Genetic variation and productivity of Populustrichocarpa and its hybrids. I. Morphology and phenology of 50 native clones

1985 ◽  
Vol 15 (2) ◽  
pp. 376-383 ◽  
Author(s):  
J. C. Weber ◽  
R. F. Stettler ◽  
P. E. Heilman
Keyword(s):  
Clonal Selection ◽  
Natural Populations ◽  
Principal Component ◽  
Black Cottonwood ◽  
Population Means ◽  
Major River ◽  
Continue Growth ◽  
Genetic Cline ◽  
Source Populations ◽  
River Valleys

Morphological and phenological variation among five black cottonwood (Populustrichocarpa Torr. & Gray) clones from each of 10 natural populations were studied at one plantation site in western Washington. Source populations are located in major river valleys, west of the Cascade Mountains, between central Oregon (latitude 44°44′ N) and southern British Columbia (latitude 49°05′ N). Populations and individual clones were selected for superior form and growth rate. Tested at a spacing of 1.2 × 1.2 m, the 50 clones displayed a large range of variation in 15 leaf, branch, and phenology characters studied. Clones and populations differed significantly in 14 and 10 characters, respectively. Population means for seven characters and a character association (principal component) varied clinally with source latitude, longitude, and (or) elevation. The most consistent genetic cline follows a geographic gradient from southwest to northeast: southwestern clones develop smaller leaves on more erect branches, and continue growth later in the fall. Variation patterns seem to reflect regional climatic gradients, annual disturbance in riparian environments, and the life history characteristics of the species. The results point to the great potential of clonal selection for black cottonwood improvement.

Genetic variation and productivity of Populustrichocarpa and its hybrids. II. Biomass production in a 4-year plantation

1985 ◽  
Vol 15 (2) ◽  
pp. 384-388 ◽  
Author(s):  
Paul E. Heilman ◽  
R. F. Stettler
Keyword(s):  
Clonal Selection ◽  
Dry Weight ◽  
N Fertilization ◽  
Genetic Constitution ◽  
Black Cottonwood ◽  
Short Rotation ◽  
Major River ◽  
Source Populations ◽  
High Yields ◽  
River Valleys

Productivities of 5 black cottonwood clones from each of 10 source populations (50 clones in total) were compared at one plantation site in western Washington. The source populations are located west of the Cascade Mountains, between central Oregon and southern British Columbia. Most source stands represented populations in major river valleys. Individual clones were selected for superior form and growth rate. Spacing was 1.2 × 1.2 m (6944 stems•ha−1) and trees were harvested after 4 years. Considerable variation in mortality, height, and productivity were found among clones within individual stands and among stands. Southwestern clones were generally more productive. Heights of individual clones averaged between 8.5 and 11.8 m at 4 years. Average dry weight production of black cottonwood clones was 12.5 Mg•ha−1•year−1 and varied between 5.2 and 23.1 Mg•ha−1•year−1 for individual clones. Three new Populustrichocarpa × P. deltoides hybrids planted in the trial were generally more productive than black cottonwood or the 'Robusta' hybrid, with average heights varying from 11.5 to 12.2 m and dry weight production ranging from 15.6 to 27.8 Mg•ha−1•year−1 for an average of 23.6 Mg•ha−1•year−1. The high yields in this experiment are attributed to favorable climate (1940 degree-days•year−1)3, cultural treatments (irrigation, N fertilization) and genetic constitution of certain clones. The data promise substantial gains in short-rotation productivity from combining clonal selection with interspecific hybridization.

Genetic variation and productivity of Populustrichocarpa and its hybrids. III. Structure and pattern of variation in a 3-year field test

1989 ◽  
Vol 19 (3) ◽  
pp. 372-377 ◽  
Author(s):  
D. L. Rogers ◽  
R. F. Stettler ◽  
P. E. Heilmann
Keyword(s):  
Block Design ◽  
Natural Populations ◽  
Large Degree ◽  
Population Variation ◽  
Black Cottonwood ◽  
Narrow Sense Heritability ◽  
Ongoing Work ◽  
Pattern Of Variation ◽  
Significant Block ◽  
River Valleys

Growth and morphology of 308 black cottonwood (Populustrichocarpa Torr & Gray) clones were studied at one plantation site in northwestern Washington. The material was derived from both open-pollinated seed and branch cuttings from 10 natural populations in major river valleys west of the Cascade Range, between central Oregon (latitude 44°44′) and southern British Columbia (latitude 49°05′). Most of the clones (258) were derived from open-pollinated seedlings, with approximately six from each of two to five selected parents per population. Fifty of the clones were ramets from five field-selected ortets per population. Each clone was represented by two ramets in each of two blocks in a randomized complete block design. Three-year height and diameter growth displayed the largest amount of variation at the clonal level, followed by lesser amounts at the family and population levels. A significant block × clone interaction, combined with some responses contrasting with earlier studies on a different site, suggests that the interaction of genotype with environment is important for this species. Weak clinal trends were observed, despite a large degree of within-population variation. Narrow-sense heritability estimates and their standard errors were 0.10 ± 0.08 and 0.13 ± 0.09 for 3rd-year height and diameter, respectively. Significant trait correlations were obtained between volume and branch characteristics. The implications of these results and their relationship to other ongoing work in black cottonwood are discussed.

Implications of phenotypic plasticity for numerical taxonomy of Ornithogalum montanum (Liliaceae)

1991 ◽  
Vol 69 (1) ◽  
pp. 34-38 ◽  
Author(s):  
M. Pigliucci ◽  
M. G. Politi ◽  
D. Bellincampi
Keyword(s):  
Principal Component Analysis ◽  
Phenotypic Plasticity ◽  
Numerical Taxonomy ◽  
Natural Populations ◽  
Principal Component ◽  
Reaction Norm ◽  
Component Analysis ◽  
Morphological Response ◽  
Numerical Taxonomic Study ◽  
High Degree

Implications of phenotypic plasticity in a subspecific numerical taxonomic study of Ornithogalum montanum Cyr. (Liliaceae) are discussed. Clones belonging to six natural populations were grown in a glasshouse, and their morphological response to three water dosages was analyzed by means of principal component analysis. PC-1 ranks the three groups of replicated populations, suggesting a high degree of phenotypic plasticity; on the other hand, PC-3 is almost environmentally independent. Proximities in the phenetic space are shown to be at least partially environmentally dependent, suggesting a reaction norm for the character correlation matrix. The results do not corroborate a previous recognition of six subspecies of O. montanum. Key words: phenotypic plasticity, numerical taxonomy, Ornithogalum, reaction norm, principal component analysis.

scholarly journals Population Genetics and Evolution Analysis Reveal Diversity and Origin of Ammopiptanthus in China.

2021 ◽  
Author(s):  
Guai-qiang Chai ◽  
Yizhong Duan ◽  
Peipei Jiao ◽  
Zhongyu Du ◽  
Furen Kang
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Association Studies ◽  
Natural Populations ◽  
Principal Component ◽  
Nucleotide Polymorphisms ◽  
Future Design ◽  
Ammopiptanthus Nanus ◽  
Genome Wide

Abstract Background：Elucidating and revealing the population genetic structure, genetic diversity and recombination is essential for understanding the evolution and adaptation of species. Ammopiptanthus, which is an endangered survivor from the Tethys in the Tertiary Period, is the only evergreen broadleaf shrub grown in Northwest of China. However, little is known about its genetic diversity and underlying adaptation mechanisms. Results：Here, 111 Ammopiptanthus individuals collected from fifteen natural populations in estern China were analyzed by means of the specific locus amplified fragment sequencing (SLAF-seq). Based on the single nucleotide polymorphisms (SNPs) and insertions and deletions (InDels) detected by SLAF-seq, genetic diversity and markers associated with climate and geographical distribution variables were identified. The results of genetic diversity and genetic differentiation revealed that all fifteen populations showed medium genetic diversity, with PIC values ranging from 0.1648 to 0.3081. AMOVA and Fst indicated that a low genetic differentiation existed among populations. Phylogenetic analysis showed that NX-BG and NMG-DQH of fifteen populations have the highest homology，while the genetic structure analysis revealed that these Ammopiptanthus germplasm accessions were structured primarily along the basis of their geographic collection, and that an extensive admixture occurred in each group. In addition, the genome-wide linkage disequilibrium (LD) and principal component analysis showed that Ammopiptanthus nanus had a more diverse genomic background, and all genetic populations were clearly distinguished, although different degrees of introgression were detected in these groups. Conclusion：Our study could provide guidance to the future design of association studies and the systematic utilization and protection of the genetic variation characterizing the Ammopiptanthus.

scholarly journals Ampelographic description of cluster, berry and seed of merlot cultivar (Vitis vinifera L.) and its selected clones

2016 ◽  
Vol 61 (1) ◽  
pp. 45-55
Author(s):  
Dragan Vujovic ◽  
Dragoljub Zunic ◽  
Boris Pejin ◽  
Jelena Popovic-Djordjevic
Keyword(s):  
Clonal Selection ◽  
Average Length ◽  
Research Work ◽  
Principal Component ◽  
Vegetation Period ◽  
Vitis Vinifera L ◽  
Cluster Number ◽  
The Third ◽  
Third Phase ◽  
Shoot Number

During a four-year period, ampelographic experiments focusing on the berry cluster (average length of grape cluster, number of grape clusters per shoot, number of berries per grape cluster and length of peduncle), berry (length of berry and berry juice yield), length of pedicel and seed (length of berry seed) of Merlot cultivar (used as a relevant standard) and 11 clones (Nos. 022, 023, 025, 026, 027, 028, 029, 030, 031, 033 and 034) were performed in order to establish the differences among them. These experiments were actually conducted in the third phase of individual clonal selection of Merlot cultivar carried out in Serbia. The lengths of grape cluster and pedicel as well as berry must yields differed significantly among the examined clones. The cluster and principal component analyses classified 12 samples into three divergent clusters/groups, respectively. The clones belonging to the cluster II /the second group/ had significantly higher values of numbers of grape clusters per shoot and berries per grape cluster; lengths of peduncle and berry; berry must yield and length of pedicel, compared both to standard Merlot /the cluster I, the first group/ and the clones of the cluster III /the third group/. The phenological observations showed no significant differences in the beginnings and durations of phenological stages and vegetation period of the examined clones. The obtained results indicate the real need for further research work focused both on the agrobiological and technological properties of the grapes and wines aiming to better describe the selected clones.

Cryptic Lineages and a Population Dammed to Incipient Extinction? Insights into the Genetic Structure of a Mekong River Catfish

2019 ◽  
Vol 110 (5) ◽  
pp. 535-547 ◽  
Author(s):  
Amanda S Ackiss ◽  
Binh T Dang ◽  
Christopher E Bird ◽  
Ellen E Biesack ◽  
Phen Chheng ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Natural Populations ◽  
Principal Component ◽  
Flood Pulse ◽  
Mekong River ◽  
Effective Population ◽  
Long Distance ◽  
Genetic Lineages ◽  
Low Genetic Diversity ◽  
Population Size Estimates

Abstract An understanding of the genetic composition of populations across management boundaries is vital to developing successful strategies for sustaining biodiversity and food resources. This is especially important in ecosystems where habitat fragmentation has altered baseline patterns of gene flow, dividing natural populations into smaller subpopulations and increasing potential loss of genetic variation through genetic drift. River systems can be highly fragmented by dams built for flow regulation and hydropower. We used reduced-representation sequencing to examine genomic patterns in an exploited catfish, Hemibagrus spilopterus, in a hotspot of biodiversity and hydropower development—the Mekong River basin. Our results revealed the presence of 2 highly divergent coexisting genetic lineages which may be cryptic species. Within the lineage with the greatest sample sizes, pairwise FST values, principal component analysis, and a STRUCTURE analysis all suggest that long-distance migration is not common across the Lower Mekong Basin, even in areas where flood-pulse hydrology has limited genetic divergence. In tributaries, effective population size estimates were at least an order of magnitude lower than in the Mekong mainstream indicating these populations may be more vulnerable to perturbations such as human-induced fragmentation. Fish isolated upstream of several dams in one tributary exhibited particularly low genetic diversity, high amounts of relatedness, and a level of inbreeding (GIS = 0.51) that has been associated with inbreeding depression in other outcrossing species. Our results highlight the importance of assessing genetic structure and diversity in riverine fisheries populations across proposed dam development sites for the preservation of these critically important resources.

scholarly journals Morphological Divergence of Snow Trout (Schizothorax Richardsonii, Gray 1932) from Rivers of Nepal with Insights from a Morphometric Analysis

2015 ◽  
Vol 3 (3) ◽  
pp. 464-473
Author(s):  
Suresh Kumar Wagle ◽  
Neeta Pradhan ◽  
Madhav Kumar Shrestha
Keyword(s):  
Size Variation ◽  
Principal Component ◽  
Head Region ◽  
Body Depth ◽  
Morphometric Characters ◽  
Significant Difference ◽  
Snow Trout ◽  
Major River ◽  
Mean Vectors ◽  
Schizothorax Richardsonii

Asala or snow trout (Schizothorax richardsonii, Cyprinidae), one of highly valued freshwater fish of Transhimalayan regions, is distributed in upper reaches of all major river systems of Nepal. Morphometric diversification between six river populations of S. richardsonii was examined to identify intraspecific unit for enabling better management of the resources. Significant differences were observed in 17 measured morphometric characters of 207 specimens among the six river populations. Multivariate analysis of variance (Wilks' test) indicated a significant difference for mean vectors of mophometric measurements (? =0.012, F85, 731 = 19.999, P<0.0001) among populations. Principal component and discriminant functions (DFs) analysis of morphometric measurements revealed high seperation of the stocks. The analysis showed that most of the shape and size variation among these populations occurs in the head region, body depth and fin length. Apparent morphometric divergence among S. richardsonii samples showed the existence of three differentiated groups viz., the Indrawati and Khudi populations, the Melamchi and Phalaku Rivers, and the Sabha and Tadi River populations of Nepal. The results of this study may be useful in fisheries management and potential exploitation of this species in coldwater aquaculture.Int J Appl Sci Biotechnol, Vol 3(3): 464-473

Variation in leaf characteristics among provenances of Eucalyptus camaldulensis Dehn. grown in Zambia

1971 ◽  
Vol 19 (2) ◽  
pp. 237
Author(s):  
J Burley ◽  
PJ Wood ◽  
AS Hans
Keyword(s):  
Principal Component Analysis ◽  
Leaf Shape ◽  
Natural Populations ◽  
Eucalyptus Camaldulensis ◽  
Principal Component ◽  
Morphological Characters ◽  
Leaf Length ◽  
Maximum Temperature ◽  
Ecotypic Variation ◽  
Old Trees

Eight morphological characters of leaves were examined in 2-year-old trees of 25 provenances of Eucalyptus camaldulensis Dehn, grown in a replicated trial in Zambia. Provenances differed significantly in leaf length and width, base angle, and oil gland density but significant effects were attributed to trees within provenances. Leaf curvature also varied between provenances, trees, and branches. The tip angle and the number of veins did not vary significantly. Leaf length and oil gland density were related to maximum temperature at seed source rather than to latitude but the reverse occurred for leaf width. Significant amounts of variation were explained by a linear combination of temperature and latitude but not by longitude, altitude, or rainfall. Information on seven traits was combined in principal component analysis in which the first component (a measure of leaf shape) accounted for 36% of total observed variation while the second (weighted largely on leaf length) accounted for 26%. Mapping of both univariate and multivariate results indicated that there are two major ecotypes and gave some evidence of clinal and ecotypic variation within them. The conclusions support those of other workers both in natural populations in Australia and in exotic populations elsewhere.

Seasonal variation and clonal selection in cyclically parthenogenetic rose aphids (Macrosiphum rosae)

1985 ◽  
Vol 27 (2) ◽  
pp. 224-232 ◽  
Author(s):  
L. R. Rhomberg ◽  
S. Joseph ◽  
R. S. Singh
Keyword(s):  
Genetic Variation ◽  
Seasonal Variation ◽  
Clonal Selection ◽  
Natural Populations ◽  
Allozyme Variation ◽  
Polymorphic Loci ◽  
Esterase Loci ◽  
Allozyme Loci ◽  
Macrosiphum Rosae ◽  
Asexual Cycle

Patterns of geographic and seasonal genetic variation were assessed in natural populations of cyclically parthenogenetic rose aphids Macrosiphum rosae (L.). Nine populations were studied for a red–green colour morph and 30 allozyme loci (20 coding for enzymes and 10 for abundant proteins). Genetic variation was found at 5 of 20 enzyme loci (20%); all 10 abundant proteins proved monomorphic. The average heterozygosity was 4.3%. At some polymorphic loci genotypic frequencies showed significant deviations from Hardy–Weinberg proportions. Six local populations from Hamilton, Ontario, were studied for seasonal variation at the colour locus and at two polymorphic esterase loci (Est-2 and Est-4). All three loci showed large changes in genotypic frequencies over the season during the asexual cycle, but only for Est-4 were changes consistent among populations. This locus undergoes a regular seasonal cycle, the directional changes during the asexual phase presumably being balanced by changes during the sexual phase. The frequencies of three-locus genotypes within each locality fluctuated dramatically over the course of a season, reflecting the domination of local infestations by a few particularly successful clones. We speculate that because of such clonal competition followed by extensive migration, much of the selectively neutral variation is purged from aphid populations. The remaining polymorphic loci, which are mostly di- or tri-allelic, are subject to balancing natural selection at the gene or at closely linked loci. The Est-4 in rose aphids is an example of such a selectively maintained polymorphism.Key words: aphids, allozyme variation, seasonal variation, parthenogenesis, clonal selection, population structure.

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