Wood Properties Variation Analysis And Superior Families Selection For Pulpwood In Half-sib Families Of Masson Pine

Variation and correlation on eight wood characters, including basic density, trachealength, tracheid width, the ratio of length to width,microfibril angle,et al, of forty fourhalf-sib families from one and a half cycle seed orchard of Pinus massoniana for pulp usewere studied in this paper. And fine families were selected with the method of restrictedsynthetic index. The results were as follows:There existed significant variation of wood characters among half-sib families andindividual trees within a family. The order of the variation was the ratio of length to width offiber from summer wood>the ratio of length to width of fiber from spring wood>the widthof fiber from spring wood>the width of fiber from summer wood> basic density>the lengthof fiber from spring wood>the length of fiber from summer wood>the microfibril angle. Thevariation among individual trees was larger than among families. The wood character wascontrolled by inheritance, and the individual heritability of wood characters was larger thanthat of family.With the selection rate of20per cent, the highest expected genetic gain was the ratio oflength to width of fiber from spring wood, could be15.01per cent. The next was ratio oflength to width of fiber from summer wood, could be12.75per cent. The lowest wasmicrofibril angle, only could be2.18per cent.The correlation level between wood characters was different. Wood basic density wasnegative to length of fiber and microfibril angle. So, when the wood basic density wasimproved, the length of fiber may be shorted, and microfibril angle may be improved also.Ten fine families were selected in this paper. Their average of wood basic densityreached0.38g/cm3, the average length of fiber from spring wood was4.60mm,the averagewidth of fiber from spring wood was0.065mm, the average length of fiber from summerwood reached5.04mm, the average width of fiber from summer wood was0.036mm, theaverageratio of length to width of fiber from spring wood was70.77and the averageratio oflength to width of fiber from summer wood was140.08.