Improvement of soybean seedling growth under salinity stress by biopriming of high-vigour seeds with salt-tolerant isolate of Trichoderma harzianum

A pot experiment evaluated the effect of seed vigour and biopriming with Trichoderma harzianum on growth of soybean seedlings under NaCl stress. The Trichoderma isolate was more effective in improving the emergence rate of seedlings produced from high-vigour seeds under saline conditions. Seedlings obtained from bioprimed vigorous seeds had a significantly higher root and shoot length as well as leaf greenness than the control group at all salinity concentrations. The treatment, non-aged high-vigour seeds showed a greater accumulation of proline in the roots and leaves of the pre-treated seedlings under saline conditions. The highest catalase activity was observed in the root and the leaf of the bioprimed low-vigour seed lot at a salt stress level of 6dS/m. A similar pattern of guaiacol peroxidase activity was induced in root and leaf of seedlings obtained from pre-treated high-vigour seeds in response to NaCl stress. It can be deduced that seed invigoration with Trichoderma harzianum diminished the deleterious impacts of salinity, although the amelioration was better in bioprimed high-vigour seeds under the present experimental conditions.