Caracterização morfoagronômica de genótipos de mamoeiro (Carica papaya L.) e seleção de descritores visando a proteção de cultivares

Abstract

The papaya (Carica papaya L.) is one of the most cultivated fruit crop in the world, however, there is need for new varieties to support the expansion and sustainability of the crop. Therefore, it is important to determine the genetic variation among papaya accessions, allowing breeders to perform more suitable crossings for the cultivar development. The characterization of these accessions represents a fundamental step in the synthesis of new genotypes. The objectives of this work were to evaluate the variation of 30 quantitative descriptors in 27 papaya genotypes, to estimate genetic parameters and to define a list of minimum descriptors with the aim of cultivar protection, from 30 quantitative and 21 multicategorical descriptors, related to the plant, leaves, flowers, fruits and seeds. The genotypes showed large polymorphism for the quantitative descriptors. For all the descriptors, most of the variability was due to genotypic variance, with heritability estimates ranging from 60.48 to 99.05%. Aiming the indication of the most informative descriptors, quantitative data were selected based on the Singh method and direct selection, while the qualitative descriptors were analyzed by correlation. Excluding uninformative descriptors, the list of minimum descriptors for papaya, aiming at variety protection and genotype classification can be composed by 18 quantitative and 13 multicategorical traits, without loss of information. In addition, one can conclude that the morphological descriptors were able to access the genetic variability in this species.