Effect Of Soil Water Stress On Different Mulberry Varieties

One-year-old seedlings of six mulberry varieties of xuan792,sha2×lun109,shinichinose,shansang305,husang32 and nongsang14 were usedas materials in this experiment, and water supply was controlled in pottedmulberry, to study the changes of plant morphology, physiological andbiochemical characters and their relationship. The test indexes include plant height, leaf area, intrenode quantity,internode length, root/top, rate of water release, RWC and WSD, waterpotential, indexes of P-V curve, chlorophyll content and chlorophylla/b,relative electric conductivity, MDA content, SOD activity, POD activity, CATactivity, PRO content, soluble carbohydrate content, soluble protein content,net photosynthetic rate, stomatal conductance, Ci, transpiration, diumalvariation of photosynthetic rate. Under water stress, the growth of mulberry was restrained, dry matterweight and the leaf area dereased, the plant height declined, internode lengthshorten, the root/top was accelerated under short-term water stress, but theroot/top was restrained along with the process of water stress. In the normal grow condition of mulberry, the leaf water Retention andthe parameters of P-V curve was tested. rate of water release, wilting pointRWC, wilting point potential, and saturation osmotic potential of differentmulberry varieties were different, and had orderliness. With water stress going on, permeative substance increased. Such assoluble carbohydrate content, PRO content increased, RWC and the content ofprotein reduced, so the water potential reduced. The above-mentioned indexeschange range differed greatly with different varieties,and the change laws ofindexes are unanimous. The cell membrane systems of mullberry were harmed and the osmoticcapability boosted up under the water stress, relative electric conductive andMDA content increased. different varieties suffered differently. Protectiveenzyme activaties of different mulberry varieties showed the variation 3土壤水分胁迫对不同品种桑树的影响tendency of falling after rising, such as SOD, POD , CAT, But the change lawsof three kinds of enzymes were different to some extent. Every test result wasanalysed, indicating that Every variety drought-resistance has greaterdifference. The date indicated that the content of chlorophyll, chlorophyll a/b, netphotosynthetic rate, stomatal conductance and transpiration of every variety ofthe mulberry tree decreased with the water stress going on. Under mild waterstress, the decline of photosynthesis was mainly limited by stomatal factor.However, it was limited by non-stomatal factor after middling water stress.Under water stress, WUE of mulberry showed the variation tendency of fallingafter rising. Under CK condition diumal change of photosynthetic rate was asingle peak curve, and under water stress it was double peak curve. The drought-resistance of the mulberry tree is a piece of complexproperties. It is a result of the comprehensive function of mechanism that fighta drought, Drought-resistance ability of different mulberry varieties wasjudged by fuzzy mathematics comprehensive appraisal analysis. A sequence todrought-resistance of different mulberry varieties was made. Ability ofdrought-resistance of the different mulberry varieties was arranged in an order.The order of drought-resistance properties of different mulberry varieties was:xuan792 > shansang305 > nongsang14 > husang32 > shinichinose > sha2×lun109. Drought-resistance of the different mulberry varieties had close connectiedwith region of the mulberry tree,strain,and multiples of chromosome. Sha2×lun109 belonged to Guangdong strain, and ability of drought-resistance ofsha2×lun109 is least; xuan792 belonged to lusang mulberry strain, and hadthe strongest drought-resistance; Shinichinose belonged to white mulberrystrain. The leaf of it is thin, transpiration is high, ability of drought-resistanceis on the small side; Shansang30...