Research On Drought Resistance Mechanism Of Several Persimmons In WeiBei Draught Area

Persimmon (Diospyros.kakiLinn) origined from changjiang river areas of china. It has been cultivated widely in the North china after hundreds of years training. WeiBei drought area has profound soil, It has 500-600mm rainfalls a year, persimmon not only existed but also became one of main fruit trees in that area. The aid of this research is to discover How the persimmon adapted to the area on physiology, and to provid theory availability for persimmon cultivating .the test has researched "Huoshi" , "shuishi", "Muwashi" and " Junqianzi" in WeiBei area from the leaves of phyllan thus emblica,the variation of photosynthesis and relative factor, compared with apple tree, pear tree in WeiBei area, and researched young persimmon trees photosynthetic characteristics and SOD, CAT, MDA contens changes under water stress, the result showes:persimmon has adapted WeiBei drought enviroment. The stoma of Junqian zi was small and lesser density, the others were big and density, all of it stomal daily variation was measured as a noon decreasing type, the ratio between palisade and spongy tissue of the spring leaves of persimmon negative correlation with Tr, and daily variation of Pn, Tr and Gs of WeiBei persimmon showed a noon decreasing types, the decreasing of Pn were affected by stomatal and nonstomatal factors, the leaves temperature had negative correlation with Pn, Gs had positive correlation with Pn, under water strees, with SRWC declined, LRWC of persimmon and content of chl were decreasing also, the Pn of " houshi", "shuishi" had a few ascended at beginning, but decreased with SRWC dedine at late stress, Both " shuishi" and "Junqian zi " were affected by stomal factor at early water stress mainly and by nonstomatal limitation at late stress, But Pn of "huoshi" and "cilangshi" were affected by nonstomatal factor all stress, the activity of SOD , CAT were increasing at early water stress, and the content of MDA was decline, but activity of SOD, CAT declined at late water stress, and the contents of MDA of "huoshi", "shuishi" and "cilangshi" were incline, but "Junqianzi" was decline. In showed "Junqian zi" had highest ability to clean activated oxygen , This is one of the drought resistance physiology bases of the persimmon with "Junqian zi" rootstock, persimmon growing well in WeiBei drought area, It is a result that persimmon adaptive to WeiBei ecosystem environment.