乐东拟单性木兰地理种源变异与选择研究

Research on Geological Provenances Variation and Selection of Parakmeria latungensis

对乐东拟单性木兰14个种源种子、苗期以及幼林期生长性状进行了调查分析。结果表明:种子千粒质量、苗高、地径、叶长和叶宽等5个性状在种源间差异极显著;造林保存率种源间差异显著,来自北部的种源,如浙江龙泉种源保存率较高,而来自南部的海南尖峰岭种源保存率较低;幼林期4年生树高、5年生树高和胸径、6年生树高和胸径等5个主要生长性状种源间差异均达到极显著水平,其生长性状广义遗传力为0.855～0.930,说明乐东拟单性木兰幼林期主要生长性状的表型差异主要受遗传因素的控制;乐东拟单性木兰苗高和地径与纬度负相关,表明随种源纬度的升高,乐东拟单性木兰种源苗期生长有减小趋势;乐东拟单性木兰幼林期树高和胸径与经度正相关,与纬度极显著正相关。根据乐东拟单性木兰种源幼林期试验结果,选择出浙江龙泉、福建顺昌和湖南新宁3个优良种源。通过聚类分析,把乐东拟单性木兰种源初步划分为3个区:西部种源区、东部种源区和南部种源区。

The growth traits of seed,seedling and young forest of 14 provenances of Parakmeria latungensis were investigated and analyzed.The results showed that the differences in seed weight,seedling height,basal diameter,leaf length and leaf width among provenances were extremely significant,and significant difference in afforestation preservation rate was also found among provenances.The provenances with higher preservation rate were from the northern source,such as Longquan provenance from Zhejiang Province.But provenances from the southern source such as Jianfengling provenance from Hainan Province showed the lower preservation rate.The differences in main growth traits were significant among provenances for young forests,such as 4-year-old tree height,five-year-old tree height and diameter at breast height,6-year-old tree height and diameter at breast height.The broad heritability of these five traits was between 0.855 and 0.930,which indicated that phenotypic differences of the main growth traits were controlled mainly by genetic factors.Tree height and diameter at breast height were negatively correlated with the latitude,indicating that the decreasing trend of tree growth with increasing latitude of provenances.Tree height and diameter at breast height of young forest were positive related to the longitude,and positively related to the latitude.According to the trial results of the young provenance forest,three superior provenances,Longquan in Zhejiang Province,Shunchang in Fujian Province and Xinning in Hunan Province,were selected.The provenance source region of Parakmeria latungensis was divided into three subregions： the western source subregion,the eastern source subregion and the southern source subregion.