Jiangsu Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, Jiangsu, China.
Sci Rep. 2020 Feb 10;10(1):2210. doi: 10.1038/s41598-020-59183-0.
Decrease in the grain yield resulted from a low percentage of opened spikelets under high temperature (HT) during anthesis is a serious problem in the seed production of photo-thermo-sensitive genic male sterile (PTGMS) rice (Oryza sativa L.) lines, and the mechanism is little understood. Elucidating the physiological mechanism underlying the effect of HT during anthesis on spikelet-opening of PTGMS lines would have great significance in exploring the effective way to mitigate the adverse effect of HT. In this study, two PTGMS lines and one restorer line of rice were used and were subjected to normal temperature (NT) and HT treatments. The results showed that, compared with NT, HT significantly decreased the percentage of opened spikelets, fertilization percentage and seed-setting by significantly increasing the percentage of wrapped spikelets and reducing the spikelet-opening angle, length of spikelet-opening time. The HT significantly decreased the contents of soluble sugars, jasmonic acid (JA) and methyl jasmonate (MeJA) in the lodicules before and at glume-opening, which were significantly correlated with and accounts for the low percentage of opened spikelets under HT for rice, especially for the PTGMS lines.
高温（HT）对抽穗期开花的不利影响会导致稻米光温敏核雄性不育系（PTGMS）结实率降低，这是 PTGMS 系种子生产中的一个严重问题，但其中的机制尚不清楚。阐明 HT 对抽穗期小穗开花的影响的生理机制，对于探索减轻 HT 不利影响的有效方法具有重要意义。本研究以两个 PTGMS 系和一个恢复系水稻为材料，分别进行常温（NT）和 HT 处理。结果表明，与 NT 相比，HT 显著降低了开花小穗的比例、受精率和结实率，同时显著增加了包裹小穗的比例，降低了小穗的开口角度和开口时间。HT 还显著降低了颖壳张开前和张开时旗叶中可溶糖、茉莉酸（JA）和茉莉酸甲酯（MeJA）的含量，这些含量与 HT 下小穗开花率低显著相关，这在水稻中，尤其是在 PTGMS 系中更为明显。
