Assessment of genetic divergence among coffee genotypes by Ward-MLM procedure in association with mixed models

Abstract

ABSTRACT. Mixed linear models have been used for the analysis of the genetic diversity and provided further accurate results in crops such as eucalyptus, castor, and sugarcane. However, to date, research that combined this analysis with Ward-MLM procedure has not been reported. Therefore, the aim of the present study was to identify divergent coffee genotypes by Ward-MLM procedure, in association with the mixed-decision models. The experiment was initiated in February 2007, in the northwestern Rio de Janeiro State. The 25 evaluated genotypes were grown with a spacing of 2.5 x 0.8 m, in a randomized block design, with 5 replications, containing 8 plants each. The following agronomic traits were evaluated: plant height, stem diameter, plagiotropic branch number, and productivity. Four measurements were performed for each character from 2009 to 2012, between May and July. Data were analyzed using REML/BLUP analysis and Ward-MLM procedure. The Ward-MLM procedure in association with mixed linear models demonstrated the genetic variability among the studied coffee genotypes. We identified two groups of most divergent coffee genotypes, which can be combined by crossings and selections in order to obtain genotypes with high productivity and variability.

ADAPTATION OF PROGENIES/CULTIVARS OF ARABICA COFFEE (Coffea arabica L.) IN MOUNTAINOUS EDAFOCLIMATIC CONDITIONS

“…The existing cultivars are classified into very early, early, middle, late and very late maturity cycles, which is a polygenic characteristic influenced by the environmental conditions, such as the region, local edaphoclimatic conditions, exposure direction, nutrition and biotic agents (GUERREIRO-FILHO et al, 2008;RODRIGUES et al, 2014;RODRIGUES et al, 2016;MARTINS et al, 2017). Therefore, varieties with different maturation periods allow harvest scheduling, and those that increase the crop yield and have desirable agronomic characteristics should be prioritized when selecting the crop for implementation.…”

Genetic diversity of promising ‘conilon’ coffee clones based on morpho-agronomic variables

“…Studies on the genetic diversity of coffee adopting multivariate analyses have been carried out by many researchers, both for C. canephora (Fonseca et al 2006, Ivoglo et al 2008, Dalcomo et al 2015, Silva et al 2015, Covre et al 2016), and C. arabica (Dias et al 2005, Guedes et al 2013, Moura et al 2015, Rodrigues et al 2016. Information in this regard provides bases to be used in breeding programs for the species.…”

Research Article Genetic diversity as tool to identify standard leaf nutrients in cassava genotypes

“…Considering other crops such as coffee, the leaf nutritional status can be interpreted using the "sufficiency range" method, which generates leaf nutrient contents that are used as a reference (Partelli et al, 2006), although it does not consider genetic diversity (Gomes et al, 2016). Regarding to this latter aspect, multivariate methods has been used as useful tool for quantifying genetic diversity (Carvalho et al, 2012, Guedes et al, 2013Rodrigues et al, 2016;Kurosawa et al, 2017). Among multivariate methods, the unweighted pair group method with arithmetic mean (UPGMA) is considered more efficacious (Hale and Dougherty, 1988) and, therefore such method has been extensively used for quantifying genetic diversity in many species, including M. esculenta (Siqueira et al, 2009;Sanoussi et al, 2015).…”