Research On Cold Resistance Of Ten Paeonia Rockii Cultivars In Haerbin

With a better property of cold hardiness than other cultivar groups, Paeonia rockii cultivar group will bear flowers earlier. They were introduced into Harbin, and greatly enriched the spring flower scenery. It is of great significance to analyze the differences on cold-resistant among different varieties, which is useful for application of Paeonia rockii in cold areas and the selection of varieties resource for cold-resistant breeding. In this subject, 10 varieties was introduced into Harbin were used as testing materials. Their physiological factors changes were compared under natural and artificial low-temperature stress. After studing the growth rhythm ornamental evaluation, the differences on cold hardiness among these 10 varieties in Harbin were researched:1 The cold-resistance of ten varieties exist differences. According to the integrated evaluation by means of subordinate function method the cold-resistance abilities of 10 Paeonia rockii cultivars could be ranged as: 'Ziguan Yuzhu' > 'Damo Fengyun' > 'Hongguan Yuzhu' > ' Zilou Xiangjin' > ' Lanyu SanCai' > ' Zhongjie Mei' > ' Hongqun Yudai' > 'Yuban Xiuqiu' > 'Heping Hong' > 'Lantian Meng' .The function value of the best variety 'Ziguan Yuzhu' is 0.8239, and the worst 'Lantian Meng' is 0.1680.2 By the agency of membrane penetrability, the result of LT50: -16.34℃,-18.27℃,-22.27℃,-22.76℃,-20.02℃,-20.07℃,-20.04℃,-23.24℃,-21.25℃,-24.34℃respectively. After the mensuration the following year ,LT50 of ten varieties go down and the cold-resistance go up completely. The result is altimately as same as the growing recovery.3 Taking MDA content, soluble sugar content, soluble protein content and SOD enzyme activity change as the bases, explain the cold resistant differences among Paeonia rockii varieties from the cold resistant physiological mechanism, and point out the correlation between various physiological targets and the cold resistant of Paeonia rockii varieties. Furthermore, the soluble sugar content, the soluble protein content and the SOD enzyme activity exhibit an positive correlation with the Paeonia rockii cold resistant ability, the MDA content exhibits a negative correlation with the Paeonia rockii cold resistant ability.4 Effect sorting for cold-resistant measures is grass curtain entity, grass curtain independent, leaves filled into the grass curtain and no measure. It indicates that the optimization cold-resistance methods is grass curtain entity, soluble sugar content, soluble protein content and SOD enzyme activity change is more greatly than the others.5 Using the analytic hierarchy process carry on the quality synthetic evaluation processing to Paeonia rockii varieties watching character. Establish a set of Paeonia rockii's quality synthetic evaluation model in cold region with the analytic hierarchy process (The AHP law). Analyze the 15 appraisal factors, and obtain its several important targets. Its weight value sorting is the flower color (38.1%), flower shape (19%), flower diameter (11%). The other weight value is relatively small. Through the model evaluation, it is divided into four ranks of the Paeonia rockii varieties' watching value: LevelⅠ(=4.0): Type of extremely high ornamental value,4 ; LevelⅡ(4.0-3.5): Type of high ornamental value,10; LevelⅢ(3.5-3.0): Type of relative high ornamental value,5; LevelⅣ(3.0-2.5): Type of general ornamental value,2.