GYT Biplot Analysis: A New Approach for Cowpea Line Selection

Cowpea beans is grown under different edaphoclimatic conditions throughout Brazilian regions causing them to perform differently due to the influence that environments have on genotypes. Thus, it is necessary to obtain lines adapted to the specific cultivation environments so that it can present high yield. The objective of this work was to select cowpea lines through the GYT biplot multivariate analysis. The experiment was carried out in Bom Jesus de Itabapoana, Rio de Janeiro State, Brazil, in the 2016 and 2017 harvests. The randomized block design was performed with four replications and four lines per plot. Variance analyzes and biplot plots were applied for the number of days of flowering, final planting, harvest value, housing, pod yield, length, average number of beans per pod, average grain weight per pod and grain weight. The analysis of variance showed that there is genetic variability among the strains, requiring a detailed study to select those with the best agronomic performance. The first two major components of the biplot chart explained almost all of the variation between strains. All yield characteristics were negatively correlated with the set of productivity combinations with housing and number of days for flowering. Lines 3, 10, 4, 2, 6, 12, 7 and 11 showed better average performance for yield characteristics.