水稻籼粳交F8、F2群体穗长QTL比较分析

Comparison of Panicle Length QTL Based on F_2 and F_8 Populations Derived from Rice Subspecies Cross

【目的】对水稻F8重组自交系群体穗长QTL进行检测,并比较分析相同亲本衍生的不同群体的遗传图谱、QTL位置、QTL效应的异同,鉴定稳定表达的穗长QTL,以期增加对穗长遗传行为的了解,且有助于通过分子聚合育种手段改良穗长性状。【方法】以籼稻品种泸恢99和粳稻品种日本晴(基因组测序)为亲本构建的F8重组自交系群体中的188个家系为研究材料,利用包含207个标记的遗传连锁图谱,采用基于混合线性模型的QTL定位软件QTLNetwork 2.0,对水稻穗长QTL进行定位和效应分析,并比较分析F8、F2群体的QTL定位和遗传图谱异同。【结果】在F8群体中检测到7个与穗长性状相关的QTL,分别位于第2、3、6、7、8、10染色体上,QTL对表型变异的贡献率为3.38%—14.8%,总贡献率为52.5%。F8、F2群体在5条相同染色体上都定位到了穗长QTL,这些QTL所在标记区间物理位置大部分是重叠和包含关系。F8、F2图谱在定位标记数、标记的位置顺序、遗传距离、平均图距等方面发生了变化。【结论】在F8、F2群体检测到一个稳定遗传的主效应QTL位点,位于第6染色体,并发现了4个尚未报道的穗长QTL。

[Objective] In this study, rice panicle length QTL was analyzed by using F8 RIL population, the similarities and differences of the genetic map, QTL locations, QTL effects in different derivative population of the same parent were compared and the stable expression of QTL of panicle length trait was identified. The results of the study will provide more information about the genetic behavior office panicle length and be benefit to the MAS （marker-assisted selection）. [Method] A F8 population containing 188 lines, which was derived from the cross between the indica variety Luhui99 and the japonica variety Nipponbare, was analyzed with a genetic linkage map consisting 207 DNA markers. The statistic soil-ware of QTL Network 2.0 was applied to detect QTL and QTL effect analysis for rice panicle length. The similarities and differences of QTL mapping and genetic map between F8 and F2 population were discussed. [ Result ] A total of 7 QTL with significant additive effects were detected on chromosomes 2, 3, 6, 7, 8 and 10 in Fs population. The proportions of phenotypic variance explained by individual QTL ranged from 3.38% to 14.8% and the QTL could jointly explain 52.5% of the total phenotypic variance. There were five same chromosomes having rice panicle length QTL in Fs and F2 genetic map and most of the QTL＇s physical locations are overlapping or containment. The F8 and F2 genetic maps differed in molecular marker number, marker arrangement, genetic distance and average distance between the markers. [Conclusion] Seven rice panicle length QTL were detected in F8 RIL population. Although there were many differences betwen Fs and F2 populations in genetic map, QTL analysis and so on, a steady main QTL was found on the sixth chromosome. In addition, four stable rice panicle length QTL were detected in the study which were not reported in previous references.