scholarly journals Effects of gamma radiation on quantitative traits and genetic variation of three successive generations of cowpea (Vigna unguiculata (L.) Walp.)

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
S Vanmathi ◽  
D Arulbalachandran ◽  
V Soundarya
Keyword(s):  
Genetic Variation ◽  
Gamma Irradiation ◽  
Vigna Unguiculata ◽  
Quantitative Traits ◽  
Mean Value ◽  
Population Variation ◽  
Maximum Increase ◽  
Three Generations ◽  
Expected Heterozygosity ◽  
Successive Generations

An annual pulse crop cowpea (Vigna unguiculata (L.) Walp.), commonly named southern pea, is a nourishing constituent for the human diet and fodder. Gamma rays are a potent mutagenic agent to stimulate genetic variation with better characteristics, improving the yield relating traits in crops. Hence, the present study focused on exploring genetic variation between three generations in the mutant populations of cowpea through SCoT markers. The mutant populations of three successive generations, M1, M2 and M3, were induced by different doses [200, 400, 600, 800, 1000 and 1200 Gray (Gy)] gamma irradiation. The results depict that the quantitative characters were reduced by increasing the dosage of gamma irradiation in the M1 generation. In contrast, the second and third generation of plants showed a significant increase in yield and yield contributing traits than control and the maximum increase was noticed at 200 Gy and 400 Gy. Days to first flowering was delayed in irradiated plants than control of M1 generation. In contrast, in consecutive generations (M2 and M3), the early first flowering was noticed at 400 Gy and late flowering was observed at 800 Gy compared respectively to control and other doses. Seed yield per plant mean value was increased at 200 Gy in both generations (M2 and M3); it may produce new genotypes to desirable traits such as yield and quality. SCoT markers were used to explore genetic variation at the genomic level of mutant populations and screened with eight primers. Among them, seven primers showed amplification of 222 bands, in which 133 bands showed polymorphism. The polymorphic bands varied from 3.03–96.07%. The genetic variation, such as the number of different alleles (Na), effective number of alleles (Ne), Shannon’s information index (I), expected heterozygosity (He) and unbiased expected heterozygosity (uHe) showed an average value of 1.352 ± 0.092, 1.278 ± 0.027, 0.293 ± 0.023, 0.184 ± 0.016, and 0.194 ± 0.016, respectively. AMOVA depicted significant genetic variation between all generations and indicated a total of 95% within populations and 5% among population variation by the marker used. The present investigations prominently showed that the variations induced by gamma irradiation were inherited from successive generations of the improvement in cowpea quantitative traits. This investigation gives acceptable proof that the SCoT markers are a valuable tool to identify the genetic variation among the three generations of cowpea.

scholarly journals Inter- and intra-population variation of local maize (Zea mays L.) populations from Slovakia and Czech Republic

2008 ◽  
Vol 43 (No. 1) ◽  
pp. 7-15 ◽  
Author(s):  
P. Múdry ◽  
J. Kraic
Keyword(s):  
Zea Mays ◽  
Genetic Variation ◽  
Czech Republic ◽  
Population Variation ◽  
Polymorphic Loci ◽  
Maize Populations ◽  
Expected Heterozygosity ◽  
Isoenzyme Polymorphism ◽  
New Alleles

Evaluation of genetic variation was performed within 62 local maize populations originating from Slovakia and Czech Republic. In total 48 alleles at 22 analyzed isoenzyme loci with an average of 2.2 alleles per locus were revealed. The percentage of polymorphic loci ranged from 14% to 59% and the frequencies of detected alleles varied from null to four per locus. No polymorphism was detected at the loci <i>Dia2</i>, <i>Got3</i>, <i>Mdh4</i>, <i>Mmm</i>, and <i>Pgm1</i>. The highest number of alleles (four) was detected at loci <i>Acp1</i>, <i>Cat3</i>, <i>Pgm2</i>. No new alleles were identified, nevertheless the frequency of seven alleles was only about 1%. The expected heterozygosity ranged from null to 0.492 with an average of 0.197. The revealed isoenzyme polymorphism confirmed that all analyzed populations were heterogeneous and as many as 17 of them were completely heterogeneous. None of the analyzed populations was identical in the frequency of alleles at all 22 analyzed loci.

Allozyme variations in six natural populations of scots pine (Pinus sylvestris) in Turkey

Biologia ◽  
2007 ◽  
Vol 62 (6) ◽  
Author(s):  
Behiye Bilgen ◽  
Nuray Kaya
Keyword(s):  
Genetic Variation ◽  
Pinus Sylvestris ◽  
Genetic Distance ◽  
Scots Pine ◽  
Natural Populations ◽  
Mean Value ◽  
Population Variation ◽  
Starch Gel Electrophoresis ◽  
The Mean ◽  
Nei's Genetic Distance

AbstractGenetic variation in six natural populations of Scots pine (Pinus sylvestris L.) was determined with isoenzyme analyses. For this purpose, haploid female gametophytes of seeds and horizontal starch gel electrophoresis technique were used. A total of 17 loci and 58 alleles were observed in studying 10 enzyme systems. The average proportion of polymorphic loci for populations ranged from 58.8% to 70.6%. The average number of alleles per locus per population was 2.65. The mean estimated expected heterozygosity (He) of populations was 0.294. A rather high proportion of genetic diversity (96.4%) was due to within-population variation and the remaining (3.6%) was due to variation among populations. The level of gene flow (Nem) was found to be 6.69 per generation. Nei’s genetic distance coefficient ranged from 0.006 to 0.027 (mean 0.017) among all possible population pairs. The mean value of Nei’s genetic distance is similar to the values reported for other European Scots pine populations. The low mean value of Nei’s genetic distance among populations is enough to explain low interpopulation variation. According to genetic variation parameters, three out of six populations (Akdagmadeni-Yozgat, Refahiye-Erzincan and Vezirkopru-Samsun) appear to be preferable populations for genetic conservation and forest tree breeding programs.

scholarly journals Genetic diversity and population structure of date palms (Phoenix dactylifera L.) in Ethiopia using microsatellite markers

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Workia Ahmed ◽  
Tileye Feyissa ◽  
Kassahun Tesfaye ◽  
Sumaira Farrakh
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Microsatellite Markers ◽  
Information Content ◽  
Date Palm ◽  
Polymorphic Information Content ◽  
Phoenix Dactylifera ◽  
Mean Value ◽  
Date Palms ◽  
Expected Heterozygosity

Abstract Background Date palm tree (Phoenix dactylifera L.) is a perennial monocotyledonous plant belonging to the Arecaceae family, a special plant with extraordinary nature that gives eminent contributions in agricultural sustainability and huge socio-economic value in many countries of the world including Ethiopia. Evaluation of genetic diversity across date palms at DNA level is very important for breeding and conservation. The result of this study could help to design for genetic improvement and develop germplasm introduction programmes of date palms mainly in Ethiopia. Results In this study, 124 date palm genotypes were collected, and 10 polymorphic microsatellite markers were used. Among 10 microsatellites, MPdCIR085 and MPdCIR093 loci showed the highest value of observed and expected heterozygosity, maximum number of alleles, and highest polymorphic information content values. A total of 112 number of alleles were found, and the mean number of major allele frequency was 0.26, with numbers ranging from 0.155 (MPdCIR085) to 0.374 (MPdCIR016); effective number of alleles with a mean value of 6.61, private alleles ranged from 0.0 to 0.65; observed heterozygosity ranged from 0.355 to 0.726; expected heterozygosity varied from 0.669 to 0.906, polymorphic information content with a mean value of 0.809; fixation index individuals relative to subpopulations ranged from 0.028 for locus MPdCIR032 to 0.548 for locus MPdCIR025, while subpopulations relative to total population value ranged from − 0.007 (MPdCIR070) to 0.891 (MPdCIR015). All nine accesstions, neighbour-joining clustering analysis, based on dissimilarity coefficient values were grouped into five major categories; in population STRUCTURE analysis at highest K value, three groups were formed, whereas DAPC separated date palm genotypes into eight clusters using the first two linear discriminants. Principal coordinate analysis was explained, with a 17.33% total of variation in all populations. Generally, the result of this study revealed the presence of allele variations and high heterozygosity (> 0.7) in date palm genotypes. Conclusions Microsatellites (SSR) are one of the most preferable molecular markers for the study of genetic diversity and population structure of plants. In this study, we found the presence of genetic variations of date palm genotypes in Ethiopia; therefore, these genetic variations of date palms is important for crop improvement and conservation programmes; also, it will be used as sources of information to national and international genbanks.

Genetic variation in allozymes of western larch

1986 ◽  
Vol 16 (5) ◽  
pp. 1013-1018 ◽  
Author(s):  
Lauren Fins ◽  
Lisa W. Seeb
Keyword(s):  
Genetic Variation ◽  
Genetic Drift ◽  
Fire History ◽  
Glacial History ◽  
Geographic Proximity ◽  
Electrophoretic Variation ◽  
Inland Empire ◽  
Genetic History ◽  
Expected Heterozygosity ◽  
History Of

Seed samples from 19 stands of Larixoccidentalis Nutt. were analyzed for electrophoretic variation at 23 loci. Because sample sizes consisted of only 9 or 10 trees per stand (18–20 alleles per locus per stand), samples were grouped by geographic proximity into four larger samples. For all measures of variation, this species scored lower than most, but within the range observed for other western conifers. Most of the variation was found within rather than between the population groups. The single southern sample appeared to be genetically distinct from the others. Although some variation was observed between individual stand samples in expected heterozygosity, the consistently low values for all samples suggest that genetic drift has played a major role in the genetic history of the species in the Inland Empire, both through its glacial history in postulated refugia and through fire history in recent times.

scholarly journals Genetic analysis of silver-fir populations in the Beskids

2011 ◽  
Vol 72 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Leon Mejnartowicz
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Analysis ◽  
Abies Alba ◽  
Genetic Distances ◽  
Silver Fir ◽  
Geographical Distance ◽  
Polymorphic Loci ◽  
Expected Heterozygosity ◽  
Rare Alleles

Twenty-eight isozymic loci were studied in the Beskid Mts., in four populations of common silver-fir (<em>Abies alba</em>): one in Beskid Makowski (BM) and three populations in Beskid Sądecki (BS). Their genetic variation and diversity were analyzed, and Nei's genetic distances between the populations were calculated. The results show that the geographical distance between the BM population and the three BS populations is reflected in genetic distances. The BM population is clearly distinct from the others. It has the lowest genetic diversity (<em>I</em> = <em>0.42</em>), percentage of polymorphic loci <em>(%PoL </em>= <em>64.29</em>) and number of rare alleles (<em>NoRa </em>= <em>5</em>). Besides, the BM population has the highest observed heterozygosity (<em>Ho </em>= <em>0.291</em>), which exceeds the expected heterozygosity (<em>He </em>= <em>0.254</em>), estimated on the basis of the Hardy-Weinberg Principle. On the contrary, BS populations are in the state of equilibrium, which is manifested, in similar values of <em>He </em>= <em>0.262 </em>and <em>Ho </em>= <em>0.264</em>.

scholarly journals HSP90 affects the expression of genetic variation and developmental stability in quantitative traits

2008 ◽  
Vol 105 (8) ◽  
pp. 2963-2968 ◽  
Author(s):  
T. A. Sangster ◽  
N. Salathia ◽  
S. Undurraga ◽  
R. Milo ◽  
K. Schellenberg ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Quantitative Traits ◽  
Developmental Stability

Population-Based Cytogenetic Banding Analysis and Phylogenetic Relationships of the Neotropical Fungus-Farming Ant Trachymyrmex holmgreni Wheeler, 1925

2019 ◽  
Vol 159 (3) ◽  
pp. 151-161 ◽  
Author(s):  
Ricardo Micolino ◽  
Maykon P. Cristiano ◽  
Danon C. Cardoso
Keyword(s):  
Genetic Variation ◽  
Phylogenetic Reconstruction ◽  
Population Based ◽  
Population Variation ◽  
Incipient Speciation ◽  
Telomeric Sequences ◽  
New Information ◽  
Banding Analysis ◽  
Pattern Characteristic ◽  
Northern Brazil

Trachymyrmex is one of the most species-rich genera within fungus-farming ants and presents intraspecific cytogenetic polymorphisms as well as possible cryptic species. This ant genus is currently paraphyletic. Therefore, to unravel systematic and taxonomic misunderstandings, it is necessary to incorporate new information. We aimed to cytogenetically and genetically examine Trachymyrmex holmgreni populations from southern and northern Brazil to identify intraspecific chromosomal variations that support incipient speciation and reveal the species' position in a molecular phylogeny. Our cytogenetic approach did not show population variation in the mapping of both 18S rDNA and the TTAGG(6) motif, presenting instead a pattern characteristic of correlated species. However, the clustered pattern of the microsatellite GA(15) showed significant differences among populations: a well-defined block in each homologue, distinctly irregular signs between homologues, and blocks in 2 pairs of homologues. Our phylogenetic reconstruction yielded unexpected results, grouping representatives of 3 former morphological groups into 1 clade, namely T. urichii, T. papulatus, and T. holmgreni. Previously, it was suggested that northern and southern populations of T. holmgreni may be undergoing incipient speciation, but we can only indicate that the southernmost population differs prominently from the others in its distribution pattern of the microsatellite GA(15). Our study also supports the uniformity of karyotypes and repetitive DNA from both telomeric sequences and ribosomal DNA in Trachymyrmex studied here. In addition, we clarify some phylogenetic uncertainties within the genus and suggest further relevant systematic changes. Finally, additional studies utilizing other probes and additional populations may allow the detection of hidden genetic variation.

Genetic diversity and differentiation in populations of invasive Eurasian (Myriophyllum spicatum) and hybrid (Myriophyllum spicatum × Myriophyllum sibiricum) watermilfoil

2020 ◽  
Vol 13 (2) ◽  
pp. 59-67
Author(s):  
Ryan A. Thum ◽  
Gregory M. Chorak ◽  
Raymond M. Newman ◽  
Jasmine A. Eltawely ◽  
Jo Latimore ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Population Genetic ◽  
Myriophyllum Spicatum ◽  
Population Variation ◽  
Efficacy Evaluation ◽  
Submerged Aquatic Plant ◽  
Myriophyllum Sibiricum ◽  
Control Response ◽  
Herbicide Response

AbstractPopulation genetic studies of within- and among-population genetic variability are still lacking for managed submerged aquatic plant species, and such studies could provide important information for managers. For example, the extent of within-population genetic variation may influence the potential for managed populations to locally adapt to environmental conditions and control tactics. Similarly, among-population variation may influence whether specific control tactics work equally effectively in different locations. In the case of invasive Eurasian watermilfoil (Myriophyllum spicatum L.), including interspecific hybrids with native northern watermilfoil (Myriophyllum sibiricum Kom.), managers recognize that there is genetic variation for growth and herbicide response. However, it is unclear how much overall genetic variation there is, and how it is structured within and among populations. Here, we studied patterns of within- and among-lake genetic variation in 41 lakes in Michigan and 62 lakes in Minnesota using microsatellite markers. We found that within-lake genetic diversity was generally low, and among-lake genetic diversity was relatively high. However, some lakes were genetically diverse, and some genotypes were shared across multiple lakes. For genetically diverse lakes, managers should explicitly recognize the potential for genotypes to differ in control response and should account for this in monitoring and efficacy evaluation and using pretreatment herbicide screens to predict efficacy. Similarly, managers should consider differences in genetic composition among lakes as a source of variation in the growth and herbicide response of lakes with similar control tactics. Finally, laboratory or field information on control efficacy from one lake may be applied to other lakes where genotypes are shared among lakes.

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