杂交水稻亲本生殖生长期耐极端高温能力差异性研究

Difference of Extreme High Temperature Tolerance of Hybrid Rice Parents at Reproductive Stage

高温对杂交水稻制种产量影响较大,培育耐高温杂交水稻亲本尤其重要。2022年在湖南长沙利用20个不育系与43个恢复系共配组150个组合进行制种试验,利用夏季极端自然高温条件,筛选耐热性强的杂交水稻亲本。结果表明,孕穗期和抽穗开花期经历长时间最高温度超过40℃的极端高温后,恢复系F81、爽恢459、8X011、湘农恢1442、乐占、湘农恢0751、X155、湘农恢887、X120、R8022、5W0373、爽恢429、R0859、4WH0818、DY3、爽恢1805、R1928、R889的自交结实率均在80%以上,耐热能力强;不育系599S、爽1S、沁886S、芯香S、展998S与多个恢复系配组的平均异交结实率分别为34.5%、31.2%、33.1%、33.3%、35.9%,最高异交结实率分别为53.6%、49.5%、46.1%、41.5%、41.3%,均高于其他不育系所配组合的平均异交结实率和最高异交结实率,耐热能力强,且所制杂交种裂颖粒率低、病粒率低、种子活力水平高。利用上述亲本选配优势组合,可在平原地区实现规模化、机械化制种。

High temperature has a great influence on the yield of hybrid rice seed production,and it is particularly important to develope high temperature tolerant hybrid rice parents.In 2022,a total of 150 hybrid combinations of 20 sterile lines and 43 restorer lines were used for seed production experiments in Changsha,Hunan Province,and extreme natural high temperature conditions in summer were used to screen heat-tolerant hybrid rice parents.The results showed that after a long period of extreme high temperature with the maximum temperature exceeding 40°C during booting and heading stage,the restorer lines F81,Shuanghui 459,8X011,Xiangnonghui 1442,Lezhan,Xiangnonghui 0751,X155,Xiangnonghui 887,X120,R8022,5W0373,Shuanghui 429,R0859,4WH0818,DY3,Shuanghui 1805,R1928 and R889 all had a selfed seed-setting rate of more than 80%,thus they had a strong heat tolerance.The average outcrossing seed-setting rates of the sterile lines 599S,Shuang 1S,Qin 886S,Xinxiang S and Zhan 998S were 34.5%,31.2%,33.1%,33.3% and 35.9%,respectively,and their highest outcrossing seed-setting rates were 53.6%,49.5%,46.1%,41.5%and 41.3%,respectively,which were higher than the average and highest outcrossing seed-setting rates of the other sterile lines,thus these sterile lines had a strong heat tolerance.In addition,the hybrid seeds produced by these sterile lines had a low glume-gapping seed rate,a low diseased seed rate and a high seed vigor level.To develop heterotic hybrid rice combinations by use of the above heat-tolerant parents,the large-scale and mechanized hybrid rice seed production can be realized in the plain area.