栽植模式对木荷幼林生长和形质性状家系变异影响

Effects of Plantation Patterns on Family Variation in the Growth and Form-Quality Traits of Schima superba Young Plantation

【目的】研究木荷幼林生长和形质性状在纯植和与杉木混交2种栽植模式下的家系遗传变异规律,为木荷良种选育和高效培育提供理论依据。【方法】以2014年营建于福建省南平市延平区纯植和与杉木混交(木荷∶杉木1∶2列状混交)2种栽植模式下的7年生木荷家系测定林为研究对象,分析其生长和形质性状的家系遗传变异规律,并对其各性状进行遗传参数估计及相关性分析。【结果】纯植和混交2种栽植模式对木荷家系的生长和形质性状有显著影响(P<0.05),区组效应显著。同纯植模式相比,与杉木混交显著促进了木荷家系各性状的表型差异,树高、胸径和树干通直度均提高,分别高出纯植模式的18%、16%和15%,树干分叉数则明显减少,仅为纯植模式下的78%。纯植模式下木荷各性状受较弱至较强的家系遗传控制(0.18~0.53)和较弱的单株遗传控制(0.03~0.13)。与杉木混交,木荷各性状的家系遗传力和单株遗传力估算值普遍得到提高,尤其是树高、胸径、树干分叉数和树干通直度的家系遗传力分别高出纯植栽植模式下的31%、72%、20%和31%。2种栽植模式下木荷生长和形质性状存在不同遗传反应,与杉木混交可显著改变木荷家系生长表现和秩次变化。相关性分析结果显示,2种栽植模式下木荷家系生长性状与形质性状(除枝下高外)间相关性不显著,生长和形质2类性状间似相互独立。树高、胸径和枝下高间关系较为紧密,不易受栽植模式影响。与杉木混交不仅会对木荷冠幅生长产生影响,同时有效减弱最大分枝角、枝下高和最粗分枝基径间的联系及树干分叉数对树干通直度的影响。【结论】纯植和混交2种栽植模式会对木荷家系生长和形质性状产生显著影响,与杉木混交可促进木荷家系的表型分化,并提高了各性状的家系和单株遗传力估算值。对于木荷人工林的营建,应根据生境条件和栽培模式选择适生优良的木荷家系进行栽植,并及时对木荷进行修枝除干以培育优质干材。

【Objective】This study aims to study the genetic variation of growth and form-quality traits of Schima superba young plantation under two different plantation patterns:pure plantation and mixed plantation with Cunninghamia lanceolata,so as to provide a theoretical basis for the selection and efficient breeding of superior varieties of S.superba.【Method】This experiment was conducted in a 7-year-old S.superba family-test trial forest that was established in 2014 in Yanping District,Nanping City,Fujian Province,under two planting modes of pure plantation and mixed plantation with C.lanceolata(S.superba∶C.lanceolata 1∶2 column mixture).The family genetic variation of its growth and form-quality traits was analyzed,and the genetic parameters were estimated and the correlation analysis was conducted.【Result】The growth and form-quality traits of S.superba families were significantly affected by the two plantation patterns of pure and mixed plantation(P<0.05),and the block effect was also significant.Compared to the pure plantation pattern,the mixed with C.lanceolata significantly promoted the phenotypic differentiation of growth and form-quality traits of S.superba family.The values of tree height,diameter at breast height,crown width and stem straightness were increased,which were 18%,16%and 15%higher than those in the pure plantation pattern,respectively.The number of forks in trunk decreased significantly,which was only 78%of that in the pure plantation pattern.In the pure plantation pattern,S.superba traits were generally controlled by weak to strong family genetic control(0.18-0.53)and weak individual genetic control(0.03~0.13).When being mixed with C.lanceolata,the estimated values of family heritability and individual plant heritability of S.superba traits were generally improved.Especially,the heritability of tree height,diameter at breast height,number of forks in trunk and stem straightness were 31%,72%,20%and 31%higher than that of pure plantation,respectively.There were different genetic responses to growth and form-quality traits of S.superba under the two plantation patterns.The growth performance and rank change of S.superba families were significantly changed when being mixing with C.lanceolata.Correlation analysis showed that there was no significant correlation between growth traits and form-quality traits(except the height under branches)of S.superba families under the two plantation patterns.Growth and form-quality traits seemed to be independent of each other.The relationship among tree height,diameter at breast height and the under branch height was close and not affected by plantation pattern.Mixing with C.lanceolata not only affected the growth of S.superba crown,but also effectively weakened the relationship between the maximum branch angle,the height under branches and the maximum branch diameter,as well as the influence of the number of branching branches on the stem straightness.The relationship between tree height,diameter at breast height and the height under branch was not easily affected by plantation pattern,but the relationship between crown width and diameter height,the relationship between maximum branch angle,the height under branches and maximum branch diameter,and the relationship between the number of forks in trunk and the stem straightness were all weakened by mixing with C.lanceolata.【Conclusion】The growth and form-quality traits of S.superba families are significantly affected by pure and mixed plantation.The mixed plantation with C.lanceolata can promote the phenotypic differentiation of S.superba families,and improve the estimated heritability of growth and form-quality traits in families and individuals.For the construction of S.superba plantation,it is necessary to select suitable and good S.superba families for plantation according to the habitat conditions and cultivation patterns,and to prune and remove the excess branches of S.superba timely to cultivate high quality wood.