Comparison and evaluation of water-use and photosynthetic characteristics of eight triticale cultivars under NaCl stress

In this study, we sought to identify salt-tolerant triticale germplasms suitable for cultivation in areas characterized by saline soil. To this end, we performed potted seedling experiments to assess the effects of simulated salt stress (0.6% NaCl solution) on the growth, water-use characteristics, photosynthetic physiological parameters, and salt tolerance of the seedlings of different triticale germplasms at different stages of growth. The results revealed that salt stress had significant effects on the growth of triticale seedling, a including significant inhibition of plant height, tiller number, total biomass, and specific leaf area. In addition, we detected significant reductions in the net photosynthetic rate, stomatal conductivity, and transpiration rates of the different triticale germplasms. Among the assessed germplasm, J-18 had the highest plant height, tiller number, net photosynthetic rate, transpiration rate, water potential, and carbon isotope content, with respective values of 46.95 cm, three, 10.08 µmol·(m²·s)⁻¹, 3.88 mmol·(m²·s)⁻¹, -1.81 MPa, and -27.15%. Conversely, compared with the control plants, we recorded 80.4% and 91.6% reductions in the above- and belowground biomasses of T-6, respectively. The results of cluster analysis indicated that the different triticale germplasms can be divided into the following three categories based on salt tolerance: good salt tolerance (‘Jian-18’ and ‘JI Forage’), general salt tolerance (‘TXWB-2’, ‘TXWB-3’, and ‘Jian-47’), and poor salt tolerance (‘TXWB-6’,’TXWB-7’, and ‘TXWB-8’). Furthermore, the salt tolerance of the different germplasms, from good to poor, could be ordered as follows: ‘Jian-18’ > ‘JI Forage’ > ‘TXWB-2’ > ‘Jian-47’ > ‘TXWB-3’ > ‘TXWB-8’ > ‘TXWB-7’ > ‘TXWB-6’.