Relationship of Carbon Isotope Discrimination to Water Use Efficiency and Productivity of Barley Under Field and Greenhouse Conditions

Abstract

This study was conducted to evaluate the application of carbon isotope discrimination (CID) as a selection criterion for improving water use efficiency (WUE) and productivity of barley (Hordeum vulgare L.) under field and droughtstress conditions in a greenhouse. A total of 54 genotypes were screened for variability in CID under field conditions, while 23 genotypes were evaluated under water-deficit conditions in the greenhouse. A survey of leaf CID of 54 genotypes at two field locations showed more than 2.14& difference between extreme genotypes. Significant (P £ 0.05) genotypic variation was found in WUE and CID that had a negative strong correlation. There was a negative correlation between leaf CID and aerial biomass in the greenhouse and among six-row genotypes in the field. Correlations between leaf CID across field locations and across irrigation regimes in the greenhouse were significant (experiment 1, r = 0.79 and 0.94 for six-and two-row genotypes), suggesting stability of the CID trait across different environments. Overall, these results indicate the potential of leaf CID as a reliable method for selecting for high WUE and productivity in barley breeding programmes in the Canadian prairies. Further work is currently underway to determine heritability ⁄ genetics of leaf CID and application of molecular marker-assisted selection for the traits in barley breeding programmes.

Genotypic Variability in Carbon Isotope Discrimination and Water Use Efficiency among Recombinant Inbred Lines of Sunflower (Helianthus annuus L.)

“…The similar results have been published by Anyia, Slaski, Nyachiro, Archambault, & Juskiw (2007) and Lambrides, Chapman, & Shorter (2004) where the heritability was high among 87 genotypes and 20 inbred lines of sunflower. Several works showed that CID had higher heritability compared to the WUE and yield, for example as reported in wheat (Ehdaie & Waines, 1994), cotton (Stiller, Read, Constable, & Reid, 2005), and rice .…”

“…To be useful, the traits must have high heritability, not result in yield losses when conditions are favorable, and easy to measure, (Anyia, Slaski, Nyachiro, Archambault, & Juskiw, 2007;Richards, Rebetzke, Condon, & van Herwaarden, 2002). Performing genotypic increases in economically important trait, like yields, under rain fed environment has been a hard objection for plant breeders (Rauf, 2008;Richards, Rebetzke, Condon, & van Herwaarden, 2002).…”

Stable carbon isotope analysis as a direct means of inferring crop water status and water management practices

“…Araus, Amaro et al 1997;Araus et al, 'Changes' 1997a;Araus, Febrero et al 2003;Craufurd et al 1991;Flohr, Mülder and Jenkins 2011;Merah, Deléens and Monneveux 1999;Monneveux et al 2006;Stokes, Mülder and Jenkins 2011;Voltas, Romagosa et al 1999) summarized in Table 5 (and the Appendix). Several key points emerge: (a) Δ¹³C values for wheat grain grown in conditions where water is not a limiting factor are typically above 17‰; (b) wheat grown under very dry conditions has grain Δ¹³C values of 14-16‰; (c) the Δ¹³C values for barley grain are at least 1‰ higher than those for wheat grown under comparable water conditions, though this offset may be another c. 1‰ higher for the more water-demanding six-row variety due to greater use of reserve carbohydrates (Anyia et al 2007;Jiang, Roche and Hole et al 2006;Voltas, Romagosa et al 1999); and (d) Δ¹³C values for rachis are c. 2‰ higher those for grain, at least for wheat for which we have sufficient data (Fig. 4).…”

Mycorrhizal inoculation and nitrogen fertilization affect the physiology and growth of spring wheat under two contrasting water regimes

“…Six measurements were taken per leaf of all 6 replicates at 15 s intervals after the CO 2 /H 2 O parameters became stable. The WUE i was calculated as Pn/Tr, the ratio of photosynthetic rate to transpiration rate (Anyia et al 2007). …”