Comparison of Photosynthetic Components of Wheat Genotypes Under Rain‐fed and Irrigated Conditions

Abstract

The major environmental factor limiting the range of adaptation for wheat is drought. Fourteen wheat genotypes (Triticum aestivum L.) were grown under two environments (irrigated and rain fed) to determine physiological and photosynthetic responses to drought. Combined analysis of variance of the data showed that the environment was a significant source of variation for leaf chlorophyll content (LCC), stomatal conductance (g(s)) and grain yield (GY). Wheat genotypes differed significantly for LCC, g(s) and GY. All the measured traits under water-stress conditions except maximum photochemical efficiency of PSII (F(v)/F(m)) were lower than those under nonstress conditions. Mean GY in rain-fed conditions was 11.26% lower than that in irrigated conditions. The genotypes number 13 (Marvdasht) and 8 (M-81-13) exhibited the highest GY per unit area in both irrigation and rain-fed conditions. It was concluded that the higher LCC and g(s) under drought-stress conditions could possibly be the proper criteria for screening the drought-tolerant wheat genotypes under field conditions.

Dry Matter Production, Photosynthesis of Flag Leaves and Water Use in Winter Wheat Are Affected by Supplemental Irrigation in the Huang-Huai-Hai Plain of China

“…An enhanced grain yield of wheat is consistently associated with changes in photosynthetic characteristics, such as P n , T r and g s of the flag leaf [ 45 ]. The magnitude of the increases in P n , T r and g s found in both our previous study by Guo et al [ 20 ] and the present study was similar to reported results concerning winter wheat from studies by Khamssi et al [ 46 ], Sun et al [ 47 ] and Zhang et al [ 48 ], reflecting the beneficial effects of SI in these photosynthetic parameters. Some studies have reported that enhancing P n and g s , particularly at the mid and later stages of grain filling, has significant effects on improving grain yield of crops, such as winter wheat, maize, rice [ 19 , 49 – 51 ].…”

Systems Responses to Progressive Water Stress in Durum Wheat

“…We propose that these combined factors are responsible for RIL2219’s inherent greater capacity for carbon assimilation and thus the ability to maintain higher yield stability than either parent under drought in the field, as supported by datasets from a large number of field trials under various drought gradients (unpublished observations). Evidence exists that wheat breeders have inadvertently selected for higher stomatal conductance in their quest for greater yield potential under optimal conditions, and this has also proved to be beneficial under water-limiting Mediterranean environments [67] , [64] , [68] , [69] , [70] , [65] , [71] , [72] , [73] , [74] . There was also evidence for greater osmotic adjustment ability in the two drought resistant lines Cham1 and RIL 2219 than in Lahn.…”

Variation and Relationships among Agronomic Traits in Durum Wheat [Triticum turgidum(L.) Thell. ssp.turgidumconv.durum(Desf.) MacKey] under South Mediterranean Growth Conditions: Stepwise and Path Analyses

“…In wheat, leaf chlorophyll content (as a proxy of leaf photosynthesis) and stomatal conductance were proposed as proper criteria for identifying drought-tolerant genotypes under field conditions [16]. ese tow traits allow as well as the identification of germplasm combining improved water use efficiency and productivity under both well-watered or water-limited conditions [17].…”