不同西南桦种源的苗期变异性研究

选择西南桦（ＢｅｔｕｌａａｌｎｏｉｄｅｓＢｕｃｈＨａｍ．）中国分布区内的１３个种源进行苗期对比试验。结果表明：各种源间在种子千粒重、苗木高生长、地径生长、苗木全株生物量方面存在明显的遗传差异；种源内部也存在个体间的遗传差异；经苗期物候观察，各种源除发芽始期遗传差异不明显外，发芽盛期、发芽末期、真叶出现期均存在一定差异。综合苗高、地径、全株生物量等指标，确定云南西畴新马街、西畴莲花塘、腾冲、潞西为苗期生长快、生物量大的种源；云南镇源、屏边、广西田林为苗期生长中等的种源；云南龙陵、景洪、广西平果、凭祥、百色、靖西为苗期生长慢的种源。

Study on Variability of Seedling Stage of Different Betula alnoides Provenance

Seedling stage contrast test were carried out on 13 Betula alnoides BuchHam.provenance selected in advance.The test results indicated as the following aspects.There were significant hereditary differences between different provenance on 1000seed weight,seedling height growth,seedling grounddiameter growth,biomass per seedling.To the same provenance,there were hereditary differences between individuals.The results of seedling stage phenological observation showed there were differences between different Betula alnoides provenance on germination stage,germination telophase,euphylla emergency time.Synthesizing the evaluation indexes of seedling height,grounddiameter,biomass per seedling, the results indicated that Xichou Xinmajie and other 3 provenance from Yunnan were the provenance with fast growth and large biomass;three provenance such as Yunnan Zhenyuan,Pingbian and Guangxi Tianlin were the provenance with medium seedling stage growth;two provenance from Yunnan and other 4 provenance from Gu angxi grew slowly in their seedling stage.