新疆5个枣品种叶片碳同位素组成、瞬时水分利用效率的季节变化及与气象因子的关系

利用稳定碳同位素技术,对新疆环塔里木盆地主栽的5个枣品种叶片δ13C值进行了比较测定,同时测定各品种的瞬时光合速率、蒸腾速率、光合有效辐射及空气温湿度等因子。结果表明,(1)新疆栽培枣品种叶片δ13C值分布在-25.559‰～-27.861‰,平均值为-26.463‰;(2)5个枣品种叶片δ13C值季节变化差异显著(P<0.05),表现为春季(-26.088‰)>夏季(-26.395‰)>秋季(-26.904‰),且品种间差异极显著,最大的为-25.559‰(骏枣春季),最小的为-27.861‰(冬枣秋季),变幅2.302‰;(3)空气相对湿度是引起δ13C值季节变化的主要因素;(4)5个枣品种长期水分利用效率(WUEsl)大小顺序为:冬枣<梨枣<灰枣<赞皇大枣<骏枣,顺时水分利用效率(WUEi)大小顺序为:冬枣<骏枣<赞皇大枣<梨枣<灰枣,2种方法测定的结果均反映出鲜食品种中冬枣对当地干旱的适应能力最弱。

Seasonal variation in carbon isotope composition and WUE_i correspond with weather factors for five cultivars of Chinese jujube in Xinjiang

Using stable carbon isotope technique,the foliar δ13C was studied,and Pn,Tr,air temperature and humidity and other meteorological factors of five leading Chinese jujube cultivars in Xinjiang were determined.The results showed that:(1) the range of foliar δ13C was between-25.559 ‰ to-27.861 ‰,the average was-26.463 ‰;(2)foliar δ13C had significant seasonal changes,that was in spring(26.088‰)> in summer(26.395‰) > in autumn(26.904‰),and the largest value of foliar δ13C(-25.559) was found in cultivar Junzao in spring and the smallest value was-27.861‰ found in Dongzao in autumn,the difference was 2.302‰;(3) the air relative humidity was a major factor causing the seasonal changes of foliar δ13C value;(4) the order of WUEsl of the five cultivars was Dongzao < Lizao < Zanhuangdazao < Huizao < Junzao,but the order of WUEi of the five cultivars was Dongzao < Junzao < Zanhuangdazao < Lizao < Huizao,which indicating that Dongzao had the worst ability to adapt to drought in Southern region of Xinjiang.