboratory press is securely tightened. It may also be equally 6. Care of sheets. Herbarium sheets are often useful if field press is kept under heavy weight. attacked by museum pests, fungi, etc. To guard The press should be placed in a warm, well-aired against them, specimen are fumed with carbon place to dry. bisulphide, 3-4 times a year. Mounted specimen may After 24 hours, press is taken out and opened. also be treated with mercuric bichloride or copper The old newspapers and blotting sheets are replaced sulphate. To prevent them from attack, powdered by new unused ones. At least such 3-4 changes are naphthalene balls or gamaxene powder be also given at an interval of 2-3 days. An average spread from time to time. This ensures durability specimen takes about a week for complete drying. and long life of the herbarium sheet. Sometimes to hasten the process of drying, plant press may be placed near the source of heat. [IT] Some important herbaria 4. Mounting. The specimen are ready for There are many institutions allover the world which mounting once they are completely dry. The standard house collections of herbarium sheets. The size of the sheet is 16'12 x 11'12 inches. However, arrangement is mostly based on either Engler's, 16 x 10 inches size also has been used. The paper Bessey's or Bentham and Hooker's system of should be of good weight and not thin and flexible. classification. A list of a few well-known herbaria The quality should be so, that it does not turn yellow of the world is given here. even with a considerable lapse of time. 1. Herbarium Nationale' de Histoire To mount, one of the following methods would Laboratories de Phanerogamie, Paris, France. be found convenient. National institute, established in 1635, more than 1. The gum is spread on a glass plate and 5,000,000 specimens, mostly phanerogams and specimen is laid on it. As soon as all the parts vascular cryptogams. come in contact with gum, it is lifted and then 2. Herbarium of Botanisches Institute de placed in a position on a mounting sheet. Universtate, Kiel, Germany. Governed by Kiel 2. The specimen is inverted and painted with gum University, established in 1875, more than 90,000 by a brush and then transferred to a mounting specimens. sheet. 3. Royal Botanic Gardens, Herbarium, Kew, 3. The specimen is placed on a herbarium sheet Great Britain. Government institution of Royal and small strips of gummed tape or cellulose Botanic Gardens, established in 1841, world-wide tape are pasted at suitable places, so that most collection, more than 6,00,000 herbarium sheets. of the part remains loose. After mounting the specimen, a label is pasted 4. British Museum of Natural History, in the right hand lower comer of the sheet. This London, Great Britain. A private body, established carries information regarding botanical name of the in 1753 more than 4,000,000 specimens, relating to plant, common name, date, collector's name, place all the plant groups. of collection etc. 5. Gordon College Herbarium, Lahore, 5. Arrangement of sheets. The sheets, are Pakistan. A private mission, established in 1893, finally arranged in accordance with standard ferns of the Himalayas and flowering plants of classification (preferably Bentham and Hooker's for Punjab, Kashmir, Afghanistan, Baluchistan, Pakistan Angiosperms or the most accepted ones for other and Nepal, numbering about 55,000. groups of plants). The sheets are arranged into 6. U.S. National Museum (Botanical groups according to species, genera, families, classes, Department), U.S. Smithsonian Institution, orders, series and sub-divisions, etc. Each group is Washington, U.S.A. Independent government placed in a separate envelope, slightly larger than agency, founded in 1868, world-wide collection of the herbarium sheets (e.g. 17 x 12 or 17 x 11 all groups, more than 2,700,000 specimens. inches). Each of such envelopes must be labelled 7. U.S. National Arboretum, Herbarium, and a proper index be written or pasted over it. Washington, U.S.A. Federal agency, established in Introduction to Laboratory 1934, 37,000 vascular plants of economic 100,000 specimens from western India and collection importance, cultivated and woody. of fungi established by Mundkur. 8. Herbarium of the Department of 11. National Botanic Research Institute, Systematic and Plant Geography of the Botanical (formerly known as National Botanic Garden) Institute of the Academy of Sciences of Lucknow, India. C.S.I.R. body, established in 1948, Leningrad, Russia. Medical garden, established in more than 40,000 specimens. 1714, herbarium added in 1823, state owned Besides these herbaria, many well-reputed institution, representing flora of U.S.S.R., northern collections exist; some of them being-Botanical Asia and world-wide collections, more than Gardens Herbarium, Singapore; National Botanic 5,000,000 herbarium sheets. Gardens Herbarium, Kirstenbosch, South Africa; 9. Indian Botanic Garden, Herbarium, Herbarium Bogoriensis, Bogor, Indonesia; Botanical Calcutta, India. Established in 1787, government Museum and Herbarium, of the State University of agency, more than 1,000,000 specimens, representing Utrecht, Netherlands; Forest Research Institute, phanerogams and ferns of India and adjacent Herbarium, Dehradun, India; Botanical Survey of region. India Herbarium, Pune, India; Indian Agricultural 10. Herbarium Blatter, St. Xavier's College, Research Institute, Botany Division Herbarium, New Bombay, India. Private body, representing more than Delhi, India. (B-14)  2 Chapter Algae Preamble Algae and Fungi were fIrst included in the group cryptogamia, established by Linnaeus. Later, this group was divided into Thallophyta, Bryophyta and Pteridophyta. Of these, Thallophyta included Algae and Fungi. The group Thallophyta shows following characteristics. (1) Absence of differentiation into stem, root and leaves. (2) Sex organs generally unicellular, if multicellular, sterile envelope or jacket is absent. (3) Zygote does not develop into multicellular embryo while inside the female sex organ. Thallophyta is one of the largest group of Plant Kingdom. The members of this group are found in almost all the types of habitats. Though algae and fungi are customarily placed under Thallophyta, they are very different from one another, in their morphological features, metabolism, reproduction and life histories. Algae and fungi differ from one another mainly due to presence of chlorophyll in the former and its absence in the latter. This makes algae autotrophic and fungi remains heterotrophic. Reserve food in Algae is the form of starch while fungi store glycogen. Algal cell walls are made of cellulose and those of fungi are composed of chitin. The present day delimitation of algae is due to A.L. de lussieu (1789). Algae is mostly found in water though some are terrestrial and some are even parasitic (Cephaleuros virescence, a green alga causes Red Rust of Tea). They are as small as bacteria and as large as Macrocystis (a brown alga, 196 feet long). Algae show a great range of thallus structure-as simple as a single cell of Chlamydomonas and as complicated as an internally differentiated kelp (brown algae). The algal cells are similar to those of higher plants. The characteristic colour of algae is due to specifIc pigments present in plastids. Algae reproduce by vegetative, asexual and sexual methods. Sexual reproduction varies from simple isogamy to advanced oogamy. Few groups of algae also exhibit a distinct and well-defIned isomorphic and heteromorphic alternation of generations. Algae have been variously classifIed by numerous phycologists, their views always differing. The most simple and practical classifIcation was proposed by British phycologist F.E. Fritsch in 1935. Distinguishing Characters of Taxa Order 1. VolvocaIes Thallus with motile flagellated cells. SUB-DIVISION. ALGAE Family 1. Cblamydomonadaceae (1) Thallus simple (1) Thallus unicellular (2) Chlorophyll present (2) Contractile vacuoles present (3) Cell wall of cellulose Example. Chlamydomonas CLASS I. CHLOROPHYCEAE Family. 2. Volvocaceae (1) Thallus colonial (1) Grass green plastids (2) Cells in a colony forming a flat plate (2) Starch is reserve food Examples. Pandorina, Eudorina, Pleodorina, Volvox (3) Flagella of reproductive structures equal in Order 2. Chlorococcales length. (1) Cells single and non-motile (B-J4) Algae (2) Cells uninucleate (3) Cells uninucleate with a single laminate and (3) Reproduction by zoospores or autospores parietal chloroplast. Family 1. Chlorellaceae Examples. Draparnaidiopsis, Fritschiella (1) Cells single, if united do not form a definite Family 2. Coleochaetaceae colony (1) Vegetative cells with setae (2) Reproduction by autospores (2) Sexual reproduction oogamous Example. Chlorella Example. Coleochaete Family 2. Hydrodictyaceae Order 6. Oedogoniales (1) Cells united to form coenobe (1) Filaments branched or unbranched (2) Reproduction by zoospores and biflagellate (2) Cell division resulting in 'cap' formation gametes (3) Chloroplast reticulate Examples. Pediastrum, Hydrodictyon (4) Zoospores and antherozoids multiflagellate Family 3. Coelastraceae Family 1. Oedogoniaceae (1) Reproduction by autospores Single family (2) Autospores apposed to one another at the Example. Oedogonium time of liberation Order 7. Zygnematales Example. Scenedesmus (1) Absence of flagellated reproductive cells Order 3. Ulotrichales (2) Sexual reproduction by conjugation (1) Thallus simple or a branched filament Family 1. Zygnemataceae (2) Cells uni-or multinucleate (1) Filaments unbranched (3) Single chloroplast with 1 or more pyrenoids (2) Chloroplast parietal and ribbon-shaped or Family 1. Ulotrichaceae single or two axial chloroplasts. (1) Unbranched filaments Examples. Spirogyra, Zygnema (2) Cell walls not articulated Family 2. Desmidiaceae (3) Cells uninucleate (1) Cells composed of two semi-cells Example. Ulothrix (2) Conjugating cells have chloroplast escaping Family 2. Ulvaceae from surrounding walls as they unite to form (1) Thallus expanded, 1 or 2 cells thick zygospores (2) Cells uninucleate with laminate cup-shaped Example. Cosmarium chloroplast Family 3. Mesotaeniaceae Examples. Ulva, Enteromorpha (1) Cells made of single piece and without pores Order 4. Cladophorales (2) Conjugating cells do not transfer contents (1) Branched or unbranched filaments from one cell to another (2) Cells cylindrical and multinucleate Example. Netrium Family 1. Cladophoraceae Order 8. Siphonales (1) Cells more than eight times longer than (1) A single, multinucleate and tubular cell broad (coenocyte) represents the thallus (2) Chloroplasts do not form distinct transverse (2) Chloroplasts many and discoid bands Family 1. Caulerpaceae Example. Cladophora (1) Thallus differentiated into rhizome, rhizoids Order 5. Chaetophorales and aerial folliar shoots, macroscopic (1) Plant body heterotrichous (2) Internally shows the presence of trabeculae (2) Hair or setae present Family 1. Chaetophoraceae Example. Caulerpa (1) Filaments branched, branches free from one Family 2. Codiaceae another or pressed together forming (1) Thallus freely branched and tubu\ar pseudoparenchymatous thallus (2) Sexual reproduction anisogamous and (2) Terminal cells modified into a long gametangia distinct colourless setae (hair) Example. Codium (B-14)  Algae Order 9. Charales (3) Reproductive cells with two unequal, lateral (1) Thallus differentiated into nodes and flagella internodes Order 1. Ectocarpales (2) Characteristic sex organs-globule and nuclei (1) Thallus filamentous Family 1. Characeae (2) Growth trichothallic Single family (3) Reproductive organs-unilocular and Examples. ehara, Nitella plurilocular sporangia CLASS II XANTHOPHYCEAE (4) Isomorphic alternation and generation (1) Chromatophores yellow-green Family 1. Ectocarpaceae (2) Photosynthetic reserves-oil droplets (1) Thallus monoaxial, branched; branches (3) Motile cells with unequal flagella uniseriate Order 1. Heterosiphonales (2) Uni-and plurilocular sporangia, terminal or (1) Thalli multinucleate, unicellular and intercalary siphonaceous Example. Ectocarpus Family 1. Botrydiaceae Order 2. Laminariales (1) Thallus unicellular, multinucleate, vesicular (1) Sporophytes large, parenchymatous (2) Zoospores biflagellate (2) Sporangia in sori, on stipe and blade (3) Sexual reproduction isogamous (3) Gametophytes microscopic and dioecious Example. Botrydium Family 1. Laminariaceae Family 2. Vaucheriaceae (1) Sporophytes differentiated into holdfast, stipe (1) Thallus branched, coenocytic, tubular and and blade filamentous (2) Blade simple or digitate (2) Zoospores multiflagellate (3) Paraphyses hyaline or with colourless (3) Sexual reproduction oogamous appendages Example. Vaucheria (4) Sporangia on both the surfaces of blade CLASS ill. BACILLARIOPHYCEAE Example. Laminaria (1) Chromatophores golden-brown or yellow Order 3. Fucales with or without pyrenoids (1) Plants parenchymatous with complex (2) Cell wall made of two silicified overlapping morphological and anatomical differentiation halves (2) Medulla filamentous (3) Food reserve oil (3) Asexual reproduction absent (4) Reproduction mostly by simple cell division (4) Sex organs in conceptacles Order 1. Centrales Family 1. Fucaceae (1) Valves circular, ornamentation radial or (1) Axes subterate to alate with midrib but not concentric foliar (2) Statospores or microspores formed (2) Vesicle when present inercalary (3) Auxospores formed by oogamy (3) Oogonia with eight oospheres Example. Melosira Example. Fucus Order 2. Pennales Family 2. Sargassaceae (1) Valves bilaterally symmetrical, ornamentation (1) Axes terete, bearing distinct foliar organs bilateral (2) Valves always with raphe (2) Vesicles usually present, lateral or immersed (3) Statospores or microspores never formed in the terminal branchlets (4) Auxospores formed by oogamy (3) Branching of the thallus radial to the central Example. Pinnularia axis CLASS IV. PHAEOPHYCEAE Example. Sargassum (1) Yellowish-brown chromatophores Order 4. Dictyotales (2) Laminarin and mannitol are reserve food (1) Plants parenchymatous, les,s' differentiated products (2) Branching often dichotomous (B-14) Algae (3) Growth by apical cells (4) Carpogonia embedded in the cortex (4) Asexual reproduction by tetraspores Family 1. Gracilariaceae (5) Isomorphic alternation of generation (1) Branches terete and firm Family 1. Dictyotaceae (2) Outer cells not radially serrate (1) Gametophytes dioecious/monoecious (3) Narrow, small celled assimilatory cortex (2) Oogonia and antheridia in definite sori bearing delicate, colourless hairs (3) Sperms motile and eggs non-motile (4) Medulla parenchymatous (4) Sporophyte with tetrasporangia (5) Tetrasporangia tetrapartite Example. Dictyota Example. Gracilaria CLASS V. RHODOPHYCEAE Order 3. Ceramiales (1) Chromatophores pure red to dark purple (1) Thalli uni- to mutiaxial (2) Photosynthetic reserve-Floridian starch or (2) Filaments corticated, polysiphonous floridoside (3) Spermatangia in c\u~ter~ (3) Male gametes and female gametes non- (4) Presence of trichoblasts motile and non-flagellated Family 1. Ceramiaceae (4) Female reproductive organ with a receptive (I) Thallus monosiphon:a", organ-trichogyne (2) N~-outer cortex j;.A~'O-----~ cortex endoderm is endoderm is '1J~--.l:----7"-:-- pericycle ~~--==;:7=--pericycle W''''f7-'.---l-_leaf trace metaxylem leaf gap xylem phloem Fig. 3. Azolla. T.s. stem (cellular). Fig. 2. Azolla. T.s. root (cellular). Pteridophyta 271 I Exercise 4 Exercise 5 Object : Study of anatomy of leaf. Object : Study of structure of sporocarp. Work procedure Work procedure Cut a vertical transverse section of the upper lobe Look for the sporocarp on the lower side of the by keeping it in suitable sized pith. Stain in safranin- plant. Identify microsporocarp and megasporocarp. fast green combination, mount in glycerine and Tease them. Stain with safranin, and study the study. internal structure. Comments Comments 1. The upper lobe of leaf is bound on both the 1. Sporocarps are borne only on the lowermost sides by upper and lower epidermal cells. leaf of a lateral branch at the end of annual 2. Both the layers possess stomata. season. 3. The upper epidermis has many unicellular or 2. Submerged lobe of the leaf bears 2-4 bicelled hairs. sporocarps. 4. Major portion of the leaf between both 3. The upper lobe of the fertile leaf forms a hood- epidermal layers is made of palisade-like like covering around the sporocarp. photosynthetic cells. Large intercellular spaces 4. The sporocarps are dimorphic i.e. these are of are present between them. two types: microsporocarps and 5. The upper lobe has a large cavity at its base. megasporocarps. It opens to the outside through a circular pore. 5. Larger sized is a microsporocarp and the 6. The cavity is filled with the filaments of blue smaller sized is a megasporocarps. green alga-Anabaena azollae. The alga has a 6. Each sporocarp is a sorus covered by indusium. symbiotic relationship with the fern. It fixes 7. Microsporocarp shows a central raised cushion atmospheric nitrogen. on which sporangia develop basipetally. Each 7. The pore is later closed by ougrowths of the micro sporangium has one layered jacket. It is tissue of the.margin. It becomes filled with followed by tapetum. The cavity encloses 64 mucilage. microspores. 8. Microsporangium has a multinucleate periplasmodium formed as a result of breakdown of tapetum. Periplasmodium forms four or more quadrately arranged massulae in which spores remain embedded at periphery. 9. The surface of massulae has many anchor- shaped barbed hairs called glochidia which help the attachment of massulae to the microspore. filaments of-=c-':.U,----...... 10. Megasporocarp shows a single large Anabaena megasporangium. It is surrounded by a flask- cavity---"'""'"-- shaped indusium. It envelops the sporangium completely except for a narrow slit at the apex. 11. Megasporangium is covered by a single layered wall. It encloses a single megaspore. 12. Megaspore is surrounded by a hardened vacuolate layer-the perispore. The megaspore wall is hard and ornamented. It is called Fig. 4. Azolla. T.s. through dorsal (floating) lobe of leaf. epispore. (B-14)  Pteridophyta filaments of Anabaena megasporangium microsporangium 8 A c E Fig. 5. Azolla. A. The fertile submerged lobe with one large microsporocarp and one small megasporocarp. B. L.s. of nearly mature microsporocarp. C. Nearly mature microsporangium. D. Massulae inside microsporangium. E. Massulae inside megasporangium. 13. At the distal end of the megaspore, four Order-Salviniales. (1) Sporocarp is a single sorus enclosing either megasporangia or microsporangia, (2) Sporocarp quadrately arranged massulae are present. These walls formed by the indusia. are formed by the remaining aborted spores Family-Salviniaceae. Single family. and the tapetal cells. Genus-Azolla. (I) Presence of endophytic blue green algae Anabaena in the leaf, (2) Each leaf divided into two Identification lobes, (2) Megasporocarp with only one megasporangium. Division-Pteridophyta. (1) Plant body differentiated into stem, Hints for Collection root and leaves, (2) A definite vascular strand present. Sub-division-Pteropsida. (1) Vascular cylinder siphonostelel Azolla forms red coloured bloom in ditches and dictyostele, (2) Plants macrophyllous with large leaf gaps, ponds. It is found floating freely on the surface of (3) Leaves bear sporangia in sori, (4) Gametophytes small, water. Common Indian species is A. pinnata. green and free living. Class-Leptosporangiatae. (1) Sporangial wall one celled thick, Another species A. filiculoides is also known to (2) Number of spores per sporangium is definite. occur frequently while the third species A. imbricata is found mostly in Eastern Himalayas. (B-14) Gymnosperms 9 Chapter Preamble Gymnosperms form a large group of evergreen, slow growing plants. Though true seeds are formed, the group differs from other group of seed-bearing plants the angiosperms, firstly in possessing naked ovules; secondly, in the lodging of pollen grains directly on the micropyle and thirdly, in the absence of true vessels and companion cells. This group is more ancient than angiosperms, claiming fossils as well as living members and form a bridge between the pteridophyta on one hand and the angiosperms on the other. The gymnosperms vary in size from small plants to very large gigantic plants. Sequoia sempervirens grows up to a height of about 150 meters (California) and Taxodium maxicanum has a trunk with the enormous diameter of about 17 meters. (Contrary to this, Zamia pygmia is the smallest gymnosperm with and underground tuberous stem. In gymnosperms, there are two main structural types, the leaves. Most of the members of this group grow in relatively dry and poor soils, the plants thus exhibit thermographic features. The fructifications (cones) are made up of an aggregation of sporophylls bearing sporangia, in which the spores are produced. The cones are generally unisexual. The male and female cones differ in shape and size. Whereas the male cones are usually smaller and short lived, the female cones are quite larger and long lived. Considerably the gametophytic generation is even more reduced than it is in any of the pteridophyta. The gymnosperms are also important from economic point of view. Some conifers as Cedrus deodara (vern.deodar) form valuable timber. Canada balsam, a chief familiar mounting medium used in biological laboratories, is the resin of Abies balsamea. Turpentine oil which is chiefly used as medicine is also extracted from a conifer tree. Last, but not the least gymnosperms have also proved themselves for their food value viz. sago palm (Cycas revoluta) yield sago or sabudana (of course the chief commercial supply now comes from Metroxylon rumphii- an angIOsperm) and the very familiar fruit of chilgoza is the seed of Pinus gerardiana. Classification of Gymnosperms Division. GYMNOSPERMS Class Order Family Examples Cycadopsida Pteridospemales Lyginopteridaceae Heterangium*, Lyginopteris* Glossopteridaceae Glossopteris* Bennettitales Williamsoniaceae Williamsonia* Cycadeoidaceae Cycadeoidea* Cycadales Cycadaceae Cycas Coniferopsida Coniferales Pinaceae Pinus Taxales Taxaceae Taxus Gnetopsida Gnetales Gnetaeceae Gnetum Ephedraceae Ephedra *Fossil members (B-14) I 274 Gymnosperms Distinguishing Characters of Taxa (5) Dioecious plants (6) Ovules orthotropous DIVISION. GYMNOSPERMS (7) Sperm with spiral band of flagella (I) Ovules naked Example. Cycas (2) Seeds attached to a scale CLASS 2. CONIFEROPSIDA (3) Scales forming a strobilus (1) Wood pycnoxylic CLASS 1. CYCADOPSIDA (2) Leaves needle-shaped, or fan-shaped (1) Wood manoxlic (3) Seeds with bilateral symmetry (2) Large frond-like leaves Order 1. Coniferales (3) Seeds with radial symmetry (1).... Plants branched, leaves needle shaped Order 1. Pteridospermales (2) Resin canals present (1) Leaves large, frond-like, pinnately (3) Male and female cones compact compound (4) Male gametes non-flagelate (2) Large leaf traces with one or more strands Family 1. Pinaceae (3) Spores formed in sporangia, aggregated in (1) Wood resinous synangia (2) Plants monoecious Family 1. Lyginopteridaceae (3) Sporophylls spirally arranged (I) Stem monostelic (4) Microsporophylls with two microsporangia (2) Petioles with a strong midrib (5) Pollen grains winged (3) Seeds small (6) Female cone woody Examples. Heterangium*, Lyginopteris* (7) Polyembryony present Family 2. Glossopteridaceae (8) Seeds dry and winged (1) Leaves with a strong midrib Example. Pinus (2) Stelar structure unusual, showing several Order 2. Taxales plates of vascular tissues (1) Profusely branched trees or shrubs (3) Reproductive structure cupulate and bisexual (2) Leaves simple, solitary, flat and spirally Example. Glossopteris* arranged Order 2. Bennettitales (3) Wood pycnoxlic wihtou parenchyma (I) Tree trunk covered by a mantle of persistent (4) Plants mostly dioecious leaf-bases (5) Female strobilus represented by a single (2) Microsporophylls in groups at the tip of terminal ovule, enclosed in aril frond-like leaves Family. Taxaceae (3) Megasporophylls in cone-like organization (1) Typical of order Family 1. Williamsoniaceae Example. Taxus (1) Stem delicate, branched CLASS 3. GNETOPSIDA (2) Inflorescence stalked or sessile, not sunk (1) Wood with vessels, in the scales of persistent leaf bases (2) Flowers in compound strobili or Example. Williamsonia* inflorescence, unisexual, usually dioecious, Family 2. Cycadeoidaceae (3) Ovule surrounded by several envelopes. (1) Trunk columnar