Genetic diversity of the rare Asian plant, Trigonobalanus doichangensis (Fagaceae)

2007 ◽  
Vol 55 (1) ◽  
pp. 10 ◽  
Author(s):  
Weibang Sun ◽  
Chunyan Han ◽  
Lianming Gao ◽  
Carol A. Wilson
Keyword(s):  
Genetic Diversity ◽  
Species Diversity ◽  
Genetic Distances ◽  
Western China ◽  
Chinese Populations ◽  
Population Conservation ◽  
The Family ◽  
Geographical Distances ◽  
Rare And Endangered ◽  
Range Of Values

Trigonobalanus doichangensis is a national rare and endangered fagaceous plant of China. It is currently restricted to five sites, four in Yunnan province in south-western China and one in northern Thailand. We investigated the genetic diversity of T. doichangensis to provide information for the effective preservation of the genetic diversity of the species. Randomly amplified polymorphic DNA (RAPD) markers were used to assess the genetic variation and structure in each of the five extant populations. Sixteen primers produced 157 fragments, of which 83 (53%) were polymorphic. The estimated species diversity of T. doichangensis, although lower than for most fagaceous species, was within the range of values that have been reported for the family. The presence of private and/or uncommon fragments in each population, the presence of unique phenotypes in all individuals sampled, and estimates of relatively high populational fixation and low gene flow indicated that the species diversity present was mostly distributed among the five isolated extant populations. Pairwise genetic distances between populations were not correlated with geographical distances as depicted by the resolution of one of the Chinese populations as most similar to the Thailand population. Conservation of this species should include preservation of each of the five distinct extant populations.

scholarly journals Genetic Diversity of Freshwater Leeches in Lake Gusinoe (Eastern Siberia, Russia)

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Irina A. Kaygorodova ◽  
Nadezhda Mandzyak ◽  
Ekaterina Petryaeva ◽  
Nikolay M. Pronin
Keyword(s):  
Genetic Diversity ◽  
Species Diversity ◽  
Molecular Marker ◽  
Species Composition ◽  
Morphological Identification ◽  
Adjacent Area ◽  
Eastern Siberia ◽  
Species List ◽  
The Family ◽  
Unidentified Species

The study of leeches from Lake Gusinoe and its adjacent area offered us the possibility to determine species diversity. As a result, an updated species list of the Gusinoe Hirudinea fauna (Annelida, Clitellata) has been compiled. There are two orders and three families of leeches in the Gusinoe area: order Rhynchobdellida (families Glossiphoniidae and Piscicolidae) and order Arhynchobdellida (family Erpobdellidae). In total, 6 leech species belonging to 6 genera have been identified. Of these, 3 taxa belonging to the family Glossiphoniidae (Alboglossiphonia heteroclita f. papillosa, Hemiclepsis marginata, andHelobdella stagnalis) and representatives of 3 unidentified species (Glossiphoniasp.,Piscicolasp., andErpobdellasp.) have been recorded. The checklist gives a contemporary overview of the species composition of leeches and information on their hosts or substrates. The validity of morphological identification of each taxon has been verified by phylogenetic approach with a molecular marker adopted for a DNA barcoding of most invertebrates.

Parasite (Schistosoma mansoni) and host (Biomphalaria glabrata) genetic diversity: population structure in a fragmented landscape

Parasitology ◽  
2001 ◽  
Vol 122 (5) ◽  
pp. 545-554 ◽  
Author(s):  
C. SIRE ◽  
J. LANGAND ◽  
V. BARRAL ◽  
A. THÉRON
Keyword(s):  
Genetic Diversity ◽  
Schistosoma Mansoni ◽  
Gene Diversity ◽  
Random Amplified Polymorphic Dna ◽  
Rattus Rattus ◽  
Biomphalaria Glabrata ◽  
Genetic Distances ◽  
Snail Host ◽  
Fragmented Landscape ◽  
Geographical Distances

Random amplified polymorphic DNA (RAPD) markers were used to quantify genetic diversity within and between 5 populations ofSchistosoma mansoniwithin its definitive host (Rattus rattus) and the 5 corresponding populations of the snail intermediate host (Biomphalaria glabrata) from a limited endemic area of murine schistosomiasis on the island of Guadeloupe. Analysis of molecular variance (AMOVA) and canonical correspondence analysis (CCA) were used to test the significance of genetic differentiation between populations. Both methods gave similar results. Of total gene diversity, 15.1% (AMOVA) and 18.8% (CCA) was partitioned between localities forS. mansoniwith an absence of association between genetic and geographical distances. Geographical localities accounted for 20.5% (CCA) of the total diversity forB. glabratapopulations. The genetic distances between pairs of parasite populations were not correlated with the genetic distances between the corresponding pairs of snail host populations. Such strong patterns of local differentiation of both parasite and snail populations are consistent with predictions based on metapopulation dynamics and may have implications on host–parasite susceptibility relationship through local adaptation processes.

scholarly journals Relationship Between Genetic Variation and Diversity of Tree Species in Tropical Forests in the El Ocote Biosphere Reserve, Chiapas, Mexico

2021 ◽  
Vol 14 ◽  
pp. 194008292097814
Author(s):  
Bárbara Cruz-Salazar ◽  
Lorena Ruiz-Montoya ◽  
Neptalí Ramírez-Marcial ◽  
Maricela García-Bautista
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Species Diversity ◽  
Tree Species ◽  
Haplotype Diversity ◽  
Biosphere Reserve ◽  
Genetic Distances ◽  
Community Diversity ◽  
Environmental Selection ◽  
Tree Communities

Knowledge of the genetic diversity of species in a biological community is useful for assessing the ecological and evolutionary processes that define the structure and dynamics of that community. We investigated the potential relationship between the trans-specific genetic diversity (or genetic diversity across tree species) and the diversity of tree species in a tropical subdeciduous forest. The nucleotide variation of the concatenated regions ITS 1 and ITS 3 (ITS1-3) was used to determine the trans-specific genetic diversity of 19 species of trees in five local communities at El Ocote Biosphere Reserve (REBISO), Chiapas, Mexico. Tree diversity was obtained by counting individual trees within 0.1 ha circular plots in each locality. The relationship between trans-specific genetic diversity and species diversity was established through simple linear regressions between genetic diversity parameters and community diversity. A correlation matrix was built with genetic distances (Kimura’s two-parameter model) and differences in species diversity between communities. A significant relationship was observed between nucleotide diversity (π) and species richness ( Sp), and a negative association between haplotype diversity and gamma diversity (γ). Our results show species-rich and genetically diverse tree communities and a weak association between trans-specific genetic variation and species diversity in tree communities at REBISO. This research suggests a possible ecological and genetic relationship within each community. Genetic diversity values may provide an important degree of variation upon which environmental selection pressures could operate, which may be helpful to face the current environmental modifications associated with climatic change.

scholarly journals Forest inventory and the genetic diversity of the remaining fragment of Hymenaea courbaril L.

2018 ◽  
Vol 42 (5) ◽  
pp. 491-500
Author(s):  
Marília Freitas de Vasconcelos Melo ◽  
Sheila Valéria Alvares-Carvalho ◽  
Erica Moraes Santos de Souza ◽  
Itamara Bomfim Gois ◽  
Robério Anastácio Ferreira ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Rapd Markers ◽  
Genetic Distances ◽  
Shannon Index ◽  
High Genetic Diversity ◽  
Coancestry Coefficient ◽  
Hymenaea Courbaril ◽  
Transition Zones ◽  
Geographical Distances ◽  
Number Of Individuals

ABSTRACT Hymenaea courbaril is a rare species in the riparian areas of the state of Sergipe, Brazil. This species is known as Brazilian cherry or Brazilian copal and it occurs in fragments of the Rainy Forest and in the transition zones between the Rainy Forest and the Caatinga Biomes. This work was carried out, in order to quantify the genetic diversity of the remaining population of Brazilian cherry, by RAPD markers. In a studied area of 100 ha in the low course of the São Francisco River, only 15 individuals were observed. The analyzed parameters were as follows: Jaccard’s genetic similarity, the number of observed alleles, the number of effective alleles, the genetic diversities of Nei, the percentages of the polymorphic loci, the genetic diversities when using the Shannon index and the coancestry coefficient. There was no correlation between the genetic distances and the geographical distances. Despite the low number of individuals, high genetic diversity was observed, a fact that contributes to the development of strategies for the conservation of the species.

Population genetic structure of Tunisian Hypericum humifusum assessed by RAPD markers

Biologia ◽  
2011 ◽  
Vol 66 (6) ◽  
Author(s):  
Afef Béjaoui ◽  
Abdennacer Boulila ◽  
Chokri Messaoud ◽  
Mohamed Boussaid
Keyword(s):  
Genetic Diversity ◽  
Arid Zone ◽  
Spatial Scales ◽  
Random Amplified Polymorphic Dna ◽  
Population Based ◽  
Genetic Distances ◽  
Ex Situ ◽  
Lower Semi ◽  
Geographical Distances ◽  
Semi Arid

AbstractThe genetic variation within and among seven Tunisian natural Hypericum humifusum L. populations belonging to three bioclimatic zones (sub-humid, upper semi-arid, and lower semi-arid) was assessed using random amplified polymorphic DNA markers. Eight selected primers produced a total of 166 bands, of which 153 were polymorphic. The genetic diversity within a population, based on Shannon’s index and percentage of polymorphic loci, was relatively high. The level of variation among populations did not differ significantly. However, the variation among populations grouped according to their bioclimates was significant.A high differentiation and a low gene flow were observed at all spatial scales among all populations. The upper semiarid populations exhibited the highest differentiation. The relationship between genetic and geographic distances was not significant indicating that structuring occurred due to founding events. The UPGMA analysis based on Nei & Li’s coefficients showed that individuals from each population clustered together. The cluster analysis based on genetic distances among populations did not show clear groupings relevant to geographical distances or bioclimates.The high differentiation among populations even through a small geographic range implies the collection of seeds from all populations to preserve, ex-situ, extant variation in the species. Populations from the upper semi-arid zone showing the highest genetic diversity should be first prospected.

scholarly journals Genetic Diversity and Differentiation of Relict Plant Liriodendron Populations Based on 29 Novel EST-SSR Markers

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 334 ◽  
Author(s):  
Xiaofei Long ◽  
Yuhao Weng ◽  
Siqin Liu ◽  
Zhaodong Hao ◽  
Yu Sheng ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Differentiation ◽  
Ssr Markers ◽  
Eastern China ◽  
Genetic Distances ◽  
Breeding Strategy ◽  
Western China ◽  
The Usa ◽  
Ssr Loci ◽  
Liriodendron Chinense

Surviving relict populations of species that were more widespread in ancient times can teach us a lot, such as evolution and genetic differentiation. One such relict plant is Liriodendron, of which populations remain in China (L. chinense (Hemsl.) Sarg.) and the USA (L. tulipifera L.). Studying the genetic structure of these populations would give insight into the genetic differentiation and the breeding strategy. In this work, we developed and characterized 29 novel simple sequence repeat (SSR) markers based on expressed sequence tags (ESTs) from hybrid Liriodendron (Liriodendron chinense × tulipifera) callus. In total, 29 SSRs with perfect primer-designed were used to assess genetic diversity and differentiation. The set of polymorphic EST-SSR loci was identified in 48 Liriodendron individuals, represented by 35 individuals sampled from 14 provenances of L. chinense and 13 individuals sampled from 5 provenances of L. tulipifera. Our results indicated that L. chinense populations possess slightly higher genetic diversity than L. tulipifera populations. Based on genetic distances, 48 Liriodendron individuals clustered into three groups (the eastern China L. chinense, the western China L. chinense and L. tulipifera), although the STRUCTURE analysis of the Liriodendron populations revealed just two clear genetic clusters (L. chinense and L. tulipifera). Among these 29 novel markers, ESSR119 showed an obvious species-specific characteristic which can be very useful in marker-assisted selection (MAS). In general, all these EST-SSR markers may have agronomic potential and constitute a basis for future studies on the identification, innovation, and even preservation of Liriodendron germplasms.

scholarly journals Effects of Habitat Fragmentation on Genetic Diversity in Cycas Balansae (Cycadaceae)

2017 ◽  
Vol 23 (3) ◽  
pp. 193
Author(s):  
Nguyen Minh Tam ◽  
Nguyen T. Phuong Trang ◽  
Vu T. Ha Giang ◽  
L. Triest Triest
Keyword(s):  
Genetic Diversity ◽  
Habitat Fragmentation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Genetic Distances ◽  
Small Population ◽  
Species Survival ◽  
Geographical Distances ◽  
Population Sizes ◽  
Over Exploitation ◽  
High Level

Habitat fragmentation is a serious threat to species survival. In Vietnam, Cycas balansae has been considered as threatened species because of the reduction and fragmentation of its habitats and over-exploitation. We assessed genetic variability and the pattern of population structure among six populations sampled in four provinces: Hoa Binh, Ha Nam, Ninh Binh and Quang Ninh. Polyacrylamide gel electrophoresis was performed on leaf tissues from 152 individuals representing 6 populations of C. balansae. Six of twelve enzyme systems were used to estimate genetic diversity at population and species levels. Eleven loci were examined. The allozyme data showed high levels of genetic diversity within all populations, ranging from 0.538 in Ba Sao to 0.628 in Tan Dan (average 0.576). The maintenance of high levels of expected heterozygosity (average 0.571) and low in observed heterozygosity (average 0.347) might be related to great heterozygote deficiency and increased frequencies of rare alleles. Genetic differentiation among populations was low (Dst = 0.036 and Gst = 0.064), indicating high level of gene flow (Nm = 3.22). Isolation by geographical distance was observed, however, no significant relationship between genetic distances and geographical distances was recorded. Our studies suggest small population sizes of cycads brought about by fragmentation of its habitats, over-exploitation, and increasing number of inbred individuals within populations. 

Genetic Diversity and Spread of Thiobencarb Resistant Early Watergrass (Echinochloa oryzoides) in California

Weed Science ◽  
2011 ◽  
Vol 59 (2) ◽  
pp. 195-201 ◽  
Author(s):  
Maria D. Osuna ◽  
Miki Okada ◽  
Riaz Ahmad ◽  
Albert J. Fischer ◽  
Marie Jasieniuk
Keyword(s):  
Genetic Diversity ◽  
Central Valley ◽  
Genetic Distances ◽  
Mantel Test ◽  
Rice Fields ◽  
Long Distance ◽  
Geographical Distances ◽  
Nuclear Microsatellite ◽  
Low Levels ◽  
Analytical Approaches

Resistance to the thiocarbamates has been selected in early watergrass populations within the rice-growing region of California. To elucidate the processes contributing to the spread of resistance among rice fields, we characterized the genetic diversity and differentiation of thiobencarb-resistant (R) and thiobencarb-susceptible (S) populations across the Central Valley using microsatellite markers. A total of 406 individuals from 22 populations were genotyped using seven nuclear microsatellite primer pairs. Three analytical approaches (unshared allele, Shannon–Weaver, and allelic-phenotype statistics) were used to assess genetic diversity and differentiation in the allohexaploid species. Low levels of genetic variation were detected within populations, consistent with other highly selfing species, with S populations tending to be more diverse than R populations.FSTvalues indicated that populations were genetically differentiated and that genetic differentiation was greater among S populations than R populations. Principal coordinate analysis generated two orthogonal axes that explained 88% of the genetic variance among early watergrass populations and differentiated populations by geographical region, which was associated with resistance phenotype. A Mantel test revealed that genetic distances between R populations were positively correlated with the geographical distances separating populations. Taken together, our results suggest that both short- and long-distance seed dispersal, and multiple local and independent evolutionary events, are involved in the spread of thiobencarb-resistant early watergrass across rice fields in the Sacramento Valley. In contrast, resistance was not detected in early watergrass populations in the San Joaquin Valley.

scholarly journals Assessment of AFLP-Based Genetic Variation in the Populations of Picea asperata

2005 ◽  
Vol 54 (1-6) ◽  
pp. 24-30 ◽  
Author(s):  
X. Xue ◽  
Y. Wang ◽  
H. Korpelainen ◽  
C. Li
Keyword(s):  
Genetic Diversity ◽  
Population Genetic ◽  
Unbiased Estimate ◽  
Natural Populations ◽  
Genetic Distances ◽  
Western China ◽  
Picea Asperata ◽  
Limited Gene Flow ◽  
The Mean ◽  
High Level

Summary Picea asperata Mast., which occurs in a restricted habitat in western China, has a wide ecological amplitude. In the present study, ten natural populations of P. asperata were studied using AFLP markers to investigate the population genetic structure and the level of genetic diversity. Of the 210 loci identified with two EcoRI/MseI primer combinations, 142 loci were found to be polymorphic. Yet, the level of genetic diversity observed within populations was quite low. The averages of NEI’s gene diversities (h) and Shannon's indices of diversity (I) calculated across populations equaled 0.156 and 0.227, respectively. The coefficient of gene differentiation among populations, based on the estimate GST and the unbiased estimate Φst, equaled 0.340 and 0.231, respectively. The mean genetic distance (D) between population pairs was 0.119 (range 0.050-0.156). Such high values indicate that there is significant differentiation among populations of P. asperata. Several factors could have contributed to the strong population differentiation, including relatively limited gene flow between populations (Nm = 0.968). Variation in environmental conditions and consequent selection pressures may be other factors attributing to the high level of genetic differentiation among populations. In addition, it was discovered that the geographic distances are not correlated with the genetic distances between the populations of P. asperata.

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