Description

Abstract: Recently, the peanut (Arachis hypogaea L.) industry has expressed a greater need for higher percentages of fancy pods and extra large kernels (ELK), especially for use in large-seeded in-shell products. Genetic control of these traits has been reported to range in complexity from simple inheritance to the inclusion of multiple modifier genes. This study was conducted to determine the General combining ability (GCA) effects of 50 peanut genotypes on pod and seed size. Each genotype was used five times as a female parent and five times as a male parent in a partial diallel crossing program. F1 hybrids were grown and their pods were harvested for measurements of pod and seed size. The F2 generation was planted the following year and similar measurements were recorded using the single pod descent procedure. Individual F2 plants were harvested and pod and seed characteristics measured for segregation information within four crosses. General combining ability effects were not well correlated between generations (r=0.53-0.56) or with the same traits measured on pure-line parents (r=0.32-0.42). PI 298845, PI 314897, PI 325079, Jenkins Jumbo, and Fla 393-8-1-1-1-1-1-2 had consistently large positive GCA effects on pod and seed weight. F2 segregation patterns indicated that some crosses exhibit predominantly additive gene action while one cross (PI 270818 / PI 269111) showed dominance toward smaller pods. Transgressive segregation occurred for pod and seed size traits in four crosses. Substantial genetic variability for pod and seed size remains in the peanut germplasm collection