Inheritance of Forage Yield and Certain Morphological and Fruiting Characteristics in Crownvetch1

Abstract

We estimated general and specific combining ability variances (GCA and SCA) and certain phenotypic and genotypic correlations in crownvetch (Coronilla varia L.) by using an unbalanced partial dialleL The unbalanced design resulted when certain clones failed to flower and cross‐incompatibility was encountered. We made estimates by using data from a field planting of 108 crosses and the parental clones. Yield data were obtained from three hay cuts, and other measurements included flower date, seed set, stem angle, leaf and stem size, and final stand percent.GCA estimates were significant for all traits, and SCA was significant for all but 2 of 12 traits. SCA estimates were small in relation to GCA for all characters except yield. The estimate of SCA for yield at the first hay cut was twice that for GCA, with SCA declining on successive cuts. Phenotypic correlations of total yield with flower date and seed set were low, but genotypic correlations were high and negative, indicating some difficulty in combining maximmn forage yield with adequate seed yield.The phenotypic range and the high GCA estimates indicate the possibility of rapidly changing crownvetch populations by selection. If hay yield were the major consideration, a variety could be produced by a limited crossing system to exploit SCA. However, a cyclic selection system would be more practical with the present objective of developing a variety for a geographic area of marginal adaptation.