Abstract:
Objective Slash pine (Pinus elliottii) is an important conifer species for pulpwood production in China. In recent years, with the increasing demand for pulpwood in the country, genetic improvement of pulpwood traits and the selection of superior families of slash pine have become research priorities. Fiber morphology and chemical composition of wood directly affect pulp quality and papermaking performance. This study aimed to analyze the genetic variation patterns of fiber and chemical traits in half-sibling families of slash pine, providing a scientific basis for wood property improvement and the breeding of new superior varieties.
Methods A total of 33 half-sibling families of 30-year-old P. elliottii from the Changle Forest Farm in Zhejiang Province were evaluated. Twelve traits were measured, including diameter at breast height (DBH), basic density, fiber morphology (e.g., fiber length, fiber width, curl index, kink index), and chemical composition (lignin, cellulose, and hemicellulose contents). Genetic variation analysis, correlation analysis, principal component analysis, and superior family selection were conducted.
Results Significant differences were observed among families in DBH, basic density, fiber morphology, and chemical composition. Traits such as fiber length, fiber length-to-width ratio, and chemical composition exhibited strong genetic control. Positive genetic correlations were observed between DBH and fiber width as well as fiber length-to-width ratio, whereas negative correlations were found with cellulose and lignin contents. Based on breeding values, selection indices, and industrial requirements, four superior families were selected, with a selection rate of 12.12%. The selected families showed average genetic gains of 10.18% in DBH, 2.18% in basic density, 5.75% in fiber length, 5.67% in fiber length-to-width ratio, and 2.47% in cellulose content.
Conclusion The selected families exhibited significant genetic gains in pulpwood traits, meeting the industrial requirements of the industry for high-quality papermaking. These results provide theoretical and practical guidance for future genetic improvement and germplasm innovation of P. elliottii.
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