弱感光型杂交稻吉丰优3550抽穗期性状QTL分析

Analysis on the Quantitative Trait Locus for the Heading Date in the Weakly Photoperiod Sensitive and Late-Maturing Hybrid Rice Jifeng You R3550

弱感光型迟熟杂交水稻是华南双季稻区水稻生产中极为重要的季节气候生态类型,其应用对于充分利用华南稻区晚稻中后期光热资源、确保晚稻高产稳产和稻米品质的提高,具有重要意义。本研究利用新育成的弱感光型迟熟杂交稻品种吉丰优3550为供试材料,研究了R3550类型迟熟弱感光型杂交稻抽穗期性状的遗传,并利用SSR标记对其相关QTL进行了分析。结果表明,吉丰优3550 F2群体抽穗期性状呈多峰分布,并且在第6、7和8号染色体上检测到6个控制抽穗期的QTLs。除qHD6-1对表型的贡献率仅有8.76%之外,其它5个QTLs qHD6-2、qHD7-1、qHD7-2、qHD8-1和qHD8-2的表型贡献率均在10%以上,分别达到14.76%、20.34%、19.28%、19.73%和15.82%。说明吉丰优3550的抽穗期性状同时受5个主效基因和1个微小基因控制。其中,qHD6-1和qHD6-2的加性效应均为正值,说明其增效等位基因来自母本吉丰A,其它4个QTL的加性效应均为负值,说明其增效等位基因均来自迟熟父本R3550,父本中的增效等位基因对于吉丰优3550弱感光迟抽穗性状的表现发挥了85.35%的决定作用。

The weakly photoperiod-sensitive and late-maturing hybrid rice varieties are one of important ecoclimate types for the rice production in the double cropping region of South China, and their application has vital significance for the late season rice to make full use of the light and heat resources in the late growing stage and ensure the obtaining high and stable yield and rising the rice grain quality. In this study, a recently developed hybrid rice variety Jifeng you 3550 with weak photoperiod sensitivity and late maturity, and its parental lines and SSR marker analysis were employed to study the genetics and map the quantitative trait locus(QTLs) for the heading date of the R3550-derived, and late-maturing and weakly photo period-sensitive hybrid rice(namely, R3550 type).The results showed that the trait heading date segregated in a multi-peak distribution in the F2 population of Jifeng you 3550, and six QTLs for heading date have been detected on chromosome 6, 7 and 8, respectively. Except for qHD6-1, with only 8.76% phenotypic variation explained, the other five QTLs qHD6-2, qHD7-1, qHD7-2,qHD8-1 and qHD8-2 had higher phenotypic variation explained of more than 10%, which was up to 14.76%,20.34%, 19.28%, 19.73% and 15.82%,respectively. This indicated that the heading date of Jifeng you 3550 was controlled by 5 major QTLs and 1 minor QTL. Among of them, the additive effect value was positive for qHD6-1and qHD6-2, as means that the effect-enhancing allele for qHD6-1 and qHD6-2 was from the maternal parent Jifeng A, but the additive effect value was negative for qHD7-1, qHD7-2, qHD8-1 and qHD8-2, it was suggested that all of the effect-enhancing alleles were from the late-maturing male parent R3550, the performance of the late heading for Jifeng you 3550 was determined by 85.35% by the restorer line R3550.