中国农业科学2025，Vol.58Issue(17)：3389-3399,11.DOI:10.3864/j.issn.0578-1752.2025.17.003
甘薯抗茎线虫病的QTL定位与分析
QTL Analysis for Resistance to Stem Nematode Disease in Sweetpotato
摘要
Abstract
[Objective]The purpose of this study was to analyze the quantitative trait loci(QTLs)related to stem nematode resistance in sweetpotato(Ipomoea batatas(L.)Lam.),lay a foundation for the fine mapping,cloning,and functional analysis of stem nematode resistance genes in sweetpotato.It also aimed to provide support for the study of the genetic mechanisms of stem nematode resistance,as well as the breeding of resistant varieties in sweetpotato.[Method]An F1 population of 212 progenies derived from a cross between the highly resistant cultivar Yushu 10 and the susceptible line Xin 24 was used.In this study,field-based natural infection assays were conducted to evaluate stem nematode resistance.QTL mapping was performed using composite interval mapping(CIM),and candidate genes within QTL confidence intervals were predicted.Additionally,genome-wide association studies(GWAS)were carried out using the rMVP software(a memory-efficient,visualization-enhanced,and parallel-accelerated R package).For further validation,the resistant cultivar Zhenghong 22 was artificially inoculated with D.destructor,and samples were collected at different post-inoculation time points.The expression patterns of five candidate genes(itf02g19880,itf02g20080,itf02g20100,itf13g18480 and itf13g18550)were analyzed via qRT-PCR.[Result]Three QTLs(qSNR02-1,qSNR02-2,and qSNR13-1)were identified,distributed on chromosomes 2 and 13.The phenotypic contribution rate of the individual QTL related to stem nematode resistance ranged from 9.6％to 11.7％.GWAS revealed one significantly associated locus with stem nematode resistance on chromosome 6.Based on the genomic annotation information,36 candidate genes related to stem nematode resistance were predicted within the QTL confidence intervals,including members of the ABC transporter family,multidrug and toxic compound extrusion(MATE)efflux proteins,E3 ubiquitin ligases,and glutathione S-transferases,which are involved in defense mechanisms,post-translational modification,and stress response.qRT-PCR results showed that the expression patterns of the five candidate genes were significantly different.The expression level of itf02g20100 reached a peak at 3 days after inoculation,which was 6.2 times that of the control;the expression level of itf02g19880 increased sharply and reached the highest level at 0.5 days after inoculation,which was 43.2 times that of the control;the expression patterns of itf13g18480 and itf13g18550 were similar,and both reached a peak at 7 days after inoculation.This indicates that different candidate genes may play different regulatory roles in the defense response after Ditylenchus destructor infection.[Conclusion]Three QTLs related to stem nematode resistance in sweetpotato were identified,and 36 related candidate genes were screened out,which can be used for the subsequent cloning and functional study of genes related to stem nematode resistance in sweetpotato.关键词
甘薯/F1群体/抗茎线虫病/QTL定位/候选基因Key words
sweetpotato/F1 population/resistance to stem nematode/QTL mapping/candidate gene引用本文复制引用
赵冬兰,马居奎,肖世卓,周志林,赵凌霄,王洁,戴习彬,孙厚俊,曹清河..甘薯抗茎线虫病的QTL定位与分析[J].中国农业科学,2025,58(17):3389-3399,11.基金项目
国家重点研发计划(2023YFD1202703)、财政部和农业农村部:国家现代农业产业技术体系(CARS-10-GW01)、江苏省重点研发计划(BE2021384)、徐州市重点研发计划(现代农业)(KC22087)、科技部和财政部:国家科技资源共享服务平台项目国家作物种质资源库(NCGRC-43) （2023YFD1202703）
