Keragaman Sumber Daya Genetik Kacang Tunggak

Cowpea [ Vigna unguiculata (L.) is more tolerant to drought and acid soil, compared to the other leguminous crops. A total of 150 cowpea germplasm accessions were grown at Muneng Research Station (Probolinggo) during dry seasson of 2014, using a randomized block design, with two replications. Each accession was planted in two rows, of 4 m. Among the total accessions they varied in qualitative and quantitative traits. Most of the accession had ovate leaf shape, purple flower color, cream color of mature pod, and brown to yellowish grain color. Grain yield had a high phenotipic and genotypic coefficient of variation. Low phenotipic and genotypic coefficient of variation was shown on days to 50% flowering and days to physiological maturing. Of the eight variables characterizing the cowpea accessions 64.2% could be explained by three factors. The first factor related to grain yield components (number of fertile nodes, number of branches, and grain weight), second factor associated with crop cycles (date of flowering and harvesting), and the third factor associated with the supporting factors (plant height, pod length, and number of grains per pod). The cowpea germplasm could be divided into three groups. Date of flowering and pod maturing were a determinant variable discriminant function. Group I consisted of 70 accessions, dominated by accessions with early maturing, medium plant height, long pod, high number of grains per pod and high grain yield. Group II consisted of 47 accessions with medium pod maturing, short plants, short pod, low number of grains per pod and low grain yield. Group III consisted of 33 accessions, characterized by medium maturing, high plant, short pod, high number of grains per pod and high grain yield. Accessions of cowpea in group I and III have a high yield and are prospective for further utilization.