Prediction of heterotic crosses for yield in Pisum sativum L.

Efficient parent's selection and heterosis prediction in pea have been of great interest for breeders in order to determine with anticipation, those crosses capable of producing a high frequency of transgresive recombinant lines. The combining ability is the most frequently used criteria to select parents, though its estimation is costly and time-consuming. In this study we examine heterotic crosses for yield determined by morphological and molecular genetic distances between parents, and compare these with the heterotic crosses established by specific combing ability in a line x tester design. To select parental lines that would generate heterotic hybrids, different criteria were applied: genetic distances between lines obtained through morphological traits and molecular markers and cluster analysis. Inspite genetic distances were more efficient than cluster analysis, the correlations values between them and heterosis were weak, and so, we propose to change the way to measure the importance of the genetic distances using the percentage of heterotic crosses that can be successfully predicted as parameter to evaluate. The percentage of heterotic crosses comparing best parent heterosis was higher than the one obtained comparing midparent heterosis. SRAP methodology based on Dice distance between the parental lines and the Euclidean distances based in morphological data collection are the best alternative to SCA grouping association, since 69% and 65% of heterotic crosses can be predicted. (C) 2014 Elsevier B.V. All rights reserved.