多环境下水稻穗粒数相关性状稳定位点的发掘

Mining of Stable Locus of Spikelet Number Related Traits in Multienvironments in Rice

为发掘控制水稻穗粒数相关性状的稳定位点,以Nipponbare为受体、Kasalath为供体的染色体片段置换系群体的54个株系,在3个不同环境中对水稻的每穗颖花数(SNP)、每穗实粒数(FGP)和结实率(SF)进行非条件QTL定位和矫正生育期的条件QTL定位。2种方法检测到的3个性状的QTL均以加性效应为主,上位性位点对均是在单个环境中检测到且表型解释率小。将生育期矫正到同一水平,检测到3个控制每穗颖花数的稳定位点q SNP6.2、q SNP6.3和q SNP8.4,1个控制每穗实粒数的稳定位点q FGP8.6和1个控制结实率的稳定位点q SF3。上述所有位点的增效等位基因均来自日本晴。其中,q SNP6.2和q SF3在3个环境中均检测到,说明利用这2个位点改良的目标性状无论是遇到高温还是低温均能稳定地增加改良株系的每穗颖花数和结实率,且这一改变不会影响改良株系的生育期(GD);而q SNP6.3、q SNP8.4和q FGP8.6均在E1和E3中检测到,说明利用这3个位点改良的目标性状(每穗颖花数或每穗实粒数)不受高温的影响且不会改变改良株系的生育期。利用上述发掘到的稳定位点改良目标性状不受高温或/和低温胁迫的影响。

The aim of this study was to mine stable loci for controlling spikelet number related traits in rice. We selected 54 strains of chromosome fragment substitution lines with Nipponbare as receptor and Kasalath as donor. We analyzed unconditional QTL mapping and conditional QTL mapping in remedial growth period for spikelet number per panicle （SNP）, filled grain number per panicle （FGP） and percentage of spikelet fertility （SF） in three different environments. QTL of 3 traits detected by 2 methods was dominated by additive effects, and epistatic loci were detected in a single environment with little phenotypic interpretation. After growth duration was adjusted to an identical level, we detected three stable loci for controlling spikelet number per panicle （qSNP6.2, qSNP6.3, qSNP8.4）, one stable loci for controlling filled grain number per panicle （qFGP8.6）, and one stable loci for controlling percentage of spikelet fertility （qSF3）. Potentiating allele of all the above sites were from Nipponbare. Among them, qSNP6.2 and qSF3 could be detected in three environments, indicating that the target characters improved by these 2 loci, both high temperature and low temperature, could increase the spikelet number per panicle and seed setting rate of the improved lines, and this change would not affect the growth duration （GD） of the improved strains. While qSNP6.3, qSNP8.4 and qFGP8.6 could be detected in E1 and E3, suggesting that the target characters （spikelet number per panicle or grain number per panicle） improved by the 3 loci were not affected by high temperature, and the growth period of the improved strain was not changed. In conclusion, by using the stable sites discovered above, target characters were not affected by high temperature and/（or） low temperature stress.