Construction of a high density linkage map and genome dissection of bruchid resistance in zombi pea (Vigna vexillata (L.) A. Rich)

Kitiya Amkul,Suhua Wang,Prakit Somta,Xuzhen Cheng,Lixia Wang

doi:10.1038/s41598-019-48239-5

Abstract

Zombi pea (Vigna vexillata) is a legume crop that is resistant to several biotic and abiotic stresses. Callosobruchus maculatus and Callosobruchus chinensis are serious stored-insect pests of legume crops. We constructed a high-density linkage map and performed quantitative trait loci (QTLs) mapping for resistance to these insect species in zombi pea. An F2 population of 198 individuals from a cross between ‘TVNu 240’ (resistant) and ‘TVNu 1623’ (susceptible) varieties was used to construct a linkage map of 6,529 single nucleotide polymorphism markers generated from sequencing amplified fragments of specific loci. The map comprised 11 linkage groups, spanning 1,740.9 cM, with an average of 593.5 markers per linkage group and an average distance of 0.27 cM between markers. High levels of micro-synteny between V. vexillata and cowpea (Vigna unguiculata), mungbean (Vigna radiata), azuki bean (Vigna angularis) and common bean (Phaseolus vulgaris) were found. One major and three minor QTLs for C. chinensis resistance and one major and one minor QTLs for C. maculatus resistance were identified. The major QTLs for resistance to C. chinensis and C. maculatus appeared to be the same locus. The linkage map developed in this study will facilitate the identification of useful genes/QTLs in zombi pea.

Highlights

The genus Vigna is an important plant taxon containing nine cultivated legume crops, including mungbean [Vigna radiata (L.) Wilczek], blackgram [Vigna mungo (L.) Hepper], cowpea [Vigna unguiculata (L.) Walp.], rice bean [Vigna umbellata (Thunb.) Ohwi and Ohashi], Bambara groundnut [Vigna subterranea (L.) Verdc.], azuki bean [Vigna angularis (Ohwi) Ohwi and Ohashi], moth bean [Vigna aconitifolia (Jacq.) Maréchal], zombi pea [Vigna vexillata (L.) A
Seeds of cultivated Vigna species are susceptible to bruchids, especially the cowpea weevil (C. maculatus L.) and azuki bean weevil (C. chinensis F.)[18,19,20]
In general, seeds of both cultivated and wild V. vexillata are completely resistant to the C. maculatus and Z. subfasciatus, and this resistance results from the presence of the non-protein amino acid para-aminophenylalanine (PAPA) in the seeds[13]

Summary

Introduction

The genus Vigna is an important plant taxon containing nine cultivated legume crops, including mungbean [Vigna radiata (L.) Wilczek], blackgram [Vigna mungo (L.) Hepper], cowpea [Vigna unguiculata (L.) Walp.], rice bean [Vigna umbellata (Thunb.) Ohwi and Ohashi], Bambara groundnut [Vigna subterranea (L.) Verdc.], azuki bean [Vigna angularis (Ohwi) Ohwi and Ohashi], moth bean [Vigna aconitifolia (Jacq.) Maréchal], zombi pea [Vigna vexillata (L.) A. Rich] and creole bean (Vigna reflexo-pilosa Hayata) which are grown in various cropping systems on over 25 million hectares in Asia, Africa, Australia and America[1,2] These Vigna crops are generally susceptible to biotic and abiotic stresses[1]. Seeds of cultivated Vigna species are susceptible to bruchids, especially the cowpea weevil (C. maculatus L.) and azuki bean weevil (C. chinensis F.)[18,19,20]. These pests are widely distributed in most continents owing to international seed trading. Our objectives were to (i) develop a high-density linkage map for V. vexillata and (ii) identify quantitative trait loci (QTL) for seed resistance to C. chinensis and C. maculatus in V. vexillata

Objectives

Methods

Results

Conclusion