QTL analysis and mapping of pi21, a recessive gene for field resistance to rice blast in Japanese upland rice
QTL analysis and mapping of pi21, a recessive gene for field resistance to rice blast in Japanese upland rice
复制标题
DOI：
10.1007/s001220100611
复制
发表时间：
2001-08-01
影响因子：
5.4
通讯作者：
Okuno, K
中科院分区：
文献类型：
--
作者：
Fukuoka, S;Okuno, K
田间抗性被定义为在自然田间条件下允许有效控制寄生虫的抗性，并且在暴露于该寄生虫的新小种时是持久的。为了鉴定水稻抗稻瘟病基因，利用RFLP和SSR标记对日本高地的抗稻瘟病数量性状位点（QTL）进行了定位。对日本晴（中度感病，低地）与尾分幡持（抗病，高地）杂交的F-4后代系进行QTL分析。在第4染色体上检测到2个QTL，在第9和第12染色体上各检测到1个QTL。每个QTL所解释的表型变异在7.9 ~ 45.7%之间，其中4个QTL所解释的表型变异占总变异的66.3%。以感病品种爱朝为轮回亲本，建立了回交后代系，以转移效应最大的QTL。在回交获得的82个F-3品系中，抗性分离的比例为抗性1：杂合2：感病1。在田间测得的抗稻瘟病性的平均得分分别为4.2 +/- 0.67、7.5 +/- 0.51和8.2 +/- 0.66，抗性组、杂合组和感病组分别为7.5 +/- 0.51和8.2 +/- 0.66。将该抗性基因定位于第4染色体上，为单隐性基因，位于RFLP标记位点G271和G317之间，距离分别为5.0cM和8.5cM。讨论了与已报道的抗稻瘟病主效基因和QTL的关系，以及标记辅助选择对提高田间抗病性的意义。
Field resistance is defined as the resistance that allows effective control of a parasite under natural field conditions and is durable when exposed to new races of that parasite. To identify the genes for field resistance to rice blast, quantitative trait loci (QTLs) conferring field resistance to rice blast in Japanese upland rice were detected and mapped using RFLP and SSR markers. QTL analysis was carried out in F-4 progeny lines from the cross between Nipponbare (moderately susceptible, lowland) and Owarihatamochi (resistant, upland). Two QTLs were detected on chromosome 4 and one QTL was detected on each of chromosomes 9 and 12. The phenotypic variation explained by each QTL ranged from 7.9 to 45.7% and the four QTLs explained 66.3% of the total phenotypic variation. Backcrossed progeny lines were developed to transfer the QTL with largest effect using the susceptible cultivar Aichiasahi as a recurrent parent. Among 82 F-3 lines derived from the backcross, resistance segregated in the expected ratio of resistant 1 : heterozygous 2 : susceptible 1. The average score for blast resistance measured in the field was 4.2 +/- 0.67, 7.5 +/- 0.51 and 8.2 +/- 0.66, for resistant, heterozygous and susceptible groups, respectively. The resistance gene, designated pi21, was mapped on chromosome 4 as a single recessive gene between RFLP marker loci G271 and G317 at a distance of 5.0 cM and 8.5 cM, respectively. The relationship to previously reported major genes and QTLs conferring resistance to blasts, and the significance of marker-assisted selection to improve field resistance, are discussed.