Genetic study in URD bean (Vigna Mungo (L.) Hepper) for inheritance of mungbean yellow mosaic virus resistance

Goodness of fit test pertaining to MYMV resistance confirmed that all the F₁cross combinations viz., MDU 1 x Mash-114, MDU 1 x VBN (Bg) 6, MDU x PU 31, MDU 1 x Uttara, LPG- 752 x Mash-114, LPG – 752 x VBN (Bg) 6 and CO 6 x VBN (Bg) 6 and BC2 were resistance to MYMV, showed that YMV resistance were controlled by dominant gene. Resistance nature of F₁ of all the crosses indicated clearly the resistance was dominant over susceptibility. Goodness of fit test pertaining to test the deviation of observed ratio to Mendelian segregation ratio for MYMV (resistance: susceptible) in the segregating population shows that, except ‘MDU 1 x PU 31’, F₂ of all crosses fitted well with 15: 1 (resistance: susceptible), exhibited the presence of duplicate dominant gene interaction. Whereas ‘MDU 1 x PU 31; was confined well with 9:7 (resistance: susceptible), showed that the presence of complementary or duplicate recessive type of epistatic gene interaction. The inheritance ratio of 3:1(resistance: susceptible) in BC1 and all resistance in BC2 showed that the male parents taken for crossing were resistance, while female parents susceptible. The putative gene symbol for MYMV resistance assigned for female parents are r1r1r2r2, whereas for male parents viz., Uttara, VBN (Bg) 6 Mash-114 and PU 31 the symbol is R1R1R2R2. Hence, presence of complex nature of inheritance, it may appropriate to suggest the recombination breeding accompanied with one or two cycles of recurrent selection should be effective to enhance the YMV resistance in blackgram.

YMV resistance was governed by dominant gene action under digenic nature of epistatic interaction.

Complex nature of inheritance necessitates the breeding programme should accompany with crossing followed by one or two recurrent cycle of selection may effective to get desirable recombinant with MYMV resistance.