南方红豆杉苗木性状种源分化和育苗环境对苗木生长的影响

利用来自10个省区27个产地的南方红豆杉种子在福建明溪和浙江淳安2个地点开展种源苗期遗传测定,系统研究苗木生长、苗高生长参数、根系特征和干物质积累等性状的种源差异及育苗环境对种源苗木生长的影响.研究结果显示:南方红豆杉苗高、地径和侧枝数存在显著的种源差异.基于苗高生长参数分析表明:种源苗高的增加主要是由于线性生长量、最高生长速率和线性生长速率的提高,而不是由于线性生长期的延长.相对于其它树种,南方红豆杉线性生长速率虽较小,但线性生长期较长.试验虽然未发现根系形态、干物质积累量的种源差异达到统计学上的显著水平,但这些性状的种源绝对值却相差较大,达20%以上.育苗环境对南方红豆杉种源生长影响较大,良好的水热资源和庇荫条件将显著促进苗木的高、径生长.苗木生长性状存在显著的种源与地点互作,但种源与遮阳处理的互作却很小.不同育苗地点南方红豆杉苗高和地径呈现出的地理变异模式是不同的:在福建明溪点,种源苗木高、径生长与产地的地理气候因子相关性较小,苗期速生种源不仅有来自自然分布区偏东部和偏北部的种源,而且还有来自偏南部和偏西部的种源;在浙江淳安点,来自偏东部和偏北部的种源苗高生长量较大,而来自偏南部和偏西部的种源生长则较慢,类似于作者对南方红豆杉有限分布区种源试验的已有研究结果.

Provenance Differentia tion of Seedling Character istics of Taxus ch inens isvar. m a ire r and Its Seedling Ra ising Env ironment Influence

Taxus chinensis var.mairer provenance trails including twenty-seven seed sources from ten provinces of primary natural distribution zone,located at Mingxi of Fujian and Chun'an of Zhejiang,were used to study provenance variation for seedling characteristics such as seedling growth,shoot elongation parameters,root character and dry matter accumulation and influence of seedling raising environment.The results indicated that there existed significant differences among provenances for seedling height,root collar diameter and branch number.Analysis of shoot elongation parameter demonstrated that increase of provenance seeding height was attributed to the acceleration of total linear growth(TLG),maximun growth rate(MGR) and linear growth rate(LGR),but the prolongation of linear growth day(LGD).Comparing with other forest species,Taxus chinensis var.mairer had the lower LGR and the longer LGD.The provenance variation of root morphology and dry matter accumulation could not reach significant level in statistics,but the biggest value was above twenty percentage more than the lowest one.There was marked effect of the seedling raising environment on the provenance growth.Good nursery site and suitable shading could enhance growth of seedling height and root collar diameter.It was found that there existed significant provenance by site interaction and small provenance by shading interaction.The geographical variation patterns of Taxus chinensis var.mairer seedling height and root collar diameter were different in various seedling raising site.At Mingxi of Fujian,provenance seedling growth was not related to the geography-climate factors of its seed source.The provenances with higher growth rate were distributed not only in the eastern and northern zone but also in the southern and western one.At Chun'an of Zhejiang,the eastern and northern provenance had higher seedling height and root collar diameter,contrasting to provenances from the southern and western,which was similar to the result founded by the authors in the former limited-distribution-area provenance trial.