Comparative effect of salinity on growth, grain yield, water use efficiency, delta C-13 and delta N-15 of landraces and improved durum wheat varieties

摘要

Supplemental irrigation with low-quality water will be paramount in Mediterranean agriculture in the future, where durum wheat is a major crop. Breeding for salinity tolerance may contribute towards improving resilience to irrigation with brackish water. However, identification of appropriate phenotyping traits remains a bottleneck in breeding. A set of 25 genotypes, including 19 landraces and 6 improved varieties most cultivated in Tunisia, were grown in the field and irrigated with brackish water (6, 13 and 18 dSm(-1)). Improved genotypes exhibited higher grain yield (GY) and water use efficiency at the crop level (WUEyield or 'water productivity'), shorter days to flowering (DTF), lower N concentration (N) and carbon isotope composition (delta C-13) in mature kernels and lower nitrogen isotope composition (delta N-15) in the flag leaf compared with landraces. GY was negatively correlated with DTF and the delta C-13 and N of mature kernels and was positively correlated with the delta N-15 of the flag leaf. Moreover, delta C-13 of mature kernels was negatively correlated with WHEyieid. The results highlight the importance of shorter phenology together with photosynthetic resilience to salt-induced water stress (lower delta C-13) and nitrogen metabolism (higher N and delta N-15) for assessing genotypic performance to salinity. (C) 2016 Elsevier Ireland Ltd. All rights reserved.