Eragrostis Tef: History and Use as Food
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Questions and Answers

Which plant family does Eragrostis tef belong to?

  • Asteraceae
  • Poaceae (correct)
  • Brassicaceae
  • Fabaceae

    • What type of plant is Eragrostis tef?

  • Woody perennial
  • Shrub
  • Herbaceous annual (correct)
  • Herbaceous perennial

    • Where was Eragrostis tef first domesticated?

  • Ethiopia (correct)
  • India
  • China
  • Egypt

    • What part of the plant is primarily used for food?

    <p>Seeds</p> Signup and view all the answers

    What is a common method of processing Eragrostis tef?

    <p>Grinding</p> Signup and view all the answers

    What type of plant is arugula (Eruca vesicaria) classified as?

    <p>Herbaceous and an annual</p> Signup and view all the answers

    What part of arugula (Eruca vesicaria) is primarily used for consumption?

    <p>Leaves</p> Signup and view all the answers

    Which of the following best describes the native distribution of arugula (Eruca vesicaria)?

    <p>Europe and Asia</p> Signup and view all the answers

    How is arugula (Eruca vesicaria) typically prepared for consumption?

    <p>Raw in salads</p> Signup and view all the answers

    Which of the following is NOT a characteristic of arugula (Eruca vesicaria)?

    <p>It is a perennial plant</p> Signup and view all the answers

    What primary factor did early plant classification systems focus on?

    <p>Appearance and medicinal properties</p> Signup and view all the answers

    Who created the first plant classification system that recognized distinct plant families?

    <p>Theophrastus</p> Signup and view all the answers

    What issue did the use of common names in plant classification present?

    <p>They caused confusion due to variability across languages.</p> Signup and view all the answers

    Which innovation in the 17th century greatly aided plant classification?

    <p>The printing press</p> Signup and view all the answers

    What does Linnaeus’ binomial system consist of?

    <p>A genus name and a species epithet</p> Signup and view all the answers

    What is the correct way to write a species name according to the International Code of Botanical Nomenclature?

    <p>Italicized with only the generic name capitalized</p> Signup and view all the answers

    What limitation did the polynomial nomenclature have before Linnaeus' system?

    <p>It was excessively lengthy and cumbersome.</p> Signup and view all the answers

    In what context did Theophrastus’ classification system remain influential until the 17th century?

    <p>In folk taxonomies</p> Signup and view all the answers

    What defines a biological species in the context of plant classification?

    <p>A group of individuals that can interbreed and produce fertile offspring.</p> Signup and view all the answers

    Which type of classification is primarily used by plant taxonomists when dealing with species?

    <p>Morphological characteristics</p> Signup and view all the answers

    What is an example of a plant that has evolved a morphology to attract pollinators?

    <p>Rafflesia, producing a corpse smell</p> Signup and view all the answers

    How do environmental conditions affect plant morphology?

    <p>They may induce variability in growth patterns and structures.</p> Signup and view all the answers

    Which plant is known for having the world's largest flower?

    <p>Rafflesia</p> Signup and view all the answers

    What type of reproduction do dandelions primarily use?

    <p>Agamospermy, a form of asexual reproduction</p> Signup and view all the answers

    What distinguishes monocots from eudicots in terms of cotyledons?

    <p>Monocots have a single cotyledon.</p> Signup and view all the answers

    Which characteristic is typical for monocots regarding their floral parts?

    <p>Three or multiples of three floral parts.</p> Signup and view all the answers

    What is a feature of eudicot root systems?

    <p>Forms a taproot which often persists.</p> Signup and view all the answers

    What evolutionary theory is primarily recognized today regarding flowering plants?

    <p>Hooker-Bessey-Cronquist system.</p> Signup and view all the answers

    Which of the following features is generally true for both monocots and eudicots?

    <p>Both may include woody plants.</p> Signup and view all the answers

    Which statement about the magnoliid angiosperms is correct?

    <p>They are considered a third group alongside monocots and eudicots.</p> Signup and view all the answers

    What is one hypothesized evolutionary result influenced by Hooker's theory?

    <p>Fusion of petals.</p> Signup and view all the answers

    In terms of leaf structure, what distinguishes monocots from eudicots?

    <p>Monocots have linear leaves with parallel veins.</p> Signup and view all the answers

    What characteristic of the Victoria Water Lily is essential for its survival?

    <p>It has maximized its surface area for light absorption.</p> Signup and view all the answers

    Which feature is commonly emphasized in phenetic classification systems?

    <p>Morphologically conservative floral characters.</p> Signup and view all the answers

    What evolutionary trait do Baobab trees exhibit to survive in their environment?

    <p>They develop large, thick trunks.</p> Signup and view all the answers

    What is a primary challenge in determining evolutionary relationships among flowering plants?

    <p>Limited preservation in the fossil record.</p> Signup and view all the answers

    What characteristic is NOT typically assessed in phenetic classification systems?

    <p>Adaptations to specific environments.</p> Signup and view all the answers

    Which flowering plant is known for growing in the foggy weather of Mt. Kilimanjaro?

    <p>Giant Senecio.</p> Signup and view all the answers

    What significant development has enhanced our understanding of plant phylogenetics?

    <p>Advancements in molecular biology.</p> Signup and view all the answers

    What morphology does Azarella compacta exhibit?

    <p>Cushion-like appearance.</p> Signup and view all the answers

    What is a major advantage of agriculture?

    <p>Ensures an adequate food supply throughout the year</p> Signup and view all the answers

    Which region is associated with the earliest evidence of agricultural development?

    <p>Fertile Crescent</p> Signup and view all the answers

    What theory proposed by Gordon Childe suggests a connection between humans and domesticated herd animals?

    <p>Neolithic Revolution Theory</p> Signup and view all the answers

    According to Carl Sauer, where did human populations first establish a sedentary existence?

    <p>In favourable habitats with resources</p> Signup and view all the answers

    What is one proposed reason for the development of agriculture in arid regions?

    <p>Native food plant species conducive to domestication</p> Signup and view all the answers

    What does the Neolithic Revolution refer to in the context of agriculture?

    <p>The transition from hunter-gatherer lifestyles to farming</p> Signup and view all the answers

    What type of species did Childe suggest might have developed due to human and animal interactions during dry periods?

    <p>Weedy grass species</p> Signup and view all the answers

    What environmental conditions likely influenced the beginning of agriculture in different regions?

    <p>Availability of arable land and water</p> Signup and view all the answers

    What practice was notably used by the Aztecs for agricultural development?

    <p>Intensive irrigation agriculture</p> Signup and view all the answers

    Which genotype is favored due to its simultaneous seed maturation in the context of agricultural selection?

    <p>Genotype 2</p> Signup and view all the answers

    What selective pressure has contributed to a reduction in seed appendages in cultivated plants?

    <p>Selection against falling off before harvest</p> Signup and view all the answers

    What characteristic has been commonly selected for in cereal crops as a result of human harvesting practices?

    <p>Uniform seed maturation</p> Signup and view all the answers

    What trait has been selected against in wild grasses due to human agricultural practices?

    <p>Both A and C</p> Signup and view all the answers

    What process is exemplified by the planting-harvesting link in agriculture?

    <p>Passive selection of agriculturally beneficial cultivars</p> Signup and view all the answers

    Which of the following best describes the effects of human cultivation on wild plant phenotypes?

    <p>It modifies plant characteristics drastically</p> Signup and view all the answers

    What was a key reason for early human populations to transition from a hunter-gatherer lifestyle to agriculture?

    <p>Access to abundant local food supplies</p> Signup and view all the answers

    Which of the following describes a lifestyle characteristic of hunter-gatherer societies?

    <p>Seasonal foraging and mobility</p> Signup and view all the answers

    What did sedentary agricultural life enable in terms of societal structure?

    <p>Increased leisure time and career specialization</p> Signup and view all the answers

    What aspect of plant domestication is considered crucial in understanding early agricultural development?

    <p>The origin of crop species</p> Signup and view all the answers

    How did hunter-gatherers' knowledge of plants influence their eventual shift to agriculture?

    <p>It cultivated expertise in specific crop planting</p> Signup and view all the answers

    What main change occurred in human populations due to the advent of agriculture?

    <p>Increased population sizes and stability</p> Signup and view all the answers

    What advantage does loss of shattering provide for crop plants?

    <p>Seeds remain on the plant until harvest, preventing degradation.</p> Signup and view all the answers

    How does intraspecific competition affect seedling growth?

    <p>Competition favors seedlings with more food reserves for better growth.</p> Signup and view all the answers

    What role do weeds play in the agricultural ecosystem during crop harvest?

    <p>Weeds mature and shed their seeds after the crop is harvested.</p> Signup and view all the answers

    Which historical event significantly altered the global distribution of food plants?

    <p>European conquest of the Americas</p> Signup and view all the answers

    What indigenous food plant is considered most notable from Asia?

    <p>Rice</p> Signup and view all the answers

    What was one of the Mediterranean species introduced to northern Europe by the Romans?

    <p>Peas</p> Signup and view all the answers

    Which of the following crops was introduced to Europe from South America?

    <p>Potatoes</p> Signup and view all the answers

    What effect do the introductions of new crops have on agriculture?

    <p>They revolutionize agriculture and the human diet.</p> Signup and view all the answers

    What is a primary concern regarding genetically engineered (GE) crops in ecosystems?

    <p>They may escape into natural habitats and hybridize.</p> Signup and view all the answers

    Which statement accurately differentiates genetic engineering from genetic modification?

    <p>Genetic engineering involves altering an organism's genome using biotechnology, while genetic modification may include various techniques.</p> Signup and view all the answers

    How has the decline of older plant cultivars impacted agricultural practices?

    <p>It has limited the genetic diversity available for breeding programs.</p> Signup and view all the answers

    What is a significant reason for consumer resistance to GE crops, especially in Europe?

    <p>They are perceived as unnatural and pose health risks.</p> Signup and view all the answers

    What does the term 'genetic diversity' imply in agriculture?

    <p>The genetic variation found within a species or between species.</p> Signup and view all the answers

    What is a potential effect of hybridizing GE crops with native plants?

    <p>It may create new, non-native varieties that could disrupt local ecosystems.</p> Signup and view all the answers

    Why are older crop varieties increasingly sought after by agricultural geneticists?

    <p>They possess unique genetic traits that may be beneficial for new varieties.</p> Signup and view all the answers

    What is a key characteristic of white flour compared to whole grain flour?

    <p>White flour keeps longer than whole grain flour.</p> Signup and view all the answers

    Which proteins are essential for traditional bread-making?

    <p>Gliadin and glutenin.</p> Signup and view all the answers

    What is the significance of the corn plant having separate male and female flowers?

    <p>It facilitates easier hybridization.</p> Signup and view all the answers

    What primary component is released by yeast during the fermentation of dough?

    <p>Carbon dioxide.</p> Signup and view all the answers

    How does corn's protein content compare to other cereal grains?

    <p>It is lower in protein overall.</p> Signup and view all the answers

    Which type of bread can be made from corn flour due to the absence of gluten?

    <p>Flatbreads like tortillas.</p> Signup and view all the answers

    In what ways is modern corn beneficial in agriculture?

    <p>It is increasingly used for bioethanol production.</p> Signup and view all the answers

    What role did corn play in the development of ancient civilizations in Central America?

    <p>It was critical to the dietary needs of societies.</p> Signup and view all the answers

    What is the main carbohydrate found in cereal grains?

    <p>Starch</p> Signup and view all the answers

    Which term is used to describe the dry indehiscent fruit produced by true cereals?

    <p>Caryopsis</p> Signup and view all the answers

    How many chromosomes are present in the final hexaploid form of bread wheat?

    <p>42</p> Signup and view all the answers

    What was the initial process used to make cereal grains edible 9,000 years ago?

    <p>Heating</p> Signup and view all the answers

    Where is bread wheat thought to have originated?

    <p>Asia Minor</p> Signup and view all the answers

    Which of the following describes the process of backcrossing in the development of bread wheat?

    <p>Mating a tetraploid with a diploid</p> Signup and view all the answers

    What is the primary use of durum wheat?

    <p>Pasta</p> Signup and view all the answers

    Which of the following statements is true about the classification of wheat species?

    <p>Einkorn is the only diploid species of wheat.</p> Signup and view all the answers

    What significant event is thought to have led to the creation of leavened bread?

    <p>An accidental fungal yeast infection</p> Signup and view all the answers

    What is the main function of the endosperm in wheat grain?

    <p>To serve as a food source for the embryo during germination.</p> Signup and view all the answers

    What processing step involves moistening the grain to toughen the bran?

    <p>Tempering</p> Signup and view all the answers

    What part of the wheat grain is primarily made up of starch?

    <p>Endosperm</p> Signup and view all the answers

    Which type of wheat is commonly grown in cool temperate regions and harvested in autumn?

    <p>Spring wheat</p> Signup and view all the answers

    What is the primary purpose of current breeding programs for wheat?

    <p>To enhance resistance to fungal pathogens.</p> Signup and view all the answers

    How does black stem rust fungus affect wheat plants?

    <p>It absorbs nutrients and damages leaves and stems.</p> Signup and view all the answers

    Which grain is mainly grown as fodder and has the highest protein content among cereals?

    <p>Oats</p> Signup and view all the answers

    What health issue was linked to the consumption of polished white rice in the early 1900s?

    <p>Beriberi</p> Signup and view all the answers

    What compound found in ergot can cause psychotic symptoms in humans?

    <p>Ergotamine</p> Signup and view all the answers

    What characterizes rye flour in baking?

    <p>Results in dense, dark bread</p> Signup and view all the answers

    Which vitamin deficiency is commonly associated with polished white rice consumption?

    <p>Vitamin B<del>1</del></p> Signup and view all the answers

    What is the primary use of oats in agriculture?

    <p>Animal fodder and forage</p> Signup and view all the answers

    How did the consumption of ergot-contaminated rye influence history?

    <p>It was linked to events like witch trials and religious visions</p> Signup and view all the answers

    Which of the following statements about the breeding process for hybrid corn is true?

    <p>A male-sterile line simplifies the breeding process.</p> Signup and view all the answers

    What consequence did the male-sterility gene carry during hybrid corn breeding?

    <p>Susceptibility to southern corn blight.</p> Signup and view all the answers

    Which rice variety is known for requiring continuous submergence in water?

    <p>Paddy rice</p> Signup and view all the answers

    How is labor typically involved in rice farming practices in Asia, Africa, and South America?

    <p>Seedlings are hand-planted and grains harvested manually.</p> Signup and view all the answers

    Which nutrient is specifically crucial for rice cultivation?

    <p>Nitrogen</p> Signup and view all the answers

    What is a key characteristic that distinguishes hybrid rice cultivars from traditional ones?

    <p>Significant increases in crop yields.</p> Signup and view all the answers

    What type of rice is characterized as short-grained and tends to be sticky when boiled?

    <p>Glutinous</p> Signup and view all the answers

    Study Notes

    Botanical Information

    • Eragrostis tef belongs to the Poaceae family, commonly known as the grass family.
    • It is an herbaceous annual plant.
    • Its native distribution is in the Ethiopian highlands.

    History as a Food Plant

    • Tef was first domesticated in Ethiopia.
    • It is most widely grown in Ethiopia and Eritrea.

    Utilization

    • The seeds of Eragrostis tef are used as a food source.
    • They can be processed in various ways:
      • Ground into flour for making injera, a flatbread that is a staple food in Ethiopia.
      • Used to make other breads, porridges, and beverages.
      • Sometimes consumed as a whole grain.

    Botanical Information

    • Arugula belongs to the Brassicaceae family, also known as the mustard family.

    • Arugula is an herbaceous annual plant.

    • Arugula is native to the Mediterranean region and parts of Central Asia.

    Utilization

    • The leaves of the arugula plant are used as a food.

    • Arugula leaves can be eaten raw in salads, sandwiches, or as a garnish. They can also be cooked in dishes like pasta or stir-fries.

    History of Plant Classification

    • Theophrastus, a disciple of Aristotle, created the first plant classification system around 2300 years ago. He identified key characteristics to distinguish natural plant groups, recognizing families like Pea, Grass, Sunflower, and Mustard.
    • The Age of Herbals (1470-1670) saw the expansion of early works, following the invention of the printing press.
    • Due to communication problems with common names, a standard Latin-based system of nomenclature was developed.
    • Carl Linnaeus introduced the binomial system, still used today, in Species Plantarum (1753). In this system, the species name consists of a generic name and a species epithet.
    • The system follows rules from the International Code of Botanical Nomenclature, including capitalization, italicization, and the use of authority designations.

    Plant Species

    • A biological species is a group of individuals that can interbreed with one another but not with individuals of another species.
    • Plants are notoriously "plastic," meaning their morphology depends on the environmental conditions under which they are grown.
    • Evolution is constantly altering morphological form.
    • Examples of morphological diversity:
      • Rafflesia, with the world's largest flower, has evolved to produce a "corpse" smell to attract insects.
      • Duckweed is an invasive species from Asia, with the world's smallest fruit.
      • Baobab trees in Madagascar have evolved to have large, thick trunks.
      • Colocynth lives in North African deserts like Libya.

    Evolutionary Relationships of Flowering Plants

    • Morphological classifications are known as phenetic classification systems.
    • Phenetic classifications emphasize conservative characters that do not vary with environmental conditions.
    • The publication of Charles Darwin's Origin of Species (1859) increased interest in the phylogenetic approach to classification, which emphasizes evolutionary relationships.
    • In the 19th century two competing theories regarding flowering plant evolution were given:
      • ENGLER, Adolf (Germany, 1844-1930): the earliest evolved flowers were small, structurally simple, and wind-pollinated
      • HOOKER, Joseph D.(England, 1817-1911): The earliest evolved flowers were large with numerous floral parts.
    • The Hooker system is accepted today; between 300 and 350 flowering plant families are recognized.
    • Molecular biology studies of plant genomes have largely confirmed the evolutionary validity of the Hooker-Bessey-Cronquist system, although many refinements have been made.

    Flowering Plants: Monocots and Eudicots

    • Traditional plant classification recognizes two major flowering plant groups: the monocotyledons (or monocots) and the eudicotyledons (or eudicots).
    • This division is based on the number of cotyledons ("seed leaves") found in the seed: monocots have a single cotyledon, whereas eudicots have two cotyledons.
    • Several additional morphological features distinguish these two groups (although there are exceptions):
      • Monocots:
        • Plant Form: Herbaceous, never woody (some are "tree-like")
        • Floral Parts: Three or multiples [3,6,9..]
        • Leaves: Linear, sheathing the base, parallel-veined.
        • Root System: Primary root is short-lived, fibrous root system developed.
      • Eudicots:
        • Herbaceous or woody ("true" trees and shrubs).
        • Four, five or multiples [4,8,10..]
        • Broad, not sheathing, net veined.
        • Primary root often persists, forming a taproot.
    • Recent genetic investigations have revealed that the division of the flowering plants into monocot and eudicot groups is too simplistic.
    • A third group, known as the magnoliid Angiosperms, evolved prior to the divergence of the monocots and eudicots.

    Early History of Plants and People

    • Domestication of plants began approximately 10,000 years ago.
    • Prior to domestication, humans lived as nomadic hunter-gatherers.
    • Hunter-gatherer populations remained below the environment's carrying capacity.
    • Hunter-gatherer societies relied on seasonal food supplies, leading to a nomadic lifestyle.
    • Humans are omnivores, and plants played critical roles in early societies, providing food, medicine, and psychoactive substances.
    • Hunter-gatherers possessed extensive knowledge of plant life cycles, habitat requirements, and edible parts.
    • Present-day !Kung people of central Africa provide insights into hunter-gatherer societies.
    • The transition from hunter-gatherer existence to agriculture offers incentives:
      • Reliable and plentiful local food supply.
      • Access to trade routes.
      • Year-round access to water.
    • Settlement leads to plant cultivation and animal domestication, resulting in:
      • More reliable and stable food supplies.
      • Larger human populations.
      • Increased control over the environment.
      • Sedentary existence with permanent settlements.
      • Greater efficiency in food production, leading to more free time and specialization.

    Origins of Agriculture

    • Agriculture involves land tilling for deliberate crop planting.
    • Agriculture emerged from plant domestication and, often, animal domestication.
    • The transition from hunter-gatherer to agricultural societies occurred gradually.
    • Archeological evidence suggests independent development of agriculture in three regions: Asia Minor, China-Southeast Asia, and the Americas.
    • Agriculture became prevalent around 5,000 to 7,000 years ago.
    • The earliest evidence of agriculture stems from arid regions, particularly the Fertile Crescent of Asia Minor.
    • Factors contributing to agriculture's development in the Fertile Crescent:
      • The need for a reliable and adequate food supply in a relatively dry region.
      • The presence of wild precursor food plants, especially cereal crops, conducive to domestication.

    Domestication of Plants

    • Theories explaining the shift from hunter-gatherer to agricultural dependence:
      • Childe's Neolithic Revolution (1928): Humans and herd animals congregated during dry periods, influencing soil and vegetation, favoring the growth of "weedy" grasses, precursors to domesticated cereal crops.
      • Sauer's Favorable Habitats (1952): Sedentary human populations developed in regions with mild climate, edible plants, good fishing, and adequate water supply.
    • Sophisticated agricultural practices emerged around 2500 years ago:
      • Aztec (Mexico): Intensive irrigation agriculture.
      • Mayan (Central America): Selective breeding of corn and beans.
      • Inca (Andes, South America): Potato domestication and irrigation systems.

    Selection Pressures on Plants

    • Plant characteristics are influenced by their genomes, which evolve through natural selection.
    • Plant cultivation significantly alters the phenotypic characteristics of wild plants.
    • The "planting-harvesting link" led to passive selection of beneficial cultivars.
    • Wild plants often produce numerous seeds, maturing over extended periods to ensure environmental resilience.
    • Selection pressures favor specific characteristics in cereal crops:
      • Uniform seed maturation.
      • Compression of tillering, reducing staggered seed maturation.
      • Loss of seed appendages that detach before harvest.
      • Loss of germination inhibitors, enabling simultaneous germination.
      • Increase in the number of florets, resulting in more seeds.
      • Reduced day-length sensitivity to facilitate cultivation in different regions.
      • Loss of shattering, ensuring seeds stay on the plant for harvesting.
      • Increase in food reserves (starch) within the seed, enhancing seedling growth and competition.
    • Selection can also affect weed species:
      • Some weeds mature before harvest, maintaining their populations.
      • Some weeds mimic crop plants, producing seeds with similar size and maturation times, contaminating harvests.

    Geographic Origin and Spread of Plants

    • Most common food plants have restricted native geographical ranges.
    • The introduction of new crops had significant impacts on agriculture and diets.
    • Examples include:
      • Potatoes from South America to Europe.
      • Tomatoes and chili peppers from South America to Europe and Asia.
      • Sugar cane from southeast Asia to the Caribbean.
    • Europe:
      • Romans introduced Mediterranean species like peas, oats, rye, and herbs into northern Europe.
      • Arabic colonization of Spain brought in rice, sugarcane, sorghum, and citrus fruits.
      • European conquest of the Americas introduced corn and potatoes to Europe.
    • Asia:
      • Asia has diverse indigenous food plants, notably rice.
      • Many cereals, cucurbits, and brassicas exhibit high mutability.

    Genetic Engineering

    • Genetic engineering involves adding genetic information from other organisms into crop plants.
    • GE crops have become more prevalent in recent years, with uses including pest, pathogen, and herbicide resistance.
    • Consumer resistance to GE crops is strong in Europe, leading to bans or strict regulations.
    • Concerns regarding GE crops:
      • Potential escape into natural habitats and hybridization with native plants.
      • Concerns about the safety and health of GE crops.
      • Higher cost of GE seeds, limiting access for farmers in developing nations.

    Genetic Diversity

    • The development of new crop varieties, crops, and medicinal drugs relies on genetic diversity.
    • The disappearance of older, less productive plant varieties poses concerns, as they may hold valuable genetic information for future breeding programs.
    • The loss of tropical rainforests and other natural ecosystems is a significant issue, as they represent a vast reservoir of genetic resources.
    • It is estimated that rainforests contain nearly three-quarters of all species on Earth.

    Cereal Crops

    • Cereal crops, like wheat, rice, and corn, were essential to the development of agriculture.
    • Cereal grain is a concentrated food source, rich in carbohydrates with some protein, oil, vitamins, and minerals.
    • Cereals can be stored for long periods due to their low water content.
    • Cereal grains are fruits belonging to the Grass family (Poaceae).
    • Grasses produce a dry indehiscent fruit called a caryopsis.
    • The caryopsis is mostly seed, with a hard pericarp fused to the seed coat.

    Bread Wheat (Triticum aestivum)

    • Bread wheat originated in Asia Minor (present-day Iraq) through a series of hybridization events involving three genera: Triticum, Agropyron, and Aegilops.
    • The final hexaploid bread wheat has 42 chromosomes (six times the base chromosome number, N=7).
    • Archaeological evidence suggests wheat cultivation in Jarmo (present-day Iraq) around 9,000 years ago.
    • Ancient grains, such as einkorn wheat (diploid) and emmer wheat (tetraploid), were first cultivated in Asia Minor around 8,000 years ago.
    • There are two main types of wheat: hexaploid bread wheat (T. aestivum) and tetraploid durum wheat (T. durum).
    • Bread wheat varieties are categorized into spring and winter types, depending on their planting season.
    • Spring wheat has a 90-day growing season and is common in cool temperate regions.
    • Winter wheat is sown in fall, germinates in late fall, overwinters as seedlings, and is harvested in mid-summer.
    • Winter wheat requires moist fall weather, a mild winter, and adequate snow cover.
    • Black stem rust fungus is a significant pathogen for wheat, and breeding programs focus on enhancing resistance.
    • Black stem fungus attacks the endosperm, reducing yield.

    Wheat Grain Structure

    • A wheat grain consists of three parts:
      • Germ: plant embryo, rich in oils and protein.
      • Bran: outer coating, includes seed coat, aleurone layer, and husk, containing protein, enzymes, and fiber.
      • White flour (semolina): endosperm tissue, primarily starch, the food source for the developing embryo.
    • The germ makes up about 6% of the grain, the bran about 4%, and the white flour about 85-90%.

    Wheat Processing (Milling)

    • Wheat grain processing involves:
      • Cleaning: removes glumes and other inedible parts.
      • Tempering: moistening grain to toughen the bran and prevent fragmentation.
      • Crushing: removes the bran and germ.
      • Separating: produces white flour (endosperm) and bran and germ (used for animal feed).
    • Wheat is unique among cereal grains because it contains both gliadin and glutenin proteins necessary for bread-making.
    • During baking, yeasts ferment sugars in the dough, releasing carbon dioxide (CO2) trapped by gluten, causing the dough to rise.

    Corn or Maize (Zea mays)

    • Corn (maize in Europe) is native to Central America and has been cultivated for at least 7,000 years.
    • Corn was critical to the Mayan, Aztec, and Inca civilizations.
    • Modern corn is a mutated derivative of the wild grass teosinte.
    • Corn is unique because its male (tassels) and female (ears) flowers are separated.
    • Corn is low in protein (especially lysine) and some vitamins compared to other cereal grains.
    • Corn lacks gluten proteins, limiting its use for bread-making.
    • Corn is widely grown in Central and North America for livestock feed, human consumption, and bioethanol production.
    • Hybrid vigor in corn cultivars is maintained by crossing inbred lines.
    • Hybrids are stronger and healthier than true breeds, and this is achieved more easily in corn due to its separate male and female flowers.
    • Traditional hybrid vigor was maintained using double-crossing, but this process is time-consuming.
    • In the 1960s, a male-sterile line was developed, which inadvertently carried a susceptibility to southern corn blight, leading to a devastating crop failure in 1970.
    • Recent molecular genetics research indicates that corn is a mutated derivative of the wild grass teosinte.

    Rice

    • Archaeological evidence suggests early rice cultivation in China and Southeast Asia.
    • Rice requires a hot, humid climate with high rainfall.
    • Most commercial varieties (paddy rice) need continuous submergence in water for 2-3 months.
    • Upland rice is grown in high-rainfall areas with saturated soils and does not need submergence.
    • Rice demands nutrient-rich soil, especially nitrogen, and is labor-intensive.
    • Rice cultivars are categorized into two major groups: long-grained (indica) and short-grained (sativa).
    • Hybridization programs have significantly boosted rice crop yields.
    • Rice is typically consumed with minimal processing.
    • Rice processing involves:
      • Threshing: separates grains from chaff.
      • Pearling and Polishing: removes bran and germ, resulting in white rice, but also significant nutrient loss.

    Polished White Rice

    • Polished white rice grains are predominantly starch (about 92%), low in protein, and lack gluten proteins.
    • Polishing removes thiamine (vitamin B1), leading to thiamine deficiency and the potential for beriberi disease.

    Beriberi Disease

    • Beriberi symptoms include weight loss, reduced sensory perception, limb pain and weakness, and emotional disturbances.
    • Beriberi became a health issue in parts of Asia in the early 1900s when polished white rice replaced traditional brown rice.

    Other Cereal Crops

    Oats (Avena sativa)

    • Oats are important as forage and fodder for cattle.
    • Oats contain a high protein content, the highest of all cereals, but lack gluten proteins.

    Rye (Secale cereale)

    • Rye likely originated from S. montanum, a weed mimicking wheat and barley crops.
    • Rye thrives in cool climates and tolerates nutrient-poor soils.
    • Rye is mainly grown for fodder and pasture, but is also used for bread flour, especially in Eastern Europe and Russia.
    • Due to its low gluten content, rye flour produces dense, dark, and bitter bread.

    Fungal Ergot

    • Rye can be infected with fungal ergot in wet seasons, causing severe symptoms like convulsions, paralysis, gangrene, and hallucinations in humans.
    • Symptoms of ergot poisoning, including convulsions, paralysis, gangrene, and hallucinations, have been linked to historical events, including witch trials, demonic possessions, and religious visions.
    • Ergot contains ergotamine, LSD, and alkaloid compounds with dangerous physiological effects in humans.

    Ergot Contamination

    • The FDA allows acceptable levels of ergot contamination in crops.

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    Description

    This quiz explores the botanical characteristics and historical significance of Eragrostis tef, a key food plant from Ethiopia. Learn about its cultivation, processing, and traditional uses in Ethiopian cuisine, particularly in making injera and other staple foods.

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