花叶夹竹桃叶片冻害调查分析

A preliminary study on freeze injury of Nerium indicum 'Variegatum' leaves

对花叶夹竹桃枝梢顶部叶片进行冻害分级调查,并与夹竹桃比较。结果表明,在-5.5℃的低温条件下,花叶夹竹桃枝梢顶端附近叶片可出现冻害现象。但未见植株冻死,且受冻部位附近能萌发新芽,枝叶生长正常。花叶夹竹桃冻害程度极显著重于夹竹桃,迎风口的冻害显著重于避风口,且越接近枝梢顶端冻害越严重。

The freeze injury of Nerium indicum ＇ Variegatum＇ leaves at the low temperature was studied in Cixi areas. The results showed that the freeze injury occurred in the leaves near the top of branch of Nerium indicum ＇ Variegatum＇ at -5.5℃ in Cixi, but no plants were frozen to death. New buds could sprout near the parts of freeze injury （ including 4 joints of branches or 12 leaves） and grow normally. In comparison with Nerium indicum, the freeze injury degrees of leaves of Ne- rium indicum ＇ Variegatum＇ was more serious. The freeze injury degrees of leaves in the windward were more serious than that in the leeward and the leaves near top branch were easier to be damaged.