Vol. 11, Issue 1 (2022)

Author(s):
Tanvi Chandra, SC Shankhdhar and Deepti Shankhdhar

Abstract:
Winter wheat is one of the most important cereal crops which occupy a key place in the cereal economy of the world particularly India as well. Its production and demand with the growing population has been continued to increase per year. Factors such as climate change, rise in temperature, inappropriate sowing timing causes declination in its production. Delay in sowing timing causes sudden elevation of air temperature during sensitive growth stages of wheat life cycle (anthesis and grain filling). Rise in air temperature causes negative effect on leaf photosynthetic pigments which are key variables in depicting photosynthetic response and gross primary production. These pigments play central role in light harvesting, photosystem protection and other growth functions. In this context, chlorophyll ‘a’,‘b’ and a/b ratio in flag leaves of eight wheat varieties (UP2628, HD3086, UP2967, UP2784, UP2526, UP2565, UP2748 and HD3059) were evaluated at the time of anthesis and grain filling under different sowing conditions; sowing in month of November (normal) and December (heat stress) during year 2018-19. Due to an elevation of 3.7 ºC at anthesis and 2.9 ºC at grain filling in average air temperature, the photosynthetic pigments were significantly and negatively affected. Least reduction in photosynthetic pigment was observed in variety UP2748 while variety UP2784 was found maximum affected by elevated temperatures. UP2565 variety also performed well under heat stress condition with maximum chlorophyll a/b ratio at the time of anthesis. On basis of correlation analysis it was found that in comparison to grain filling anthesis was more sensitive for photosynthetic pigments to elevated temperature.