利用InDel分子标记辅助选育辣椒抗黄瓜花叶病毒病种质

Innovation of pepper germplasm resource with resistance to cucumber mosaic virus by InDel molecular marker assisted selection

黄瓜花叶病毒(Cucumber mosaic virus,CMV)是危害中国辣椒生产的第一大病毒,创制抗性育种材料、培育抗性品种是防治CMV最有效的方法。以高抗CMV材料PBC688为母本,与感病甜椒材料G29为父本杂交,通过连续自交获得F6代自交系。利用与抗性基因qCmr2.1紧密连锁的3个InDel分子标记,结合人工接种鉴定和农艺性状调查对109个株系进行筛选。分子标记鉴定结果显示,携带纯合抗性片段的株系有28个,携带纯合感病片段的株系有65个,携带杂合片段的株系有16个,杂合率为14.7%。农艺性状调查结果显示,大部分携带qCmr2.1基因的自交系果实较小,首花节位高,花期和成熟期显著晚于感病材料G29。筛选到1份高抗CMV且农艺性状优良的育种材料H6-223,人工接种鉴定结果显示,21个纯合抗病型对CMV表现为高抗、抗;在14个纯合感病型中,13个株系表现为感病,1个株系表现为中抗;9个杂合型株系的抗病性出现分离,表现为抗、中抗;3个在分子标记间出现重组的自交系中,H6-223表现为高抗,另外2个表现为中抗。由研究结果可以看出,3个InDel分子标记可以辅助创制辣椒抗CMV种质,创制的高抗CMV且农艺性状优良的种质H6-223可进一步用于辣椒抗CMV育种。

Cucumber mosaic virus(CMV)is the most serious virus threatening the production of pepper in China.Innovation of pepper germplasm resources and breeding varieties with resistance to CMV is the most effective method to prevent CMV.Using the resistant material PBC688 as female parent and the susceptible sweet pepper G29 as male parent,F6 inbred lines were obtained through successive inbreeding in this study.Totally 109 F6 inbred lines were identified by three InDel markers tightly linking to qCmr2.1.The pepper germplasms with resistance to CMV were chosen by combining with the artificial inoculation identification and the investigation of agronomic traits.The results of molecular marker identification showed that there were 28 lines carrying homozygous resistant fragment,65 lines carrying homozygous susceptible fragment,and 16 lines carrying heterozygous fragments.The heterozygous rate was 14.7%.The investigation results of agronomic traits indicated that most inbred lines carrying qCmr2.1 gene had smaller fruits,higher node position of the first flower,and significantly later flowering and ripening than susceptible material G29.A breeding material H6-223 with high resistance to CMV and excellent agronomic characters was screened.The results of artificial inoculation identification indicated that 21 disease-resistant materials with homozygous genotypes showed high resistance or resistance to CMV.The 13 lines with homozygous susceptible fragment were susceptible to CMV and one line was middle resistance to CMV.The resistance to CMV of nine lines with heterozygous genotypes was separated proportionally.Among the three inbred lines with recombinant molecular markers,H6-223 showed high resistance and the other two showed moderate resistance.In general,we established InDel molecular marker assisted selection system for pepper resistance to CMV,and innovated one germplasm H6-223 with resistance gene qCmr2.1 and excellent agronomic traits,which could be applied in breeding for resistance to CMV in pepper.