YIELD STABILITY OF SOME WINTER WHEAT GENOTYPES IN DIFFERENT ENVIRONMENTS

Abstract

Increasing the availability and stability of wheat grain production is a major objective of breeding in present and in the future. Our paper presents some yields stability parameters for 24 Romanian cultivars and breeding lines and the long term check Bezostaya 1, tested in south and west Romania during the year 2018. The experiment were conducted in nine locations and five specifically technology in 3 replications, so that the number of plots were 1125. The diversity of conditions is reflected by the genotypes amplitude of yield variations (from 2932 kg/ha to 5384 kg/ha). The coefficient of regression (b) correlated (positive or negative) with all other stability indicators, except the yield averages of genotypes. Plotting genotypic variance or coefficient of variances against yield averages, permit us to identifier the genotypes with smaller yield variation than expected: Dacic, Adelina and Albota 4-10. The regression analysis identified genotypes adapted to favorable environmental conditions, with b>1 and lower a (Zamolxe, Zamfira, Lovrin 6107), or adapted to less favorable conditions, with b< and a great (Bezostaya 1, Dacic, Adelina and Albota 4-10). The genotypes with b> and a relative large are wide adaptability, like: Alex, Zina, Voinic and Fundulea 11.424 G1. Our study suggests that the coefficient of regression, intercept and the plotting against yield averages are the most useful in characterizing the yield stability and specifically reactions of genotypes to vary environment conditions. Important information brings the minimum yields analyses regarding the genotypes reactions to unfavorable environmental conditions.