Effects of climatic factors on grain vitreousness stability and heritability in durum wheat

Abstract

Modern durum wheat breeding programs are becoming more oriented toward creation of not only high-yield cultivars but also high quality, with good stability for the trait of interest. Vitreousness of grain is associated with semolina granulation, color, and protein content; it is regarded as one of the most important characteristics in the grading industry, affecting the commercial value of the commodity. A set of 15 winter and facultative durum wheat genotypes was tested for grain vitreousness across 6 environments for 2 consecutive years. Three-way analysis of variance showed that genotype, location, and year contributed 4.1%, 20.6%, and 42.2% to the total sum of squares, respectively. Interaction terms, including genotype, contributed 6.1% to the total sum of squares, and location x year contributed 27.0%. Stability of grain vitreousness for the examined breeding lines and cultivars of durum wheat was shown by the site's regression. Broad-sense heritability of grain vitreousness was estimated to be 71%. Climatic variables were used for factorial regression modeling, and most of the interaction term for grain vitreousness was explained by mean temperatures in June (54.4%) and April (14.2%), and precipitation (14.4%) and sunshine hours (14.3%) in March. During the grain filling and grain ripening stages, the most influential climatic variables in explaining interaction were maximum temperature (43.4%), precipitation (30.9%), and sunshine hours (5.6%).