The AVRDC - The World Vegetable Center mungbean (Vigna radiata) core and mini core collections.

Roland Schafleitner,Yen-Wei Wang,Jian-Cheng Chang,Andreas W Ebert,Shu-Hui Chu,Chen-Yu Lin,Ramakrishnan Madhavan Nair,Abhishek Rathore,Pin-Yun Lin

doi:10.1186/s12864-015-1556-7

Abstract

BackgroundLarge ex situ germplasm collections generally harbor a wide range of crop diversity. AVRDC – The World Vegetable Center is holding in trust the world’s second largest mungbean (Vigna radiata) germplasm collection with more than 6,700 accessions. Screening large collections for traits of interest is laborious and expensive. To enhance the access of breeders to the diversity of the crop, mungbean core and mini core collections have been established.ResultsThe core collection of 1,481 entries has been built by random selection of 20% of the accessions after geographical stratification and subsequent cluster analysis of eight phenotypic descriptors in the whole collection. Summary statistics, especially the low differences of means, equal variance of the traits in both the whole and core collection and the visual inspection of quantile-quantile plots comparing the variation of phenotypic traits present in both collections indicated that the core collection well represented the pattern of diversity of the whole collection. The core collection was genotyped with 20 simple sequence repeat markers and a mini core set of 289 accessions was selected, which depicted the allele and genotype diversity of the core collection.ConclusionsThe mungbean core and mini core collections plus their phenotypic and genotypic data are available for distribution to breeders. It is expected that these collections will enhance the access to biodiverse mungbean germplasm for breeding.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-1556-7) contains supplementary material, which is available to authorized users.

Highlights

Large ex situ germplasm collections generally harbor a wide range of crop diversity
We describe the establishment and molecular characterization of a core collection derived from AVRDC – The World Vegetable Center’s collection of cultivated mungbean (Vigna radiata) and the creation of a mini core collection
Comparative analysis of the phenotypic data of the whole and core collection by summary statistics demonstrated that the core collection was highly representative for the whole collection of 5,234 accessions

Summary

Introduction

Large ex situ germplasm collections generally harbor a wide range of crop diversity. AVRDC – The World Vegetable Center is holding in trust the world’s second largest mungbean (Vigna radiata) germplasm collection with more than 6,700 accessions. Mungbean is currently grown on about 6 million hectares, mainly in South and Southeast Asia, but increasingly extends into Australia, USA, Canada and Ethiopia [2]. It is a cheap source of carbohydrates and digestible protein [3,4] and contributes folate and iron to the diet, nutrients that often are in short supply. Mungbean landraces have low yields of around 400 kg/ ha, while improved varieties can produce more than 2 tons per hectare [6], but viral, bacterial and fungal diseases and insect pests limit commercial yields of mungbean [2] Current breeding addresses these constraints, targets improved nutritional value, and, due to the expansion of the cultivation range, adaptation of the crop to new environments [2]. The mungbean whole genome sequence became available recently [7], paving the path for molecular breeding approaches that will make trait introgression into

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