Relationship between Carbon Isotope Discrimination and Grain Yield in Spring Wheat under Different Water Regimes and under Saline Conditions in the Ningxia Province (North‐west China)

Abstract

The relationship between grain yield and carbon isotope discrimination (Δ) was analysed in wheat grown under different water regimes in the Ningxia Province (north‐west of China). When the association was significant, the relationships between grain yield, Δ and other drought tolerance related traits, such as leaf ash content (ma), chlorophyll concentration (Chl), relative water content (RWC), stomatal conductance (gS) and the ratio of internal CO2 leaf concentration to ambient CO2 concentration (Ci/Ca), were also examined. Using correlation analysis, the relationships were determined during two consecutive years in a set of 20 spring wheat cultivars (landraces, improved varieties and advanced lines) under rainfed and irrigated conditions, including saline conditions. The relationship between Δ and yield within environments highly depended on the quantity of water stored in the soil at sowing, the quantity and distribution of rainfall during the growth cycle, and the irrigation before anthesis. Δ predicted grain yield under limited irrigation (post‐anthesis water stress) but not under pre‐anthesis water stress (rainfed conditions), fully irrigated and saline conditions. Under limited irrigation, grain Δ correlated significantly to grain yield leaf ma at heading and maturity. It also significantly positively correlated to Chl, RWC, gS and Ci/Ca assessed at anthesis. A precise characterization of the timing and intensity of the abiotic constraints experienced by the crop is consequently needed before implementing the use of Δ in wheat breeding programmes.

Relationships between foliar carbon isotope discrimination with potassium concentration and ash content of the riparian plants in the extreme arid region of China

“…For example, positive association between leaf Δ and ash content, and a negative relationship between grain Δ and grain ash content were found in several cereals (Masle et al 1992, Voltas et al 1998, Merah et al 1999, 2001b, Xu et al 2007. The positive correlations between Δ and K concentration were found in grassland species (Masle et al 1992, Tsialtas et al 2002, Artemisia ordosica and Hedysarum scoparium (Zhao et al , 2007.…”

“…In ecological studies, the number of measurements of stable isotopes naturally occurring in biological materials have increased in recent years (Ehleringer 1993, Warren et al 2001, Su et al 2005, Xu et al 2007, Tsialtas et al 2008. Δ (the 13 C/ 12 C ratio in plant tissues compared to the air), determined mainly in leaves, has proved a powerful tool for studying plant ecophysiology under field conditions (Dawson et al 2002).…”

Does water-use efficiency explain the relationship between carbon isotope discrimination and wheat grain yield?

“…A negative correlation between^and WUE in wheat has been reported (e.g., Farquhar & Richards, 1984;Ehdaie & Waines, 1994;Monneveux et al, 2005), suggesting that genotypes showing lowv alues might be more efficient in water use (Rafi et al, 1992); this is especially to be expected in pot studies (see Araus et al, 2003, and citations therein). As Xu et al (2007a) show, relationships between wheat grain yield and^vary from strongly negative to strongly positive (see, e.g., Xu et al, 2007b, for citations concerning water regimes). Even though, as the authors claim, these differences come from different organs sampled to measure^, the time of sampling, and environmental conditions, this situation is alarming and may show that^is not as good an indirect selection criterion as has been proclaimed.…”

Relationship of Carbon Isotope Discrimination with Biomass and Water Use Efficiency for Alfalfa in Northwestern China

“…In postanthesis stress scenarios, the relationship between D and grain yield is significantly positive and stable across environments in cereals (Ansari et al, 1998;Araus et al, 1998;Voltas et al, 1999;Xu et al, 2007;Zhu et al, 2010). In postanthesis stress scenarios, the relationship between D and grain yield is significantly positive and stable across environments in cereals (Ansari et al, 1998;Araus et al, 1998;Voltas et al, 1999;Xu et al, 2007;Zhu et al, 2010).…”

“…In postanthesis stress scenarios, the relationship between D and grain yield is significantly positive and stable across environments in cereals (Ansari et al, 1998;Araus et al, 1998;Voltas et al, 1999;Xu et al, 2007;Zhu et al, 2010). Under rainfed conditions, the relationship between D and yield varies highly depending on rainfall amount and distribution, and the quantity of water stored in the soil at sowing for wheat (Triticum aestivum L.) (Xu et al, 2007;Zhu et al, 2008b). Under rainfed conditions, the relationship between D and yield varies highly depending on rainfall amount and distribution, and the quantity of water stored in the soil at sowing for wheat (Triticum aestivum L.) (Xu et al, 2007;Zhu et al, 2008b).…”