Relationship between genetic distance based on single nucleotide polymorphism markers and hybrid performance in Robusta coffee (Coffea canephora)

The choice of parents is a vital first step in any variety development process. This is particularly imperative in tree crops that require minimally 15-20 years to complete a varietal development. The present study was conducted to determine genetic distances (GDs) between parental clones of Robusta coffee hybrids and assess the relationship between GD and hybrid performance. The experimental material consisted of 64 parental clones and 56 hybrids. The hybrids were evaluated over 11 years, planted in a randomized complete block design with six replications. GD among parental clones was determined based on 120 SNP markers. The results revealed a significant correlation (r = 0.351, p < 0.0082) between GD of parental clones and yield performance of their hybrids. Posterior selection of highest GD hybrids revealed an increase in yield gain over general mean with increasing GD between parental clones of hybrids. Furthermore, comparison of inter- and intra-population hybrids classified using Bayesian clustering analysis revealed consistent outcome where inter-group hybrids outperformed intra-group hybrids for cumulative yield. These results supported the hypothesis that GD is related to the yield performance of Robusta coffee hybrids and is an efficient predicator of hybrid performance for yield.

Automated summary

The study analyzed the genetic distances between parental clones of Robusta coffee hybrids and found a significant correlation between genetic distances and hybrid yield performance. Selecting hybrids with higher genetic distances can increase yield gain, and inter-group hybrids outperformed intra-group hybrids in cumulative yield.