Selection of descriptors in characterization and preliminar evaluation of pigeonpea germplasm

Abstract

For the characterization of plant entries in germplasm collection, the evaluation of a big number of descriptors without evaluating the relative contribution of each one has been a generalized practice. In order to analyze the discriminant descriptors on pigeonpea (Cajanus cajan (L.) Millsp.), 54 entries were characterized in 1991 and 34 in 1992 at EMBRAPA-CPATSA, Petrolina, PE, Brazil, using the analysis of principal components for the set of variables and the multiple regression, with grain yield (g/plant) as the dependent variable. In the analysis of principal components, the variables number of seeds/pod, 100-seed weight, flower location and seed main color were considered. In the multiple regression analysis, the most important variables for explaining grain yield per plant were: number of pods/plant, number of seed/pod, 100-seed weight, hilum size, seed shape and pod length.