Evaluation of Physiological Traits, Yield and Yield Components at Two Growth Stages in 10 Durum Wheat Lines Grown under Rainfed Conditions in Southern Syria

Abstract

Water stress, which limits the distribution and productivity of durum wheat (Triticum durum Desf.) in the Mediterranean region, is also considered to be a major factor reducing yield in semiarid regions. Improving drought resistance is thus an important objective in plant breeding programs for rainfed agriculture. The current study was carried out to identify drought-tolerant durum wheat lines among 10 lines and one variety (Douma1, the control) in the first and second settlement zones in the Southern part of Syria and to recognize the most important physiological parameters associated with drought tolerance. Membrane stability index, chlorophyll (chl) content, relative water content and chl fluorescence were recorded at the vegetative and anthesis stages, as were yield and yield components. Data recorded at vegetative and anthesis stages in both zones showed that there were significant differences between all lines growing in the first and second settlement zones and that all characters in the second zone were significantly lower than those in the first zone. Line 1 was superior to Douma1 in terms of membrane stability index, relative water content, chl content and chl florescence, also showing better yield and higher total plant biomass, tiller number/m2, 1000 grain weight and grain number/ear than the control. The ability of wheat cultivars to perform reasonably well in variable rainfall and water-stressed environments is an important trait since it allows for stable production under drought stress. Moreover, prior to genetic manipulation, it is important to characterize the physiological parameters of known drought-tolerant or drought-sensitive wheat cultivars with the objective of better understanding their physiological responses under drought

Chlorophyll Fluorescence and Drought Tolerance in a Mapping Population of Durum Wheat

“…1), which is consistent with the findings of Araus et al (1998). In contrast to a study reporting a rather positive correlation between grain yields and chlorophyll contents in bread wheat under drought conditions (Paknejad et al, 2007), the results obtained herein show a positive and significant correlation between the quantum yield Fm/Fv and the CHLSPAD (r = 0.146*) (which is consistent with the findings of Avenson et al (2005) and Almeselmani et al (2015). Chlorophyll contents were found to be in a positive correlation with photosynthetic rates.…”

“…Similar findings were reported in previous studies by Roostaei et al (2011), Papageorgiou & Govindjee (2011) and Wang et al (2016). The increase in the F 0 values and the decrease in the F m values under drought stress can be attributed to chronic photo-inhibition due to the photo-inactivation regulation of PSII reaction centers, and even the D1 protein damage (Oxboroug, 2004;Roostaei et al, 2011;Almeselmani et al, 2015;Mohammadi et al, 2019). Moreover, all these effects show that the photosynthetic process is strongly affected by drought stress (Paknejad et al, 2007).…”

Diallel Analysis for Area, Chlorophyll and Temperature of Flag Leaf in Bread Wheat under Well Watered and Drought Stress Conditions

“…Generally, in F 1 the drought stress reduced the FLA and FLCC by 12.40 and 9.80% respectively, also the flag leaf temperature of F 1 increased by 3.25 o C under drought stress. Similar results were found by Almeselmani et al (2015). Note.…”

Cotton Genotypes Appraisal for Morpho-Physiological and Yield Contributing Traits Under Optimal and Deficit Irrigated Conditions

“…According to past studies, a rise in temperature from 2 °C to 4 °C will reduce precipitation by 30%, impacting productivity and water availability in 2050 (Ben-Asher et al, 2007;Gornall et al, 2010). Thus, drought is a global problem for food security, which has highlighted the need to create different crop cultivars that produce good yields under water-deficit conditions (Almeselmani et al, 2015).…”