GENIC DIVERSITY OF NATURAL POPULATIONS OF A CLONE- FORMING TREE POPULUS TREMULOIDES

1982 ◽  
Vol 24 (5) ◽  
pp. 611-616 ◽  
Author(s):  
William M. Cheliak ◽  
Bruce P. Dancik
Keyword(s):  
Plant Species ◽  
Populus Tremuloides ◽  
Animal Species ◽  
Woody Plant ◽  
Neutral Theory ◽  
Natural Populations ◽  
Trembling Aspen ◽  
Insufficient Time ◽  
Selection For ◽  
Genic Diversity

Effects of asexual reproduction as a primary reproductive strategy on population structure and levels of variability were investigated electrophoretically in natural populations of a woody plant species, trembling aspen (Populus tremuloides Michx.), from Alberta. As expected, levels of genic diversity, 42%, and proportion of polymorphic loci, 92%, averaged over all clones are considerably greater than those reported for comparable samples of sexually reproducing plant and animal species. These measures of genic variability of a primarily asexual plant species are similar to those reported for asexual species of insects, fish and bacteria. In addition, each of the 222 clones was electrophoretically unique. Since neutral theory would predict each individual clone to be heterozygous for a unique mutation at each gene locus at equilibrium, these results can be interpreted in a number of ways: (i) insufficient time to reach equilibrium, (ii) inability of electrophoresis to detect all variation at a locus, (iii) periodic establishment of sexually derived propagules in the population, and (iv) selection for similar genotypes at each location or against mutations at particular gene loci. Re-invasion of Pleistocene-glaciated areas by trembling aspen likely was by sexual means, with subsequent reproduction being primarily asexual.

scholarly journals Why and How to Switch to Genomic Selection: Lessons From Plant and Animal Breeding Experience

2021 ◽  
Vol 12 ◽  
Author(s):  
◽  
Aline Fugeray-Scarbel ◽  
Catherine Bastien ◽  
Mathilde Dupont-Nivet ◽  
Stéphane Lemarié
Keyword(s):  
Genetic Diversity ◽  
Genomic Selection ◽  
Plant Species ◽  
Animal Species ◽  
Animal Breeding ◽  
Breeding Cycle ◽  
Breeding Programs ◽  
The Third ◽  
Wide Range ◽  
Selection For

The present study is a transversal analysis of the interest in genomic selection for plant and animal species. It focuses on the arguments that may convince breeders to switch to genomic selection. The arguments are classified into three different “bricks.” The first brick considers the addition of genotyping to improve the accuracy of the prediction of breeding values. The second consists of saving costs and/or shortening the breeding cycle by replacing all or a portion of the phenotyping effort with genotyping. The third concerns population management to improve the choice of parents to either optimize crossbreeding or maintain genetic diversity. We analyse the relevance of these different bricks for a wide range of animal and plant species and sought to explain the differences between species according to their biological specificities and the organization of breeding programs.

Occurrence of hybrids between bigtooth and trembling aspen in Michigan

1985 ◽  
Vol 63 (10) ◽  
pp. 1888-1890 ◽  
Author(s):  
Burton V. Barnes ◽  
Kurt S. Pregitzer
Keyword(s):  
Gene Flow ◽  
Relative Abundance ◽  
Populus Tremuloides ◽  
Woody Plant ◽  
Parent Species ◽  
Trembling Aspen ◽  
Upper Peninsula ◽  
Populus Grandidentata

Tree hybrids are commonly reported and described but little is known about their actual abundance compared with that of their parents. The hybrid between bigtooth aspen (Populus grandidentata Michaux) and trembling aspen (Populus tremuloides Michaux), Populus χsmithii Boivin, is one of the most common spontaneous woody plant hybrids. The purpose of the study was to determine the relative abundance of the hybrid and parents in three geographic areas of Michigan. In southeastern Michigan, 1.5% of all aspen clones were hybrids, whereas in northern Lower Michigan and in western Upper Michigan the proportions were only 0.04 and 0.05%, respectively. Bigtooth aspen is most common in northern Lower Michigan, trembling aspen is more abundant in the Upper Peninsula than in northern Lower Michigan, and both parents are relatively infrequent in southeastern Michigan. Hybrids are typically disease prone and short-lived, and both parents and hybrids are being replaced in southeastern Michigan by longer-lived species. Thus, the opportunity for gene flow between the parent species continues to decline.

Phomopsis subordinaria and associated stalk disease in natural populations of Plantago lanceolate

1987 ◽  
Vol 65 (11) ◽  
pp. 2318-2325 ◽  
Author(s):  
Marianne P. de Nooij ◽  
Huub A. van der Aa
Keyword(s):  
Natural Selection ◽  
Plant Species ◽  
Plant Tissue ◽  
Plantago Lanceolata ◽  
Natural Populations ◽  
Taxonomic Position ◽  
Selection For ◽  
Viable Seeds

Natural populations of Plantago lanceolata L. can be infected by the fungus Phomopsis subordinaria (Desm.) Trav., which causes a stalk disease. Inoculation experiments revealed that the fungus needs a wound to enter the plant tissue. Symptoms of the disease in the field and from inoculation experiments in the greenhouse are described and the taxonomic position of the fungus is discussed. The pathogen could not be isolated from other plant species in heavily infected Pl. lanceolata populations and can be regarded as specialized on Pl. lanceolata. Other species of the genus Plantago differed considerably in their susceptibility to the disease. Comparison of Pl. lanceolata genotypes indicated that there is variation in susceptibility among host genotypes. Because the disease may reduce the production of viable seeds, the possibility of natural selection for resistance in the host is considered.

scholarly journals The distribution of woody species in relation to climate and fire in Yosemite National Park, California, USA

Fire Ecology ◽  
2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Jan W. van Wagtendonk ◽  
Peggy E. Moore ◽  
Julie L. Yee ◽  
James A. Lutz
Keyword(s):  
Plant Species ◽  
Sierra Nevada ◽  
Species Distribution ◽  
National Park ◽  
Woody Plant ◽  
Fire Regime ◽  
Yosemite National Park ◽  
Distribution Models ◽  
Ecological Zones ◽  
Woody Plant Species

Abstract Background The effects of climate on plant species ranges are well appreciated, but the effects of other processes, such as fire, on plant species distribution are less well understood. We used a dataset of 561 plots 0.1 ha in size located throughout Yosemite National Park, in the Sierra Nevada of California, USA, to determine the joint effects of fire and climate on woody plant species. We analyzed the effect of climate (annual actual evapotranspiration [AET], climatic water deficit [Deficit]) and fire characteristics (occurrence [BURN] for all plots, fire return interval departure [FRID] for unburned plots, and severity of the most severe fire [dNBR]) on the distribution of woody plant species. Results Of 43 species that were present on at least two plots, 38 species occurred on five or more plots. Of those 38 species, models for the distribution of 13 species (34%) were significantly improved by including the variable for fire occurrence (BURN). Models for the distribution of 10 species (26%) were significantly improved by including FRID, and two species (5%) were improved by including dNBR. Species for which distribution models were improved by inclusion of fire variables included some of the most areally extensive woody plants. Species and ecological zones were aligned along an AET-Deficit gradient from cool and moist to hot and dry conditions. Conclusions In fire-frequent ecosystems, such as those in most of western North America, species distribution models were improved by including variables related to fire. Models for changing species distributions would also be improved by considering potential changes to the fire regime.

scholarly journals Polygenic and single gene responses to selection for resistance to diazinon in Lucilia cuprina.

Genetics ◽  
1992 ◽  
Vol 130 (3) ◽  
pp. 613-620 ◽  
Author(s):  
J A McKenzie ◽  
A G Parker ◽  
J L Yen
Keyword(s):  
Resistant Strain ◽  
Single Gene ◽  
Natural Populations ◽  
Susceptible Strain ◽  
Selection Line ◽  
Base Population ◽  
Gene Response ◽  
Biochemical Profiles ◽  
Resistant Strains ◽  
Selection For

Abstract Following mutagenesis with ethyl methanesulfonate, selection in a susceptible strain with a concentration of the insecticide diazinon (0.0004%, w/v) above that required to kill 100% of the susceptible strain, the LC100 of that strain, resulted in a single gene response. The resultant four mutant resistant strains have equivalent physiological, genetical and biochemical profiles to a diazinon-resistant strain derived from a natural population and homozygous for the Rop-1 allele. Modification of the microsomal esterase E3 is responsible for resistance in each case. The Rop-1 locus maps approximately 4.4 map units proximal to bu on chromosome IV. Selection within the susceptible distribution, at a concentration of diazinon [0.0001% (w/v)] less than the LC100, resulted in a similar phenotypic response irrespective of whether the base population had been mutagenized. The responses were polygenically based, unique to each selection line and independent of Rop-1. The relevance of the results to selection for insecticide resistance in laboratory and natural populations is discussed.

scholarly journals Ethylene enhances root water transport and aquaporin expression in trembling aspen (Populus tremuloides) exposed to root hypoxia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiangfeng Tan ◽  
Mengmeng Liu ◽  
Ning Du ◽  
Janusz J. Zwiazek
Keyword(s):  
Gas Exchange ◽  
Water Transport ◽  
Populus Tremuloides ◽  
Leaf Gas Exchange ◽  
Hydraulic Conductance ◽  
Root Hydraulic Conductance ◽  
Trembling Aspen ◽  
Expression Levels ◽  
Root Hypoxia ◽  
Exogenous Ethylene

Abstract Background Root hypoxia has detrimental effects on physiological processes and growth in most plants. The effects of hypoxia can be partly alleviated by ethylene. However, the tolerance mechanisms contributing to the ethylene-mediated hypoxia tolerance in plants remain poorly understood. Results In this study, we examined the effects of root hypoxia and exogenous ethylene treatments on leaf gas exchange, root hydraulic conductance, and the expression levels of several aquaporins of the plasma membrane intrinsic protein group (PIP) in trembling aspen (Populus tremuloides) seedlings. Ethylene enhanced net photosynthetic rates, transpiration rates, and root hydraulic conductance in hypoxic plants. Of the two subgroups of PIPs (PIP1 and PIP2), the protein abundance of PIP2s and the transcript abundance of PIP2;4 and PIP2;5 were higher in ethylene-treated trembling aspen roots compared with non-treated roots under hypoxia. The increases in the expression levels of these aquaporins could potentially facilitate root water transport. The enhanced root water transport by ethylene was likely responsible for the increase in leaf gas exchange of the hypoxic plants. Conclusions Exogenous ethylene enhanced root water transport and the expression levels of PIP2;4 and PIP2;5 in hypoxic roots of trembling aspen. The results suggest that ethylene facilitates the aquaporin-mediated water transport in plants exposed to root hypoxia.

The bacteria in sapwood, wetwood, and heartwood of trembling aspen (Populus tremuloides)

1973 ◽  
Vol 51 (2) ◽  
pp. 498-500 ◽  
Author(s):  
Donald M. Knutson
Keyword(s):  
Populus Tremuloides ◽  
Trembling Aspen ◽  
Indigenous Bacteria ◽  
Large Populations ◽  
Xylem Tissue

Bacteria (Erwinia, Bacillus) were consistently isolated from all samples of aspen sapwood and heartwood. In wetwood zones (water-soaked xylem tissue) or discolored heartwood, large populations often occur. No organisms unique to wetwood were isolated. Wetwood probably is formed by nonmicrobial means and, once formed, merely supports large populations of indigenous bacteria.

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