Mode of inheritance and allelic relationships of gene(§) governing resistance to gall midge (Orseolia otyzae Wood Mason) in some rice cultivars

Abstract

Mode of inheritance and allelic relationships of genes conforming resistance to gall midge {Orseolia oryzae Wood Mason) were investigated in four rice {Oryza saliva L.) genotypes viz. ARC 5984, ARC 6619, RP 2068- 16-4-5 and R-296-421-2. Inheritance studies revealed presence of a single dominant gene for resistance in ARC 6619 and R-296-421-2, whereas resistance to gall midge was found to be governed by a single recessive gene in ARC 5984. Two independent dominant genes for resistance were observed in RP 2068-16-4-5. Susceptible parent R-2270 was found to possess a single dominant gene for resistance along with an inhibitory gene, which inhibits manifestation of resistance. Allelic tests also confirmed the presence of a recessive gene for resistance to gall midge in ARC 5984. This recessive gene was non-allelic to Gm-1 (Samridhi) and Gm-2 (Surekha). ARC 6619 was found to posses the same gene for resistance as present in Surekha (Gm-2). Out of the two independent dominant genes conferring resistance in RP-2068-16-4-5, one was found to be allelic to Gm-1 (Samridhi). The single dominant gene present in R-296-421-2 was non-allelic to Gm-1 and Gm-2.