Selection of triple-cross Theobroma grandiflorum genotypes, aiming at fruit production and resistance to Moniliophthora perniciosa

Abstract

In this study, we evaluated triple-cross Theobroma grandiflorum progenies from two successive hybridizations aiming to select families and individuals within them that aggregate high fruit production with resistance to the witches' broom disease, as well as to evaluate the possibility of incorporating the production methodology of triple-cross hybrids in the breeding program of the species. The study was conducted in a commercial area located in Tomé Açu, Pará, from 2007 to 2018, in a consortium with a black pepper plantation. Twenty-five progenies of T. grandiflorum were used, in a randomized block design, with five replicates and three plants per plot. The variables “number of fruit”, “fruit production” and the occurrence rate of witches' broom, during eight harvests, were all analysed. Eight progenies with excellent production and low damage levels caused by witches' broom were selected. Within these, 16 plants were identified, which will be propagated vegetatively for clonal evaluations in different environments and later turn into parents of a new population. The obtained results served as an indication from the efficiency of the triple-crossing methodology in the breeding program of the species.