Research On Drought Stress Affect Morphological And Physiological Characteristic Of Different Cultivars Of Bluegrass

This paper researched on the two supplied materials which were common in the northern cultivars and one European Bluegrass (SupraNova) under the experimental condition. After the continuous drought treatment, the method of water recovery was adopted, the associated field experiment and greenhouse test were combined in the lab and the effects of drought on the physiological, biochemical, morphological characteristics of bluegrass were studied, the purpose of this experiment was based on theoretical foundation for Bluegrass exploitation and utilization. The main results were showed as the following:1. Drought stress made the three varietal wilting upgraded, the quality of Bluegrass decreesed, furthermore, compared to the other brands, the quality of turfgrass in SupraNova, the extent of the descent went down sharply, after water recovery four days, the recovery capability in SupraNova was less than the other two brands. This demonstrated that the extent of drought stress harm in SupraNova was more serious than the other two brands.2. The root system of the bluegrass was underground 0~30 cm where the distribution was maximum in soil horizon. As the degree of the drought stress aggravated, the density of root system increased, the root ratio of shoot raised, the biomass in upground and underground lowered,relative growth rate decreased, little water stress contributed to the growth of root system.3. Drought stress influenced stomata status (open or close). But the status of stomata was not related to the stomata density. Stomata response was different in different cultivars under drought stress, there were differences in stomata density between different cultivars, the largest stomata density cultivars was Brooklawn , the smallest one was SupraNova, Impact were between them.4. Drought stress affected growth and development of plants. The perimeter of fascicular and diameter of vessel were shorter than CK.For the purpose of reducing vascular bundle and the diameter of vessels in adaptation of drought, and reduced water transpiration. The length of motor cell all lowered. Brooklawn was the most degcreased. Which illustrated that extent of involution was great under drought stress. Number treatment of motor cell was smiliar to CK. The motive condition of motor cell was regulated with drought. The amount was not affected external factor.5.The relative water content of different cultivars was diminished as the drought stress aggravated under drought stress, as the leave vivo time elongated, the rate of the dehydration in the blade of the different cultivars increased under different stress level, the rate of the dehydration changed quickly after the sixteen drought days. After water recovery four days, the index of water metabolism regained some extent,there were some differences among the recovery of different cultivars.6.The soluble sugar and free proline increased under drought stress, after rewatering four days, these substance decreased of different cultivars, the ability for accumulation and restore was: Brooklawn> Impact >SupraNova.7.The soluble protein and starch of three different cultivars decreased, after water recovery four days increased under drought stress, the ability for accumulation and restore was: Brooklawn>Impact > SupraNova.8. Brooklawn had the lowest membrane conductance which indicated it had strong drought resistance, Impact had higher resistance, SupraNova has the highest membrane conductance that indicated it had weak drought resistance.9. Protecting enzymes activities were different between different cultivars under drought stress, SOD of Brooklawn and Impact activities were higher than SupraNova, but SOD of Brooklawn were higher than Impact; POD activities were similar among the cultivars, but the smallest one was SupraNova; The order of CAT activities was that Brooklawn>Impact>Supra -Nova.the activity of SOD, POD, CAT was recovered in different extent, there were significant deviations of three cultivars.10. The changes of chlorophyll content of the bluegrass reflected that the rate of chlorophyll content increased first, then decreased later. During the initial drought stress stage, the rate of chlorophyll content increased, but the degree of convalescent was different in varieties.the chlorophyll content accumulation of three varieties was that: BrookIawn>Impact>SupraNova.11. The content of ABA were different among the different cultivars under drought stress, ABA content of Brooklawn was the highest, Impact was the higher; the smallest one was SupraNova.12. After drought persistence; poured water recovery showed that Bluegrass had invariably recovery capability; the recovery of SupraNova was slow, even impossible recovery. Three varietal of Bluegrass recovery capability after water recovery showed that Brooklawn not only had great drought resistance, but also had great recovery capability,and had extensive adapt capability, SupraNova not only had little drought resistance,but also had little recovery capability.