Physiological Traits Associated with Wheat Yield Potential and Performance under Water-Stress in a Mediterranean Environment

Abstract

Different physiological traits have been proposed as key traits associated with yield potential as well as performance under water stress. The aim of this paper is to examine the genotypic variability of leaf chlorophyll, stem water-soluble carbohydrate content and carbon isotope discrimination (Δ13C), and their relationship with grain yield (GY) and other agronomical traits, under contrasting water conditions in a Mediterranean environment. The study was performed on a large collection of 384 wheat genotypes grown under water stress (WS, rainfed), mild water stress (MWS, deficit irrigation), and full irrigation (FI). The average GY of two growing seasons was 2.4, 4.8, and 8.9 Mg ha−1 under WS, MWS, and FI, respectively. Chlorophyll content at anthesis was positively correlated with GY (except under FI in 2011) and the agronomical components kernels per spike (KS) and thousand kernel weight (TKW). The WSC content at anthesis (WSCCa) was negatively correlated with spikes per square meter (SM2), but positively correlated with KS and TKW under WS and FI conditions. As a consequence, the relationships between WSCCa with GY were low or not significant. Therefore, selecting for high stem WSC would not necessary lead to genotypes of GY potential. The relationship between Δ13C and GY was positive under FI and MWS but negative under severe WS (in 2011), indicating higher water use under yield potential and MWS conditions.

Using Carbon Isotope Discrimination to Assess Genotypic Differences in Drought Resistance of Parental Lines of Common Bean

“…3). These differences in the relationship between D 13 C and grain yield depending on the tissue analyzed and the water environment have been observed before in common bean and wheat (Zhou et al, 2014;del Pozo et al, 2016;Polania et al, 2016b). Given that shoot samples were collected earlier in the season in comparison with grain samples and with respect to the TDS imposition, the closer relationship of grain D 13 C to grain yield was not surprising and was consistent with the D 13 C signature integrating the plant response to environmental conditions over different time periods (Farquhar et al, 1989;Condon et al, 2004).…”

“…Like common bean, observations in other species also indicate complex relationships of D 13 C and seed yield (Brito et al, 2014;Vadez and Ratnakumar, 2016). For instance, in wheat (Triticum aestivum L.), D 13 C signature and yield were positively correlated under moderate drought conditions Fischer et al, 1998;Merah et al, 2001), but negatively correlated under severe drought conditions (del Pozo et al, 2016). Although relationships with yield can be inconsistent, D 13 C signatures generally closely relate to g s and WUE and, as such, can provide valuable information about physiological mechanisms associated with drought resistance.…”

The Effect of Supplemental Irrigation on Canopy Temperature Depression, Chlorophyll Content, and Water Use Efficiency in Three Wheat (Triticum aestivum L. and T. durum Desf.) Varieties Grown in Dry Regions of Jordan

“…These different yield responses to irrigation for the three spring wheat cultivars in the first season were probably related to little rainfall (especially in spring) coupled with poor distribution. Indeed, Loss and Siddique [52], Passioura [89] and Del Pozo et al [90] showed that the best yield was produced when SI matches plant growth and water demand, while Rasmussen et al reported that yield was commonly greater if rainfall was partially distributed during the spring months, predominantly in May and June. To avoid a possible decline in yield with small rainfall amounts in spring months, SI supply during this stage of the crop growth was found to regulate and stabilize yield under the Mediterranean conditions of northern Jordan.…”

Trait means predict performance under water limitation better than plasticity for seedlings of Poaceae species on the eastern Tibetan Plateau

“…Water stress has been considered a cause of variable impacts on plant growth (Bernal et al, 2015;Chaves, Maroco, & Pereira, 2003;Llorens, Penuelas, Estiarte, & Bruna, 2004;del Pozo et al, 2016), and the responses of plant species to water stress may vary among species, as mediated by their functional traits (Körner, 2003;Llorens et al, 2004;Smirnoff, 1993;Violle et al, 2007). Considering a plant species as having a set of morphological and physiological traits which have impacts on the performance of plants (Violle et al, 2007) greatly increases our possibility for examining the differences among plant species in response to environmental variability.…”