PHOTOPERIODISM

                            INTRODUCTION  The plants in order to flower require a certain day length i.e the relative length of day and night which is called as PHOTOPERIOD. The response of plants to the photoperiod expressed in the form of flowering called as PHOTOPERIODISM.  DISCOVERY The phenomenon of discovery was first discovered by GARNER and ALLARD (1920-1922).Who observed that the Biloxi variety of soybeans (Glycine max) and Maryland mammoth...

Read More

PLANT HORMONES

1901, Dimitry Neljubov, a graduate student at the Botanical Institute of St. Petersburg in Russia, observed that dark-grown pea seedlings growing in the laboratory exhibited symptoms that were later termed the triple response: reduced stem elongation, increased lateral growth (swelling), and abnormal, horizontal growth.However when  these plants were allowed to grow in fresh air, they regained their normal morphology and rate of growth. Neljubov identified ethylene, which was present in the laboratory air from coal gas, as the molecule causing...

Read More

CONTRIBUTION OF A,H STURTEVANT ,C.B BRIDGES AND H.J MULLER.

T.H MORGAN done his studies of Heredity on Drosophilla and was soon joined in the famousfly room at Colombia University by three principal students A.H STURTEVANT ,C.B BRIDGES and H.J MULLER. Within the space of 5 years ,they formulated a revolutionary 'CHROMOSOME THEORY OF HEREDITY'. Their accomplishment ,which led to Morgan wining the Noble prize in 1933 are all more remarkable because their sole experiment method was to do controlled crosses  with these mutants and count progeny. In 1913 Sturtevant constructed the first...

Read More