Inheritance characteristics of F1 and F2 offsprings obtained from full diallele crosses of five cowpea cultivars (Vigna unguiculata L. Walp) against pseudocercospora leaf spot disease

The experiment was carried out at the Experimental Farm, Department of Agricultural Technology, Mahasarakham University, Mahasarakham Province in the 2005 (February to April) for F1 offsprings and also at the Experimental Farm, Khon Kaen University, Khon Kaen Province, Northeast Thailand for F2 offsprings (July to October), i.e., four experiments were carried out, each location had two experiments. The research aimed to investigate inheritance characteristics of F1 and F2 offsprings derived from full diallele crosses of five cowpea cultivars (20 pairs of crosses) against a pathogenic disease of Pseudocercospora cruenta (Sacc,) Deighton. The first two experiments were carried out under field and glasshouse conditions at Mahasarakham University for F1 offsprings and the other two experiments were carried out at Khon Kaen University for F2 offsprings. A Chi square test method was used to justify dominant genes on the infection of the disease. The results showed that the cowpea plants of F1 and F2 offsprings gave only one pair of dominant gene that had its complete dominant effect over recessive gene of the cowpea offsprings.