Identification and mapping of a novel resistance gene to the rice pathogen, Cercospora janseana
Identification and mapping of a novel resistance gene to the rice pathogen, Cercospora janseana
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DOI：
10.1007/s00122-021-03821-2
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发表时间：
2021-04-07
影响因子：
5.4
通讯作者：
Famoso, Adam N.
中科院分区：
文献类型：
--
作者：
Addison, Christopher K.;Angira, Brijesh;Famoso, Adam N.
关键信息对玉米灰霉病抗性的遗传结构进行了研究，确定了一个单一的抗性基因座。鉴定了一个SNP标记，并验证了其在美国育种种质资源中的应用。是引起水稻窄叶褐斑病的一种真菌病原菌。尽管NBLS是美国南部的一种主要病害，而且美国水稻种质资源之间存在抗性差异，但人们对该性状背后的遗传结构知之甚少。在本研究中，对一个重组自交系群体进行了为期三年的田间自然病害侵染下的NBLS抗性鉴定。检测到1个大效应QTL CRSP-2.1，可解释81.4%的表型变异。QTL被定义为532kb的物理区间，并在整个区域检测到13个单核苷酸多态(SNPs)，以表征美国水稻种质资源的单倍型多样性。对387份美国水稻种质资源进行了13个单倍型SNPs的基因分型，并在两年多的时间里进行了NBLS抗性的表型鉴定。共鉴定出14种单倍型，其中6种单倍型占总样本数的94%。来自RIL群体的感病单倍型是在美国种质中观察到的唯一感病单倍型。对感病单倍型和抗病单倍型进行了单核苷酸多态性分析，解释了52.7%的抗病表型变异。历史种质的系谱分析和单倍型鉴定表明，感病单倍型是通过加州品系L-202导入美国南部的路易斯安那州柏树品种。在过去的25年里，柏树被广泛用作亲本，导致在现代美国种质资源群中，CRSP-2.1等位基因的频率从零增加到44%。
Key message The genetic architecture of resistance to Cercospora janseana was examined, and a single resistance locus was identified. A SNP marker was identified and validated for utilization in U.S. breeding germplasm Cercospora janseana (Racib.) is a fungal pathogen that causes narrow brown leaf spot (NBLS) in rice. Although NBLS is a major disease in the southern United States and variation in resistance among U.S. rice germplasm exists, little is known about the genetic architecture underlying the trait. In this study, a recombinant inbred line population was evaluated for NBLS resistance under natural disease infestation in the field across three years. A single, large-effect QTL, CRSP-2.1, was identified that explained 81.4% of the phenotypic variation. The QTL was defined to a 532 kb physical interval and 13 single nucleotide polymorphisms (SNPs) were identified across the region to characterize the haplotype diversity present in U.S. rice germplasm. A panel of 387 U.S. rice germplasm was genotyped with the 13 haplotype SNPs and phenotyped over two years for NBLS resistance. Fourteen haplotypes were identified, with six haplotypes accounting for 94% of the panel. The susceptible haplotype from the RIL population was the only susceptible haplotype observed in the U.S. germplasm. A single SNP was identified that distinguished the susceptible haplotype from all resistant haplotypes, explaining 52.7% of the phenotypic variation for NBLS resistance. Pedigree analysis and haplotype characterization of historical germplasm demonstrated that the susceptible haplotype was introduced into Southern U.S. germplasm through the California line L-202 into the Louisiana variety Cypress. Cypress was extensively used as a parent over the last 25 years, resulting in the susceptible CRSP-2.1 allele increasing in frequency from zero to 44% in the modern U.S. germplasm panel.