Selection of Coffea canephora parents from the botanical varieties Conilon and Robusta for the production of intervarietal hybrids

Seleção de genitores de Coffea canephora das variedades botânicas Conilon e Robusta visando à produção de híbridos intervarietais

ABSTRACT:

The objective of this research was to quantify the genetic divergence of potential Coffea canephora parents, with the goal of developing progenies that associate the best traits of the Conilon and Robusta botanical varieties for hybrid vigor expression. Thus, 10 morphological and productive characteristics of 130 clones of Conilon and Robusta botanical varieties and their intervarietal hybrids were evaluated over 2 years. The experiment was conducted in a randomized block design with four replicates of four plants per plot. For selection of parents, the main component analysis was used to associate values with reference points obtained from the average of each botanical variety. The first two principal components allowed for the separation of the botanical varieties representing the variability contained in the original data with 76% for the first year and 69% for the second year. Although, the genotype × years interaction had significant effects, there were minor differences in the grouping from one year to the next, which is associated with the higher repeatability estimates observed in this study. It was observed that crosses with the 16-1-81^I, 9-1-82^L, and 13-1-61^I parents of the botanical variety Robusta and the 167^I, 890^E, and 130^I parents of the Conilon botanical variety presented greater potential for obtaining selection gains.

Key words:
Coffea canephora; genetic divergence; heterosis