Genetic variation among local populations of jack pine (Pinus banksiana)

1986 ◽  
Vol 28 (3) ◽  
pp. 453-458 ◽  
Author(s):  
Howard A. Ross ◽  
Janice L. Hawkins

Genetic variability in three jack pine (Pinus banksiana) populations, spaced 10 km apart in southern Manitoba, was analyzed electrophoretically for 15 enzymes encoded by 20 structural loci. These populations were studied as spatial and temporal controls in an investigation of the effects of long-term gamma irradiation on boreal tree species. Individual populations were, on average, polymorphic at 53.3% of the loci and had 2.0 alleles per locus. Individual trees were heterozygous at 20.7% of their loci. An F-statistic analysis revealed an overall 10% excess of heterozygotes over Hardy–Weinberg expectations. Only 2% of the genetic variation occurred among populations. Consequently Nei's genetic distance between populations was small [Formula: see text]. The amount and disposition of the genetic variation in neighbouring populations resembled that observed by others among widely spaced populations. The similarity of the genetic structure of jack pine populations at the meso- and macro-geographic levels might result from the antagonistic effects of long distance gene flow via pollen transport (increasing homogeneity) and adaptation to fire or other patchily distributed environmental factors (reducing homogeneity).Key words: Jack pine, Pinus banksiana, allozymic variation, genetic structure.

1991 ◽  
Vol 69 (3) ◽  
pp. 547-551 ◽  
Author(s):  
Chang Yi Xie ◽  
Peggy Knowles

Spatial autocorrelation analysis was used to investigate the geographic distribution of allozyme genotypes within three natural populations of jack pine (Pinus banksiana Lamb.). Results indicate that genetic substructuring within these populations is very weak and the extent differs among populations. These results are in good agreement with those inferred from mating-system studies. Factors such as the species' predominantly outbreeding system, high mortality of selfs and inbreds prior to reproduction, long-distance pollen dispersal, and the absence of strong microhabitat selection may be responsible for the observed weak genetic substructuring. Key words: jack pine, Pinus banksiana, genetic substructure, allozyme, spatial autocorrelation analysis.


2021 ◽  
Vol 664 ◽  
pp. 103-116
Author(s):  
L Martínez-García ◽  
B Hansson ◽  
J Hollander

Seagrass meadows are one of the most important habitats in coastal regions since they constitute a multifunctional ecosystem providing high productivity and biodiversity. They play a key role in carbon sequestration capacity, mitigation against coastal erosion and as nursery grounds for many marine fish and invertebrates. However, despite these ecosystem functions and services, seagrass meadows are a threatened ecosystem worldwide. In the Baltic Sea, seagrass meadows have declined rapidly, mainly because of eutrophication, anthropogenic activities and climate change. This decline has the potential to erode the genetic variation and genetic structure of the species. In this study, we assessed how genetic variation and genetic differentiation vary among Zostera marina meadows and with a number of environmental characteristics in the county of Scania in southern Sweden. A total of 205 individuals sampled at 12 locations were analysed with 10 polymorphic microsatellite loci. Results showed that in spite of anthropogenic impacts and climate change pressures, locations of Z. marina possessed high genetic variation and weak genetic differentiation, with 3 major genetic clusters. Long-distance dispersal and/or stepping-stone dispersal was found among locations, with higher migration rates within the west coast. Organic matter, salinity and maximum depth appeared to be factors most strongly associated with the genetic structure and morphological variation of Z. marina. These findings contribute significantly in the identification of potential donor sites and the viability of impacted areas to recover from natural recruitment, for the development of effective transplantation measures of Z. marina in the southern Baltic Sea and temperate regions elsewhere.


2005 ◽  
Vol 83 (4) ◽  
pp. 420-426 ◽  
Author(s):  
Rebecca T Tague ◽  
Stephanie A Foré

In early successional species, short life span and frequent spatial relocation may affect the distribution of genetic variation but the pattern may be altered by reproductive patterns. Passiflora incarnata L. (Passifloraceae), an early successional vine found throughout the southeastern United States, reproduces sexually and asexually through clonal sprouts. We examined the genetic structure of P. incarnata in recently disturbed habitats at three spatial scales: within a patch, among patches separated by 250 m, and between sites separated by 10 km. Genetic variation may be clumped at the scale of neighboring plants if stem resprouting is significant. In each patch, eleven arbitrarily selected plants and their four nearest neighbors were mapped and leaf samples were collected for genetic analysis. The multilocus genotype of each individual for seven polymorphic allozymes was determined. Potential clones were determined by estimating the probability of a second occurrence of each genotype and a multilocus coefficient of coancestry. Data indicated P. incarnata was reproducing primarily sexually. Most of the genetic variation was within a patch with little variation among patches. These data suggest that the genetic structure of this colonizing species was determined by founder effects interacting with long distance pollen movement.Key words: allozymes, passionflower, spatial, genetic structure, early colonizer, Passiflora incarnata.


1966 ◽  
Vol 44 (3) ◽  
pp. 275-295 ◽  
Author(s):  
J. T. Basham

A survey was made of the fungi inhabiting the heartwood of living jack pine (Pinus banksiana Lamb.) in Ontario, particularly in stained and decayed wood. Two Basidiomycetes encountered frequently were Fomes pini (Fr.) Karst., associated with red stain and white pocket rot, and Peniophora pseudo-pini Weres. & Gibson, isolated almost exclusively from stained wood. F. pini was the only fungus consistently associated with white pocket rot, the principal type of heart rot in jack pine. The three most abundant microfungi, a member of the Coryne sarcoides complex, Tympanis hypopodia Nyl., and Retinocyclus abietis (Crouan) Groves & Wells, were encountered frequently in stained wood, but less frequently in decayed and normal wood.Many aspects of the occurrence of these five fungi in jack pine were investigated, including their distribution in the stems and branch stubs of individual trees and their association with normal, stained, and decayed wood therein; and the relation between their occurrence and tree growth rate, various heartwood properties, and different stand conditions. The apparent means by which the fungi enter jack pine, and the possible existence of a succession of fungi in the heartwood of living trees, are discussed.


2001 ◽  
Vol 79 (8) ◽  
pp. 871-878 ◽  
Author(s):  
Cuauhtemoc Saenz-Romero ◽  
Raymond P Guries ◽  
Andrew I Monk

Many of Wisconsin's jack pine forests originated following fire or agricultural abandonment creating a forest mosaic fragmented by a history of disturbance and past land use. The extent and patterning of genetic diversity at a landscape scale (30 × 30 km) was investigated in 82 natural Pinus banksiana Lamb. (jack pine) stands in Wisconsin using 14 polymorphic allozymes. Most measures of genetic diversity and overall allelic frequencies varied little among these stands, and Reynolds' (coancestry) genetic distances were small (mean = 0.026). Genetic differentiation among stands was limited but significant ([Formula: see text]ST = 0.022). Gene flow (Nm) is extensive, estimated to be slightly more than 11 migrants per generation. Autocorrelation analysis provided evidence for a weak pattern of genetic structure at a few loci with a spatial scale of 8–15 km. However, when all loci were examined together the populations did not present a clear spatial pattern across the landscape, probably because of extensive gene flow among stands.Key words: jack pine, allozymes, genetic diversity, population differentiation, spatial autocorrelation, gene flow.


2011 ◽  
Vol 28 (3) ◽  
pp. 138-145 ◽  
Author(s):  
Katherine P. Bleiker ◽  
Allan L. Carroll

Abstract Introgressive hybridization between species generates novel gene combinations and phenotypes. We required an accessible, objective method of rating introgression between lodgepole pine (Pinus contorta var. latifolia [Engelm.] Critchfield) and jack pine (Pinus banksiana Lamb.) for individual trees where their ranges overlap in Canada for use in another study on host species effects on resistance to an eruptive herbivore that has recently expanded its range. We adapted, simplified, and fully quantified a morphological index developed to rate introgression of pine populations and applied it to individual trees. In addition to principal component analysis (PCA), we also used discriminant function analysis (DFA), a potentially more powerful method given a priori knowledge of parent taxa, to generate introgression ratings. Among-tree variation in morphological traits and introgression was high at sites within the hybrid zone but very low at pure parent sites. PCA and DFA produced similar introgression ratings at the stand level, but ratings differed substantially for some individual trees. Certain morphological traits may be omitted from both PCA and DFA with little impact on stand-level ratings. The discriminant functions presented here are based on easy-to-measure, fully quantifiable morphological traits and can be used by other researchers to produce relative introgression ratings for lodgepole and jack pine. The approach may also be applied to other plant hybrid systems.


1966 ◽  
Vol 44 (7) ◽  
pp. 849-860 ◽  
Author(s):  
J. T. Basham

Two Basidiomycetes, Fomes pini (Fr.) Karst. and Peniophora pseudo-pini Weres. & Gibson, and three microfungi (Ascomycetes), Tympanis hypopodia Nyl., Retinocyclus abietis (Crouan) Groves & Wells, and a member of the Coryne sarcoides complex, are the fungi most frequently isolated from the heartwood of living jack pine (Pinus banksiana Lamb.) in the Province of Ontario. Of these, only F. pini is consistently associated with decayed wood. In laboratory tests all five caused significant weight losses in jack pine heartwood samples, and all but the C. sarcoides complex appreciably altered the color of the wood. T. hypopodia was exceedingly antagonistic towards F. pini, both in malt agar culture and when inoculated in advance of F. pini in jack pine wood samples. The activity of P. pseudo-pini in the test samples was reduced slightly by the prior establishment of T. hypopodia and the C. sarcoides complex, but was stimulated somewhat by the presence of R. abietis. The presence of the C. sarcoides complex in jack pine samples resulted in a moderate increase in the activity of F. pini.In some cases competitive interactions among heartwood-inhabiting fungi may partly explain the marked variability in defectiveness frequently observed among individual trees in forest stands.


Genome ◽  
2013 ◽  
Vol 56 (10) ◽  
pp. 577-585 ◽  
Author(s):  
Catherine I. Cullingham ◽  
Janice E.K. Cooke ◽  
David W. Coltman

Forest trees exhibit a remarkable range of adaptations to their environment, but as a result of frequent and long-distance gene flow, populations are often only weakly differentiated. Lodgepole and jack pine hybridize in western Canada, which adds the opportunity for introgression through hybridization to contribute to population structure and (or) adaptive variation. Access to large sample size, high density SNP datasets for these species would improve our ability to resolve population structure, parameterize introgression, and separate the influence of demography from adaptation. To accomplish this, 454 transcriptome reads for lodgepole and jack pine were assembled using Newbler and MIRA, the assemblies mined for SNPs, and 1536 SNPs were selected for typing on lodgepole pine, jack pine, and their hybrids (N = 536). We identified population structure using both Bayesian clustering and discriminate analysis of principle components. Introgressed SNP loci were identified and their influence on observed population structure was assessed. We found that introgressed loci resulted in increased differentiation both within lodgepole and jack pine populations. These findings are timely given the recent mountain pine beetle population expansion in the hybrid zone, and will facilitate future studies of adaptive traits in these ecologically important species.


1998 ◽  
Vol 28 (12) ◽  
pp. 1784-1793 ◽  
Author(s):  
W Jan A Volney

The fate of jack pine (Pinus banksiana Lamb.) trees growing in a variety of stand conditions was assessed annually for a decade following an outbreak of jack pine budworm (Choristoneura pinus Freeman) in central Saskatchewan. Mortality was clearly associated with the severity and damage sustained by the trees during the second year of the defoliation episode. The pattern of mortality was remarkably similar among stands that originated in decades that spanned 60 years. Mortality rates were highest in stands that originated in the 1890s and were lowest in stands of the most recent origin (1940s). Defoliation severity, the length of dead top, diameter at breast height, and relative tree height expressed as a standard normal variable accounted for 94% of the variability in survival time. A nonparametric proportional hazards model was developed to evaluate the relative risk of individual trees dying. Defoliation is an important process in determining stand density, basal area, and volume after juvenile stand development is complete. The results presented suggest a novel method to determine the hazard of trees in stands and thus assess the vulnerability of stands to future budworm attack.


Sign in / Sign up

Export Citation Format

Share Document