Vegetables Pricing and Varieties Quiz

Classification of Seeds

• Seeds categorized by usage include cereals, oil seeds, pulses, fiber, green manure, vegetables, and medicinal/sylvicultural species.
• Classification based on cotyledons divides seeds into monocots (one cotyledon) and dicots (two cotyledons).
• Endospermic (albuminous) seeds, which retain endosperm at maturity, include all cereals, castor, and fenugreek. Non-endospermic (ex-albuminous) seeds, where endosperm is consumed, include all legumes.

Germination Types

• Hypogeal germination: Epicotyl elongates, cotyledons remain below ground; observed in monocots, gram, pea, and several other species.
• Epigeal germination: Cotyledons emerge above ground; occurs in beans, castor, cotton, and others.
• Hypo-epigeal germination is seen in species like Peperomia peruviana.

Seed Storage Behaviour

• Orthodox seeds remain viable for extended periods when stored at low moisture (5-10%) and temperature, include most food crops like beans, apples, and cereals.
• Recalcitrant seeds lose viability quickly when dried below 12% moisture and are sensitive to low temperatures, typical of species like avocado and mango.

Pollination

• Pollination involves pollen transfer from anthers to stigmas, occurring in self-pollination (autogamy) or cross-pollination (allogamy).

Pollen Grain Dissemination

• Pollen is dispersed by various agents:
  • Wind (Anemophily)
  • Water (Hydrophily)
  • Insects (Entomophily)
  • Birds (Ornithophily)
  • Snails (Malacophily)
  • Wasps (Waspophily)
  • Flies (Myophily)
  • Bats (Chiropterophily)

Fertilization Process

• Fusion of male and female gametes forms an embryo; the embryo sac contains 7 cells and 8 nuclei.
• Double fertilization in angiosperms occurs involving two male nuclei.

Seed Anatomy

• Embryos develop from seeds containing either monocot (one cotyledon) or dicot (two cotyledons) structures.
• Endosperm can be albuminous (persists at maturity) or exalbuminous (completely absorbed), with reserved food differing by type—carbohydrates in cereals, proteins in legumes, fats in some seeds.
• Seed coats (testa and tegmen) provide protection; can be unitegmic (single layer) or bitegmic (two layers).

Seed Appendages

• Seed appendages aid in identification and dispersal including awns (paddy), hilum (pulses), caruncle (castor), aril (nutmeg), hairs (cotton), and wings (moringa).

Seed Quality Characteristics

• Genetic purity refers to a seed's genetic fidelity, affecting yield; breeder seed has 100% purity, foundation seeds have 99.5%, and certified seeds have 99%.
• Physical purity indicates the composition of seed lots, aiming for high percentages (~96-98%) with uniform size and shape.

Seed Classifications Based on Usage and Types

• Seed classes include nucleus seeds (100% purity), breeder seeds (100% purity, golden yellow tag), foundation seeds (99.5% purity, white tag), and certified seeds (99% purity, azure blue tag).
• The seed certification process is essential for maintaining genetic and physical seed quality.

Seed Multiplication Process

• Generation model follows: breeder seed → foundation seed → certified seed.
• Varietal seed production utilizes open pollination, yielding lower profits and requiring less care, whereas hybrid seed production necessitates controlled conditions and generates higher yields.

Storage Behaviour Types

• Orthodox seeds can survive under low moisture conditions and are able to undergo dormancy; suitable for ex-situ conservation.
• Recalcitrant seeds are highly sensitive to moisture and temperature, requiring in-situ conservation strategies.