| At present, the chinese paper and paperboard production and consumption are first in theworld, but the self-sufficiency of papermaking fibrous materials were deficiency.Poplar issuitable for use in man-made board and pulp processing, and cultivating high yield and goodquality peeler and pulp poplar varieties has become an important way to solve thecontradiction between timber supply and demand in our country. In order to solve theshortage and single problems of good poplar clones, which has high-yield, high-quality andefficient production for industrial timber. Researches on poplar growth, from characteristics,morphological characteristics, resistance to diseases and pests, wood pulping and plywoodperformance and genetic traits were done to selection good poplar clones for plywood andpulpwood purpose. The result showed that:1. Four poplar clones named B1、B33、B40and B53were preliminary selected from the24Fl clones through testing high resistance, stability and adaptability, in which the frist poplarclone was good with traits of high growth rate,high asexual propagation ability, highresistance to pest&disease quality,mechanical properties and was suitable for both pulpwoodand plywood purpose. Its volume growth was14.5%higher than CK at Jianan Chang qingtested sites at the age of6years. Through selecting many indexes such as growth, form andwood quality traits and with Euclidean distance method, the results showed: poplar clone B1and L35were similar，and poplar clone B1with big growth, taper, more and fine branches,small and many leaves.Through Fuzzy comprehensive evaluation method of multi characters,B1was good poplar clone for pulpwood purpose, and itsn, basic density was0.377g/cm3, thefiber length was1.153mm, fiber aspect ratio was49.5.2.Genetic analysis showed that:4-year-old growth traits of28clones all had high broadheritability, including diameter, height and so on, and most were above75%, and geneticvariation coefficient was6.85~37.86%; Compared with group, height, DBH and volumegenetic gains of the selected poplar clone B1were21.2%,14.7%and66.8%，and comparedwith the control, its’s genetic gains were1.6%,6.0%and10.8%.3. In order to understand the relationship of main Populus varieties in Shandong provinceand give basis for their classification, identification and better use, eight pair primers wereused for AFLP analysis of23main Populus varieties. The results showed that,1183fragments were generated totally, and average percentage of polymorphism fragments produced by eachprimer was77.3%, and the identification percentage of per primer combination was100%.The genetic differences among tested varieties were big, genetic distance among23materials tested was0.14~0.51and average was0.31. Materials tested were classed into8categories at similarity coefficient0.728, system cluster results based on similarity coefficientwere similar with classical taxonomy. Molecular criteria of23varieties was put forwardaccording to special bands.4. In the poplar plantation of different density percentage including2m×3m,2m×4m,2m×5m and2m×6m, there were differences of height growth among per plant, but thedifferences were not significant.The bigger the density, the smaller the crown. Above-groundbiomass of per plant decreases with the increase of density, but plantational above-groundbiomass increases with the increase of density.There were differences of biomass amongplantation, but the differences were not significant.5. The allocation proportions of trunk, branches and leaves biomass were accordantamong different density. The correlation indexes between that trunk, branches and leavesbiomass and DBH, tree was positive.there were differences of branche number, branchingangle, branch length, branch base diameter and branch biomass among four plantation density,but only branch number’s difference reached significant level. Leaf area index generallydecreases with the increase of density. And there were significant correlation between leafarea index and ground biomass, trunkbiomass and branches biomass. |
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