Relationships between hard‐seededness and seed weight in mungbean (Vigna radiata) assessed by QTL analysis

Abstract

Weather damage reduces the value of commercial mungbean. but hard‐seededness can reduce the level of damage. However. attempts lo breed large‐ and hard‐seeded mungbean varieties have been unsuccessful. To understand the relationship between seed weight and hard‐seededness. these trails were investigated using a quantitative trail loci (QTL) mapping approach with a recombinant inbred population derived from a cross between a completely soft‐seeded variety and a completely hard‐seeded genotype. The two parental genotypes also had a sixfold difference in seed weight. QTL analyses revealed four loci for hard‐seededness and 11 loci for seed weight. Two of the hard‐seeded ness loci co‐localized with seed weight QTL. When seed weight was used as a covariate in the analysis of hard‐seededness from the field data, two of the four hard‐seeded QTL remained significant with the effect al one of these remaining unchanged. These results explain why retaining hard‐seededness in large seeded mungbean lines has been unsuccessful. The existence of a persistent locus, however. indicated that breeding large and persistently hard‐seeded varieties of mungbean may be possible.

QTLs CONTROLLING SEED WEIGHT AND DAYS TO FLOWERING IN MUNGBEAN [Vigna radiata (L.) Wilczek], THEIR CONSERVATION IN AZUKI BEAN [V. angularis (Ohwi) Ohwi & Ohashi] AND RICE BEAN [V. umbellata (Thunb.) Ohwi & Ohashi]

“…PVE of the qSW5.1 in both seasons were very similar. The number of QTLs for seed weight found in this study was only about a half of those reported by Humphry et al (2005) who reported 11 QTLs for seed weight in a RIL from a cross between wild and cultivated mungbeans. The lower number of QTLs found in our study was possibly stem from narrow difference in seed size of the parents used.…”

“…Similarly, days to flowering is controlled by polygenes which has moderate to high heritability (43% to 93%) (Yimram et al, 2009). Quantitative trait loci (QTL) controlling seed weight of mungbean has been identified (Fatokun et al, 1992;Humphry et al, 2005;Sompong et al, 2012). Fatokun et al (1992) reported that seed weight is controlled by one major and three minor QTLs.…”

“…Fatokun et al (1992) reported that seed weight is controlled by one major and three minor QTLs. Humphry et al (2005) found that the trait is controlled by as many as 11 QTLs with moderate to minor effect. Sompong et al (2012) reported that five QTLs with moderate to minor effect govern seed size.…”

“…Seed size is a polygenic trait with high heritability (>80%) (Imrie et al, 1985;Humphry et al, 2005;Yimram et al, 2009). Similarly, days to flowering is controlled by polygenes which has moderate to high heritability (43% to 93%) (Yimram et al, 2009).…”

Comparison of the Pattern of Crop Domestication between Two Asian Beans, Azuki Bean (Vigna angularis) and Rice Bean (V. umbellata)

“…Many domestication related traits for different organs have been analyzed in azuki bean 7,10 , rice bean 8 , mungbean 2,6 (Isemura et al in preparation), cowpea 2 , common bean 14 and soybean 12,13,15,16,19 . These studies have revealed that domestication related traits are always controlled by a few major genes plus some minor genes.…”