Direct and indirect effects of morphophysiological traits on kernel protein content of confectionary sunflower

Abstract

The most important criterion for introducing new confectionary sunflower hybrids into production is high protein yield. In the breeding process it is important to identify traits which could be used as selection criteria for increased kernel protein content. Increase of kernel protein content results in increased protein yield. This research was conducted during three vegetation seasons on 22 NS high-protein two-line confectionary sunflower hybrids produced within the breeding program at IFVCNS, Novi Sad, Serbia. Strong and very strong correlations were found among the largest number of examined traits. Based on the analysis of simple correlation coefficients, strong negative correlation was determined between kernel protein content and kernel ratio (-0.516*). A weak negative interdependence was determined between head diameter, seed protein content, and kernel protein content. Positive but weak correlation was determined between kernel protein content and thickness of seed, length of seed, width of seed, and 1000 seed weight. Path coefficient analysis for kernel protein content at phenotypic level showed that the thickness of seed had a strong positive direct effect on kernel protein content (DE=382*). Kernel ratio and width of seed had a very strong direct negative effect on kernel protein content (DE=-0.990**; DE=0.600**). A weak direct positive effect of head diameter, seed protein content and length of seed was established, whereas 1000 seed weight had a weak direct negative effect on kernel protein content. Path coefficient analysis indicates showed that the thickness of seed has high great influence on kernel protein content, and an important selection criterion for breeding for high protein yield.