A 6x6 half diallel cross was used to study gene action involved in the inheritance of 9
agronomical characters in garden pea ( Pisum Sativum L.) and estimation of general and specific
combining ability effects. The genotypes used in the present study were; Metior, Snow wide, Herawt,
Dwarf gray sugar, Early perfection and Alaska. Significant genotypic differences were observed for all
studied characters which included plant height, No. of branches and pods per plant, No. of green pods
per plant, green pod weight per plant, total soluble solid (TSS), No. of seeds per pod, ten pods weight
and green pod width. Both additive and non-additive effects are important in the control of these traits,
while additive effects is predominant. Meanwhile, the TSS after two days storage was mainly
controlled by dominance effects. The Wr/Vr graphs indicated partial dominance for green pods weight,
green pods number, TSS in fresh pods, Ten pods weight and green pod width. complete dominance
was inferred for TSS after two days storage and No. of seeds per pod. While, overdominance was
found for number of branches and plant height. The cultivar Alaska was the best combiner for No. of
branches per plant, pods weight per plant and No. of pods per plant. While, Early perfection was the
best combiner for seed number per pod and ten pods weight. Snowwide was the best combiner for pod
width. While, Metior was the best combiner for TSS fresh. Favorable additive genes for TSS fresh,
seed number per pod and pod width were also found in the parent Herawt. Further dominance effects
due to specific combinations and/or epistasis (Sij) were observed for most studied characters.
Phenotypic correlation between the tested traits was also studied. The parental genotypes used in the
present study possessed favorable genes for most studied traits, which could be utilized in the breeding
programs designed to improve garden pea