稻瘟病抗性基因Pi25特异性CAPS标记的开发与验证(英文)

Development and Validation of CAPS Markers for Marker-Assisted Selection of Rice Blast Resistance Gene Pi25

为在水稻育种中快速与高效利用稻瘟病抗性基因Pi25,本文利用该基因不同等位基因编码区序列差异开发了4套CAPS标记(CAP1/HincII、CAP3/BglII、CAP3/NdeI和CAP3/Hpy99I),并利用169份稻种资源、98个重组自交系(RIL)以及217个水稻转基因后代,对4套标记的准确性和选择效果进行了验证。结果表明,4套标记均能准确地检测Pi25/pi25座位。其中,标记CAP1/HincII和CAP3/Hpy99I特异性识别并酶切显性等位基因,而标记CAP3/BglII和CAP3/NdeI特异性识别并酶切隐性等位基因。利用稻瘟病菌株JS001-20接种RIL与转基因材料,抗性表现与标记检测的结果完全一致,表明该CAPS标记准确可靠。分析稻种资源后发现,Pi25基因频率较低(1.2%),说明该基因在我国水稻稻瘟病抗性育种中还没有被充分利用。本文的研究结果特别是开发的2对识别并酶切显性等位基因的CAPS标记可用于分子标记辅助选择,改良我国早籼稻的稻瘟病抗性。

To promote the application of rice blast resistance gene Pi25 in rice breeding programs, we developed four sets of gene-specific CAPS markers （CAP1/Hinc Ⅱ, CAP3/Bgl Ⅱ, CAP3/Nde I, and CAP31Hpy 991） based on the coding sequences of the locus. One hundred and sixty-nine rice accessions, 98 recombinant inbred lines （RILs） and 217 transgenic plants were used for the validation of the markers. The results showed that all the four sets of markers were able to accurately and efficiently detect the Pi25/pi25 locus, CAP1/Hinc Ⅱ and CAP3/Hpy 991 could digest specifically the dominant allele Pi25 while CAP3/Bgl Ⅱ and CAP3/Nde I were able to digest specifically the recessive allele pi25. RILs and transgenic lines carrying Pi25 allele were resistant to the blast isolate JS001-20 while the lines carrying pi25 allele were susceptible, indicating a perfect detection of the target locus by the CAPS markers. In addition, a low frequency （1.2%） of the dominant allele was detected in the germplasm collections, in- dicating this gene has not been fully utilized in rice breeding programs in China. Markers CAP1/Hinc Ⅱ and CAP31Hpy 99I are recommended and will be useful for the improvement of blast resistance, especially for the early-season indica rice.