Increased Growth Respiration and Panicle Cooling Contributes for stable Grain Weight in Rice under High Night Temperature

Author: Sharma N. and Anand A.

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Abstract

Night-time warming poses a serious threat to rice production in terms of yield loss, especially during the reproductive phase. The current study examined the effects of high night temperatures (4°C above control) from anthesis to physiological maturity on two rice cultivars, Vandana and Nagina 22, which differ in their sensitivity to night-time temperatures. For the first 20 DAA, the relative growth rate declined by 31% in Vandana while it increased significantly in Nagina 22 indicating amplified growth respiration component. HNT inflicted no effect on the grain weight in Nagina 22 due to minor spikelet fertility changes (5%), consistent higher grain weight under HNT throughout the grain filling period and greater panicle cooling throughout the night. Thus, our study revealed that tolerant cultivars offset HNT damage by increasing relative growth rate, cooling its panicle throughout night and maintaining higher grain filling rate.

Keywords

Rice, High night temperature, Grain Weight, Panicle temperature, Thermal imaging

Conclusion

Nagina 22 showed increased relative growth rate during the first 20 DAA which is the active grain filling period. Grain weight is consistently higher during the entire grain filling period and cooler panicle throughout the night under HNT indicates Nagina 22 is able to offset adverse effect of HNT while Vandana is unable to tolerate HNT and grain weight is throughout lower during the entire grain filling period and decreased panicle temperature depression.

References

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How to cite this article

Sharma N. and Anand A. (2023). Increased Growth Respiration and Panicle Cooling Contributes for stable Grain Weight in Rice under High Night Temperature. Biological Forum – An International Journal, 15(7): 51-54.