Genetic diversity of segregating Carica papaya genotypes using the Ward-MLM strategy
Progenies from crosses between distinct accessions are potentially exploitable sources of genetic variability, through either evaluation or selection of segregants to obtain promising genotypes. Successful selection can be achieved based on a large number of descriptors that are simultaneously evaluated. Multivariate methods are used initially that fulfill two prerequisites: the estimation of similarity (or dissimilarity) measures between the parents and the use of a clustering technique for group formation. The multivariate method using Ward - Modified Location Model (MLM) allows the determination of the number of groups and their means with high precision, favoring the use of all information on the genotypes. We quantified the genetic diversity in a segregating F2 population of papaya consisting of 92 plants based on morphoagronomic descriptors, using the Ward-MLM strategy. This method clustered the 92 plants into three groups, with the most promising genotypes for selection of plant architecture clustered into group I; the descriptors that contributed the most to the genetic diversity were fruit length, petiole length, first fruit insertion height and fruit mass.