不同产地苦楝苗木抗寒性差异

The difference of cold resistance in Melia azedarach seedlings among different provenances

采集苦楝自然分布区内10个产地种子,在镇江开展田间苗期试验,探讨不同产地苦楝苗木抗寒能力的差异。结果表明:在遭遇2008年初-7.4℃极端低温后,全部产地的苗木均遭受不同程度的冻害,各产地苦楝苗木的冻害率、平均冻害级值和冻害指数存在显著的差异,按受害程度大小可排序为广西南宁>湖南长沙>福建平潭>江苏南京>浙江杭州>江西九江>陕西杨凌>湖北黄冈>安徽歙县>河南中牟。10个产地苦楝根据抗寒能力可分为3类群。苦楝苗木的抗寒性与纬度极显著正相关,与年均气温、无霜期极显著负相关,而与经度、海拔和年降雨量无显著相关;不同产地间苦楝苗木的抗寒性与地径极显著负相关,而同一产地内苗木的抗寒性与地径极显著正相关。

Seeds from 10 provenances were collected to conduct an experiment on differences of cold resistance in Melia azedarach seedlings from different provenances through field survey in Zhenjiang.The results showed that all seedlings of 10 provenances were suffered from freezing injuries in different levels when subjected to an extreme low temperature of -7.4℃ in 2008.There were significant differences in freezing injury rate,average freezing injury level and freezing injury index of M.azedarach seedlings from different provenances.The extent of injury could be arranged from high to low as Nanning,GuangxiChangsha,HunanPingtan,FujianNanjing,JiangsuHangzhou,ZhejiangJiujiang,JiangxiYangling,ShanxiHuanggang,HubeiShe County,AnhuiZhongmu,Henan.According to the cold resistance,the natural range of M.azedarach from 10 different provenances could be divided into 3 districts.There was a significant positive relationship between cold resistance and latitude,a significant negative relationship between cold resistance and annual mean temperature as well as frost-free period.There were no significant relationship between cold resistance and longitude,altitude and annual precipitation.There was a significant negative relationship between cold resistance and seedling caliper among different provenances,a significant positive relationship between cold resistance and seedling caliper in the same provenance.