GENOTYPIC SPECIFICITY OF SOME WINTER WHEAT TRAITS AND THEIR EFFECT ON GRAIN YIELD

Deletic N., S. Stojkovic, S. Gudzic, V. Djuric, and M. Aksic (2012): Genotypic specificity of some winter wheat traits and their effect on grain yield. - Genetika, Vol. 44, No. 2, 249 - 258. This paper presents the two year results of a study dealing with genotypic specificity of some nitrogen accumulation parameters and yield components, as well as their individual and joint influence on grain yield per plant, in twenty Serbian winter wheat cultivars. There were significant differences among the investigated cultivars regarding the all studied traits. Coefficient of variation ranged from 6.81% for 1000 grain mass to 12.91% for total nitrogen accumulation. Cluster analysis showed the studied genotypes divided into two clusters, where larger one was further divided into several smaller clusters. Good definition of clusters is a sign that these traits' pattern is a distinctive property of a genotype. Multiple regression analysis showed that the all four studied traits, as well as intercept value, had significant effect on grain yield. The greatest effect was expressed by number of grain per spike, where standardized regression coefficient (beta) was 0.535. Adjusted R-2 value (0.984) showed that 98.4% of the observed variation in grain yield was explained by the studied four traits. When biological yield is regarded, only total nitrogen accumulation and intercept value were significant. beta value for total NA was 0.713, and adjusted R-2 was 0.787.