Genetic Studies on Differential Expression of Mungbean Yellow Mosaic Virus Resistance Related to Trichome Density in Urd bean (Vigna mungo (L.) Hepper)

In blackgram, five cross combinations were taken for generation mean analysis to study the inheritance pattern of Mungbean yellow mosaic virus (MYMV) disease which revealed different gene actions. It is found that the crosses Co5 x VBN (Bg) 4 and Co5 x VBG 66, the segregation was governed by digenic complementary interaction. However, in Co5 x VBG 73 the YMV incidence was governed by digenic duplicate interaction. In contrast, in the crosses KBG 98005 x VBN (Bg) 4 and KBG 98005 x VBG 73, the incidence of YMV was governed by trigenic inhibitory interaction. The putative gene symbols assigned for the five genotypes viz., Co5, KBG 98005, VBN (Bg) 4, VBG 66 and VBG 73 are r₁r₁r₂r₂r₃r₃r₄r₄, r₁r₁r₂r₂r₃r₃r₄r₄II, R₁R₁R₂R₂ii, R₁R₁R₂R₂ and R₃R₃R₄R₄ii, respectively. Besides this, the presence of trichomes in leaf of urdbean genotypes reveals that trichomes do not hinder the activities of whitefly and the resistance to MYMV may be due to some other factors like chemical, physiological and morphological factors.