scholarly journals Genetic diversity of Avena strigosa Schreb. ecotypes on the basis of isoenzyme markers

2009 ◽  
Vol 15 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Katarzyna Kubiak

Genetic diversity ofAvena strigosaSchreb. ecotypes on the basis of isoenzyme markersGenetic diversity was analyzed in 19 ecotypes of the diploid oatA. strigosaoriginating from various geographical regions of the world. Six isoenzyme systems (AAT, ACP, EST, LAP, MDH, PX) were studied and 16 loci were identified. Only two loci (Est4andMdh2) were polymorphic. Ecotypes were characterized by the percentage of polymorphic loci (P=3.3%), the mean number of alleles per locus (A=1.04) and intrapopulation diversity (HS=0.013). Total genetic diversity (HT=0.07) and interpopulation diversity (DST=0.057) were examined as well. The value of the coefficient of gene differentiation (GST=0.821) indicated that diversity among populations was an important contributor to total variability. Genetic similarity betweenA. strigosapopulations was very high (IN=0.94). Cluster analysis did not demonstrate strongly differentiated groups among the ecotypes examined.

2002 ◽  
Vol 50 (1) ◽  
pp. 93 ◽  
Author(s):  
Alison Shapcott

Triunia robusta, which until recently was thought to be extinct, is now classified nationally as endangered. It is an understorey species restricted to the subcoastal rainforests in a small region of the Sunshine Coast, Queensland. The project involved sampling the genetic variation and measuring the population size and size distribution of T. robusta and its geographically closest congener T. youngiana, which occurs further south and has a wider geographic distribution. A total of 877 T. robusta plants were recorded across the 11 populations, approximately half (56.8%) of these were juveniles less than 1 m tall, whereas in T. youngiana only about 36.4% of a population was composed of juveniles. Genetic diversity was similar but significantly higher for T. robusta than T. youngiana if the very small T. robusta populations (2 or 3 plants) were excluded from analysis (P < 0.05). The mean percentage of polymorphic loci among populations was high for both species. Triunia robusta is not, on average, more inbred than the more common T. youngiana. There was more differentiation between the T. robusta populations, which were in close proximity, than between the more geographically separated T. youngiana populations. Thus, there is evidence of more gene flow between populations of T. youngiana than between those of T. robusta. However, there was no geographic relationship between genetic similarity and geographic proximity in T. robusta


2020 ◽  
Author(s):  
Bagheri Motahareh ◽  
Bahram Heidrai ◽  
Zolfaghar Shahriari ◽  
Ali Dadkhodaie ◽  
Zahra Heidari ◽  
...  

AbstractAnalysis of genetic diversity in medicinal plants assists germplasm conservation and selection for use in breeding schemes. The aims of the present study were to assess genetic diversity and differentiation of several Plantago species using Inter Simple Sequence Repeats (ISSR) markers and identify marker-trait associations (MTAs). Thirty-one Plantago accessions belonging to eight species with various mating system and chromosome number were collected from geographical regions of Iran environments. Polymorphism in the DNA of Plantago accessions were analyzed using polymerase chain reaction (PCR) of 25 ISSR primers. The data for number of polymorphic bands were analyzed on the basis of several genetic diversity parameters. The results of gel analysis indicated that the ISSR primers amplified 5 to 21 polymorphic bands with 100 to 3000 bp size. The mean polymorphism was 83.83% and five primers showed 100% polymorphism among Plantago accessions. The Polymorphism Information Content (PIC) for ISSR as a dominant marker ranged from 0.1103 to 0.3829 with the mean 0.2727 in the species tested. Accessions in P. amplexicaulis and P. pysillum species represented the highest Nei’s and Shannon’s genetic diversity whilst the lowest obtained for P. lagopus. Analysis of phylogenetic network generated by the Neighbor-Net Algorithm showed moderate split of the eight species tested and the network depicted moderate conflict. The principal coordinate analysis (PCoA) results showed lower conflict in separation of accessions of the eight species. Fifty-six significant MTAs were detected for the traits tested in Plantago accessions, of which six were shared between three seed and mucilage traits and 24 were common between two traits. The coefficient of determination (R2) for the identified MTAs varied between 32 and 73%. In conclusion, the results of genetic diversity analysis suggested that ISSR marker could efficiently differentiate Plantago species and the information of genetic diversity might assist Plantago improvement and conservation.


2020 ◽  
Vol 2 (SP1) ◽  
pp. 179-184

Introduction: The outbreak of a novel coronavirus disease (COVID-19; previously known as 2019-nCoV) was the beginning of one of the largest and most critical COVID-19 clusters in the world since late December 2019. Despite intensive prevention measures, the epidemic tends to propagate and the number of patients infected is growing. The case-fatality incidence was very high and is driven by very elderly people. Methods: in this study, we collected data from the (Covidgraph.com) database as the number of infection cases in the world reached 2736188 infections and the number of recovery cases reached 751805 and the number of deaths reached 191423.Results: it turns out that the virus infects older people and the older a person is, the higher the chance of infection with the virus. Results from this analysis the mean age of death is 78 years. Data from 106,399 cases and 12,550 deaths in Italy, to 2 April. In Spain, they are based on 7 April, 88,144 cases, and 3,479 deaths. There were less than 80 deaths in patients younger than 50 years of age. Conclusion: Coronavirus is a global epidemic, and it's hard to control, and it's not enough to prevent people from spreading the virus. The age groups most vulnerable to lethality are shown in this paper, in Italy, the virus destroys people over 75 years of age, In Spain, however, the virus destroys people aged over 85 Taking into account numerous comorbidities, including psychiatric, cerebrovascular, endocrine, metabolic, and respiratory disorders.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Mahilet Tadesse ◽  
Mulugeta Kebede ◽  
Dejene Girma

Genetic variability is the fundamental prerequisite of any crop-breeding program to develop superior cultivars. There are about 350 Eragrostis1 species, of which, tef is the only species cultivated for human consumption. Currently, the Ethiopian Biodiversity Institute (EBI) collected over five thousand tef accessions from different geographical regions, diverse in terms of climate and elevation, which are uncharacterized yet. The objective of this study was to evaluate the genetic diversity among 64 tef accessions using 10 selected polymorphic simple sequence repeats (SSRs) markers. A total of 314 alleles were detected with an average of 14.5 alleles per locus and amplicon size ranged from 90 bp–320 bp. The mean value of polymorphic information content (PIC) was 0.87, appearing polymorphic for all loci. The lowest Fst value (0.05) was recorded among the studied tef populations. The mean value of major allele frequency and the number of effective alleles were 0.33 and 3.32, respectively. The mean value of gene flow (Nm) and Shannon’s information index (I) was 4.74 and 1.65, respectively. The observed (Ho) and expected (He) heterozygosities varied from 0.34 to 0.56 and from 0.58 to 0.76, respectively. The cluster analysis has grouped the 64 tef accessions into three distinct clusters based on their similarity. The PCoA analysis showed that clustering is basing on the geographical origin of accessions. Analysis of molecular variance revealed 56%, 39% and 5% of the total variation due to variation within populations, among individuals and among populations, respectively. Structure bar-plot also inferred three gene pools, but with high level of admixtures. Thus, the present study shows that the identified tef accessions could be of great interest for the initiation of a planned breeding and conservation programs.


Genetika ◽  
2016 ◽  
Vol 48 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Mashhid Henareh ◽  
Atilla Dursun ◽  
Babak Abdollahi-Mandoulakani ◽  
Kamil Haliloğlu

Tomato is one of the most economically important vegetable crops in many parts of the world. Turkey and Iran are the main producers of tomatoes in the world. The objective of this study was to assess the genetic variation of 93 tomato landraces from East Anatolian region of Turkey and North-West of Iran, along with three commercial cultivars using 14 ISSR primers. The percentage of polymorphic loci (PPL) for all primers was 100%. The mean of expected heterozygosity (He) for the primers varied from 0.153 (UBC808) to 0.30 (UBC848). The dendrogram placed the landraces and commercial cultivars into nine groups. The genotypes originating from the same region, often located in the same group or two adjacent groups. The highest likelihood of the data was obtained when population were located into 2 sub-populations (K = 2). These sub-populations had Fst value of 0.16 and 0.21.


2015 ◽  
Vol 13 (1) ◽  
pp. 27-36 ◽  
Author(s):  
M Kumar ◽  
V Ponnuswami ◽  
C Rajamanickam ◽  
TL Preethi

Determination of genetic variation is important to the plant breeders for development of high yielding variety. The aim of the current study was to investigate the genetic diversity of nine tamarind cultivars, out of nine four flowering cultivars using random amplified polymorphic DNA (RAPD) markers. Ten Random amplified polymorphic DNA (RAPD) primers were used to assess the genetic diversity in four flowering cultivars and five non-flowering of tamarind trees. The average genetic similarity level among the four flowering cultivars and five non-flowering accessions grouped into six clusters groups at 0.76%. RAPD profiles of all the tamarind were compared and a total of 58 scorable bands were produced with seven primers ranging from one for OPG-13 to twelve for OPA-R15. Genotypes which were morphological closely related were found to be unrelated at the molecular level. A sizeable amount of intrapopulation diversity recorded in the present study which can be utilized in hybridization programmes to efficiently introgress the desirable trait of interest.SAARC J. Agri., 13(1): 27-36 (2015)


Encuentro ◽  
2016 ◽  
pp. 28-39
Author(s):  
Arlen Tijerino ◽  
Lourdes Callejas ◽  
David A. Cerda-Granados

The goal of this study was to assess the genetic diversity of Nicaraguan populations of Cedrela odorata using Random Amplified Polymorphic DNA (RAPD) markers. Thus, genomic DNA was isolated from leaf samples collected from ninety-two trees belonging to five Nicaraguan natural populations of C. odorata. The mean number of alleles per locus, effective number of alleles per locus, percentage of polymorphic loci, genetic diversity (He ) of Nei and diversity index (Ho ) of Shannon were estimated for each population assuming that the populations were in HardyWeinberg equilibrium. Total genetic diversity was partitioned in intrapopulational and interpopulational diversity using Nei’s genetic differentiation (GST) and through an Analysis of Molecular Variance (AMOVA). The ΦST matrix was used to construct a dendrogram by the neighbor-joining method. According to values of both He and Ho , Esquipulas (Deparment of Matagalpa) presented the lowest diversity level; while La Trinidad (Department of Estelí) showed the highest diversity level. Genetic differentiation was calculated obtaining a GST value of 13.36%. AMOVA also showed a similar differentiation value ΦST =13.81%). Neighbour-joining dendrogram clustered the five populations in two groups, where the group formed by La Trinidad and El Refugio (Department of Granada) presented the biggest differentiation. Correlation between genetic and geographical distances was not found.


2018 ◽  
Vol 64 (4) ◽  
pp. 173-182
Author(s):  
Hamed Al-Nadabi ◽  
Mumtaz Khan ◽  
Rashid Abdullah Al-Yahyai ◽  
Abdullah Mohammed Al-Sadi

Abstract A study was conducted to evaluate genetic relatedness of 27 citrus cultivars and 6 wild citrus accessions using AFLP fingerprinting. The 27 citrus cultivars belonged to Citrus sinensis, C. aurantifolia, C. aurantium, C. paradise, C. reticulata, C. limon, C. latifolia, C. maxima, C. limettoides, C. limetta, C. medica and C. Jambhiri. The wild cultivars were obtained from Oman while the other cultivars originated from Oman and other countries. AFLP analysis using 4 primer pair combinations resolved 910 polymorphic alleles. All citrus cultivars and accessions had low genetic diversity (H = 0.0281 to 0.1300), with the percent polymorphic loci ranging from 8 to 35%. Populations of the six wild citrus accessions showed a very low level of genetic diversity (< 0.0700). Cluster analysis of the 33 cultivars and accessions showed that they share a high level of genetic similarity (81‒99%; mean = 92%). The six wild accessions clustered into two main clusters, with the analysis indicating that the six wild accessions may make up six distinct cultivars. The study provides information on the phylogeny of citrus cultivars and citrus diversity in Oman, a country through which citrus moved in the past from Asia to different African and European countries. In addition, it shows that some distinct citrus cultivars are present in this part of the world.


Author(s):  
N.K. Verma ◽  
Rekha Sharma ◽  
R.A.K. Aggarwal ◽  
P.S. Dangi

Background: The goat population of Andhra Pradesh and Telangana states is about five million, respectively. The goats of these two states lack phenotypic uniformity. But it is not known whether these populations have any genetically uniform group that can be registered as a breed. The study was undertaken to explore possibility of any potential new goat germplasm.Methods: Study was carried out at ICAR-NBAGR during 2017-19. Genetic diversity and differentiation was evaluated by using 22 microsatellite markers in three goat populations: Telangana Black (TB, n=26), Telangana Mixed (TM, n=49) and one Andhra Pradesh goat population (AP, n=45). Their genetic differentiation was compared with that of geographically closely distributed registered breeds viz. Bidri (n=28) and Nandidurga (n=48) of Karnatka and Ganjam (n=48) of Odisha. Result: The mean allele frequency observed was 6.59 (TB), 7.27 (TM) and 8.36 (AP). Expected number of alleles varied from 3.33 in (TB) to 3.69 in AP goats. Observed heterozygosity was lowest in the TM (0.474) followed by TB (0.504) and was highest in the AP goats (0.569). AP goat population had 6.3% heterozygote deficiency, whereas, both TB (15.4%) and TM (17.5%) had very high inbreeding coefficients. A total of 344 alleles were detected across the 22 loci in six goat groups. F-statistics, the pair-wise Nei’s genetic distance, assignment test and Baysian approach suggested that AP goats are distinct from two Telangana goat populations as well as from the other geographically closely related registered goat breeds. Genetic bottleneck analysis indicated the absence of any detectably large, recent genetic bottleneck in AP population. Altogether, the study identified Andhra Pradesh (AP) goats to be a new potential goat germplasm of India.


2000 ◽  
Vol 23 (2) ◽  
pp. 375-380 ◽  
Author(s):  
Marcos Aparecido Gimenes ◽  
Catalina Romero Lopes

There are more than 200 races of maize (Zea mays L.) divided into three groups (ancient commercial races, the recent commercial races, and indigenous races). Although the indigenous races have no commercial value, they have many important characteristics which can be incorporated into maize breeding programs. Most Brazilian indigenous germplasm race stocks were collected at least 40 years ago, and nothing is known of the genetic variability present in this germplasm. The genetic variability was assayed in 15 populations from four indigenous races of maize (Caingang, Entrelaçado, Lenha and Moroti) and five indigenous cultivars, using five isoenzymatic systems encoded by 14 loci. The analysis revealed a low level of variability among the samples studied. Overall, the mean number of alleles/polymorphic locus was three, 64.3% of the loci analyzed being polymorphic and the estimated heterozygosity was 0.352. The mean number of alleles/polymorphic locus per population was 1.6. A mean of 47.5% of the loci were polymorphic. The mean expected heterozygosity was 0.195, the mean genetic identity was 0.821 and the proportion of total genetic diversity partitioned among populations (Gst) was 0.156. A founder effect could explain the low variability detected.


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