Estimates of correlations and path analyses for eight high protein and grain yield soybean populations

Abstract

Estimates of phenotypic correlations and the direct and indirect effects of grain yield and protein content components on grain and protein yields per plant were studied as source of information on eight soybean populations. Four BC1F4 and four F4 populations from crosses of high protein content materials and commercial varieties were studied. Protein yield and grain yield per plant followed an analogous tendency. The CD201-BC population presented positive correlations of protein content with protein and grain yields. All yield components presented positive direct effects for both grain and protei n yields. The number of pods per plant, amongst the yield components, presented the largest direct effects on grain and protein yields, except in the OC13-CR population. The direct effect of the protein content on protein yield was positive, yet small. Gr ain yield per plant was the main determining factor for protein yield per plant.