Partial correlations between production traits and grain protein in wheat

Abstract

The objective of this study was to check whether there are linear relations between production traits and grain protein in early-, medium- and late-cycle wheat. Data from 204 competition trials of wheat genotypes conducted in the states of Rio Grande do Sul and Paraná were used, 78 trials with early-cycle, 34 with medium -cycle and 92 with late-cycle genotypes. The trials were conducted in a randomized block design, with 149 early-cycle, 95 medium-cycle and 193 late-cycle genotypes being evaluated from 2015 to 2019. Three production traits (grain yield, in kg ha-1, thousand-grain weight, in g, and hectoliter weight, in kg hL-1) and grain protein, in %, were evaluated. Scatter plots were created and the partial correlation coefficients between these four traits were calculated, based on 4330, 2497 and 4714 observations, referring to the early, medium and late cycles, respectively. There are linear relations between production traits and grain protein in early-, medium- and late-cycle wheat. Early- and late-cycle wheat genotypes show a negative correlation between grain yield and grain protein. Medium-cycle wheat genotypes show no correlation between grain yield and grain protein. Selection of wheat genotypes with higher grain yield and hectoliter weight can be carried out indirectly by means of thousand-grain weight.