水稻复合农艺性状QTL剖析

Dissection of QTLs for agronomic complex traits in rice

为了解水稻复合性状的数量性状基因座(QTL),在利用单片段代换系进行QTL鉴定的基础上,剖析了水稻株高QTL与主茎高和穗长QTL,主茎高与倒一节间长、倒二节间长、倒三节间长和倒四及以下节间长QTL,谷粒长宽比QTL与粒长和粒宽QTL,每穗粒数QTL与一次枝梗数和二次枝梗数QTL的关系。结果表明:鉴定出株高QTL的6个单片段代换系中有4个只检测出了主茎高QTL,其加性效应百分率为86.00%~99.55%,有1个只检测出了穗长QTL,其加性效应百分率为48.31%,有1个同时检测出了主茎高QTL和穗长QTL,其中主茎高QTL的加性效应百分率为81.72%,穗长QTL加性效应百分率为18.28%;在检测出主茎高QTL的7个单片段代换系中,有1个只检测出倒一节间长QTL,有2个只检测出倒二节间长QTL,有2个检测出倒一节间长QTL和倒二节间长QTL,有2个只检测出倒三节间长QTL;不同的单片段代换系中检测出的节间长的QTL加性效应百分率变化范围为-128.62%~172.07%;7个检测出谷粒长宽比QTL的单片段代换系中,有5个只检测出粒长QTL,1个只检测出粒宽QTL,1个同时检测出了粒长QTL和粒宽QTL;检测出每穗粒数QTL的3个单片段代换系中,有2个只检测出二次枝梗数的QTL,有1个同时检测出一次枝梗数QTL和二次枝梗数的QTL。这些结果表明,代换片段中如能检出复合性状QTL,也可以检出其构成性状QTL;复合性状QTL的加性效应的大部分可由其构成性状QTL的综合效应来解析,但相同的复合性状,不同代换片段检出的构成性状QTL不同。

In order to understand quantitative traits loci(QTLs) for complex traits in rice, in this study, the relationships, between the QTL of plant height and the QTL of main stalk height and panicle length, between the QTLs main stem height and updown 1, updown 2, updown 3, updown 4 and lower internode length, between the QTLs of grain length to width ratio and the QTLs of grain length and grain width, and between the QTLs of grain number per panicle and the QTL of primary branch number and secondary branch number. The results showed that:(1) 4 of 6 SSSLs detected were QTLs of main stem height with the percentage of additive effect, 86.00%-99.55%. One of 6 was QTL for panicle lengt with the percentage of additive effect, 48.31%. And, one was the QTLs for both main stem height and panicle length, with the percentage of additive effects, 81.72% and 18.28% respectively.(2) Out of the 7 SSSLs that detected with QTLs for the main stem height, one is with the QTL for updown1 internode length, two with SSSLs QTL for updown 2 internode length, and two with the QTL for updown 3 internode length, Two SSSLs were detected with QTL for updown 1 internode length and updown 2 internode length with the percentage of additive effect of QTLs for internode length ranging from –128.62% to 172.07% in different SSSLs.(3) Out of the 7 SSSLs that detected QTLs for grain length-to-width ratio, 5 SSSLs were the QTLs for grain length.(4) In three SSSLs detected as QTLs for grain number per panicle, 2 were QTLs for the number of secondary branches. In summary, the QTLs for constituent traits can be detected in the condition that QTLs for compound traits can be detected in the substitution segments. And, most of the additive effects of QTLs for compound traits can be analyzed by the combined effects of QTLs for constituent traits, with different QTLs of the constituent trait detected in different substitution segments.