Effects On The Growth And Physiological Characteristics Of Ramie Under Water Stress

In the ramie planting, water is one of the important factors that affect the yield and quality of ramie that both drought and flooding will cause adverse effect on growth of ramie. Based on the greenhouse of ramie in Hunan Agricultural University, this study selected Zhongzhu-1, Xiangzhu-1and Tri-1as experiment materials. The pot experiment was performed to study the effects of different degree of drought stress and flooding stress on the influence of ramie growth and physiological characteristics. The main results are as follows:Under drought stress, the growth rate of ramie will lower. With the increase of drought stress, could aggravate ramie wilting. Persistent droughts in six days had a little effect on ramie. If persistent droughts in12days, the height growth rate of ramie dropped substantially, compared fell by0.37-0.51cm/d, to the continuous dry after24days, the ramie growth severely affected. The ramie leaf SPAD value and root vitality decreased under drought stress. With the increase of stress, the more serious the leaf SPAD value and root activity dropped. Zhongzhu-1and XiangZhu-7root POD activity in drought is on the rise, compared with before treatment were reached significant level.Tri-1root POD activity showed a trend of rise-fall, namely under the mild drought stress and moderate drought stress, the root POD activity increase, under severe drought stress, the root POD activity began to decline.Water logging stress could inhibit the growth of ramie, and the growth slowed significantly. Ramie flooded after24hours, three varieties of ramie in appearance were normal, the growth rate fell slightly. Gradually with the increase of flood time, ramie leaves curl prolapsed, fall off, young leaves gradually died, stem tip curvature, growth rate dropped substantially until death. Flooded for24hours, ramie leaf SPAD value, root activity has no changes. The more intensive the water stress, the greater all those above changes. Three days after discharge, a slight rebound in Zhongzhu-1leaf SPAD value and root activity, but the Tri-1and XiangZhu-7down again. Under flooding stress, the ramie root POD activity was on the rise. Flooding stress after96hours, Tri-1root POD activity began to decline, while the Zhongzhu-1and Xiangzhu-7root POD activity continues to rise. Drainage in3days, Tri-1root POD activity continues to decline, XiangZhu-7rise slightly, but the Zhongzhu-1rise significantly.From what has been discussed above, under the stress of drought and flooding, ramie growth rate was reduced, leaf SPAD values and root activity decreased, root POD activity was ascended, the greater the stress degree, the deeper influence on ramie, and there are differences between the different ramie varieties.