Cotton ontogeny

Abstract

The chapter deals with fundamental transformation in cotton during various developmental phases from germinating seeds to formation of mature seeds. Initially, the complex metabolic changes occur in seeds followed by rehydration. The storage lipids and protein act as a source of energy during germination process and following energy requirement is fulfilled from photosynthesis. The cotton crop enters a reproductive growth following a 4-5 weeks of germination. The flavonoids are responsible for appearance of flower's colour. The nutrient uptake increases from flowering to fruiting and declines at maturity. Depending upon the mobility, the nutrients accumulated in leaves are translocated to developing bolls. The developing seeds start accumulation of oil and protein. Among three boll components, the fibres and seed coat are rich in cellulose and starch, respectively. Oil and protein are accumulated in the developing embryos. The oil contents increase with boll age and starch initially increases and then drops down. However, protein contents are initially high and drop down during second week of anthesis and then followed by steady increase. The auxin and ethylene production in developing bolls decreases with age.