Management of viviparous germination in rice: a strategy for development of climate resilient rice cultivation

Rice yield has been affected severely by recent incidence of cyclonic storms with heavy rains flooding rice fields in the grain maturation period of October-November in the eastern part of India. The high yielding cultivars, the cultivation of which mostly sustain rice bowl of the farmers and consumers, lack dormancy to escape onslaught of the erratic weather. Pre-harvest grains absorb rain water as the plants lodge on the ground. Viviparous germination spoils food quality of rain soaked seeds down grading market value of the produce. Incidence of such calamities on the rise, stability of rice production can be maintained through introgression of seed dormancy trait of wild into non-dormant high yielding rice. Similar to other angiosperms, dormancy is regulated in rice seed by a balance between ABA and GA, both steroidal hormones, one being counter productive to the other. The role of ethylene in dormancy release has been proposed more recently for several plants. Rice being sensitive to ethylene should be included in the list, but evidences are wanting in favour of the assumption. The review elucidates the pathway for ethylene production in germinating rice seeds and suggests management of viviparous germination for climate resilient cultivation.

Author : PK Mohapatra* and E Kariali