EXOGENOUS ROOTING AGENT (GGR-6) ALLEVIATES HARMFUL EFFECT OF DROUGHT STRESS ON SEEDLINGS OF PERENNIAL RYEGRASS

摘要

Drought stress is one of the most serious environmental factors influencing plant growth and development. GGR-6 is a plant growth regulator that can regulate plant endogenous hormone content and enzyme activity, which can also enhance stress resistance of many plants. However, little is known about how GGR-6 influences perennial ryegrass physiological changes under drought stress condition. Here, perennial ryegrass variety (Shenshi) was used, and drought condition (drought stress for 0, 6, 8, 10, 12 and 15 days) was simulated. GGR-6 (0, 0.1 g/L, 0.2 g/L and 0.3 g/L) was also applied to test its mitigative effect on this species during seedling stage under such condition. The results showed that due to the intensification of drought stress, the SOD and POD contents increased in the seedlings of this species and long-term drought stress lead to a decrease in enzyme content. Perennial ryegrass enhanced osmotic regulation ability through adjusting of SOD and POD enzyme contents, and also increasing of the proline content at the same time, so as to keep MDA content in the seedlings at a low level. GGR-6 could significantly improve the ability of resisting drought stress of this grass species, and the most effective way of GGR-6 application was 0.1 g /L and 0.2g/L one week after sowing seeds (W1). The Above results suggest that GGR-6 application is an effective way to increase stress tolerance of perennial ryegrass under drought condition in production practice.