Relationship between Chlorophyll and other Features in Durum Wheat (Triticum turgidum L. var. durum) Using SPAD and Biplot Analyses

The aim of this study was to evaluate Genotype×Environment Interaction (GEI) of chlorophyll meter readings (SPAD) of ten durum wheat cultivars, using data obtained from multi-environment trials during two years, at eight locations. Stability and genotypic superiority for SPAD reading was identified using ANOVA and GGE biplot analysis. Furthermore, the interrelationships among SPAD reading and other yield components and cultivars-by-traits, environment-by-traits, and cultivars-by-environment were studied using scatter, ranking, and comparison of biplot techniques. Substantial variations were found among SPAD reading, yield components, and quality criteria as related to each other, environment, and cultivars. There were positive correlations among SPAD reading with GY, some quality criteria [Protein Content (PC); Wet Gluten (WG), Vitreous Kernels (VIT)], and yield components [stalks m-2 (SS); ear m-2 (ES); Plant Height (PH), Length of Spike (LS)], while Maturation Time (MT) had negative correlation with SPAD. Also, there was relationship among SPAD and SC (Semolina Color) and SDS (Mini Sedimentation) with obtuse angles (< 900), but the correlation was not significant. The GGE biplot indicated that Kızıltepe environment (E6) and Eyyubi cultivar (G3) were the best in terms of SPAD reading. The GGE biplot provided useful information for experimentation of SPAD readings of cultivars when grown under multi-environment. Moreover, SPAD should be considered as the preferred tool, when the breeder is looking for the best and useful tool to determine flag leaf chlorophyll content.