高级检索+

水稻低温发芽性QTL的分子标记定位

Mapping of QTL Controlling Low-temperature Germinability in Rice

  • 摘要: 利用1个粳/籼交来源的重组自交系群体,采用纸卷法在15℃低温条件下进行发芽试验,在发芽培养的6~14d中每天观测统计1次发芽率(%)。结合一张含有198个DNA标记的连锁图谱,用复合区间作图法定位水稻低温发芽性QTL。共检测到7个主效应QTL,分别位于水稻1、3、5、6和8号染色体上,单个QTL对性状的贡献率为5%~16%。其中,位于3号染色体标记区间RM148-RM85的qLTG-3-2和位于8号染色体标记区间RM223-RM210的qLTG-8-1对性状的贡献率最大,分别达16%和14%。QTLqLTG-3-2在发芽培养6~10d中表达,其效应由强渐弱,对性状的贡献率由发芽培养6d时的16.4%逐渐降低为发芽11d时的5.1%;而QTLqLTG-8-1则在发芽培养9~14d中起作用,其效应值由小逐渐增大,对性状的贡献率由发芽9d时的8.6%逐渐上升为发芽13~14d的14%。尽管这2个QTL加性效应的大小在低温发芽过程中按一定趋势变化,但加性效应的方向始终是一致的。QTLqLTG-3-2的增效基因来源于亲本特青,而QTLqLTG-8-1的增效基因来自于亲本Lemont。这2个QTL的增效等位基因有望作为分子标记辅助育种的操作对象,用于水稻品种低温发芽性的遗传改良。

     

    Abstract: A recombinant inbred line population derived from a japonica/indica cross were assessed for low-temperature germinability by germination tests at 15°C.Together with a linkage map consisting of 198 marker loci,the main-effect QTL for the trait were mapped via composite interval mapping.A total of 7 QTL for the trait were identified,which were mapped to chromosomes 1,3,5,6 and 8,respectively.These QTL individually explained 5%-16% of the phenotypic variation.Two QTL with the largest effects on the trait were QTL qLTG-3-2 and qLTG-8-1 which were located to the interval RM148-RM85 of chromosome 3 and the interval RM223-RM210 of chromosome 8,respectively.The effect of QTL qLTG-3-2 decreased gradually during (6-10) days after inoculation while that of QTL qLTG-8-1 increased gradually during 9-14 days after inoculation.Although so,however,the effect directions of these two QTL were kept consistent during the whole germination process.The positive allele at QTL qLTG-3-2 came from the parent Teqing while that at qLTG-8-1 from the parent Lemont.These two alleles would be used as potential targets in genetic improvement of low-temperature germinability via marker-assisted selection in rice breeding.

     

/

返回文章
返回