Author(s)

Qiuping Li^1,2*, Xiaoyuan Zhong^1,2*, Fan Yang^1,2, Lianhua He^1,2, Yuling Zeng^1,2, Hong Chen^1,2, Li Wang¹, Wanjun Ren^1,2, Fei Deng^1,2

¹Key Laboratory of Crop Ecophysiology and Farming System in Southwest China of Ministry of Agriculture, Sichuan Agricultural University, Chengdu, China.
²Crop Ecophysiology and Cultivation, Key Laboratory of Sichuan Province, Chengdu, China.

In rice (Oryza sativa L.), yield is related to characteristics of branches and spikelets. To investigate the effects of late sowing date on differentiation and degeneration of spikelets in rice, field experiments were conducted in Chongzhou and Hanyuan, China. Differentiation and survival of branches and spikelets in Hanyuan were lower than that of Chongzhou, whereas degeneration was greater than that of Chongzhou. In Chongzhou, sowing date affected differentiation and survival of primary, secondary, and total branches, as well as differentiation and degeneration of secondary and total spikelets. In Hanyuan, sowing date affected degeneration of secondary and total branches, and the survival and degeneration of primary spikelets. Late-sown plants experienced higher temperatures in the jointing to heading period, and there were higher sunshine hours. Rainfall and humidity were higher in Chongzhou, but lower in Hanyuan. Late sowing increased differentiation, degeneration, and survival number of branches and spikelets in Chongzhou. However, in Hanyuan, late sowing increased differentiation and degeneration of branches, but decreased survival of branches, which reduced spikelet differentiation and degeneration, resulting in fewer branches. Thus, the key to higher yield in Chongzhou was to increase differentiation of spikelets, whereas in Hanyuan, it was to reduce degeneration of branches and spikelets.

Spikelet Differentiation, Spikelet Degeneration, Sowing Date, Rice

Li, Q. , Zhong, X. , Yang, F. , He, L. , Zeng, Y. , Chen, H. , Wang, L. , Ren, W. and Deng, F. (2020) Effects of Late Sowing on Differentiation and Degeneration of Branches and Spikelets of Indica Rice under Different Ecological Conditions. Agricultural Sciences, 11, 124-142. doi: 10.4236/as.2020.112008.