Chailakhyan Theory of flowering explained.pptx

Explains about Chailkhyan Theory of flowering

1. Chailakhyan theory of flowering

2. Spring Flowers Image 1 Flowering is the process of formation of flowers Different scientists proposed various theories to explain the formation of flowers The most important theory was proposed by chailakhyan He was a soviet American scientist He proposed the existence of universal plant hormone that is involved in flowering The hormone is called -FLORIGEN FLOWERING

3. Spring Flowers Numbers 1 Mikhail Kristoforovich Chailakhyan is a Soviet American scientist He studied the mechanism of flowering tuberization and sex expression in plants. His pioneer work included the agricultural applications of phytohormones and synthetic analogs.

4. Spring Flowers Image 2 Florigen Florigens are flowering hormone They are the proteins capable of inducing flowering time in the angiosperms The protypical florigen is encoded by the FT gene and its orthologs in Arabidopsis and other plants Florigen are produced in the leaves, and act in the shoot apical meristems of the buds and growing tips For a plant to began flowering it must undergo changes in its shoot apical meristems

5. Spring Flowers Numbers 2

6. Spring Flowers Image 3 Chailkhyan hypothesis This hypothesis assumes that – The flowering hormone Florigen is a complex of two types of substances – Gibberellin and Anthesins and involves two phases Gibberellin is essential for the growth of the plant stems Anthesins are required are required for the formation of flowers The flowering in all annual seed plants require two phases (1) floral stem formation phase (2) flower formation phase First phase involves increased carbohydrate metabolism and respiration with increased GA in leaves Second phase requires intensive nitrogen metabolism, higher content of anthesins in leaves and nucleic acid metabolites in stem buds

7. Spring Flowers Image 3 Plants - Flowering Long day plants : plants that show flowering only when they receive more than 12 hours light Short day plants: plants that show flowering when they receive less than 12 hours of light Long day plants favour the first phase Short day plants or conditions favour second phase i.e. flower formation phase

8. Spring Flowers Image 3 Plants - Flowering In long day plants gibberellins are critical since they show first phase i.e. floral stem formation stage In short day plants anthesis are critical because they show second phase of flowering i.e formation of flowers Gibberllins and anthesins are localized in different zones of the apices of long and short day plants The gibberellins are present in the medullary zone, to facilitate stem maturation and growth The anthesins are present in the central zone to facilitate flower formation

9. Spring Flowers Image 4 THANK YOU