Genetic diversity of the genus Prunus based on per se evaluation of peach clonal rootstocks

Abstract

The multivariate analyses application and genetic divergence quantification can provide parameters that aid the selection of superior rootstocks. The objective of this study was to evaluate the technical feasibility of using the genetic diversity of the genus Prunus as a clonal rootstock of the peach cultivar ‘BRS-Libra’. The experimental orchard used was part of a national network for evaluation of rootstocks for prunaceous trees, under the general coordination of Embrapa Clima Temperado. The design was randomized and data were collected during the 2016/2017 production cycle. Physical analyses (trunk section area, average fruit mass), chemical analysis (soluble solids), and quantification of estimated productivity of the plants were performed. The data were subjected to the Shapiro-Wilk normality test at a 5% probability level, after which the grouping of the rootstocks was performed using the Unweighted Pair Group Method Using an Arithmetic Average (UPGMA) hierarchical method. The grouping resulted in the formation of five groups. The cultivars of group I, Mirabolano 29C and Marianna 2624, showed graft incompatibility with the evaluated cultivar scion. Similarly, cultivars of group II showed characteristic symptoms of graft incompatibility, resulting in poor development. Group III and IV were composed of cultivars that showed low and medium vigor, with good characteristics for use in orchards with high density, while the cultivars of the group V stood out because they showed high vigor, recommended for orchards with low density. The use of various rootstocks influenced the behavior, vigor and fruit production of the BRS Libra cultivar, with genetic divergence.