Inheritance of certain morphological characters and fusarium wilt resistance in castor, Ricinus communis L.

Abstract

Inheritance studies to understand the genetics of stem colour, internode nature, leaf shape, bloom, spiny nature of the capsule and resistance to fusarium wilt was conducted in castor in the present study utilizing two crosses viz., VP-1 x PCS-142 (VP-1 green stem, condensed internode, cup shaped leaf, triple bloom, spiny capsule and susceptible to wilt; PCS 142 red stem, elongated internode, flat leaf, double bloom, nonspiny capsule and resistant to wilt) and M-574 x PCS-154 (M-574 green stem, condensed internode, cup shaped leaf, triple bloom, spiny capsule and resistant to wilt; PCS 154 red stem, elongated internode, flat leaf, zero bloom, non-spiny capsule and susceptible). Monogenic nature of inheritance was observed for stem colour (red dominant over green), internode nature (elongated dominant over condensed), leaf shape (flat dominant over cup), and bloom nature (triple dominant over double, triple partially dominant over zero) and spiny nature of the capsule (spininess is partially dominant over non-spininess). Wilt resistance to Fusarium oxysporum f. ricini was governed by two complementary genes. Joint segregation for different pairs of traits suggested independent segregation of all the traits studied and no evidence of linkage was detected except leaf shape and internode. All the plants with condensed internode had cup shaped leaves indicating pleotropic effect or tight linkage of genes.