scholarly journals Genetic Dissimilarity in Conyza sumatrensis Revealed by Simple Sequence Repeat (SSR) Markers

2020 ◽  
Vol 38 ◽  
Author(s):  
T. SCHNEIDER ◽  
M.A. RIZZARDI ◽  
S.P. BRAMMER ◽  
S.M. SCHEFFER-BASSO ◽  
A.L. NUNES

ABSTRACT: In view of the rapid evolution of Conyza sumatrensis populations resistant to glyphosate, it is necessary to understand the genetic diversity aimed to improve strategies for managing this weed. We investigated the genetic dissimilarity among 15 biotypes of C. sumatrensis from different geographic regions using microsatellite loci. The biotypes, were cultivated in a greenhouse to obtain vegetal material for DNA extraction. Nineteen microsatellite markers (SSR), were developed for C. sumatrensis biotypes. The genetic dissimilarity was estimated by the Jaccard coefficient (JC) and the biotypes grouped by the UPGMA method. The results demonstrated a high dissimilarity (JC = 7.14 to 82.62) of the analyzed material, with the biotypes forming five groups, being one group formed just by the susceptible biotype and in the others grouped by biotypes from distinct locations in the same group The high genetic diversity of C. sumatrensis indicates that the biotypes may show different responses to different management strategies, and that the mechanisms of resistance to herbicides and characteristics of evolution of populations due to adaptability may be some of the factors involved in the genetic variability of the species.

2021 ◽  
Author(s):  
Fernando Hernandez ◽  
Roman Boris Vercellino ◽  
Claudio Pandolfo ◽  
Jennifer R. Mandel ◽  
Alejandro Presotto

Hybridization between crops and their wild relatives may promote the evolution of de-domesticated (feral) weeds. Wild sunflower is typically found in ruderal environments, but crop-wild hybridization may facilitate the evolution of weedy biotypes. Using one crop-specific mitochondrial marker (CMS-PET1) and 14 nuclear SSR markers, we studied the origin and genetic diversity of BRW, a recently discovered weedy biotype. Then, using a resurrection approach, we tested for rapid evolution of weedy traits (seed dormancy, herbicide resistance, and competitive ability) by sampling weedy and wild biotypes 10 years apart (2007 and 2017). All the weedy plants present the CMS-PET1 cytotype, confirming their feral origin. At the nuclear markers, BRW showed higher genetic diversity than the cultivated lines, as high genetic diversity as the most diverse wild biotypes, and low differentiation with one wild biotype, suggesting that wild hybridization increased the genetic diversity of the feral BRW. Regarding weedy trait evolution, we found support for rapid evolution towards higher seed dormancy, but not for higher competitive ability or herbicide resistance. Standing genetic variation probably facilitated the evolution of seed dormancy and limited the evolution of herbicide resistance, as no resistant alleles were found in the ancestral biotype. Our results demonstrate that natural crop-wild hybrids can evolve quickly in farmers' fields, leading to the establishment of weedy biotypes of cultivated origin. Although herbicide resistance did not evolve in BRW, management strategies aimed at preventing the evolution of resistance should be a priority in order to avoid the emergence and spread of herbicide resistant biotypes in Argentina.


2020 ◽  
Vol 40 (5) ◽  
pp. 574-583
Author(s):  
Shaokui Yi ◽  
Long Zhang ◽  
Yanhe Li ◽  
Linlin Shi ◽  
Jing Chen ◽  
...  

Abstract The red swamp crayfish, Procambarus clarkii (Girard, 1852), is a paradox in China because it has developed as a popular aquaculture species while becoming a notorious invasive species. We investigated the population genetic diversity and population dynamics of wild Chinese populations of P. clarkii based on proPO fragments and the morphological traits across these populations. The results showed that the populations of P. clarkii exhibit high genetic diversity and significant population structure, inferring that the crayfish was artificially transferred rapidly among different locations for different reasons. Results also revealed distinct phenotypic differentiation, with individuals of some populations having a shorter pleon and wider carapace width, whereas other populations have a small length to width ratio. This study provided comprehensive insights into the population dynamics and morphological variations of P. clarkii, which contribute to understanding the rapid evolution of phenotypic traits after its successful invasion. Results should help establish efficient management strategies for the control of the invasion and at the same time using the genetic information in crayfish aquaculture.


BMC Genetics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Cun Chen ◽  
Yanguang Chu ◽  
Changjun Ding ◽  
Xiaohua Su ◽  
Qinjun Huang

Abstract Background Black cottonwood (Populus deltoides) is one of the keystone forest tree species, and has become the main breeding parents in poplar hybrid breeding. However, the genetic diversity and population structure of the introduced resources are not fully understood. Results In the present study, five loci containing null alleles were excluded and 15 pairs of SSR (simple sequence repeat) primers were used to analyze the genetic diversity and population structure of 384 individuals from six provenances (Missouri, Iowa, Washington, Louisiana, and Tennessee (USA), and Quebec in Canada) of P. deltoides. Ultimately, 108 alleles (Na) were detected; the expected heterozygosity (He) per locus ranged from 0.070 to 0.905, and the average polymorphic information content (PIC) was 0.535. The provenance ‘Was’ had a relatively low genetic diversity, while ‘Que’, ‘Lou’, and ‘Ten’ provenances had high genetic diversity, with Shannon’s information index (I) above 1.0. The mean coefficient of genetic differentiation (Fst) and gene flow (Nm) were 0.129 and 1.931, respectively. Analysis of molecular variance (AMOVA) showed that 84.88% of the genetic variation originated from individuals. Based on principal coordinate analysis (PCoA) and STRUCTURE cluster analysis, individuals distributed in the Mississippi River Basin were roughly classified as one group, while those distributed in the St. Lawrence River Basin and Columbia River Basin were classified as another group. The cluster analysis based on the population level showed that provenance ‘Iow’ had a small gene flow and high degree of genetic differentiation compared with the other provenances, and was classified into one group. There was a significant relationship between genetic distance and geographical distance. Conclusions P. deltoides resources have high genetic diversity and there is a moderate level of genetic differentiation among provenances. Geographical isolation and natural conditions may be the main factors causing genetic differences among individuals. Individuals reflecting population genetic information can be selected to build a core germplasm bank. Meanwhile, the results could provide theoretical support for the scientific management and efficient utilization of P. deltoides genetic resources, and promote the development of molecular marker-assisted breeding of poplar.


Author(s):  
Manish Kapoor ◽  
Pooja Mawal ◽  
Vikas Sharma ◽  
Raghbir Chand Gupta

Abstract Background Various Asparagus species constitute the significant vegetable and medicinal genetic resource throughout the world. Asparagus species serve as important commodity of food and pharmaceutical industries in India. A diverse collection of Asparagus species from different localities of Northwest India was investigated for its genetic diversity using simple sequence repeat (SSR) markers. Results Polymorphic SSR markers revealed high genetic diversity. Primer SSR-15 amplified maximum of 8 fragments while 3 primers, namely, SSR-43, SSR-63, and AGA1 amplified minimum of 3 fragments. Collectively, 122 alleles were amplified in a range between 3 and 8 with an average of 5 alleles per marker. The size of the amplified alleles ranged between 90 and 680 base pairs. Polymorphism information content (PIC) value varied from a highest value of 0.499 in primer AGA1 to a lowest value of 0.231 in primer SSR-63 with a mean value of 0.376 showing considerable SSR polymorphism. Dendrogram developed on the basis of Jaccard’s similarity coefficient and neighbor-joining tree segregated all the studied Asparagus species into two discrete groups. Structure analysis based on Bayesian clustering allocated different accessions to two independent clusters and exhibited low level of individual admixture. Conclusions The genetic diversity analysis showed a conservative genetic background for maximum species of asparagus. Only Accessions of Asparagus adscendens were split into two diverse clusters suggesting a wide genetic base of this species as compared to other species. Overall genetic diversity was high, and this germplasm of Asparagus can be used in future improvement programs. The findings of current research on Asparagus germplasm can make a momentous contribution to initiatives of interbreeding, conservation, and improvement of Asparagus in future.


2021 ◽  
Vol 12 ◽  
Author(s):  
Haftom Brhane ◽  
Teklehaimanot Haileselassie ◽  
Kassahun Tesfaye ◽  
Cecilia Hammenhag ◽  
Rodomiro Ortiz ◽  
...  

Finger millet (Eleusine coracana (L.) Geartn.) is a self-pollinating amphidiploid crop cultivated with minimal input for food and feed, as well as a source of income for small-scale farmers. To efficiently assess its genetic diversity for conservation and use in breeding programs, polymorphic DNA markers that represent its complex tetraploid genome have to be developed and used. In this study, 13 new expressed sequence tag-derived simple sequence repeat (EST-SSR) markers were developed based on publicly available finger millet ESTs. Using 10 polymorphic SSR markers (3 genomic and 7 novel EST-derived), the genetic diversity of 55 landrace accessions and 5 cultivars of finger millet representing its major growing areas in Ethiopia was assessed. In total, 26 alleles were detected across the 10 loci, and the average observed number of alleles per locus was 5.6. The polymorphic information content (PIC) of the loci ranged from 0.045 (Elco-48) to 0.71 (UGEP-66). The level of genetic diversity did not differ much between the accessions with the mean gene diversity estimates ranging only from 0.44 (accession 216054) to 0.68 (accession 237443). Similarly, a narrow range of variation was recorded at the level of regional states ranging from 0.54 (Oromia) to 0.59 (Amhara and Tigray). Interestingly, the average gene diversity of the landrace accessions (0.57) was similar to that of the cultivars (0.58). The analysis of molecular variance (AMOVA) revealed significant genetic variation both within and among accessions. The variation among the accessions accounted for 18.8% of the total variation (FST = 0.19; P < 0.001). Similarly, significant genetic variation was obtained among the geographic regions, accounting for 6.9% of the total variation (P < 0.001). The results of the cluster, principal coordinate, and population structure analyses suggest a poor correlation between the genetic makeups of finger millet landrace populations and their geographic regions of origin, which in turn suggests strong gene flow between populations within and across geographic regions. This study contributed novel EST-SSR markers for their various applications, and those that were monomorphic should be tested in more diverse finger millet genetic resources.


2019 ◽  
Vol 109 (7) ◽  
pp. 1280-1292 ◽  
Author(s):  
Noel L. Knight ◽  
Niloofar Vaghefi ◽  
Julie R. Kikkert ◽  
Melvin D. Bolton ◽  
Gary A. Secor ◽  
...  

Cercospora leaf spot, caused by Cercospora beticola, is a highly destructive disease of Beta vulgaris subsp. vulgaris worldwide. C. beticola populations are usually characterized by high genetic diversity, but little is known of the relationships among populations from different production regions around the world. This information would be informative of population origin and potential pathways for pathogen movement. For the current study, the genetic diversity, differentiation, and relationships among 948 C. beticola isolates in 28 populations across eight geographic regions were investigated using 12 microsatellite markers. Genotypic diversity, as measured by Simpson’s complement index, ranged from 0.18 to 1.00, while pairwise index of differentiation values ranged from 0.02 to 0.42, with the greatest differentiation detected between two New York populations. In these populations, evidence for recent expansion was detected. Assessment of population structure identified two major clusters: the first associated with New York, and the second with Canada, Chile, Eurasia, Hawaii, Michigan, North Dakota, and one population from New York. Inferences of gene flow among these regions suggested that the source for one cluster likely is Eurasia, whereas the source for the other cluster is not known. These results suggest a shared origin of C. beticola populations across regions, except for part of New York, where population divergence has occurred. These findings support the hypothesis that dispersal of C. beticola occurs over long distances.


2011 ◽  
Vol 57 (6) ◽  
pp. 717-724 ◽  
Author(s):  
Jiandong Yang ◽  
Zhihe Zhang ◽  
Fujun Shen ◽  
Xuyu Yang ◽  
Liang Zhang ◽  
...  

Abstract Understanding present patterns of genetic diversity is critical in order to design effective conservation and management strategies for endangered species. Tangjiahe Nature Reserve (NR) is one of the most important national reserves for giant pandas Ailuropoda melanoleuca in China. Previous studies have shown that giant pandas in Tangjiahe NR may be threatened by population decline and fragmentation. Here we used 10 microsatellite DNA markers to assess the genetic variability in the Tangjiahe population. The results indicate a low level of genetic differentiation between the Hongshihe and Motianling subpopulations in the reserve. Assignment tests using the Bayesian clustering method in STRUCTURE identified one genetic cluster from 42 individuals of the two subpopulations. All individuals from the same subpopulation were assigned to one cluster. This indicates high gene flow between subpopulations. F statistic analyses revealed a low FIS-value of 0.024 in the total population and implies a randomly mating population in Tangjiahe NR. Additionally, our data show a high level of genetic diversity for the Tangjiahe population. Mean allele number (A), Allelic richness (AR) and mean expected heterozygosity (HE) for the Tangjiahe population was 5.9, 5.173 and 0.703, respectively. This wild giant panda population can be restored through concerted effort.


2020 ◽  
Vol 21 (3) ◽  
Author(s):  
Uslan Uslan ◽  
NUR JANNAH

Abstract. Uslan, Jannah N. 2020. Genetic diversity of local corn (Zea mays) cultivars from South Amarasi, Kupang District, Indonesia by Inter Simple Sequence Repeats marker. Biodiversitas 21: 1208-1214. Corn (Zea mays L.) is one of the most important food crops in Indonesia. However, the studies described their genetic variation is relatively poor. Therefore, the aim of this study was to analyze the genetic diversity of local corn cultivars from South Amarasi, Kupang District, East Nusa Tenggara (NTT), Indonesia using ISSR markers. The sampling was conducted in 4 different sites in Sub-district of Amarasi, Kupang District. A total of 11 corn cultivars from Sub-district of South Amarasi was collected. DNA isolation was performed by using CTAB Method. Clustering analysis was conducted on MSVP 3.2 software. It was shown that all ISSR-primers used (UBC 811, UBC 814 and UBC 824) were successfully produced polymorphic bands and represents the high genetic diversity of the local corn cultivars. The genetic distance index indicated that several corn cultivars from two different populations were geographically unclustered, although there are samples from several populations that have a low genetic distance. The genetic variation index also showed high genetic diversity among the populations. Further research on the exhaustive sample collection was needed to give an insight into the genetic diversity of local corn cultivars (Zea mays L.) from South Amarasi, Indonesia. Please write implementation of this research


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