Genetic variation among Stipa grandis P. Smirn populations with different durations of fencing in the Inner Mongolian Steppe

2010 ◽  
Vol 32 (4) ◽  
pp. 427 ◽  
Author(s):  
Jian-bo Wu ◽  
Yu-bao Gao ◽  
Xiao-ying Bao ◽  
Hui Gao ◽  
Mei-qing Jia ◽  
...  

The genetic structure of a population should be carefully considered in ecological restoration because it may play a critical role in maintaining the persistence of a restored ecosystem. In the present study, we examined genetic diversity and genetic structure of Stipa grandis P. Smirn populations from fenced and grazed plots using amplified fragment length polymorphism markers. Molecular genetic variation showed that the genetic diversity of the fenced populations was greater compared with the overgrazed population. There was a significant variation among the populations (Fst = 0.3689, P < 0.001) by AMOVA analysis, and the gene flow was 0.4039 among the populations. The results from a comparison of limited morphological characteristics and from an unweighted pair group method with arithmetic mean cluster analysis and non-metric multi-dimensional scaling analysis suggested that genetic differentiation had occurred between the fenced populations and the grazed populations. The largest genetic diversity was in the moderately grazed population, which might be related to higher population density and greater sexual reproduction due to less disturbances in the plots. The genetic diversity of the long-term (24 years) fenced population was similar to that of a short-term fenced population (fenced for 11 years). These results suggested that the genetic diversity in the overgrazed population might be increased to some extent through fencing, but this effect did not occur beyond 11 years.

1996 ◽  
Vol 26 (8) ◽  
pp. 1454-1462 ◽  
Author(s):  
Naoki Tani ◽  
Nobuhiro Tomaru ◽  
Masayuki Araki ◽  
Kihachiro Ohba

Japanese stone pine (Pinuspumila Regel) is a dominant species characteristic of alpine zones of high mountains. Eighteen natural populations of P. pumila were studied in an effort to determine the extent and distribution of genetic diversity. The extent of genetic diversity within this species was high (HT = 0.271), and the genetic differentiation among populations was also high (GST = 0.170) compared with those of other conifers. In previous studies of P. pumila in Russia, the genetic variation within the species was also high, but the genetic differentiation among populations was low. We infer that this difference originates from differences in geographic distribution and ecological differences between the two countries. The genetic variation within each population tended, as a whole, to be smaller within marginal southern populations than within northern populations. Genetic relationships among populations reflect the geographic locations, as shown by unweighted pair-group method with arithmetic means and neighbor-joining phylogenetic trees.


1995 ◽  
Vol 30 (3) ◽  
pp. 349-358 ◽  
Author(s):  
James A. Richmond

Genetic variation among 14 populations of Dioryctria disclusa Heinrich adults was examined using starch gel electophoresis. The average number of alleles per locus exceeded 2.0 in all populations. The number of polymorphic loci exceeded 70% in 11 populations. Genetic structure data suggest moderate differentiation (average Fst, 0.111) among the populations. Most of the differentiation is attributable to three of the eight loci (MDH, ME, and IDH). Nei's genetic identity ranged from 0.77–1.00 between populations. A phenogram based on genetic identity and unweighted pair-group method of analysis (UPGMA) clustered five of six populations in North Carolina closely together. With a cophenetic correlation of 0.96 the phenogram constructed is acceptable.


2014 ◽  
Vol 35 (2) ◽  
pp. 263-269 ◽  
Author(s):  
Evanthia Thanou ◽  
Sinos Giokas ◽  
Panagiotis Kornilios

Two slow worm species are distributed at the southernmost part of the Balkan Peninsula: Anguis cephallonica, an endemic of the Peloponnese and the islands Zakynthos, Ithaki and Kephallonia, and A. graeca. Here, we investigate the intraspecific genetic diversity of A. cephallonica from the Peloponnese and Kephallonia and analyse A. graeca, from the northern Peloponnese, where it is found in sympatry with A. cephallonica. MtDNA and nDNA phylogenetic analyses confirm the genetic similarity of Peloponnesian and Kephallonian populations of A. cephallonica and reveal significant mtDNA genetic variation within it, probably related to the occurrence of multiple subrefugia in the Peloponnese. Peloponnesian A. graeca populations are genetically similar to non-Peloponnesian conspecifics implying recent dispersal to the Peloponnese. In contrast to the genetic markers, morphological characteristics (such as the number of mid-body scale-rows) failed to distinguish between Peloponnesian A. cephallonica and A. graeca. Although the former species is believed to be well-differentiated from its congeneric taxa, a thorough morphological study is needed.


Genome ◽  
2003 ◽  
Vol 46 (6) ◽  
pp. 1037-1048 ◽  
Author(s):  
Patrick Pollefeys ◽  
Jean Bousquet

French-American hybrid grapevines are most popular in eastern and mid-western North America: they are hardy cultivars derived from crosses between the European Vitis vinifera and American wild vines. The aim of this study was to characterize their genetic background using 6 microsatellite (SSR) markers and a set of 33 diagnostic RAPD markers. The latter were reproducible with different PCR thermal cyclers. Two SSR loci were found to be synonymous, VrZAG47 and VVMD27. The DNA profile frequencies estimated for each cultivar were much lower with multi-locus SSR data than that obtained from multi-fragment RAPD data. There was no significant correlation between the multi-locus DNA profile frequencies derived from SSRs and those from RAPDs. Estimates of genetic diversity derived from SSRs were generally higher and the average similarity between cultivars was generally lower than values reported for subgroups of V. vinifera, in accordance with expectations for hybrid cultivars. The phenetic relationships depicted by UPGMA (unweighted pair-group method with arithmetic averaging) and neighbor-joining analyses of microsatellite data were congruent and, to a large extent, in agreement with the known pedigree or history of each cultivar. A major dichotomy was observed between one group where the known genetic background was dominated by the North American Vitis riparia and Vitis labrusca, and another one where the genetic background was dominated by the European V. vinifera. Two Kulhmann varieties thought to be synonymous were found to be different, though closely related.Key words: French-American hybrids, genetic diversity, RAPD, SSR, Vitis.


Author(s):  
Jun Seok Oh ◽  
Kyu Jin Sa ◽  
Hyeon Park ◽  
Do Yoon Hyun ◽  
Sookyeong Lee ◽  
...  

Using morphological characteristics and SSR markers, we evaluated the morphological and genetic variation of 200 Perilla accessions collected from the five regions of South Korea and other region. In morphological characteristics analysis, particularly, leaf color, stem color, degree of pubescence, leaf size were found to be useful for distinguishing the characteristics of native Perilla accessions cultivated in South Korea. A total of 137 alleles were identified in the 20 simple sequence repeat (SSR) markers, and the number of alleles per locus ranged from 3 to 13, and the average number of alleles per locus was 6.85. The average gene diversity (GD) was 0.649, with a range of 0.290-0.828. From analysis of SSR markers, accessions from the Jeolla-do and Gyeongsang-do regions showed comparatively high genetic diversity values compared with those from other regions in South Korea. In the unweighted pair group method with arithmetic mean (UPGMA) analysis, the 200 Perilla accessions were found to cluster into three major groups and an outgroup with a genetic similarity of 42%, and did not showed a clear geographic structure from the five regions of South Korea. Therefore, it is believed that landrace Perilla seeds are frequently exchanged by farmers through various routes between the five regions of South Korea. The results of this study are expected to provide useful information for conservation of these genetic resources and selection of useful resources for the development of varieties for seeds and leafy vegetables of cultivated var. frutescens of Perilla crop in South Korea.


2008 ◽  
Vol 90 (6) ◽  
pp. 455-465 ◽  
Author(s):  
ADRIANA SUÁREZ G. ◽  
GENIS CASTILLO ◽  
MARIA I. CHACÓN S.

SummaryThe geographical scale of genetic structure in a continuous population is highly dependent on its breeding system and dispersion capabilities, and this knowledge is important for the study of population dynamics as well as for conservation purposes. In the present study, spatial autocorrelation statistics and intersimple sequence repeat (ISSR) markers were used to describe the genetic structure of a natural population of a prominent aromatic plant, Lippia origanoides, native to the Chicamocha Canyon in northeastern Colombia. For this purpose, individuals were sampled from two localities within the Chicamocha Canyon, where the species is abundant and continuously distributed. Cluster (principal coordinate analysis (PCO) and unweighted pair group method using arithmetic averages (UPGMA)), analysis of molecular variance (AMOVA) and Bayesian analyses revealed a low level of genetic differentiation among the two localities, suggesting that they belong to a single population. Genetic diversity levels in this population, described as the percentage of polymorphic loci (P=86·21%) and quantified using Shannon's diversity index (I=0·453) and the average panmictic heterozygosity (HB=0·484), were shown to be comparable to or higher than that in other plant species with allogamous breeding systems and to other related Verbenaceae species. Fine-scale autocorrelation analyses showed a pattern consistent with the classical model of isolation by distance with moderate but significant levels of local spatial structure. Our results suggest that sampling individuals at distances greater than ~1·2 km may result in the collection of different genotypes, which could help preserve the levels of genetic diversity in a propagation programme. The causes of this spatial pattern are currently unknown and could be influenced by many contemporary factors such as restricted seed dispersal and/or short-distance pollen movement, among others.


Genome ◽  
2004 ◽  
Vol 47 (3) ◽  
pp. 510-518 ◽  
Author(s):  
Young Hoon Park ◽  
Marilyn A.L West ◽  
Dina A St. Clair

Cultivated tomato (L. esculentum L.) germplasm exhibits limited genetic variation compared with wild Lycopersicon species. Amplified fragment length polymorphism (AFLP) markers were used to evaluate genetic variation among 74 cultivars, primarily from California, and to fingerprint germplasm to determine if cultivar-specific patterns could be obtained. All 74 cultivars were genotyped using 26 AFLP primer combinations; of the 1092 bands scored, 102 AFLP bands (9.3%) were polymorphic. Pair-wise genetic similarity coefficients (Jaccard and Nei–Li) were calculated. Jaccard coefficients varied from 0.16 to 0.98 among cultivar pairs, and 72% of pair-wise comparisons exceeded 0.5. UPGMA (unweighted pair-group method with arithmetic averaging) clustering and principle component analysis revealed four main clusters, I–IV; most modern hybrid cultivars grouped in II, whereas most vintage cultivars grouped in I. Clusters III and IV contained three and two cultivars, respectively. Some groups of cultivars closely related by pedigree exhibited high bootstrap values, but lower values (<50%) were obtained for cluster II and its four subgroups. Unique fingerprints for all 74 cultivars were obtained by a minimum of seven AFLP primer pairs, despite inclusion of some closely related cultivars. This study demonstrated that AFLP markers are effective for obtaining unique fingerprints of, and assessing genetic diversity among, tomato cultivars.Key words: Lycopersicon esculentum, AFLPs, DNA fingerprinting, genetic diversity, phenetic relationships.


2015 ◽  
Vol 140 (2) ◽  
pp. 120-128
Author(s):  
Amanda J. Hershberger ◽  
Tracie M. Jenkins ◽  
Carol Robacker

Despite the ecologic and ornamental potential of southeastern U.S. native Spigelia, little is known about the intraspecific or the interpopulation genetic variation. The southeastern U.S. native Spigelia habitat is becoming more and more fragmented as a result of human activity, making it imperative to gain an understanding of natural genetic variation among and within species and populations for the purpose of obtaining variability for plant breeding and preserve the genetic variability in Spigelia. Therefore, the objective of this study was to use amplified fragment length polymorphism analysis to determine interspecific and intraspecific genetic variation and to evaluate gene flow. Thirteen populations of two species of native Spigelia, S. marilandica (SM), S. gentianoides var. gentianoides (SGG), and S. gentianoides var. alabamensis (SGA), were analyzed using four primer pairs that amplified a total of 269 bands. Based on analysis of molecular variance and estimates of Nei’s coefficients of gene diversity (percentage of polymorphic loci, average genetic diversity within populations, average genetic diversity within species, and proportion of species genetic diversity attributed to among population variation), the majority of variation found in Spigelia occurs within populations. Both among-species and among-population variation was low, likely the effect of common ancestry as well as relatively frequent introgression among individuals (and populations) of Spigelia. When all individuals were evaluated using Nei’s unbiased genetic distances and viewed as a unweighted pair group method with arithmetic mean phenogram, three main groups were shown, one with two samples of SGG from one population, one with 13 individuals from both SGG populations used in this study, and one with all of the SM, SGA, and remaining SGG individuals. Further evaluation using STRUCTURE software showed introgression between populations and species, although all allele clusters have not entirely introgressed into all populations. The significance of these results is discussed in relation to breeding in Spigelia.


2021 ◽  
Vol 13 (12) ◽  
pp. 6830
Author(s):  
Murat Guney ◽  
Salih Kafkas ◽  
Hakan Keles ◽  
Mozhgan Zarifikhosroshahi ◽  
Muhammet Ali Gundesli ◽  
...  

The food needs for increasing population, climatic changes, urbanization and industrialization, along with the destruction of forests, are the main challenges of modern life. Therefore, it is very important to evaluate plant genetic resources in order to cope with these problems. Therefore, in this study, a set of ninety-one walnut (Juglans regia L.) accessions from Central Anatolia region, composed of seventy-four accessions and eight commercial cultivars from Turkey, and nine international reference cultivars, was analyzed using 45 SSR (Simple Sequence Repeats) markers to reveal the genetic diversity. SSR analysis identified 390 alleles for 91 accessions. The number of alleles per locus ranged from 3 to 19 alleles with a mean value of 9 alleles per locus. Genetic dissimilarity coefficients ranged from 0.03 to 0.68. The highest number of alleles was obtained from CUJRA212 locus (Na = 19). The values of polymorphism information content (PIC) ranged from 0.42 (JRHR222528) to 0.86 (CUJRA212) with a mean PIC value of 0.68. Genetic distances were estimated according to the UPGMA (Unweighted Pair Group Method with Arithmetic Average), Principal Coordinates (PCoA), and the Structure-based clustering. The UPGMA and Structure clustering of the accessions depicted five major clusters supporting the PCoA results. The dendrogram revealed the similarities and dissimilarities among the accessions by identifying five major clusters. Based on this study, SSR analyses indicate that Yozgat province has an important genetic diversity pool and rich genetic variance of walnuts.


2011 ◽  
Vol 46 (9) ◽  
pp. 1035-1044 ◽  
Author(s):  
Patrícia Coelho de Souza Leão ◽  
Sérgio Yoshimitsu Motoike

The objective of this work was to analyze the genetic diversity of 47 table grape accessions, from the grapevine germplasm bank of Embrapa Semiárido, using 20 RAPD and seven microsatellite markers. Genetic distances between pairs of accessions were obtained based on Jaccard's similarity index for RAPD data and on the arithmetic complement of the weighted index for microsatellite data. The groups were formed according to the Tocher's cluster analysis and to the unweighted pair‑group method with arithmetic mean (UPGMA). The microsatellite markers were more efficient than the RAPD ones in the identification of genetic relationships. Information on the genetic distance, based on molecular characteristics and coupled with the cultivar agronomic performance, allowed for the recommendation of parents for crossings, in order to obtain superior hybrids in segregating populations for the table grape breeding program of Embrapa Semiárido.


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