Relationship between Carbon Isotope Discrimination, Ash Content and Grain Yield in Wheat in the Peninsular Zone of India

Abstract

Carbon isotope discrimination (D) and ash content (m a ) have been proposed as indirect selection criteria for grain yield in wheat. The associations between D, m a and grain yield were found, however, to depend highly on the environmental conditions, the organ sampled and the time of sampling. In this study, carried out in the warm conditions of the Peninsular Zone of India, the relationship between D, m a and yield was studied in 30 bread and durum wheat cultivars under residual soil moisture stress (RSMS), post-anthesis water stress (PAWS) and well-watered (WW) conditions. Both D and m a were analysed in young seedlings (four-leaf stage), leaves at anthesis and grain at maturity. Ash content was also evaluated in leaves at booting stage and maturity. Grain D was lower under PAWS and RSMS than under WW, while seedling and leaf D did not significantly differ among water regimes. Grain yield was positively correlated to grain D under PAWS and negatively correlated to grain m a under RSMS. A significant positive correlation was noted under RSMS and WW treatments between m a L m and grain yield. Ash content in leaf at maturity consequently appears to be a useful indirect selection criterion in environments where D does not show any correlation with yield. The results highlight the potential of D and m a as indirect selection criteria for wheat yield in the conditions of the Peninsular Zone of India.

Carbon isotope discrimination and water use efficiency in Iranian diploid, tetraploid and hexaploid wheats grown under well-watered conditions

“…A significant positive association was reported between grain yield and grain and leaf D in wheat submitted to drought after anthesis (Araus et al 1998;Merah et al 2001a). Under residual soil moisture (out of season rainfall) conditions (Misra et al 2006) and pre-anthesis water stress conditions (Xu et al 2007), the relationship between grain D and grain yield was found to highly depend on the quantity of water stored in the soil at sowing and the quantity and distribution of rainfall during the growth cycle. Under well-watered conditions, the relationship between grain D and grain yield is generally not significant (Monneveux et al 2005;Xu et al 2007).…”

“…The variation for D has been mainly studied in durum and bread wheat . Misra et al (2006) reported significantly higher D in bread wheat, compared to durum wheat, under postanthesis water stress, but not under irrigated conditions. Whatever the water regime, bread and durum wheat did not differ for D before anthesis.…”

Physiological characterization of Turkish bread wheat genotypes for resistance to late drought stress

“…The differences in leaf and grain ash content between the irrigated and late drought conditions were related to the soil moisture content. Previous studies have reported a decrease in leaf ash content (Misra et al, 2006;Zhu et al, 2008) and an increase in grain ash content (Zhu et al, 2008;) with a decrease of soil water. However, Monneveux et al (2005) and Misra et al (2010) determined the highest grain ash content in irrigated conditions.…”

“…The highest leaf ash contents were noted in irrigated conditions, suggesting that transpiration rates were much higher in this experiment. Under late drought, photosynthesis is more affected than translocation (Loss and Siddique, 1994) and the translocation of minerals from the leaves is higher than in irrigated conditions, which led to a decline of leaf ash content and an increase in grain ash content (Misra et al, 2006;Zhu et al, 2008). …”

Straw production, carbon and ash content variations after ten cycles of recurrent selection in bread wheat grown under tilled and non-tilled soils

“…Masle et al (1992) found that *Corresponding author; E-mail: rimaich@agro.unc.edu.ar genotypes with low transpiration efficiency (high Δ) had higher ash content in leaf dry matter. Moreover, a positive correlation was found between leaf ash content and grain yield under drought or residual soil moisture stress (Misra et al 2006). Consequently, higher values of stomatal conductance (indicator of transpirative gas-exchange activity) and ash content on vegetative organs should be positive related with grain yield.…”