Genotype-environment-attribute interaction in an advanced cashew population through joint biplot graphical analysis

Abstract

ABSTRACT: Despite the progress achieved, the cashew cultivar (Anacardium occidentale L.) breeding program at Embrapa Agroindústria Tropical (CNPAT) has not yet peaked in terms of primary and secondary yield components, and the quality properties of the peduncles. Significant improvement is expected with the breeding program in obtaining new elite clones (cultivars). This this study investigated genotype x environment x attribute interaction in cashew trees using principal component analysis with multiple data matrices. The experimental design was completely randomized, in a factorial scheme with repeated measures over time, applying the confounding technique, with 3 treatments and 4 replications, totaling 48 plots. The total number of plants was represented by 30 plants of each clone in each environment. Around 30 ripe cashew peduncles of each genotype were harvested early in the morning and sent to the post-harvest laboratory of Embrapa Agroindústria Tropical (CNPAT). The factors considered for joint biplot graphical analysis were three genotypes (G1, G2, G3), four environments (combination of two locations, Alto Santo and Beberibe, municipalities in the state of Ceará, two agricultural years (2013 and 2014), and eight physicochemical peduncle properties. The study was implemented using principal component analysis (PCA), with a three-way data array (genotypes x environments x variables). The genotypes did not exhibit phenotypic stability for the variables assessed and environments studied because these cultivars are located far from the center of the graph, that is, away from the origin. The three genotypes showed positive and negative phenotypic adaptations for different variables and environments, qualifying them for consumption of pseudofruits as table fruits, industrially processed products, or even displaying dual purpose consumption suitability.