Agriculture & Food, Volume 11, 2023

Abstract: Durum wheat (Triticum turgidum L. var. durum) under Mediterranean conditions is frequently limited by both high temperature and drought during grain growth stages. The research was carried out in the 2017-2018 cycles, with 25 genotypes in randomized completely blocks design with 4 replications. Data on grain yield, seedling fresh weight, root fresh weight, flag leaf area, tillering number, normalized difference vegetative index, canopy temperature, chlorophyll content, days of heading, peduncle length, spike length, spikelet number per spike, number of kernel per spike, and relationships among characters were investigated. The analysis of variance revealed highly significant differences (p<0.01) among the genotypes parameters investigated except for canopy temperature. In the study, G21, G6 and G22 had higher grain yields. The largest flag leaf area was measured in G3 (31.3 cm2), followed by G9 and G3. The seedling fresh weight and root fresh weight were established at the Z25 growth stages. The highest seedling fresh weight was determined in G23, followed by G19 and G18. Genotypes G5 and G8 had the highest root fresh weight. G15 had the highest tillering capacity. The longest spike was determined in G8, the highest spikelet number per was in G10 and the kernel number per spike was in G25. The lowest canopy temperature was measured in G15 and the highest chlorophyll content was measured in G25, G19 and G23. Correlation analysis showed that there are different coefficients between the parameters examined. Flag leaf area positively correlated with grain yield. Seedling fresh weight was positively correlated with chlorophyll content (r=0.517**), peduncle length and kernel number per spike. Root fresh weight in genotypes had a positive effect on peduncle length, spike length, spikelet number per spike and kernel number per spike. A significant positive correlation was determined between the normalized difference vegetative index at Z55 with spike length (r=0.412*), and spikelet number per spike (r=0.620**). Canopy temperature measured at the heading stage had a slightly negative effect on peduncle length, spike length and spikelet number per spike. Chlorophyll content measured at the heading stage had a positive effect on peduncle length (r=0.402) and spikelet number per spike (r=0.300). Although the research was conducted under rainfed conditions, positive correlations were found between some physiological and yield components.