Genotypic and phenotypic correlations among coffee leaf rust symptoms of Arabica coffee genotypes in North Sumatra. Indonesia

Abstract

Coffee leaf rust (CLR) is a pandemic and a serious threat for coffee sustainability in many coffee producing countries. To overcome this CLR, the world's consensus is to use of resistant cultivars which can be created through coffee breeding program. This research aimed to study genotypic and phenotypic correlations between CLR symptoms of seven arabica coffee (Coffea arabica L.) genotypes that were selected from different districts of North Sumatra Province, Indonesia. This experimental research using a randomized complete block design with three replications was conducted at the experimental garden of the Faculty of Agriculture, Universitas HKBP Nommensen in Medan. The result of this study indicate that leaf rust severity (LRS) had a genotypic component variance of 86.8% which indicated that LRS was controlled more dominantly by plant genetics than other unknown factors. Severity indicated by LRS showed no genotypic and phenotypic correlation with dispersal indicated by branch rust incidence (BRI) and leaf rust incidence (LRI). BRI genotypically correlated with LRI. The results of this study could contribute to resistance coffee breeding for CLR.