Gene Action for Seed Yield, Its Attributes and Wilt Resistance in Castor (Ricinus comunis L.)

Castor ( Ricinus communis L.) is an important non-edible oil seed crop of arid and semi-arid regions of India. Like other crops, castor also suffers from many diseases and so far 15 different diseases have been recorded in castor in India. As a result, area under the crop has tremendously increased. Due to intensive cultivation, with high inputs, high fertilizers and more number of irrigations without proper crop rotation, wilt disease started its appearance in Gujarat and now, wilt (Fusarium oxysporum f. sp. ricini Nanda and Prasad) of castor has become a serious problem in India in general and Gujarat in particular which causes serious quantitative and qualitative losses. This indicates the necessity to reduce the wilt incidence for increase the production as well as productivity. The pre-requisite for this is the knowledge of gene action because the genetic constitution of genotype is only way for the control of wilt incidence. This being the motivation , an objective was set to understand the nature and magnitude of gene action involved in controlling the complex traits like seed yield, 100 seeds weight, oil content and yield attributes which would be of considerable importance in planning a sound breeding programme. Ten parents were subjected to diallelic crosses excluding reciprocals. The data obtained indicated that dominant positive genes were responsible for the expression of these traits.