Agarwal Chiti, Chen Weidong, Varshney Rajeev Kumar, Vandemark George
Department of Plant Pathology, Washington State University, Pullman, WA, United States.
USDA-ARS, Grain Legume Genetics and Physiology Research Unit, Pullman, WA, United States.
Front Genet. 2022 Aug 15;13:945787. doi: 10.3389/fgene.2022.945787. eCollection 2022.
The soilborne oomycete plant pathogen causes seed rot and pre-emergence damping-off of chickpea ( L). The pathogen has been controlled for several decades using the fungicide metalaxyl as seed treatment but has re-emerged as a severe problem with the detection of metalaxyl-resistant isolates of the pathogen from infested fields in the United States Pacific Northwest. The objective of this study was to identify genetic markers and candidate genes associated with resistance to in an interspecific recombinant inbred line population (CRIL-7) derived from a cross between (PI 599072) x (FLIP 84-92C) and conduct genome-wide association studies (GWAS) for disease resistance using a chickpea diversity panel consisting of 184 accessions. CRIL-7 was examined using 1029 SNP markers spanning eight linkage groups. A major QTL, "qpsd4-1," was detected on LG 4 that explained 41.8% of phenotypic variance, and a minor QTL, "qpsd8-1," was detected on LG8 that explained 4.5% of phenotypic variance. Seven candidate genes were also detected using composite interval mapping including several genes previously associated with disease resistance in other crop species. A total of 302,902 single nucleotide polymorphic (SNP) markers were used to determine population structure and kinship of the diversity panel. Marker-trait associations were established by employing different combinations of principal components (PC) and kinships (K) in the FarmCPU model. Genome-wide association studies detected 11 significant SNPs and seven candidate genes associated with disease resistance. SNP Ca4_1765418, detected by GWAS on chromosome 4, was located within QTL qpsd4-1 that was revealed in the interspecific CRIL-7 population. The present study provides tools to enable MAS for resistance to and identified genomic domains and candidate genes involved in the resistance of chickpea to soilborne diseases.
土壤传播的卵菌植物病原菌会导致鹰嘴豆（ ）种子腐烂和出土前猝倒。几十年来，一直使用杀真菌剂甲霜灵进行种子处理来控制这种病原菌，但随着在美国太平洋西北部受侵染田地中检测到该病原菌的甲霜灵抗性分离株，它又重新成为一个严重问题。本研究的目的是在由 （PI 599072）× （FLIP 84 - 92C）杂交产生的种间重组自交系群体（CRIL - 7）中鉴定与对 抗性相关的遗传标记和候选基因，并使用由184份种质组成的鹰嘴豆多样性面板进行全基因组关联研究（GWAS）以研究抗病性。使用跨越八个连锁群的1029个SNP标记对CRIL - 7进行了检测。在LG 4上检测到一个主要QTL“qpsd4 - 1”，它解释了41.8%的表型变异，在LG8上检测到一个次要QTL“qpsd8 - 1”，它解释了4.5%的表型变异。还使用复合区间作图法检测到七个候选基因，包括几个先前在其他作物物种中与抗病性相关的基因。总共使用302,902个单核苷酸多态性（SNP）标记来确定多样性面板的群体结构和亲缘关系。通过在FarmCPU模型中采用主成分（PC）和亲缘关系（K）的不同组合来建立标记 - 性状关联。全基因组关联研究检测到11个与抗病性相关的显著SNP和七个候选基因。通过GWAS在4号染色体上检测到的SNP Ca4_1765418位于种间CRIL - 7群体中揭示的QTL qpsd4 - 1内。本研究提供了用于鹰嘴豆对 抗性的分子标记辅助选择的工具，并鉴定了参与鹰嘴豆对土传病害抗性的基因组区域和候选基因。
