杂种杨树纸浆用材良种材性的遗传变异和选择

The 12-year-old tree height(Ht),DBH(Dt) and volume(Vt) of 14clones from Suihua poplar test plantation in Heilongjiang were examined.

测定了黑龙江绥化杨树品种试验林１４个无性系１２龄的树高Ｈ＿ｔ、胸径Ｄ＿ｔ和材积Ｖ＿ｔ。由胸径处钻取木芯，按２ａ一段分６个生长轮，研究了生长轮直径Ｄ＿ｒ、容重Ｓ＿ｇ、纤维长Ｌ＿ｆ、纤维宽Ｗ＿ｆ、长宽比Ｌ＿ｗ、纤维（双）壁厚Ｔ＿ｆ、腔径Ｄ＿ｆ和壁腔比Ｔ＿ｄ的遗传变异和选择。以年龄、无性系综合地进行方差分析，结果表明所有性状在无性系间都有显著差异，最好的比最差的高出１０６％～２０％。Ｄ＿ｔ、Ｌ＿ｆ和Ｌ＿ｗ对年龄直线回归，Ｓ＿ｇ和Ｗ＿ｆ对年龄曲线回归。基于小区平均值估算的性状重复力（Ｒ＿ｃ）：Ｈ＿ｔ、Ｄ＿ｔ和Ｖ＿ｔ分别为０．８５、０．６２和０．６４；基于无性系平均值估算的重复力（Ｒ＿ｃ）：Ｓ＿ｇ、Ｗ＿ｆ、Ｔ＿ｆ和Ｔ＿ｄ都达０．９１以上，Ｄ＿ｔ、Ｄ＿ｆ和Ｌ＿ｗ达０．８６以上，最低的Ｌ＿ｆ也达０．６３，说明这些性状的遗传性都较强。按１２龄表型值进行单性状选择，增益最高（Ｖ＿ｔ）２５．２％，最低（Ｌ＿ｆ）３．４％，以Ｖ＿ｔ、Ｓ＿ｇ、Ｌ＿ｆ、Ｗ＿ｆ、Ｌ＿ｗ和Ｔ＿ｆ６个重要性状进行综合指标选择，选出全面优良的３个无性系，增益高达３１．９％。

Diameter(Dr) , specific gravity(Sg) , fiber length(Lf),widness(Wf), ratioof length to widness(Lw),(double) wall thickness(Tf),lumen diameter(Df)and ratio of wall thickness to lumen diameter( Td ) for each 2-year'sgrowth ring of the cores which extracted from sanipled trees at breast heightfrom bark to pith were evaluated.Analysis of variance showed significantdifferences among clones for all traits The best clone exceeds the worstone by 106%～20%. Reapitabilities calculated on plot mean basis(Rc)for Ht,Dt and Vt are 0. 85,0.62 and 0.64 respectively, whereas reapitabilities onclone mean basis (Re)for Sg,Wf, Tf and Td are 0.91 or more, for Dr,Dfand Lw 0.86 or more, for Lf 0.63. The high parameters indicate the stronginheritance of these traits.Dr,Lf and Lw were linearly regressed to age,Sgand Wf were curvely regressed to age. The gains from single trait selectionbased on 12 -year-old's phenotypes were ranged from 25.2%for Vt to 3.4%for Lf. The gain from combined(Vt,Sg, Wf,Lw and Tf) index selectionwas as high as 31.9%when the best 3 clones were selecled.