Lodgepole pines Pinus contorta (Douglas) were treated by girdling to assess the response by an endemic population of mountain pine beetle Dendroctonus ponderosae (Hopkins) (Coleoptera: Scolytidae). Capture in 'sticky traps' indicated that the beetles were attracted while in flight towards the wounded trees. A significant difference in the landing rates of bark beetles between the treated and untreated trees indicated that the beetles were able to distinguish wounded from non-wounded trees while still in flight. Pressure chamber readings demonstrated that water stress developed in the girded trees when compared to the non-girdled trees.

Data from nuclear ribosomal internal transcribed spacer regions (nrITS) and chloroplast DNA (cpDNA) have failed to resolve phylogenetic relationships in Pinus. To provide greater interspecific resolution, five low-copy nuclear genes were developed from mapped conifer anchor loci. Four genes were sequenced from species representing all Pinus subsections. Individual loci do not uniformly support the nrITS or cpDNA hypotheses. Combined analysis of low-copy nuclear loci produces a well-supported subsectional topology. The phylogenetic positions of P. nelsonii and P. krempfii are of systematic interest. Results strongly support P. nelsonii as sister to sect. Parrya, and suggest a moderately well-supported position of P. krempfii as sister to the remaining sect. Quinquefoliae. The most informative locus, a Late Embryogenesis Abundant-like gene, was used to explore phylogenetic relationships among closely related species in subg. Strobus. Thirty-nine species were sequenced, with two or more alleles representing 33 species. Nineteen of 33 species exhibited allelic nonmonophyly in the strict consensus tree. Nucleotide diversity was strongly associated (P<0.0001) with the degree of species monophyly. While species nonmonophyly complicates phylogenetic interpretations, this locus offers greater topological support than cpDNA or nrITS. Lacking evidence for hybridization, recombination, or imperfect taxonomy, incomplete lineage sorting remains the best explanation for trans-species polymorphisms. The absence of allelic coalescence is a severe constraint in the application of phylogenetic methods in Pinus, and taxa sharing similar life history traits may show analogous patterns. While lack of coalescence may limit their utility in traditional phylogenetics, nuclear genes remain highly informative in describing speciation events. Pinus chiapensis is a threatened species originally described as a variety of P. strobus. Prior morphological work suggests P. chiapensis is a distinct species, but that taxonomy is not universally accepted. Multiple accessions of three probable progenitors were sequenced at three nuclear loci. No interspecific allele sharing occurs with P. chiapensis, and its alleles are monophyletic at two loci. Results demonstrate that P. chiapensis is a distinct species. However, determination of the sister species is complicated by lack of species monophyly and interlocus variability. Pinus ayacahuite is the least likely progenitor, but the relationship of P. chiapensis to P. monticola or P. strobus is unclear. / Graduation date: 2006

Thesis (M.Sc.)--York University, 2004. Graduate Programme in Earth and Space Science. / Typescript. Includes bibliographical references (leaves 126-134). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss&rft%5Fval%5Ffmt=info:ofi/fmt:kev:mtx:dissertation&rft%5Fdat=xri:pqdiss:MQ99363

Drought is a major constraint for attaining economic yield in tree crops. As an initial step to understand molecular response to water-deficit-stress in trees, gene expression in response to water stress was quantified using real-time RT-PCR. The specific objectives established for this to were I. to identify and characterize the genes induced by drought stress in Aleppo pine (Pinus halepensis) and II to identify and quantify the differentially expressed genes in different populations of Loblolly pine (Pinus taeda.L) due to water deficit (chapter III). Results of these studies may be used to identify candidate genes for future breeding programs against water-deficit-stress.

Drought is a major constraint for attaining economic yield in tree crops. As an initial step to understand molecular response to water-deficit-stress in trees, gene expression in response to water stress was quantified using real-time RT-PCR. The specific objectives established for this to were I. to identify and characterize the genes induced by drought stress in Aleppo pine (Pinus halepensis) and II to identify and quantify the differentially expressed genes in different populations of Loblolly pine (Pinus taeda.L) due to water deficit (chapter III). Results of these studies may be used to identify candidate genes for future breeding programs against water-deficit-stress.

Thesis (doctoral)--Swedish University of Agricultural Sciences, 2003. / Thesis documentation sheet inserted. Appendix includes reproductions of four papers and manuscripts, three co-authored with others. Includes bibliographical references. Abstract also available online.

The mechanism of drought resistance in the seedlings of Aleppo pine (Pinus halepensis) and Brutia pine (Pinus brutia) was investigated. Both species showed anatomical and morphological adaptations to conserve moisture. Aleppo pine had a thicker cuticle, fewer stomata per unit length, per unit area, and per needle than Brutia pine. A significant number of Aleppo pine stomata were sealed with a waxy layer. Brutia pine had shorter needles, smaller needle surface area, a smaller surface area-to-volume ratio, and longer main root length. The two species were similar in height growth and in the seasonal trend of total non-structural carbohydrates (reducing sugars and starch). Brutia pine had more reducing sugars and less starch in its shoots than Aleppo pine. The latter had a greater amount of total non-structural carbohydrates and starch when the seedlings were subjected to dry down moisture stress. Electron microscopy techniques were used to monitor ultrastructural changes in the chloroplasts of mesophyll cells. Aleppo pine was found to contain chloroplasts exhibiting water stress-related damage at a relative water content of 62 percent, where as Brutia pine chloroplasts were disrupted. It is suggested that future investigations examine the physiological manifestation of drought mechanism at the cellular and molecular levels of both species.

No description available.

Managed pine forests are central to the economic vitality of the southeastern US. Over the past fifty years, the productivity of managed pine forests of this region have increased significantly with the development of new silvicultural technologies and the use of improved tree genetic material. Of the pine species present in the southeastern US, loblolly pine has arguably been the most intensively studied and widely planted by forest managers. Efficient operational deployment of improved genetic materials requires an understanding of how possible site conditions and silvicultural treatment may interact to affect maximum yield. There are a wide range of site conditions in the south as the result of regional climate gradients, soil type and soil drainage patterns. On the western edge of loblolly pine’s natural extent, Texas has a drier climate than areas to the east, and in Louisiana, there are also poorly drained Ultisols that are found in areas with little relief and are prone to flooding. However, on the basis of 10-year forest inventory data of pure-family plots from three different sites and under two levels of cultural regime intensity, my study found that superior genotype, Lob 5 from South Carolina, still showed best performance in the Western Gulf area, and high intensive treatment could improve stand growth and resistance to wind damage significantly. Further, my study compared the stand production and dynamics between pure- and mixed-family plots. I found that Lob 5 and Lob 4 showed the growth traits of competitive ideotype, and low intensive treatment increased the deployment effect significantly for competitive ideotype. Finally, my study examined leaf area index (LAI) and foliar nitrogen concentration (foliar N). The result showed that fast growing genotype had lower LAI and foliar N than slow growing one. It indicated that fast growing genotype had high resource use efficiency and nutrient requirement. This research provided critical information to guide industrial forest management in the WG (Western Gulf) area. First, introduced superior genotype continued to show good performance in this area. Second, combination of good genotype and high intensive treatment would increase plantation production significantly. Third, identification of ideotype would increase the accuracy of growth potential estimation in progeny test.

Thesis (M.S.)--University of Nevada, Reno, 2007. / "May, 2007." Includes bibliographical references (leaves 54-57). Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2007]. 1 microfilm reel ; 35 mm.