以籼粳杂交稻甬优系列及杂交籼稻钱优2号和常规粳稻浙粳88为材料,于主茎见穗开花日起,用人工气候箱低温(17℃)和适温(25℃)分别处理4 d和7 d,以室外自然温度为对照,研究不同籼粳成分水稻低温胁迫下籽粒的结实特性。结果表明,低温处理显著降低甬优系列的籽粒结实率和穗重,低温胁迫效应以处理7 d较大。按照耐冷性指数来划分,甬优538、浙粳88、甬优10号、甬优6号和甬优15号为耐冷型,甬优8号、甬优12号、甬优9号和甬优17号为冷敏感型,其余为中间型。此外,甬优系列耐冷型与冷敏感型籼粳成分并无明显的差异。进一步分析表明,低温处理7 d,相对冷敏指数与水稻结实率和空粒率极显著相关(r=-0.9552, 0.9602)。

Yongyou series (indica-japonica hybrid rice) and Qianyou 2 (indica hybrid rice), Zhejing 88 (inbred japonica rice) were subjected to low temperature stress (17℃) and normal temperature treatment(25℃) for 4 days and 7 days in phytotron to investigate the grain filling characteristics during flowering stage with the ambient temperature as control. The results showed that seed setting rate and grain yield per panicle of Yongyou series were decreased significantly under low temperature treatment, especially under the 7-day chilling stress. Based on the cold resistance index, Yongyou 538, Zhejing 88, Yongyou 10, Yongyou 6, Yongyou 15 were chilling tolerant lines, Yongyou 8, Yongyou 12, Yongyou 9, Yongyou 17 were chilling sensitive ones, and the others were intermediate type. There was no significant difference in the ratio of indica and japonica background between chilling tolerant lines and chilling sensitive ones. The correlation analysis indicated that under 7-day of chilling stress, the relative cold sensitivity index was significantly correlated with seed setting rate and grain sterility rate at the 0.01 probability level with the correlation coefficients of -0.9552 and 0.9602, respectively.