关键词: 水稻, 灌浆期, 高温, 2, 4-表油菜素内酯, 产量, 稻米品质

Abstract:

The purpose of this study was to explore the effects of spraying 2,4-epibrassinolide （EBR） at high temperature during rice grain filling stage on yield components and quality of rice, the high-quality rice variety Zhehexiang 2 was used as the test material. At the beginning of grain filling stage, high temperature （HT） and normal treatment （NT） were carried out for 15 days in automatic temperature- and humidity-controlled climate chambers. Plants were sprayed with 0.15 mg·L^-1 2,4-epibrassinolide （EBR）, or the BR biosynthesis inhibitor brassinazole （BRZ）, or the same volume of distilled water （H₂O, control） at the beginning of the temperature treatments. The results showed that the high temperature treatment during the grain filling stage significantly reduced the spikelet fertility rate of Zhehexiang 2, but had a small effect on the grain weight. Meanwhile, high temperature treatment reduced the processing quality, grain appearance quality and eating quality of rice. Exogenous spraying of EBR under high temperature could increased the yield of Zhehexiang 2, and increased the brown rice recovery, milled rice recovery, and head rice recovery of rice, but the EBR treatment decreased significantly the chalky grain rate, chalkiness and protein content. The results provides a theoretical basis for further clarifying the effects of EBR on alleviating high temperature damage in rice.

Key words: rice, high temperature, grain filling stage, 2, 4-Epibrassinolide, yield, grain quality