海南临高山地木麻黄的材性遗传变异与种源选择

Genetic Variation and Selection in Wood Properties of Casuarina junghuhnina Provenances at Lingao, Hainan

通过山地木麻黄材性遗传参数的估算及材性与生长性状的相关性研究,了解其材性的遗传变异规律,为山地木麻黄优良种源选择和种质资源合理开发利用提供科学依据。以海南临高种源试验地18个山地木麻黄种源为试验材料,对造林后7年时木材密度、纤维长度、纤维宽度和纤维长宽比4个材性性状的遗传变异规律进行分析。研究表明,山地木麻黄的木材密度和纤维长度在18个种源间存在极显著差异(p<0.01),纤维长宽比在种源间存在显著差异(p<0.05),纤维宽度在种源间差异不显著(p≥0.05)。18个种源间木材密度、纤维长度、纤维宽度及纤维长宽比的变幅范围分别为0.48~0.70 g/cm3、0.68~0.87 mm、15.98~20.02 m和39.15~50.07,平均值分别为0.62 g/cm3、0.80 mm、17.39μm和46.41。除了纤维宽度的种源遗传力比较小,接近于0外,木材密度、纤维长度和纤维长宽比的种源遗传力分别为42.10%、18.10%和10.90%。当入选率为20%时,山地木麻黄木材密度、纤维长度、纤维宽度和纤维长宽比的种源选择增益分别为4.87%,1.26%,8.33×10-9和0.64%。相关分析表明,木材密度、纤维长及纤维长宽比3个材性性状间都呈现显著遗传和表型相关。利用指数选择法对木材密度、纤维长度和纤维长宽比3个材性性状进行综合选择,筛选出4个材性优良的山地木麻黄种源,分别为17877、19490、19489、18849。

Based on the estimation of the genetic parameters and the correlations between the genetic properties and the growth traits of Casuarina equisetifolia, the genetic variation of the woody characters was studied, which provided scientific basis for the selection of proven provenances of Casuarina equisetifolia and the rational exploitation and utilization of germplasm resources. In this research we took 18 Casuarina equisetifolia provenances from Lingao, Hainan provenance test ground as materials to analysis the genetic parameters for wood density, fiber length, fiber width and fiber length-width ratio, which were estimated at 7 years old after planting. The results showed that significant difference existed among provenances in wood density, fiber length（p〈0.01） and fiber length-widthratio（p0.05）. Fiber width was not significant among provenances（p≥0.05）. The variation ranges of wood density,fiber length, fiber width and fiber length width ratio of different provenances were 0.48-0.70 g/cm^3, 0.68-0.87 mm,15.98-20.02 m and 39.15-50.07, with mean values of 0.62 g/cm^3, 0.80 mm, 17.39 m and 46.41, respectively. The provenance heritability of wood density, fiber length and fiber length-width ratio were 42.10%, 18.10% and10.90%, respectively, but the provenance heritability of fiber width is near to zero. When the selection rate was20%, the genetic gains of wood density, fiber length, fiber width and fiber length width ratio can be expected to4.87%,1.26%,8.33 ×10^-9 and 0.64%, respectively. Among the wood basic density, fiber length and fiber length width ratio, there were signif-icantly positive genetic and phenotypic correlations. The three traits for wood basic density, fiber length and fiber length-width ratio were analyzed and four provenances of Casuarina equisetifolia were screened by index selection method named Which 17877, 19490, 19489 and 18849, respectively.