Genetic Analysis of Epicuticular Wax (Bloom) Locus in Sorghum

The inheritance pattern of epicuticular wax (bloom) locus in F₁ and F₂ generations of seven sorghum crosses involving a bloomless mutant, RS647 and bloom sorghum parents was studied during the post-rainy season of 2012-13. The plants were scored for bloom and bloomless expression at boot leaf stage. The study revealed that the five crosses BTx623 x RS647, 27A x RS647, 296A x RS647, RS647 x Swathi and IS22380 x RS647 segregated in 3 (bloom) :1 (bloomless) indicating the monogenic control of bloom locus in these crosses. The F₂ of the cross Phule Maulee x RS647 showed a di-genic ratio of 13 (bloom):3 (bloomless) while RS647 x M35-1 cross segregated with 9 (bloom):7 (bloomless) di-genic ratio. The study indicated that the bloom expression is under the control of 1-2 genes based on the genetic background of the parents.