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PP 608/SST 608 PHYSIOLOGY OF SEEDS                                                                                 (2L+1P) III

Objective
  To apprise students regarding seed germination, dormancy, physiological processes involved in regulation of seed development and physiological processes governing seed quality and its survival.

Theory

UNIT I
  Introduction, importance of seeds, seed structure and function, chemical composition of seeds, seed development and maturation - physiological and molecular aspects; hormonal regulation of seed development, desiccation tolerance and sensitivity in relation to seed longevity, LEA protein.

UNIT II
  Physiological and biochemical changes during seed maturation, assimilate movement to seeds, storage of carbohydrates, proteins and fats in seeds and biosynthesis.

UNIT III
  Seed germination, factors inf luencing, breakdown and mobilization of  stored products, carbohydrates, fat, protein, respiration and pathways of interconversion, control processes in the mobilization of food reserves, hormonal control of germination. Seed dormancy, different types, environmental influences, mechanisms and control including phytochrome, method for breaking seed dormancy.

UNIT IV
  Factors influencing loss of seed viability during storage, physiological and biochemical changes associated with seed ageing, theories of seed ageing, seed viability and its evaluation, seed storage, protection from water, temperature and contaminants, desiccation tolerance and sensitivity in relation to seed longevity.

UNIT V
  Seed vigour, concept, importance, measurement; seed invigoration, methods, physiological and molecular basis of seed invigoration, effect of vigour on field emergence and yield, seed hardening.

Practicals
  Chemical composition of seeds, testing seed vigour and viability, breaking of seed dormancy and germination, seed invigoration and priming treatments, accelerated ageing treatments, seed imbibition and leakage, enzyme activities during germination, sink ability of ovules, seed respiration.

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