scholarly journals The length, number, and endodermis area of needles discriminate two genetically distinct populations of Cedrus atlantica Manetti in the Moroccan Middle Atlas

2018 ◽  
Vol 87 (3) ◽  
Author(s):  
Nezha El Bakkali ◽  
Mohammed Bendriss Amraoui
Keyword(s):  
Genetic Diversity ◽  
Discriminant Analysis ◽  
Environmental Conditions ◽  
Central Cylinder ◽  
Vascular Bundles ◽  
Cedrus Atlantica ◽  
Middle Atlas ◽  
Anatomical Characters ◽  
Genetic Distinctiveness ◽  
Two Populations

The variation in some adaptive characters of cedar needles was studied in two different regions of the Moroccan Middle Atlas that have different local environmental conditions and levels of genetic diversity. The two populations are localized in the Azrou and Ifrane regions. Tukey’s tests showed that the needle/brachyblast number (Nn/R), length (Nl), and needle width (Nw) showed the greatest variation. In addition, all anatomical characters studied showed a significant correlation with Nw, whereas only the area of the vascular bundles (AVb) was related to Nl. Discriminant analysis revealed that Nn/R, Nl, and the area of the central cylinder (ACc) are high-discriminating characters among populations of Azrou and Ifrane and confirms their isolation. These adaptations of the morphological and anatomical traits of the Atlas cedar needles of the Azrou and Ifrane regions are discussed in relation to the local environmental conditions and have been found to be in harmony with their genetic distinctiveness revealed previously.

scholarly journals Discrimination of Picea chihuahuana Martinez populations on the basis of numerous dendrometric, climatic and edaphic traits and genetic diversity

2017 ◽  
Author(s):  
Iliana Karina Dominguez-Guerrero ◽  
Samantha Mariscal-Lucero ◽  
José Ciro Hernández-Díaz ◽  
Berthold Heinze ◽  
José Ángel Prieto-Ruiz ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Discriminant Analysis ◽  
Population Size ◽  
Environmental Conditions ◽  
Diversity Indices ◽  
Ex Situ ◽  
Assisted Migration ◽  
Tree Community ◽  
Southern Central ◽  
The Mean

Background. Picea chihuahuana, which is endemic to Mexico, is currently listed as “Endangered” on the Red List. Chihuahua spruce is only found in the Sierra Madre Occidental (SMO), Mexico. About 42,600 individuals are distributed in forty populations. The populations are fragmented and can be classified into three distinct clusters in the SMO of the two States (south, center and north), each group separated by a distance of about 300 km. The total area covered P. chihuahuana trees is less than 300 ha. A recent study suggested assisted migration as an alternative to the ex situ conservation of P. chihuahuana, taking into consideration the genetic structure and diversity of the populations and also predictions regarding the future climate of the habitat. However, detailed background information is required to enable development of plans for protecting and conserving species and for successful assisted migration. Thus, it is important to identify differences between populations in relation to environmental conditions. The vitality and genetic diversity of populations, which affect vigour, evolution and adaptability of the species, must also be considered. In this study, we examined the P. chihuahuana tree community growing in fourteen different locations, with the overall aim of discriminating the populations and clusters of this species using 22 climatic, 27 edaphic and 15 dasometric variables and three genetic diversity indices. Methods. Each location was represented by one 50 x 50 m plot established in the center of the location in which was measured the climate, soil, dasometric and genetic variables. The putative neutral and adaptive AFLP were used to calculate genetic diversity. Multivariate discriminant analysis including cross-validation was considered to test for significant differences in variables in the southern, central and northern populations and locations of the P. chihuahuana tree community. Spearman's correlation test was used to analyze the relationships between genetic diversity, population size, and the climatic, soil and dasometric variables. Results. The discriminant analysis revealed 22 highly significant variables, which separated the southern, central and northern populations. The mean genetic diversity of P. chihuahuana was significantly correlated with the mean temperature in the warmest month. Genetic diversity of P. chihuahuana calculated with putative adaptive AFLP was not statistically significantly correlated with any environmental factor. Finally, no significant correlations were observed between any of the three genetic diversity indices and population size. Discussion. At least three different ecotypes of P. chihuahuana probably exist, as local adaptation may take place because of the different environmental conditions. Therefore, future reforestation programs should take into account these different ecotypes and environmental conditions.

scholarly journals Discrimination of Picea chihuahuana Martinez populations on the basis of numerous dendrometric, climatic and edaphic traits and genetic diversity

2017 ◽  
Author(s):  
Iliana Karina Dominguez-Guerrero ◽  
Samantha Mariscal-Lucero ◽  
José Ciro Hernández-Díaz ◽  
Berthold Heinze ◽  
José Ángel Prieto-Ruiz ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Discriminant Analysis ◽  
Population Size ◽  
Environmental Conditions ◽  
Diversity Indices ◽  
Ex Situ ◽  
Assisted Migration ◽  
Tree Community ◽  
Southern Central ◽  
The Mean

Background. Picea chihuahuana, which is endemic to Mexico, is currently listed as “Endangered” on the Red List. Chihuahua spruce is only found in the Sierra Madre Occidental (SMO), Mexico. About 42,600 individuals are distributed in forty populations. The populations are fragmented and can be classified into three distinct clusters in the SMO of the two States (south, center and north), each group separated by a distance of about 300 km. The total area covered P. chihuahuana trees is less than 300 ha. A recent study suggested assisted migration as an alternative to the ex situ conservation of P. chihuahuana, taking into consideration the genetic structure and diversity of the populations and also predictions regarding the future climate of the habitat. However, detailed background information is required to enable development of plans for protecting and conserving species and for successful assisted migration. Thus, it is important to identify differences between populations in relation to environmental conditions. The vitality and genetic diversity of populations, which affect vigour, evolution and adaptability of the species, must also be considered. In this study, we examined the P. chihuahuana tree community growing in fourteen different locations, with the overall aim of discriminating the populations and clusters of this species using 22 climatic, 27 edaphic and 15 dasometric variables and three genetic diversity indices. Methods. Each location was represented by one 50 x 50 m plot established in the center of the location in which was measured the climate, soil, dasometric and genetic variables. The putative neutral and adaptive AFLP were used to calculate genetic diversity. Multivariate discriminant analysis including cross-validation was considered to test for significant differences in variables in the southern, central and northern populations and locations of the P. chihuahuana tree community. Spearman's correlation test was used to analyze the relationships between genetic diversity, population size, and the climatic, soil and dasometric variables. Results. The discriminant analysis revealed 22 highly significant variables, which separated the southern, central and northern populations. The mean genetic diversity of P. chihuahuana was significantly correlated with the mean temperature in the warmest month. Genetic diversity of P. chihuahuana calculated with putative adaptive AFLP was not statistically significantly correlated with any environmental factor. Finally, no significant correlations were observed between any of the three genetic diversity indices and population size. Discussion. At least three different ecotypes of P. chihuahuana probably exist, as local adaptation may take place because of the different environmental conditions. Therefore, future reforestation programs should take into account these different ecotypes and environmental conditions.

Allozyme Variation and Population Substructuring in the Caucasian Ground Lizards Lacerta derjugini and Lacerta praticola

2011 ◽  
Vol 4 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Ross D. MacCulloch ◽  
Ilya S. Darevsky ◽  
Robert W. Murphy ◽  
Jinzhong Fu
Keyword(s):  
Genetic Diversity ◽  
Allozyme Variation ◽  
Close Proximity ◽  
Geographic Separation ◽  
Population Substructuring ◽  
Allozyme Loci ◽  
Two Populations

Genetic diversity at 35 allozyme loci was surveyed in Lacerta derjugini (3 populations) and L. praticola (2 populations). Indices of variability were consistent with those found in other Caucasian Lacerta. There was little genetic substructuring between two populations of L. praticola despite considerable geographic separation. Conversely, populations of L. derjugini in close proximity to one another exhibited considerable substructuring.

scholarly journals Morphological Variations of Wild Populations of Brycon dentex (Characidae, Teleostei) in the Guayas Hydrographic Basin (Ecuador). The Impact of Fishing Policies and Environmental Conditions

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1901
Author(s):  
Ana Gonzalez-Martinez ◽  
Carmen De-Pablos-Heredero ◽  
Martin González ◽  
Jorge Rodriguez ◽  
Cecilio Barba ◽  
...  
Keyword(s):  
Discriminant Analysis ◽  
Environmental Conditions ◽  
Anthropogenic Activity ◽  
Freshwater Species ◽  
Fishing Pressure ◽  
Wild Populations ◽  
Morphometric Variation ◽  
Morphological Variations ◽  
Body Development ◽  
The Impact

The Guayas, located in Ecuador, is the largest basin in the Pacific Ocean and has an inventory of 123 native freshwater species. Most of these are endemic species that are threatened or at-risk due to anthropogenic activity and the modification, fragmentation, and destruction of habitats. The aim of this study was to determine the morphometric variation in three wild populations of Brycon dentex in the Guayas basin rivers and their connections to fishing management and environmental conditions. A total of 200 mature fish were captured, and 26 morphometric parameters were measured. The fishing policies (Hypothesis 1) and environmental conditions (Hypothesis 2) were considered fixed factors and were validated by t-tests. The morphological variation among the three populations (Hypothesis 3) was validated through a discriminant analysis. Fishing policies and resource management were found to generate morphological differences associated with body development. In addition, the environmental conditions were found to influence the size and structure of Brycon dentex populations. The analyzed populations were discriminated by the generated morphometric models, which differentiated Cluster 1 (Quevedo and Mocache rivers) with high fishing pressure from Cluster 2 (Pintado river) with medium–low fishing pressure. Morphometric differentiation by discriminant analysis is a direct and economic methodology that can be applied as an indicator of diversity maintenance.

Host range and physiologic specialization in Rhynchosporium secalis

1974 ◽  
Vol 25 (1) ◽  
pp. 21 ◽  
Author(s):  
SM Ali ◽  
WJR Boyd
Keyword(s):  
Genetic Diversity ◽  
Host Range ◽  
Environmental Conditions ◽  
Host Specialization ◽  
Rhynchosporium Secalis ◽  
Host Reaction ◽  
Genetic Studies ◽  
Barley Cultivars ◽  
Adequate Sampling ◽  
Pathogenic Variability

The pathogenic variability of isolates of R. secalis collected in Western Australia has been examined on different host genera of the Gramineae and on selected barley cultivars. Depending on the host-isolate combination and the conditions of the test, evidence has been obtained of inter- and intra-isolate variability in both host reaction and isolate pathogenicity. This complicates definitive interpretation of the results, militates against identification of conventional 'races' of the pathogen and shows that R. secalis does not exhibit strict host specialization. Hosts which consistently express resistance or susceptibility under different environmental conditions, and isolates which express their pathogenic characteristics consistently, have been identified. The need for more precise genetic studies and adequate sampling of genetic diversity is emphasized.

Genetic Diversity among Calamus brandisii Becc. (Arecaceae) Populations in Kerala Part of Western Ghats

2021 ◽  
Vol 43 (1) ◽  
pp. 38-42
Author(s):  
Kavungal Priya ◽  
◽  
Indira . ◽  
Vadakkethil Balakrishnan Sreekumar ◽  
Renuka . ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Western Ghats ◽  
Rapd Markers ◽  
Gene Diversity ◽  
Issr Markers ◽  
High Genetic Diversity ◽  
Western Ghats Of India ◽  
The Mean ◽  
Two Parameters ◽  
Two Populations

Calamus brandisii Becc. is one of the endemic slender rattans found in the Western Ghats of India. The genetic diversity of two main populations available in Kerala was investigated using 20 RAPD and 9 ISSR markers. Two parameters viz., gene diversity and genetic diversity within and among populations were analyzed. ISSR analysis showed quite high genetic diversity in Pandimotta compared to Bonacaud population whereas in RAPD markers both these populations were moderately diverse. The percentage of total genetic differentiation (Gst) among two populations is relatively higher than the mean Gst value indicating high genetic diversity within the populations. The genetic distance between these two populations was 0.1739 with ISSR markers and 0.1971 with RAPD markers. Because of its high genetic diversity, Pandimotta population can be treated as an important population of gene diversity with potentially useful genes. This may be included in the high priority reservoir for genetic conservation also.

scholarly journals Low genetic diversity in the endangered Taxus yunnanensis following a population bottleneck, a low effective population size and increased inbreeding

2016 ◽  
Vol 65 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Y. C. Miao ◽  
Z. J. Zhang ◽  
J. R. Su
Keyword(s):  
Genetic Diversity ◽  
Habitat Fragmentation ◽  
Population Size ◽  
Effective Population Size ◽  
Spatial Genetic Structure ◽  
Population Bottleneck ◽  
Effective Population ◽  
Taxus Yunnanensis ◽  
Low Genetic Diversity ◽  
Two Populations

Abstract Taxus yunnanensis, which is an endangered tree that is considered valuable because it contains the effective natural anticancer metabolite taxol and heteropolysaccharides, has long suffered from severe habitat fragmentation. In this study, the levels of genetic diversity in two populations of 136 individuals were analyzed based on eleven polymorphic microsatellite loci. Our results suggested that these two populations were characterized by low genetic diversity (NE = 2.303/2.557; HO = 0.168/0.142; HE = 0.453/0.517), a population bottleneck, a low effective population size (Ne = 7/9), a high level of inbreeding (FIS = 0.596/0.702), and a weak, but significant spatial genetic structure (Sp = 0.001, b = −0.001*). Habitat fragmentation, seed shadow overlap and limited seed and pollen dispersal and potential selfing may have contributed to the observed gene tic structure. The results of the present study will enable development of practical conservation measures to effectively conserve the valuable genetic resources of this endangered plant.

scholarly journals Allelic diversity in populations of Solanum lycocarpum A. St.-Hil (Solanaceae) in a protected area and a disturbed environment

2011 ◽  
Vol 25 (4) ◽  
pp. 937-940 ◽  
Author(s):  
Tânia Maria de Moura ◽  
Alexandre Magno Sebbenn ◽  
Karina Martins ◽  
Maria Andreia Moreno ◽  
Giancarlo Conde Xavier Oliveira ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Protected Areas ◽  
Allelic Diversity ◽  
Rare Allele ◽  
Conservation Unit ◽  
Long Distance ◽  
Disturbed Area ◽  
Disturbed Areas ◽  
Pasture Area ◽  
Two Populations

This study aimed to compare the genetic diversity of populations of Solanum lycocarpum A.St.-Hil between natural and human disturbed environments, with the assumption that protected areas have greater genetic diversity than disturbed areas. For this study, two populations were sampled in Goiás State, Brazil. One was located in a conservation unit, Serra de Caldas Novas State Park, in the Caldas Novas municipality. The other was located in a pasture area in the municipality of Morrinhos. The two populations are 41 km apart. We sampled 60 individuals from each population, which were genotyped with five microsatellite loci (SSR). The highest number of alleles was recorded in the population of the conservation unit, where we found 11 exclusive and five rare alleles. In the disturbed area, we recorded only three exclusive alleles and one rare allele. Although we did not observe significant inbreeding in these populations, genetic divergence between them was high (G ST (Hedrick)=0.147 =0.147) for a species with long distance seed dispersal. The results corroborate the hypothesis that the population in the less disturbed area harbors greater allelic diversity. They also confirm the effectiveness of using protected areas to preserve the genetic diversity of the species.

scholarly journals The role of environment, local adaptation and past climate fluctuation on the amount and distribution of genetic diversity in the teosinte in Mexico

2019 ◽  
Author(s):  
Jaime Gasca-Pineda ◽  
Yocelyn T. Gutiérrez-Guerrero ◽  
Erika Aguirre-Planter ◽  
Luis E. Eguiarte
Keyword(s):  
Genetic Diversity ◽  
Local Adaptation ◽  
Environmental Conditions ◽  
Wide Distribution ◽  
Wide Range ◽  
Significant Genetic Structure ◽  
Nuclear Microsatellite ◽  
Genetic Clusters ◽  
Assignment Analysis ◽  
Climate Fluctuation

AbstractWild maize, commonly known as teosinte, has a wide distribution in central Mexico and inhabits a wide range of environmental conditions. According to previous studies, the environment is a determinant factor for the amount and distribution of genetic diversity. In this study, we used a set of neutral markers to explore the influence of contemporary factors and historical environmental shifts on genetic diversity, including present and three historical periods. Using a set of 22 nuclear microsatellite loci, we genotyped 527 individuals from 29 localities. We found highly variable levels of genetic diversity (Z. m. parviglumis HE= 0.3646–0.7699; Z. m. mexicana HE= 0.5885–0.7671) and significant genetic structure among localities (average DEST= 0.4332). Also, we recovered significant values of heterozygote deficiency (average FIS= 0.1796) and variable levels of selfing (sg2=0.0–0.3090). The Bayesian assignment analysis yielded four genetic clusters dividing the sample into subspecies, that in turn, were separated into two clusters. Environmental conditions played a strong influence in the distribution of genetic diversity, as demographic analysis and changes in species range revealed by modeling analyses were consistent. We conclude that current genetic diversity in teosinte is the result of a mixture of local adaptation and genetic isolation along with historical environmental fluctuations.

scholarly journals Use of morphological and anatomical characters to delimit varieties of Paliurus spina-christi Mill. (Rhamnaceae)

2018 ◽  
Vol 6 (2) ◽  
pp. 1-14
Author(s):  
Saleem E. Shahbaz ◽  
Nazar M. Shareef
Keyword(s):  
Stomatal Density ◽  
Vascular Bundles ◽  
Epidermal Layer ◽  
Adaxial Side ◽  
Anatomical Features ◽  
Northern Iraq ◽  
Anatomical Characters ◽  
Palisade Cells ◽  
Different Parts ◽  
Fruit Diameter

Introduction: Paliurus spina-christi Mill is a species with two varieties namely Paliurus spina-christi L. var. spina-christi and Paliurus spina-christivar. macrocarpa Beck native to mountains of Kurdistan, rarely growing in the upper plains of northern Iraq. Materials and Methods: A total of 15 plants from different parts of Kurdistan region were sampled. 30measurements for each characters of Leaf, Inflorescence, Flowers, Fruit, seeds, and leaf anatomical characters were measured for comparison between the two varieties. Results and Discussion: Fruit diameter of var. macrocarpa is significantly larger than fruit diameter of var. spina-christi. Most mean flower parts especially the ovary, in addition to seed size is larger in var. macrocarpa. Upper epidermal layer is always thicker than the lower epidermal layer for the same blade. The isobilateral mesophyll includes 2 layers of long palisade cells adaxially and 2-3 layers of short cells abaxially. Many vascular bundles are seen equally spaced in the mesophyll tissue.With the exception of the presence of simple hairs on the petiole adaxial side of the var. spina-cristi and the absence of these hairs from the same site of var. macrocarpa, all other anatomical features are considered to be of no taxonomic application. Stomatal density of the adaxial leaf side is up to 19 stomata per mm² in var. spina-christi while it is up to 38 stomata per mm² in var. macrocarpa. Conclusions: Both fruit diameter and the stomatal density of the adaxial leaf side constitute diagnostic characters for separating between the two varieties of Paliurus spina-christi Mill

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