GENETIC DIVERGENCE IN BABUL (ACACIA NILOTIKA)

2019 ◽  
Vol 25 (1) ◽  
Author(s):  
SUDHANSHU SHEKHAR ◽  
V.P. DWIVEDI ◽  
N.K. SRIVASTAVA
Keyword(s):  
Genetic Distance ◽  
Genetic Divergence ◽  
Acacia Nilotica ◽  
Hybridization Programme

Genetic divergence of Babul (Acacia nilotica) was assessed using Mahalanobis 0 statistics. They were grouped into eight clusters. Maximum genetic distance was recorded between III & VIII ciusters indicating greater distance between two clusters that showed maximum diversity amount the genotype and helps in hybridization programme.

scholarly journals Genetic Divergence in Indigenous Wild and Cultivated Rice Species of Manipur Valley

ISRN Genetics ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
K. Medhabati ◽  
K. Rajiv Das ◽  
M. Rohinikumar ◽  
H. Sunitibala ◽  
Th. Dikash Singh
Keyword(s):  
Genetic Divergence ◽  
Wild Rice ◽  
Flag Leaf ◽  
Cluster Formation ◽  
Leaf Length ◽  
Cultivated Rice ◽  
And Performance ◽  
Flag Leaf Length ◽  
The Individual ◽  
Hybridization Programme

Genetic divergence of 32 indigenous rice germplasms and five wild rice of which three from Manipur and two wild rice procured from IRRI, Philippines was investigated using Mahalanobis, D2 statistic. Based on twelve agromorphological characters, the thirty-seven germplasms both wild and cultivated were grouped into five clusters based on the relative magnitudes of D2 values following Tocher's method of cluster formation. Based on the rank totals, the characters which contributed maximum towards genetic divergence in the present studies were grain yield/plant, spikelet/panicle, 100 grain weight, grain length, days to 50% flowering, ear bearing tillers/plant, and flag leaf length. In the present study, maximum intercluster distance was estimated between cluster III and (D2=14.09) which was closed followed by clusters II and V (D2=12.50). On the basis of their greater intercluster distance, high value of cluster mean according to the character to be improved and performance of the individual germplasms for the character, the germplasms could be used in hybridization programme for improvement of different plant characters in the rice germplasms of Manipur.

scholarly journals Genetic divergence correlates with the contemporary landscape in populations of Slimy Salamander (Plethodon glutinosus) species complex across the lower Piedmont and Coastal Plain of the southeastern United States

2018 ◽  
Vol 96 (11) ◽  
pp. 1244-1254 ◽  
Author(s):  
Walter H. Smith ◽  
Jessica A. Wooten ◽  
Carlos D. Camp ◽  
Dirk J. Stevenson ◽  
John B. Jensen ◽  
...  
Keyword(s):  
South Carolina ◽  
Genetic Distance ◽  
Principal Components ◽  
Coastal Plain ◽  
Genetic Divergence ◽  
Species Complex ◽  
Isolation By Distance ◽  
Geographic Distance ◽  
Plethodon Glutinosus ◽  
Isolation By Environment

A primary goal of landscape genetics is to elucidate factors associated with genetic structure among populations. Among the important patterns identified have been isolation by distance (IBD), isolation by barrier (IBB), and isolation by environment (IBE). We tested hypotheses relating each of these possible patterns to genetic divergence in the Slimy Salamander (Plethodon glutinosus (Green, 1818)) species complex across the lower Piedmont and Coastal Plain of Georgia, USA, and adjacent areas of South Carolina, USA. We sequenced 2148 total bp, including three regions of the mitochondrial genome and a nuclear intron, and related genetic distance to GIS-derived surrogate variables representing possible IBD (geographic distance), IBE (principal components of 19 climate variables, watershed, and normalized difference vegetation index (NDVI)), and IBB (streams of fourth order and higher). Multiple matrix regression with randomization analysis indicated significant relationships between genetic distance and two principal components of climate, as well as NDVI. These results support roles for environment (IBE) in helping to drive genetic divergence in this group of salamanders. The absence of a significant influence of IBD and IBB was surprising. It is possible that the signal effects of geographic distance and barriers on genetic divergence may have been erased by more recent responses to the environment.

Heterosis in relation to genetic divergence in short duration maize (Zea mays L.)

2021 ◽  
pp. 137-142
Author(s):  
Bal Krishna ◽  
Birender Singh ◽  
Shyam Sundar Mandal ◽  
Rashmi Kumari ◽  
Tushar Ranjan
Keyword(s):  
Genetic Distance ◽  
Genetic Divergence ◽  
Zea Mays L ◽  
Correlation Coefficients ◽  
Negative Association ◽  
Coefficient Of Determination ◽  
Maize Hybrids ◽  
Single Cross ◽  
Per Se ◽  
Linear Regressions

Thirteen lines and three testers were used to produce 39 single cross maize hybrids by line Ítester mating design. The genetic divergence among thirteen lines and three tester of maize were estimated by using Mahalanobis D2 statistic for twelve characters. The genotypes were grouped into five clusters. Cluster I comprised 12 parental genotypes (L1, L2, L3, L4, L5; L6, L7, L8, L9, L11; L12, L13), while Cluster II (T3), III (T1), IV (L10) and V (T2) were mono-genotypic, suggesting more variability in genetic makeup of the genotypes included in these clusters. The correlation coefficients and linear regressions were used to know the effects of parental genetic distance in determining heterosis and per se performance of the hybrids. Parental genetic distance exhibited significant negative association and significant linear regression along with very low coefficient of determination with better parent heterosis (BPH) and non-significant with per se performance of the hybrids. The present investigation, therefore, the parental genetic distance has significant role in determining heterosis and hybrid performance in kharif maize.

GENETIC DIVERGENCE AMONG EASTERN NORTH AMERICAN CONE BEETLES, CONOPHTHORUS (COLEOPTERA: SCOLYTIDAE)

1992 ◽  
Vol 124 (1) ◽  
pp. 189-199 ◽  
Author(s):  
Peter de Groot ◽  
George T. Harvey ◽  
Pat M. Roden
Keyword(s):  
Genetic Distance ◽  
Genetic Divergence ◽  
Null Hypothesis ◽  
Red Pine ◽  
Fixation Index ◽  
Pairwise Comparisons ◽  
White Pine ◽  
Genotype Frequencies ◽  
Electrophoretic Data ◽  
Pine Cones

AbstractGenetic divergence among populations of cone beetles, Conophthorus banksianae McPherson, C. coniperda (Schwarz), and C. resinosae Hopkins, was assessed by isozyme electrophoretic data. All but one of the eight loci examined were polymorphic, and one locus (Pgi) was sex-linked for C. coniperda. Genotype frequencies generally met Hardy-Weinberg expectations, and fixation index (FST) values indicated low-to-moderate genetic differences among conspecific populations. Fixed allele differences were detected at two loci, Pgi and Dia-2, which separated C. resinosae from C. coniperda, and thus confirmed their specific status established previously by morphological, karyological, and other biochemical characters. Electrophoretic data strongly suggested C. coniperda does not attack red pine cones, and C. resinosae does not attack white pine cones. No diagnostic loci were found to separate C. resinosae from C. banksianae. Phenetic clustering and pairwise comparisons of genetic distance coefficients indicated very little genetic divergence between C. resinosae and C. banksianae. These data were interpreted as failing to reject the null hypothesis that C. resinosae and C. banksianae are one species, an interpretation consistent with available taxonomic evidence from ecological, karyological, and other biochemical characters.

scholarly journals Genetic distance estimated by RAPD markers and its relationship with hybrid performance in maize

2006 ◽  
Vol 41 (10) ◽  
pp. 1491-1498 ◽  
Author(s):  
Daniela Cristina Bruel ◽  
Valéria Carpentieri-Pípolo ◽  
Antonio Carlos Gerage ◽  
Nelson da Silva Fonseca Júnior ◽  
Cássio Egídio Cavenaghi Prete ◽  
...  
Keyword(s):  
Genetic Distance ◽  
Genetic Divergence ◽  
Random Amplified Polymorphic Dna ◽  
Block Design ◽  
Heterotic Group ◽  
Hybrid Performance ◽  
Jaccard Coefficient ◽  
Genetic Associations ◽  
Heterotic Groups ◽  
Random Block Design

The objective of this work was to evaluate the genetic diversity of 16 maize inbred lines, and to determine the correlation between genetic distance and hybrid performance, using random amplified polymorphic DNA (RAPD) molecular markers. Twenty-two different random primers were used, which resulted in the amplification of 265 fragments, 237 (84.44%) of them being polymorphic. A genetic similarity matrix was created from the RAPD data, using Jaccard coefficient, and a dendrogram was constructed. Hybrid analyses were carried out using random block design and Griffing method VI for diallel crossings. The genetic associations showed five distinct heterotic groups. Correlations between genetic divergences detected by RAPD, as well as the means observed in the diallel crossings were positive and significant for plant height, ear height, prolificacy, and grain weight. The correlation of genetic divergences, detected by RAPD, and the specific combining ability between heterotic group associations, showed significance in all characteristics under study, except prolificacy. A direct relationship between genetic divergence and productivity was found in 79.2% of the 120 hybrids confirming the hypothesis that genetic divergence is directly related to the performance of hybrids and is efficient in predicting it.

scholarly journals GENETIC CHANGE AND RATES OF CLADOGENESIS

Genetics ◽  
1975 ◽  
Vol 81 (4) ◽  
pp. 757-773
Author(s):  
John C Avise ◽  
Francisco J Ayala
Keyword(s):  
Genetic Differentiation ◽  
Genetic Distance ◽  
Genetic Divergence ◽  
Natural Populations ◽  
Genetic Distances ◽  
Genetic Change ◽  
The Other ◽  
Limited Information ◽  
History Of ◽  
The Relationship

ABSTRACT Models are introduced which predict ratios of mean levels of genetic divergence in species-rich versus species-poor phylads under two competing assumptions: (1) genetic differentiation is a function of time, unrelated to the number of cladogenetic events and (2) genetic differentiation is proportional to the number of speciation events in the group. The models are simple, general, and biologically real, but not precise. They lead to qualitatively distinct predictions about levels of genetic divergence depending upon the relationship between rates of speciation and amount of genetic change. When genetic distance between species is a function of time, mean genetic distances in speciose and depauperate phylads of equal evolutionary age are very similar. On the contrary, when genetic distance is a function of the number of speciations in the history of a phylad, the ratio of mean genetic distances separating species in speciose versus depauperate phylads is greater than one, and increases rapidly as the frequency of speciations in one group relative to the other increases. The models may be tested with data from natural populations to assess (1) possible correlations between rates of anagenesis and cladogenesis and (2) the amount of genetic differentiation accompanying the speciation process. The data collected in electrophoretic surveys and other kinds of studies can be used to test the predictions of the models. For this purpose genetic distances need to be measured in speciose and depauperate phylads of equal evolutionary age. The limited information presently available agrees better with the model predicting that genetic change is primarily a function of time, and is not correlated with rates of speciation. Further testing of the models is, however, required before firm conclusions can be drawn.

scholarly journals Genetic Divergence Studies in Ailanthus excelsa Using D2 Analysis

2019 ◽  
pp. 416-424
Author(s):  
S. Umesh Kanna ◽  
N. Krishnakumar ◽  
K. Md. Mohideen Abdul Kather Jailani
Keyword(s):  
Genetic Diversity ◽  
Genetic Distance ◽  
Genetic Divergence ◽  
Volume Index ◽  
Maximum Percentage ◽  
Ailanthus Excelsa ◽  
Cluster Distance ◽  
Growth Attributes ◽  
Diversity Studies ◽  
Statistical Results

Aims: To estimate the genetic diversity studies among the biometric attributes of 30 progenies in Ailanthus excelsa Roxb. Place and Duration of Study: The study has conducted at Forest College and Research Institute, TNAU, Mettupalayam during 2015-2018. Methodology: The D2 statistics was adopted for the estimation of genetic divergence. Using D2 statistical results, the clustering of progenies was done. The progenies were grouped into different clusters using ‘GENERES’ statistical package on the basis of D2 values according to Tocher’s method as suggested by Rao. Results: The 30 progeny of Ailanthus excelsa has grouped into nine clusters and among the nine clusters, the cluster IV has ten progenies. The maximum intra cluster distance was exhibited by the cluster VIII followed by cluster IV. The maximum inter cluster distance was in cluster III which indicated the presence of wider genetic distance between Ailanthus excelsa progenies. Among the growth attributes, volume index contributed maximum percentage towards genetic divergence. Conclusion: The results of 30 progeny of Ailanthus excels showed the presence of wider genetic distance between Ailanthus excelsa progenies.

scholarly journals Characterization and Heterotic Grouping of Traditional Assam rice (Oryza sativa L.)

2021 ◽  
Author(s):  
Praveen Kumar ◽  
Debojit Sarma ◽  
Mainu Hazarika
Keyword(s):  
Genetic Distance ◽  
Genetic Divergence ◽  
Upland Rice ◽  
Oryza Sativa L ◽  
Heterotic Groups ◽  
Heterotic Grouping ◽  
Rice Genotypes ◽  
Half Diallel ◽  
Simple Sequence

AbstractParents of heterotic hybrids are derived from different heterotic groups with high genetic divergence. Classification of traditional Assam rice germplasm in divergent pools will be advantageous to maximize the heterosis and thereby to ensure food security. In the present investigation, a group of 60 upland rice genotypes were characterized using 53 polymorphic simple sequence repeats (SSR) markers out of 83 molecular markers. The genetic divergence study using unweighted Neighbour-joining (UNJ) method clustered the 60 genotypes into 3 major clusters. The eleven most divergent genotypes identified were crossed in half diallel fashion to determine the mid-parent and better-parent heterosis values for the objective of heterotic grouping. No correlation between heterosis and genetic distance can be attributable to the use of a subset of markers not linked to yield or concerned. In genetic distance based heterotic grouping, the intra-group hybrids were recorded a higher frequency of crosses, grain yield per plant, specific combining ability effect, mid parent heterosis, better parent heterosis and standard parent heterosis value than those of inter-group hybrids. Overall, sn extensive choice of parents with attractive traits constellation leading to increased yield of the hybrids for much better complementation must be stressed along with a substantial hereditary distance for augmentation of yield heterosis.

scholarly journals IMPACT OF PARENTS GENETIC DIVERGENCE ON HETEROSIS OF F1-HYBRIDS OF SPRING TRITICALE

2012 ◽  
Vol 10 (3) ◽  
pp. 3-9
Author(s):  
Olga A Orlovskaya ◽  
Lidia V Koren ◽  
Lubov V Khotyleva
Keyword(s):  
Genetic Distance ◽  
Genetic Relationship ◽  
Genetic Divergence ◽  
Rapd Markers ◽  
F1 Hybrids ◽  
Molecular Heterogeneity ◽  
Spring Triticale

Molecular heterogeneity was studied in 20 spring triticale accessions by using ISSR- and RAPD-markers, which allowed the studied material to be grouped according to the degree of genetic relationship and to choose genetically distant parental pairs for crosses to obtain heterotic hybrids. Expression of heterosis of F1 triticale hybrids was studied. Evaluation of the degree of parents genetic divergence on the heterosis level of F1-hybrids revealed that increase of genetic distance values between parental components leads to higher probability of obtaining heterotic hybrids.

Genetic divergence in mandible form in relation to molecular divergence in inbred mouse strains.

Genetics ◽  
1988 ◽  
Vol 120 (1) ◽  
pp. 239-253
Author(s):  
W R Atchley ◽  
S Newman ◽  
D E Cowley
Keyword(s):  
Genetic Distance ◽  
Genetic Divergence ◽  
Inbred Mouse ◽  
Inbred Strains ◽  
Morphological Data ◽  
Mouse Strains ◽  
Genealogical Relationship ◽  
Inbred Strains Of Mice ◽  
Molecular Divergence ◽  
Highly Correlated

Abstract Genetic divergence in the form of the mandible is examined in ten inbred strains of mice. Several univariate and multivariate genetic distance estimates are given for the morphological data and these estimates are compared to measures of genealogical and molecular divergence. Highly significant divergence occurs among the ten strains in all 11 mandible traits considered individually and simultaneously. Genealogical relationship among strains is highly correlated with genetic divergence in single locus molecular traits. However, the concordance between genealogical relationship and multivariate genetic divergence in morphology is much more complex. Whether there is a significant correlation between morphological divergence and genealogy depends upon the method of analysis and the particular genetic distance statistic being employed.

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