株龄和插穗直径对甘蒙柽柳插穗成活率的影响

Effects of tree age and cutting diameter on survival rate of Tamarix austromongolica cuttings

甘蒙柽柳（Tamarix austromongolica Nakai）为柽柳科（Tamaficaceae）柽柳属（Tamarix L．）灌木或乔木[1]。2010年7月，中国科学院西北高原生物研究所科研人员在海拔2700In的青海省同德县境内发现1片野生甘蒙柽柳古乔木居群，其中最大的1株胸径达327cm，株高为1130cm，树龄初步估测为400～500a。这片甘蒙柽柳古林资源对于研究气候变化和柽柳属植物的演化过程具有重要的科学意义。现今，这片珍贵稀有的甘蒙柽柳古林正面临因水电站建设而被淹没的危险，必须对这片珍贵的甘蒙柽柳古林资源进行保育，但由于其种子难以获得，因而，必须通过无性扦插的方式进行繁殖。

Effects of tree age and cutting diameter on survival rate of Tamarix austromongolica Nakai cuttings were researched, and rooting position of cuttings was observed. The results show that survival rate of T. austromongolica cuttings decreases with increasing of tree age （1-3 a, 5-10 a and 400-500 a） and with reducing of cutting diameter （0.8-1.4 cm, 0.5-0.8 cm and less than 0.5 cm）. In which, survival rate of cuttings with tree age 1-3 a and diameter 0.8-1.4 cm is the highest with a value of 84.13%, and that with tree age 400-500 a and diameter less than 0.5 cm is the lowest with a value of 25.43%. Rooting model of T. austromongolica cuttings has two types, which can root from cortex and callus of cuttings, meaning that the cuttings have stronger rooting ability. It is suggested that cuttings with diameter above 0.5 cm should be selected for cutting propagation of T. austromongolica ancient tree.