中国常用水稻保持系及恢复系开花灌浆期耐热性评价

摘要

Fifteen common rice maintainer lines and 26 high-yielding restorer lines were used to evaluate their thermal resistance and fertility during flowering and early grain filling stages. The rice plants were subjected to high temperature stress at 39 - 43 C for 1 -15 d from main stem flowering. Based on the high temperature stress index, they were divided into thermal resistant lines, semi-thermal resistant lines, semi-thermal sensitive lines and thermal sensitive lines. Therefore, the maintainer lines K22B, Bobai B and V20B belonged to thermal resistant lines, whereas Ⅱ -32B. Zhongzhe B and Zhong 9B to thermal sensitive lines. The rice restorer line Minghui 63 had the highest thermal resistance, followed by R207, P929, and the lowest thermal-resistant P62-2-2, R8006 and P51. The correlation analysis indicated that the high temperature stress index was not significantly correlated with seed-setting rate, abortive grain rate, unfilled grain rate under natural conditions, but significantly correlated with seed-setting rate and unfilled grain rate under high temperature stress. This indicated that high temperature stress occurred during flowering-early grain filling stage mainly decreased the seed setting rate and significantly increased the unfilled grain rate in both rice maintainer and restorer lines.%以我国常用的15个水稻保持系和26个丰产性较好的恢复系为材料,于主茎见穗当天起连续15 d进行高温胁迫处理(9:00- 15:00,39-43℃),研究花期高温胁迫对水稻保持系和恢复系结实特性的影响.结果表明.根据高温胁迫指数,可把水稻品种分为热钝感型、耐热型、不耐热型和热敏感型等4个类型.其中,水稻保持系K2213,博白13和V20B为热钝感型材料,Ⅱ-3213、中浙B和中913为热敏感型材料;水稻恢复系明恢63耐热性鼓强,其次为8207和P929,P62-2-2,88006和P51等耐热性最弱.进一步分析表明,高温胁迫指数与水稻在自然条件下结实率、空壳率和批谷率之间相关不显著,但与胁迫环境下结实率和空壳率的相关性均达极显著水平.花期高温胁迫致使水稻保持系和恢复系结实率下降.空壳率大幅度上升.