Manipulation of Flowering Time to Mitigate High Temperature Stress in Rice (Oryza sativa L.)

High temperature is an important abiotic stress affecting the productivity of rice. Early morning flowering trait is an escape mechanism from heat. This trait is present in wild rice cultivars. Here we tried to induce early morning flowering trait by the application of methyl jasmonate.

A pot culture experiment was conducted during Rabi, 2017 and 2018 to study the effect of foliar application of methyl jasmonate on high temperature stress (more than 35°C) mitigation in rice was conducted in the Department of Plant Physiology, College of Agriculture, Vellayani during 2017-2019. The variety used was Uma (MO 16). Methyl jasmonate was applied as foliar spray to the spikelet in varying concentration with different time. Physiological observations were taken at 50% flowering stage and yield parameters were taken at harvest stage.

There was significant variation for physiological and yield components among treatments. 4 mM L^-1 methyl jasmonate at 7 am treatment exhibited increase in pollen viability, spikelet fertility percentage, yield per plant and 1000 grain weight. Hence, it is found that methyl jasmonate can advance anthesis time and thereby plants can escape from the severity of temperature experiencing at the normal flowering time in rice.