SELECTION OF DESCRIPTORS IN CHARACTERIZAT ION AND PRELIMINAR EVALUATION OF PIGEONPEA GERMPLASM

For the characterization of plant entries in germplasm collection, the evaluation of a big number of descriptors without evaluating the rela tive contribution of each one has been a generalized practice. In orde r 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 principa l components for the set of variables and the multiple regression, wit h grain yield (g/plant) as the dependent variable. In the analysis of principal components, the variables number of seeds/pod, 100-seed weig ht, flower location and seed main color were considered. In the multip le regression analysis, the most important variables for explaining gr ain yield per plant were: number of pods/plant, number of seed/pod, 10 0-seed weight, hilum size, seed shape and pod length.