Inheritance of black testa colour in lentil (Lens culinaris Medik.)

Abstract

The inheritance of testa (seed coat) colour and interaction of cotyledon and testa colours were studied in seven crosses of lentil (Lens culinaris Medik.) involving parents with black, brown, tan or green testa and with orange, yellow or dark green cotyledons. Analysis of F2 and F3 seed harvested from F1 and F2 plants, respectively, revealed that although black testa is dominant over nonblack testa, its penetrance is not complete since both F1 plants and heterozygous F2 plants produced varying proportions of seeds with either black or nonblack testa. The F2 populations of the crosses between parents with brown and tan, as well as brown and green, testa segregated in the ratio of 3 brown : 1 tan and 3 brown : 1 green, respectively, indicating monogenic dominance of brown testa colour over tan or green. The expression of testa colour was influenced by cotyledon colour when parents with brown or green testa are crossed with those having orange or green cotyledons. Thus F2 seeds from these crosses with a green testa always had green cotyledons and never orange cotyledons. F2 seeds from these crosses with a brown testa always had orange cotyledons and never green cotyledons. These results suggest diffusion of a soluble pigment from the cotyledons to the testa.