Inheritance and AFLP Tagging of Leaflet Mutants in Mungbean (Vigna radiata (L.) Wilczek)

Abstract

Leaflet type is a canopy characteristic related to light interception, thus modification of canopy structure can alter seed yield. Two multiple leaflet mutants were obtained from gamma-rays irradiation and used in studying the mode of inheritance and tagging with AFLP marker. The cross between largeheptafoliate leaflet with small-pentafoliate leaflet mutants gave all F1 plants with normal trifoliate leaflets. The F2 plants segregated in a 9:3:3:1 ratio of large-trifoliate: large-heptafoliate: small-pentafoliate: small-heptafoliate plants, suggesting that the genes controlling leaflet size and leaflet number were independent loci. The gene symbols N₁,n₁ and N₂,n₂ were proposed to control leaflet number. Since there was no plant found with large-pentafoliate leaflets, it was hypothesized that the N2 allele expressed pleiotropic effect on both leaflet number and leaflet size. Thus the genotypes of the above-mentioned F2 could be assigned as N_{1_}N_{2_}, n₁n₁N_{2_}, N_{1_}n₂n₂, and n₁n₁n₂n₂, respectively. Another possibility was that there was another locus with S and s alleles controlling the leaflet size and tightly linked with N₂ and n₂, respectively. There were 3 AFLP markers linked to number of leaflets per leaf and all of them corresponded to the N₁ allele of the small-pentafoliate parent.