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Screening Of Sueperior Geniotypes For Pulpwood And Its Genecology Of Masson Pine

Posted on:2001-10-12Degree:DoctorType:Dissertation
Country:ChinaCandidate:Z C ZhouFull Text:PDF
GTID:1103360155976371Subject:Tree breeding
Abstract/Summary:PDF Full Text Request
The wood from thirty provenances and twenty open-pollinated families of masson pine (Pinus massoniana Lamb.) with fast growth was pulped using the kraft process to firstly study variation and inheritance for wood chemical compositions and properties of unbleached kraft pulp. Large differences between provenance and families were observed for most traits above, which are under strong genetic control. The growth traits such as tree height, DBH and stem volume were significantly and negatively related to wood specific gravity and seemed to be independent of wood chemical components. The absolute differences between families for holocellulose and lignin content are small, however, i.e. 2 to 3%, suggesting that it is impractical to breed for increased cellulose content through a selection program. Correlation analysis suggests that wood density and hot water extract could be recommended as two indirect selection criterion for kraft paper properties. Based on Kg fiber per tree, wood consumption per dry tons of pulp and kraft paper properties, six optimum seed sources were screened which are distributed over the southeastern end of NanLing mountains, two side of Yunkai Hill and southern end of Wuyi mountains. Production cost functions for unbleached masson pine kraft pulp (UBMKP) under different management models were used to determine the economic weights and value to breeding of standing volume, specific gravity and pulp yield and establish corresponding breeding objectives and index selection equations. Importance of breeding objectives was found to related to cost structures of pulp production. For the pulp mill from growing trees to UBMKP production, increasing pulp yield and specific gravity had major effects on reducing production cost, since pulp yield and specific gravity primarily influenced the future costs (harvesting, transport, and pulping). Increasing the discount rate should result in decreasing of importance of pulp yield and specific gravity. For a purely forest production system with no affiliation to pulp mill, the breeder's attention should be focused on genetic improvement standing volume not specific gravity and pulp yield. The set of data from multi-locations provenances test was used to systematically study genoecology about extension of improved materials in changing environment. There existed significant seed sources by site interaction, but its pattern was largely unpredictable. The stability appeared to be related to the latitude of the seed source. The temperature of seed source was found to be a main reason for this geographic pattern. Based on the investigation of seed sources by location interaction, three breeding zones and 3 subzones may be established within the natural range of masson pine to overcome the problem of GEI. Response functions of masson pine provenances to different environments indicated that three response function parameters including mode latitude, homeostatic parameter and scale parameter were strongly related to provenance latitude. For the northern seed sources, mode latitudes were more than 3°-6°below latitudes of origin, whereas the southern seed sources attained best growth at latitudes near their origin. In general, larger estimate for a homeostatic parameter and scale parameter was obtained for the southern seed source, compared with the northern seed source. The southern provenances were less sensitive to environmental changes if planted over good sites. Considered the vigorous in height growth of various provenances extended in different latitudes and the safe factors in seed transfer, the range of suitable planting site was determined for several famous superior provenances of masson pine. Based on Matyas's growth response model and author's research foundation, the author modeled response functions of various provenances at average yearly temperature gradient. The results indicated that impacts of climate warming on masson pine height growth at different geographic zones could be predicted with response model of height change. An increase in average yearly temperature by 2℃will result in accelerated growth at the northern part of the distribution if precipitation if sufficient, and at the southern of distribution growth will decline. This paper is firstly deals with the research on provenance by phosphorus interaction of masson pine. Response patterns of height growth was found to vary with provenances tested. Some provenances were more sensitive to phosphorus supply than others. This response difference could be explained by shoot behavior of provenances. Fertilizer techniques for young stand of different provenances were preliminarily made according to response pattern of each provenance to phosphorus supply. It was observed that phosphorus environment of seedling greatly influenced genetic variation of height growth between provenances tested. Appreciate phosphorus supply were able to improve preciseness of masson pine provenance test.
Keywords/Search Tags:Pinus massoniana Lamb, Pulpwood, screening, genotype by environment interaction, genecology
PDF Full Text Request
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