Estimativas de parâmetros genéticos e seleção em famílias de irmãos completos de Jatropha curcas L. em três safras

Abstract

The marked use of renewable energy sources, driven by the growing global energy demand, added to the constant increases in oil prices and especially by climate changes at a global level, have made Brazil recognized worldwide as the leader in bioethanol production, and more recently, in production of biomass for biodiesel. The improvement of physic nut is very recent and few research groups in the world have been dedicated to the species. In certain plant species it is not possible to obtain segregating populations derived from inbreeding lines, due to self-incompatibility, inbreeding depression, or a long youthful period. Thus, in such species it is necessary to employ genetic designs of exogamous populations such as Families of Half Brothers (IMF) and Families of Full Brothers (FIC). In this sense, the objective of this work was to estimate the genetic parameters and genetic gains in families of complete siblings (FIC) of Jatropha curcas; indicate the best families and progenies that can contribute to the genetic improvement program of this species. Six biparental crossings were carried out that originated six families (A, B, C, D, E and F) of complete siblings with 18 individuals in each family. Vegetative and reproductive characteristics have low genetic variability, with low magnitudes for genetic variances and heritabilities. For the vegetative characteristic, mean branch diameter (DRP), the same selected individuals can be used for both parents and clones. The individual selection of progenies with the potential to be parents or for new clones indicated for the vegetative characters the progenies belonging to the C family. The individual selection of progenies with the potential to be parents or for new clones indicated for the reproductive characteristic, number of inflorescences (NIF), progenies belonging to family D.