scholarly journals High Genetic Diversity but Absence of Population Structure in Local Chickens of Sri Lanka Inferred by Microsatellite Markers

2021 ◽  
Vol 12 ◽  
Author(s):  
Amali Malshani Samaraweera ◽  
Ranga Liyanage ◽  
Mohamed Nawaz Ibrahim ◽  
Ally Mwai Okeyo ◽  
Jianlin Han ◽  
...  

Local chicken populations belonging to five villages in two geographically separated provinces of Sri Lanka were analyzed using 20 microsatellite markers to determine the genetic diversity of local chickens. Population genetic parameters were estimated separately for five populations based on geographic locations and for eight populations based on phenotypes, such as naked neck, long legged, crested or crown, frizzle feathered, Giriraj, commercial layer, crossbreds, and non-descript chicken. The analysis revealed that there was a high genetic diversity among local chickens with high number of unique alleles, mean number of alleles per locus (MNA), and total number of alleles per locus per population. A total of 185 microsatellite alleles were detected in 192 samples, indicating a high allelic diversity. The MNA ranged from 8.10 (non-descript village chicken) to 3.50 (Giriraj) among phenotypes and from 7.30 (Tabbowa) to 6.50 (Labunoruwa) among village populations. In phenotypic groups, positive inbreeding coefficient (FIS) values indicated the existence of population substructure with evidence of inbreeding. In commercial layers, a high expected heterozygosity He = 0.640 ± 0.042) and a negative FIS were observed. The positive FIS and high He estimates observed in village populations were due to the heterogeneity of samples, owing to free mating facilitated by communal feeding patterns. Highly admixed nature of phenotypes was explained as a result of rearing many phenotypes by households (58%) and interactions of chickens among neighboring households (53%). A weak substructure was evident due to the mating system, which disregarded the phenotypes. Based on genetic distances, crown chickens had the highest distance to other phenotypes, while the highest similarity was observed between non-descript village chickens and naked neck birds. The finding confirms the genetic wealth conserved within the populations as a result of the breeding system commonly practiced by chicken owners. Thus, the existing local chicken populations should be considered as a harbor of gene pool, which can be readily utilized in developing locally adapted and improved chicken breeds in the future.

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.


PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2936 ◽  
Author(s):  
Caroline E. Dubé ◽  
Serge Planes ◽  
Yuxiang Zhou ◽  
Véronique Berteaux-Lecellier ◽  
Emilie Boissin

Quantifying the genetic diversity in natural populations is crucial to address ecological and evolutionary questions. Despite recent advances in whole-genome sequencing, microsatellite markers have remained one of the most powerful tools for a myriad of population genetic approaches. Here, we used the 454 sequencing technique to develop microsatellite loci in the fire coralMillepora platyphylla, an important reef-builder of Indo-Pacific reefs.We tested the cross-species amplification of these loci in five other species of the genusMilleporaand analysed its success in correlation with the genetic distances between species using mitochondrial 16S sequences. We succeeded in discovering fifteen microsatellite loci in our target speciesM. platyphylla,among which twelve were polymorphic with 2–13 alleles and a mean observed heterozygosity of 0.411. Cross-species amplification in the five otherMilleporaspecies revealed a high probability of amplification success (71%) and polymorphism (59%) of the loci. Our results show no evidence of decreased heterozygosity with increasing genetic distance. However, only one locus enabled measures of genetic diversity in the Caribbean speciesM. complanatadue to high proportions of null alleles for most of the microsatellites. This result indicates that our novel markers may only be useful for the Indo-Pacific species ofMillepora.Measures of genetic diversity revealed significant linkage disequilibrium, moderate levels of observed heterozygosity (0.323–0.496) and heterozygote deficiencies for the Indo-Pacific species. The accessibility to new polymorphic microsatellite markers for hydrozoanMilleporaspecies creates new opportunities for future research on processes driving the complexity of their colonisation success on many Indo-Pacific reefs.


Author(s):  
Dainis Edgars Ruņģis ◽  
Baiba Krivmane

Abstract Changing climatic conditions are transforming the ecological and silvicultural roles of broadleaf tree species in northern Europe. Small-leaved lime (Tilia cordata Mill.) is distributed throughout most of Europe, and is a common broadleaf species in Latvia. This species can tolerate a broad range of environmental and ecological conditions, including temperature, water availability, and soil types. The aim of this study was to assess the genetic diversity and differentiation of Latvian T. cordata populations using nuclear microsatellite markers developed for Tilia platyphyllos. After testing of 15 microsatellite markers, Latvian T. cordata samples were genotyped at 14 micro-satellite loci. Latvian T. cordata populations had high genetic diversity, and were not overly isolated from each other, with moderate gene flow between populations. No highly differentiated populations were identified. Vegetative reproduction was identified in most analysed populations, and almost one-third of analysed individuals are of clonal origin. T. cordata has high timber production potential under the current climatic and growth conditions in Latvia, and therefore this species has potential for use in forestry, as well as playing a significant role in maintaining biodiversity and other ecosystem services.


2019 ◽  
Vol 11 (20) ◽  
pp. 5863 ◽  
Author(s):  
Qingqing Yu ◽  
Qian Liu ◽  
Yi Xiong ◽  
Yanli Xiong ◽  
Zhixiao Dong ◽  
...  

Elymus breviaristatus is a grass species only distributed in the southeast of Qinghai-Tibetan Plateau (QTP), which has suffered from serious habitat fragmentation. Therefore, understanding patterns of genetic diversity within and among natural E. breviaristatus populations could provide insight for future conservation strategies. In this study, sequence-related amplified polymorphism markers were employed to investigate the genetic diversity and hierarchical structure of seven E. breviaristatus populations from QTP, China. Multiple measures of genetic diversity indicated that there is low to moderate genetic variation within E. breviaristatus populations, consistent with its presumed mating system. In spite of its rarity, E. breviaristatus presented high genetic diversity that was equivalent to or even higher than that of widespread species. Bayesian clustering approaches, along with clustering analysis and principal coordinate analysis partitioned the studied populations of E. breviaristatus into five genetic clusters. Differentiation coefficients (Fst, GST, etc.) and AMOVA analysis revealed considerable genetic divergence among different populations. BARRIER analyses indicated that there were two potential barriers to gene flow among the E. breviaristatus populations. Despite these patterns of differentiation, genetic distances between populations were independent of geographic distances (r = 0.2197, p = 0.2534), indicating little isolation by distance. Moreover, despite detecting a common outlier by two methods, bioclimatic factors (altitude, annual mean temperature, and annual mean precipitation) were not related to diversity parameters, indicating little evidence for isolation caused by the environment. These patterns of diversity within and between populations are used to propose a conservation strategy for E. breviaristatus.


2012 ◽  
Vol 37 (3) ◽  
pp. 389-398 ◽  
Author(s):  
S Islam ◽  
MS Haque ◽  
RM Emon ◽  
MM Islam ◽  
SN Begum

A study was undertaken to examine the genetic diversity of 12 wheat (Triticum aestivum L.) genotypes, using 4 simple sequence repeats (SSRs). A total of 10 alleles were found. Allele number per locus ranged from 2 to 4 with an average of 2.5. The polymorphic information content (PIC) values ranged from 0.2755 to 0.5411 with an average of 0.3839. The average gene diversity over all SSR loci for the 12 wheat genotypes was 0.4688, ranging from 0.3299 to 0.6042. Cluster analysis based on microsatellite allelic diversity discriminated the varieties into different clusters. Genetic diversity was the highest between variety Gourab and Akbar as well as Gourab and BAW-1064, showing a genetic distance value of 0.4697. The genetic distance was lowest between Balaka and Aghrani as well as Triticale and BAW-1036. Positive correlations were found between gene diversity, number of alleles, the allele size range and the types of repeat motif of microsatellite markers. It was found from this study that microsatellite markers could characterize and discriminate all of the genotypes. More primers should be used for saturation of different regions in further studies. Bangladesh J. Agril. Res. 37(3): 389-398, September 2012 DOI: http://dx.doi.org/10.3329/bjar.v37i3.12082


Parasitology ◽  
2014 ◽  
Vol 141 (7) ◽  
pp. 880-890 ◽  
Author(s):  
SHARMINI GUNAWARDENA ◽  
MARCELO U. FERREIRA ◽  
G. M. G. KAPILANANDA ◽  
DYANN F. WIRTH ◽  
NADIRA D. KARUNAWEERA

SUMMARYHere we examined whether the recent dramatic decline in malaria transmission in Sri Lanka led to a major bottleneck in the local Plasmodium vivax population, with a substantial decrease in the effective population size. To this end, we typed 14 highly polymorphic microsatellite markers in 185 P. vivax patient isolates collected from 13 districts in Sri Lanka over a period of 5 years (2003–2007). Overall, we found a high degree of polymorphism, with 184 unique haplotypes (12–46 alleles per locus) and average genetic diversity (expected heterozygosity) of 0·8744. Almost 69% (n = 127) isolates had multiple-clone infections (MCI). Significant spatial and temporal differentiation (FST = 0·04–0·25; P⩽0·0009) between populations was observed. The effective population size was relatively high but showed a decline from 2003–4 to 2006–7 periods (estimated as 45 661 to 22 896 or 10 513 to 7057, depending on the underlying model used). We used three approaches – namely, mode-shift in allele frequency distribution, detection of heterozygote excess and the M-ratio statistics – to test for evidence of a recent population bottleneck but only the low values of M-ratio statistics (ranging between 0·15–0·33, mean 0·26) were suggestive of such a bottleneck. The persistence of high genetic diversity and high proportion of MCI, with little change in effective population size, despite the collapse in demographic population size of P. vivax in Sri Lanka indicates the importance of maintaining stringent control and surveillance measures to prevent resurgence.


Author(s):  
Ahmed Medhat Mohamed Al-Naggar ◽  
Mohamed Abd El-Maboud Abd El-Shafi ◽  
Mohamed Helmy El-Shal ◽  
Ali Hassan Anany

To increase the genetic progress in wheat (Triticum aestivum L.) yield, breeders search for germplasm of high genetic diversity, one of them is the landraces. The present study aimed at evaluating genetic diversity of 20 Egyptian wheat landraces and two cultivars using microsatellite markers (SSRs). Ten SSR markers amplified a total of 27 alleles in the set of 22 wheat accessions, of which 23 alleles (85.2%) were polymorphic. The majority of the markers showed high polymorphism information content (PIC) values (0.67-0.94), indicating the diverse nature of the wheat accessions and/or highly informative SSR markers used in this study. The genotyping data of the SSR markers were used to assess genetic variation in the wheat accessions by dendrogram. The highest genetic distance was found between G21 (Sakha 64; an Egyptian cultivar) and the landrace accession No. 9120 (G11). These two genotypes could be used as parents in a hybridization program followed by selection in the segregating generations, to identify some transgressive segregates of higher grain yield than both parents. The clustering assigned the wheat genotypes into four groups based on SSR markers. The results showed that the studied SSR markers, provided sufficient polymorphism and reproducible fingerprinting profiles for evaluating genetic diversity of wheat landraces. The analyzed wheat landraces showed a good level of genetic diversity at the molecular level. Molecular variation evaluated in this study of wheat landraces can be useful in traditional and molecular breeding programs.


2019 ◽  
Author(s):  
Vanlalsanga No Surname ◽  
Sagolshem Priyokumar Singh ◽  
Yengkhom Tunginba Singh

Abstract Background Rice (Oryza sativa L.) is one of the most important crops of the world and a major staple food for half of the World’s human population. The Northeastern (NE) region of India lies in the Indo-Burma biodiversity hotspot and about 45% of the total flora of the country is found in the region. Local rice cultivars from different states of NE India were analyzed for genetic diversity and population structure using microsatellite markers, and their zinc and iron content. Results A total of 149 bands were detected using twenty-two microsatellite markers comprising both random and trait-linked markers, showing 100% polymorphism and high value of expected heterozygosity (0.6311) and the polymorphism information content (0.5895). Nali Dhan cultivar of Arunachal Pradesh possessed the highest genetic diversity (0.3545) among studied populations while Moirangphou Khonganbi of Manipur exhibited the lowest genetic diversity (0.0343). The model-based population structure revealed that all the studied 65 rice cultivars were grouped into two clusters. Cluster I was represented by 36 cultivars and cluster II by 29 cultivars. Badalsali cultivar of Assam possessed the highest Zn content (75.8 μg/g) and Kapongla from Manipur possessed the lowest (17.98 μg/g). The highest and the lowest Fe content was found in Fazu (215.62 μg/g) and Idaw (11.42 μg/g) of Mizoram. Conclusion The result suggested rice cultivars of NE India possessing high genetic diversity (Nali Dhan), high Zn (Badalsali) and Fe (Fazu) content can be useful as a source of germplasm for future rice improvement programs.


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