Genetic Dissection of Azuki Bean Weevil (Callosobruchus chinensis L.) Resistance in Moth Bean (Vigna aconitifolia [Jaqc.] Maréchal).

Prakit Somta,Norihiko Tomooka,Chutintorn Yundaeng,Xingxing Yuan,Achara Jomsangawong,Xin Chen,Jingbin Chen

doi:10.3390/genes9110555

Abstract

The azuki bean weevil (Callosobruchus chinensis L.) is an insect pest responsible for serious postharvest seed loss in leguminous crops. In this study, we performed quantitative trait locus (QTL) mapping of seed resistance to C. chinensis in moth bean (Vigna aconitifolia [Jaqc.] Maréchal). An F2 population of 188 plants developed by crossing resistant accession ‘TN67’ (wild type from India; male parent) and susceptible accession ‘IPCMO056’ (cultivated type from India; female parent) was used for mapping. Seeds of the F2 population from 2014 and F2:3 populations from 2016 and 2017 were bioassayed with C. chinensis, and the percentage of damaged seeds and progress of infestation severity were measured. Segregation analysis suggested that C. chinensis resistance in TN176 is controlled by a single dominant gene, designated as Rcc. QTL analysis revealed one principal and one modifying QTL for the resistance, named qVacBrc2.1 and qVacBrc5.1, respectively. qVacBrc2.1 was located on linkage group 2 between simple sequence repeat markers CEDG261 and DMB-SSR160 and accounted for 50.41% to 64.23% of resistance-related traits, depending on the trait and population. Comparative genomic analysis suggested that qVacBrc2.1 is the same as QTL Brc2.1 conferring C. chinensis resistance in wild azuki bean (V. nepalensis Tateishi and Maxted). Markers CEDG261 and DMB-SSR160 should be useful for marker-assisted selection for C. chinensis resistance in moth bean.

Highlights

The genus Vigna is an important plant taxon that contains more than 10 species cultivated as human food and animal feed
TN67 and IPCMO056 exhibited contrasting phenotypes for two traits related to C. chinensis resistance, namely, the percentage of damaged seeds and the progress of damage severity (Figure 1)
Postharvest seed loss due to bruchid infestation is a major problem in moth bean and other crops of the leguminous genus Vigna

Summary

Introduction

The genus Vigna is an important plant taxon that contains more than 10 species cultivated as human food and animal feed. Among Vigna species, cowpea (Vigna unguiculata [L.] Walp.), mungbean (Vigna radiata [L.] Wilczek), and black gram (Vigna mungo [L.] Hepper) are internationally well-known, economically important crops, especially in Africa and Asia. Adult bruchids emerge from the seeds and start a secondary infestation by laying eggs directly on seeds. The azuki bean weevil (Callosobruchus chinensis L.) and cowpea weevil (Callosobruchus maculatus L.) are serious bruchid pests of most Vigna species, especially cultivated ones. The azuki bean weevil is widely distributed in Asia, whereas the cowpea weevil is mainly found in Africa; both species are found in several other locations as a result of the international seed trade [1]. The best way to manage bruchid infestation is by using resistant cultivars [3]

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