A half diallel set of crosses involving six parental lines were evaluated to estimate heterosis and
combining ability for maturity, yield, yield components, total shedding percentage, severity for rust and
chocolate spot disease, infestation of Aphids craccivora (Koch) and Liriomyza congesla (Beeher). Significant
differences among genotypes were obtained for all traits. The parental line M. 127 was the earliest one and the
best for yield per plant. The parents M. 109 and Rebaya 40 gave the lowest values for total shedding percentage
and number of aphids! loo leaves.
Mean squares for parents vs. crosses as an indication to average heterosis over all crosses were
significant for all traits except number of pods/plant, number of seeds/pod and total shedding percentage. The
most desirable heterotic effects were presented by; three crosses R. 40 x G 461, M. 109x G 461 and M. 109 x R,
40 for seed yield! plant, cross R. 40 x G 461 for rust resistance, three crosses M. 109 x G 716, M. 109 x 0461
and 40 x G 716 for chocolate spot resistance, five crosses M. 109 x R. 40, M. 127 x 0461, M. 127 x G 714, R.
40 x 0. 716 and R. 40 x G 461 for number of aphids! 100 leaves and five crosses M 109 x G 461, M 127 x M
109,M l09x046l,M 127xG716andG716XG46l fornumberofleafminor.
Significant variances associated with general and specific combining ability were detected for all
studied traits. With the exception of maturity date, total shedding percentage, rust disease and number of
aphids!100 leaves, high ratio of OCA! SCA which exceed the unity were detected, revealing that the largest part
of the total genetic variability associated with these traits was a result of additive gene action. The parental line
M 127 expressed significant positive, g, effects for number of pods/plant, 100 seed weight and seed yield! plant.
R. 40 was considered as the bet combiner for maturity date and resistance for aphids. G. 716 was a good
combiner for maturity date, 100 seed weight, seed yield and resistance for leafminor. G. 461 expressed
significant positive g, effects for number of seeds/pod, chocolate spot and number of aphids!100 leaves.
The most desirable inter- and intra allelic interactions were represented by five crosses for maturity
date, four crosses for number of pods! plant, three crosses for number of seeds/pod, nine crosses for 100 seed
weight, and seed yield/plant, two crosses for total shedding percentage, one cross for rus? severity, one cross for
chocolate spot, five crosses for number of aphids and four crosses for resistance of leafminor.