抽穗扬花期耐热水稻种质资源的筛选鉴定

Selection and Identification of Rice Germplasm Resources Tolerant to High Temperature at Heading-flowering Stage

对江西27份籼型早稻材料在抽穗扬花期的耐热性进行了鉴定评价。研究结果表明:在高温胁迫下不同品种间的结实率和结实率降低率差异均达到了极显著水平;其中R66、洪早籼1号、R402在高温胁迫下的结实率分别为76.8%、73.2%和70.9%,结实率降低率分别为8.5%、13.0%和5.8%,均与耐热水稻种质Nagina 22相似,因此认为这3个品种的耐热性较强;在高温胁迫下参试品种的垩白粒率、垩白大小和垩白度的平均值分别比自然条件下增加了28.5、14.5、13.8个百分点;香优早、早香玉、莲香早在自然条件和高温胁迫下的垩白粒率均小于10%,垩白度均小于1%,这3个品种可作为耐热水稻品种在优质稻育种中加以利用。

Heat tolerance of 27 indica early-season rice varieties which were released in Jiangxi province were selected and identified at heading-flowering stage. The result showed that the differences in seed setting rate and its reduced rate among rice varieties were very significant under high temperature conditions. Under high temperature condition,the seed setting rate of R66,Hongzaoxian No. 1,R402 was 76.8%,73. 2% and 70. 9%,respectively,and the reduced rate of seed setting rate was 8. 5%,13.0% and 5.8%,respectively,which was close to the high-tolerant variety Nagina 22,showed high heat tolerance. The percentage of grains with chalkiness（ PGWC）,area of chalky endosperm（ ACE）,degree of endosperm chalkiness（ DEC） under high temperature condition were 28.5%,14.5% and 13.8% higher than those under nature condition,respectively. For three varieties Xiangyouzao,Zaoxiangyu and Lianxiangzao,their PGWC was less than 10%,DEC less than 1%,which could be used in highquality rice breeding with heat tolerance.