Path coefficient analysis of the effect of yield, oil content and the duration of vegetative and reproductive periods on seed protein content in soybean

Abstract

During 1991 and 1992, a study was carried out to determine the effect of yield, oil content, and the duration of the vegetative and reproductive periods on protein content in soybean seeds. In 1991 protein content was highly negatively correlated with yield, oil content, and the duration of the vegetative period; in 1992 only the duration of the vegetative period was associated with seed protein. Path-coefficient analysis showed that in 1991 only oil content had a significant direct effect on protein content, whereas in 1992 only length of the vegetative period had a direct effect on seed protein content. Our findings have shown that, despite its high heritability, protein content primarily depends on environmental factors and other traits, such as oil content.