Relationship Between Genetic Distance and Heterosis for Yield and Morphological Traits in Dry Edible Bean and Faba Bean1

Abstract
The association of genetic distance and heterosis was investigated in dry edible bean (Phaseolus vulgaris L.) and faba bean (Viciafaba L.). Dry bean materials consisted of 28 F2 populations of an 8 × 8 diallel, and their respective parents, grown in eight replications in the field at East Lansing, Mich. in 1981. Faba bean materials comprised the 64 F1's and parents of an 8 × 8 diallel grown in 1975, and 120 populations grown in 1976 como prised of F1's, F2's, and parents of the same diallel, grown in four replications at the Agricultural Research Center at Giza, Egypt. Mahalanobis' D2 was used to estimate genetic distance between parents. Heterosis was measured as deviation from midparent. Correlations in dry beans between heterotic effects and parental distances were positive and highly significant for yield at harvest and for two of the three yield components, namely, number pods/plant and number seeds/pod. No relationship was found for 100‐seed weight. A highly significant positive correlation was obtained for leaf weight. Both significantly positive and negative correlations were found in faba beans for an array of “number” traits related to yield, but heterosis for yield of seed per se in faba beans was not associated with the Mahalanobis D2's