| China is a country with serious shortage of freshwater resources. Ramie is an important fiber plant. Its growing area will transfer to arid or semi-arid hills. So it will face a more serious threat of drought. Now improving drought resistance by cultivation measures is one of the feasible approaches. In this study,"Hua Zhu No.5" was chosen to conduct water tress experiments. The treatments are:spraying different times of0.5g/L betaine (GB), spraying different times of1.Og/L fulvic acid (FA), and straw mulching. We studied the effects of these measures on agronomic traits, physiological and biochemical indexes and yield to explore the relationship between cultivation measures and drought resistance in ramie, and to provide a theoretical basis for the ramie cultivation against drought. The results were as follows:1) Under drought stress, the height growth rate of ramie was significantly decreased. Spraying betaine solution and fulvic acid solution treatments had no significant effects on the height growth rate. Straw mulching treatment significantly improved the height growth rate during stress, and the large amount of coverage (11200kg/hm2) treatment (M2) was significantly higher than the small amount of coverage (5600kg/hm2) treatment (M1).2) The change rate of ramie leaf relative conductivity during stress significantly increased. Spraying GB sulotion, spraying FA Solution and straw mulching significantly decreased the change rate of ramie leaf relative conductivity.3) The soluble sugar content of ramie leaves significantly increased under drought stress. The treatment of praying GB solution increased the soluble sugar content in the first harvest season. GB2significantly increased it in the second harvest season. The treatment of spraying FA solution also increased the soluble sugar content of ramie leaves in under drought stress. But there was no significant difference between the treatments of FA1and FA2. The treatment of straw mulching decreased the rise of the soluble sugar content of ramie leaves.4) Under drought stress, the leaf peroxidase (POD) activity increased all the time in the first harvest season, while it increased at the beginning and then declined in the second harvest season. In the first harvest season, the treatment of spraying GB solution significantly increased the POD activity during stress. But there is no significant difference between the treatment and the control after rehydration. In the second harvest season, the POD activity of the GB2treatment was significantly higher than that of the GB1treatment and the control during stress, while significantly lower after rehydration. The treatment of spraying FA solution significantly increased the POD activity under stress. But there was no significant difference between the FA1and FA2treatment in most time. In the first harvest season, the M1treatment had no significant effect on the leaf POD activity, while the M2treatment significantly decreased it from the20d to the end of stress. After dehydration, there was no significant difference between the mulching treatment and the control. In the second harvest season, the POD activity of the mulching treatment was lower than the control from0d to20d, while higher at30d. And it was significantly lower than the control after dehydration.5) Drought stress significantly increased the malondialdehyde (MDA) content of ramie leaves. The treatment of spraying GB solution significantly decreased the MDA content under stress in the first harvest season and most time of the second harvest season. After dehydration, the MDA content of the GB2treatment was significantly lower than that of the GB1treatment and the control. The treatment of spaying FA solution significantly decreased the MDA content under stress. From10d on, the MDA content of the mulching treatment was significantly lower than that of the control.6) Drought stress significantly decreased the fresh stem weight and the fresh bast weight of ramie. The treatment of spraying GB solution and the treatment of spraying FA solution significantly increased the fresh stem weight and the fresh bast weight. But they had no significant effect in the second harvest season. The treatment of straw mulching significantly increased the fresh stem weight and the fresh bast weight. And there was significant difference between the M1and M2treatments. |
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