利用分池分析获得南大2419中一个抗赤霉病位点的分子标记

Development of a PCR-based Marker Associated with a Scab Resistance Locus in Wheat Cultivar Nanda 2419 Using F_2-based Bulked Analysis

赤霉病是小麦的一种灾难性病害。为了发掘抗赤霉病基因,对小麦品种望水白×南大2419的F2群体及其重组自交系群体进行了赤霉病表型鉴定,并根据F2抗性表型分别配制抗病池和感病池,用RAPD方法筛选与抗赤霉病基因连锁的候选标记。通过F2代选择基因型分析,发现S1021与抗赤霉病性有关。利用重组自交系群体证实了上述结果。这一标记在重组自交系中解释了8 %以上的表型变异。为了便于该基因在育种中的应用,将该RAPD标记转化成了SCAR标记并定位于染色体2B。区间作图表明南大2419是这一QTL的供体亲本。本研究表明,将分池法与选择基因型分析相结合,可以利用F2代群体定位效应较小的QTL位点。

Scab or Fusarium head blight （FHB） is a destructive disease of wheat （Triticure aestivum L. ）. To identify scab resistant genes, the F2 population and the recombinant inbred line （RIL） population developed from the crossing of two wheat cultivars Wangshuibai and Nanda2419 were evaluated for scab resistance. A resistant bulk and a susceptible bulk were prepared according to the F2 resistance evaluation data and screened for candidate markers associated with scab resistance with randomly amplified polymorphic DNA markers （RAPD）. One such marker, S1021, was identified and confirmed through selective genotyping of the F2 individuals. It was then converted into a sequence characterized amplified region （SCAR） marker and mapped to chromosome 2B. This marker explained over 8% of the phenotypic variation in the RIL population. Interval mapping indicated that Nanda2419 contributed to the resistance allele at this QTL. This study demonstrated the feasibility of using bulk-based approach coupled with selective genotyping in identifying markers for QTL with moderate effects in the F2 generation.