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水稻红莲型CMS育性恢复QTL分析

Mapping of QTL for Fertility Restoration of HL-type Cytoplasmic Male Sterility in Rice(Oryza sativa L.)

  • 摘要: 红莲型CMS是在我国杂交水稻生产中被广泛利用的雄性不育细胞质之一。为了同时定位红莲型CMS育性恢复主效和微效QTL,利用红莲型CMS不育系粤泰A(YTA)与"Lemont/特青"RIL群体测交,结合1张含有198个DNA分子标记的高密度遗传图谱,对测交F1群体的小穗育性和花粉育性进行复合区间作图。在对YTA的育性恢复性方面,该RIL群体的2个亲本之间具有明显差异,特青的恢复性较强,其测交F1的小穗育性和花粉育性分别为72%和51%;而Lemont测交F1的小穗育性和花粉育性分别为32%和9%。复合区间作图定位到4个育性恢复QTL,分别位于水稻第1、2和10号染色体上,单个QTL的贡献率在5%~24%之间。其中,除1个QTL的增效基因来源于Lemont外,其余3个QTL的增效基因均来源于特青。效应最大的QTL为qRF-10-1,该QTL位于10号染色体RM258-C16标记区间,对小穗育性表型变异的贡献率为24%,对花粉育性的贡献率为17%,且该QTL被检测到的LOD值显著较高,因此是1个主效QTL,其增效基因来源于特青。除了主效QTLqRF-10-1外,其它3个QTL对性状的贡献率均在10%以下(5%~8%)。由此表明,该RIL群体对红莲型CMS的育性恢复由1个主效QTL控制,并受其它几个微效QTL的影响。该QTL定位结果与小穗育性在测交F1群体中呈连续的双峰分布的结果相一致。与主效QTLqRF-10-1紧密连锁的SSR标记为RM258.该主效Q0I'I.可作为分子标记辅助育种的操作目标之一,用于杂交稻分子育种中培育红篷型CMS的强恢复系。

     

    Abstract: Honglian-type CMS(CMS-HL)is one of the most extensively used cytoplasms in hybrid rice of China.In order to map both major and minor QTL controlling fertility restoration for CMS-HL,a Honglian-type male sterility line(YTA)was test-crossed to the RILs derived from a cross between Lemont and Teqing.Composite interval mapping was conducted based on the data of spikelet fertility and pollen fertility in the test-cross population of YTA/RILs.Significant difference between the two parents Lemont and Teqing in fertility restoration was observed and Teqing showed a much stronger fertility restoration than Lemont.Totally,four QTL for spikelet fertility and pollen fertility were mapped to chromosomes 1,2 and 10 of all the twelve rice chromosomes,each explaining 5%-24% of the trait variation.Among these QTL,three QTL with their positive alleles were from the parent Teqing.QTL qRF-10-1,mapped onto the interval RM258-C16 of chromosome 10,produced the largest effects on both the two traits,accounting for 24% of the spikelet fertility variation and 17% of the pollen fertility variation.Comparatively,the other three QTL produced much small effects on the traits,each explaining less than 10% of the trait variation.These results indicated that the fertility restoration of the RILs was mainly controlled by the major QTL qRF-10-1 and was also modified by the other three minor QTL.This suggestion was further confirmed by the continuous binary frequency distribution of spikelet fertility in the test-cross population of YTA/RILs.QTL qRF-10-1 with the most closely linked SSR marker of RM258 could be used as a target to be manipulated in breeding restoration lines for HL-CMS.

     

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