Selection in half-sib progenies of Annona squamosa L.: An important step in the development of new cultivars

There are limited number of studies on the genetic improvement of sugar apple (Annona squamosa L.), in addition to this there are few studies available on the in situ and ex situ characterization and conservation of its germ plasm, this has restricted the advancement of the cultivation of its fruit in Brazil. The present study aims to estimate the genetic parameters, establish Pearson's correlations between agronomic traits, and predict the genetic gains in half-sib progenies of sugar apple for selection purposes. The experiment included four half-sib progenies of sugar apple (UNI-1, UNI-2, UNI-3, and UNI-4) distributed in a random-block experimental design with three repetitions and five plants per plot. Field evaluation using eight quantitative traits were assessed over eight harvests during the fourth, fifth, sixth, and seventh years of production. Flower length had a high heritability (66%). There was a positive Pearson correlation between total yield and number of fruits per plant, and flower length was strongly correlated with traits related to fruit size. Flower number, flower length, fresh fruit mass, fruit diameter and fruit length also showed high repeatability. It was observed that five harvests are an adequate number for the selection of superior genotypes, and that these evaluations should be carried out between the fourth and sixth year after planting. The Mulamba and Mock 2 index (MM2) was used as criterion for simultaneous selection of genotypes. Genotypes 25 (UNI-1), 10 and 47 (UNI-2), and 11 (UNI-3) stood out for achieving high scores in more than one trait. They should be considered for selection as they allow the best offspring to be selected, are potential candidates for new cultivars and will be prioritized for the next recombination cycle of the breeding program.

Automated summary

There are limited studies on the genetic improvement of sugar apple and the characterization and conservation of its germ plasm, which has hindered the fruit cultivation in Brazil. This study estimated the genetic parameters, correlations between agronomic traits, and predicted genetic gains in sugar apple half-sib progenies. The results showed that flower length had high heritability and there were positive correlations between total yield and fruit per plant. Five harvests were found to be sufficient for selecting superior genotypes, and the Mulamba and Mock 2 index was used for simultaneous selection.