Analysis of phenotypic and genetic variations among populations of Oryza malampuzhaensis show evidence of altitude-dependent genetic changes

2001 ◽  
Vol 79 (9) ◽  
pp. 1090-1098 ◽  
Author(s):  
George Thomas ◽  
Latha Joseph ◽  
George Varghese ◽  
Sreejayan K Kalyanaraman ◽  
Philomena Kuriachan

Oryza malampuzhaensis Krish. et Chand., one of the tetraploid taxa in the genus Oryza (Poaceae), is geographically restricted to Western Ghats, southern India. This is one of the poorly understood taxa in the genus, and not much is known about the nature and distribution of its genetic diversity. Five individuals each were selected randomly from 11 populations of O. malampuzhaensis from different altitudinal habitats and were grown in a common-garden experiment for 3 years (1994-1997). Sixty morphological traits and 87 random amplified polymorphic DNA (RAPD) markers, generated by 14 random primers, were used to study the genetic variation among the populations. Elevation-dependent phenotypic variation was observed for a suite of metric traits. A scatterplot of mean values for these traits separated the populations from low, middle, and high altitudes into distinct groups. Cluster analysis using RAPD distance grouped the populations according to their altitudinal habitat, and a similar pattern of clustering was observed with respect to morphological distance also. The mean of both RAPD- and morphology-based pairwise genetic distance of populations belonging to similar altitudinal levels differed significantly. These estimates also depicted a significant decrease in genetic distance with increasing altitude. The results demonstrate that (i) effective isolation from gene flow coupled with natural selection governs genetic structure in O. malampuzhaensis and (ii) ecological heterogeneity associated with elevational gradient has a crucial role in the evolution of O. malampuzhaensis.Key words: Oryza malampuzhaensis, altitude, RAPD, morphological traits, genetic variations, molecular ecology.


2001 ◽  
Vol 79 (9) ◽  
pp. 1090-1098 ◽  
Author(s):  
George Thomas ◽  
Latha Joseph ◽  
George Varghese ◽  
Sreejayan K. Kalyanaraman ◽  
Philomena Kuriachan


2011 ◽  
Vol 41 (No. 2) ◽  
pp. 73-78 ◽  
Author(s):  
L. Milella ◽  
J. Salava ◽  
G. Martelli ◽  
I. Greco ◽  
E.F. Cusimamani ◽  
...  

Random amplified polymorphic DNA (RAPD) markers are widely used for evaluating the genetic relationship of crop germplasm. Five different landraces of yacon (Smallantus sonchifolius (Poepp. and Hendl.) H. Robinson; Asteraceae) collected in various countries and showing different morphological traits were investigated using a total of 61 decamer primers. A total of 282 RAPD markers were scored and 28.7% of them were polymorphic at least within landraces. RAPD markers generated by one primer (OBP14) discriminated between all landraces. Markers were used to calculate genetic similarity coefficient and to build a dendrogram representing the genetic relationship between analysed landraces. The results suggest that RAPD markers could be used as a reliable tool to perform fingerprinting studies in Smallantus sonchifolius genome. This is the first report on the use of RAPDs to evaluate genetic distance and to distinguish between different landraces in yacon.  



2013 ◽  
Vol 20 (1-2) ◽  
pp. 1-8
Author(s):  
MM Rahman ◽  
L Rahman ◽  
SN Begum ◽  
F Nur

Random Amplified Polymorphic DNA (RAPD) assay was initiated for molecular genetic analysis among 13 F3 rice lines and their parents. Four out of 15 decamer random primers were used to amplify genomic DNA and the primers yielded a total of 41 RAPD markers of which 37 were considered as polymorphic with a mean of 9.25 bands per primer. The percentage of polymorphic loci was 90.24. The highest percentage of polymorphic loci (14.63) and gene diversity (0.0714) was observed in 05-6 F3 line and the lowest polymorphic loci (0.00) and gene diversity (0.00) was found in 05-12 and 05-15 F3 lines. So, relatively high level of genetic variation was found in 05-6 F3 line and it was genetically more diverse compared to others. The average co-efficient of gene differentiation (GST) and gene flow (Nm) values across all the loci were 0.8689 and 0.0755, respectively. The UPGMA dendrogram based on the Nei’s genetic distance differentiated the rice genotypes into two main clusters: PNR-519, 05-19, 05-14, 05-12 and 05-17 grouped in cluster 1. On the other hand, Baradhan, 05-9, 05-13, 05-11, 05-5, 05-6, 05-1, 05-4, 05-15 and 05-25 were grouped in cluster 2. The highest genetic distance (0.586) was found between 05-4 and 05-17 F3 lines and they remain in different cluster.DOI: http://dx.doi.org/10.3329/pa.v20i1-2.16839 Progress. Agric. 20(1 & 2): 1 – 8, 2009



Mobile DNA ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guillaume Wos ◽  
Rimjhim Roy Choudhury ◽  
Filip Kolář ◽  
Christian Parisod

Abstract Background Plant genomes can respond rapidly to environmental changes and transposable elements (TEs) arise as important drivers contributing to genome dynamics. Although some elements were reported to be induced by various abiotic or biotic factors, there is a lack of general understanding on how environment influences the activity and diversity of TEs. Here, we combined common garden experiment with short-read sequencing to investigate genomic abundance and expression of 2245 consensus TE sequences (containing retrotransposons and DNA transposons) in an alpine environment in Arabidopsis arenosa. To disentangle general trends from local differentiation, we leveraged four foothill-alpine population pairs from different mountain regions. Seeds of each of the eight populations were raised under four treatments that differed in temperature and irradiance, two factors varying with elevation. RNA-seq analysis was performed on leaves of young plants to test for the effect of elevation and subsequently of temperature and irradiance on expression of TE sequences. Results Genomic abundance of the 2245 consensus TE sequences varied greatly between the mountain regions in line with neutral divergence among the regions, representing distinct genetic lineages of A. arenosa. Accounting for intraspecific variation in abundance, we found consistent transcriptomic response for some TE sequences across the different pairs of foothill-alpine populations suggesting parallelism in TE expression. In particular expression of retrotransposon LTR Copia (e.g. Ivana and Ale clades) and LTR Gypsy (e.g. Athila and CRM clades) but also non-LTR LINE or DNA transposon TIR MuDR consistently varied with elevation of origin. TE sequences responding specifically to temperature and irradiance belonged to the same classes as well as additional TE clades containing potentially stress-responsive elements (e.g. LTR Copia Sire and Tar, LTR Gypsy Reina). Conclusions Our study demonstrated that the A. arenosa genome harbours a considerable diversity of TE sequences whose abundance and expression response varies across its native range. Some TE clades may contain transcriptionally active elements responding to a natural environmental gradient. This may further contribute to genetic variation between populations and may ultimately provide new regulatory mechanisms to face environmental challenges.



2008 ◽  
Vol 88 (2) ◽  
pp. 307-312
Author(s):  
Zhao Mengli ◽  
Han Bing ◽  
Walter D Willms

Mountain rough fescue (Festuca campestris Rydb.) is a tufted native grass in southern Alberta and British Columbia, Canada, and has attracted interest for use in reclamation. However, its seed is often available from only a few localized sources and may not be adapted for areas removed from the collection site. We conducted a study to determine the genetic variability among rough fescue populations to assess its potential adaptation. Thirty plants were collected from each of six populations and analyzed using Random Amplified Polymorphic DNA (RAPD). One population (Kamloops, BC) was separated by several mountain ranges from the five easterly Alberta populations.The Kamloops population was also separated from the Alberta populations by genetic distance in two clusters. Of the total genetic variation present in the data, 21% was found among populations while the remaining (79%) was found within populations. Nei’s genetic distances among populations were related to their geographical distances. Genetic differences among populations appeared to be caused primarily by differences in gene frequencies rather than rare genes. Also, genetic diversity appeared to increase from west to east suggesting that the more easterly populations had greater adaptation potential. We speculate that the more easterly populations are less likely to share genes since the prevailing winds are from the west. Germplasm from the more easterly populations may be used with suitable precautions within Alberta and possibly around Kamloops. Key words: Genetic distance, geographic distance, reclamation, potential adaptation



2021 ◽  
Vol 20 (4) ◽  
pp. 848-854
Author(s):  
Md Faruque Miah ◽  
Md Shad Ebna Rahaman ◽  
Sanjana Fatema Chowdhury ◽  
Mohammad Golam Rob Mahmud

Background: The genetic variability of Umbilical Cord Blood (UCB) is most important for newborn screening, therapeutic possibility of haematological disorders as well as for the establishment of cord blood banking and stem cell research. Method: Genetic variability of umbilical cord blood (UCB) of 22 human subjects was evaluated first time by applying Random Amplified Polymorphic DNA (RAPD) assay using six decamar primers (B-14, OPB-05, OPB-08, OPB-12, OPB-19 and UBC-122). Result: A total number of bands were recorded 312 from 116 polymorphic loci and single monomorphic locus. All the markers showed highest polymorphism (100%) except the primer OPB 08 (92.31%) among tested individuals. The genetic distance was observed with highest 1.0 and lowest 0.72 respectively whereas mean genetic distance was recorded 0.90. Considering Shannon-Wiener index average diversity was recorded 0.139365. The mean Nei genetic similarity was found 0.17 which was found opposition to genetic distances. A phylogenetic relationship among the individual subjects was also observed between the linkage distances of 11 to 27 with 8 clades, 3 subclusters and a cluster. In addition, average allele frequency p and q was observed 0.08156 and 0.948751 respectively whereas highest intra locus gene diversity and average gene diversity were found 3.323817 and 0.144572 respectively. Conclusion: Considering different parameters, higher genetic variability was found among the experimental subjects, probably due to the mixture DNA of parents and newborn. Bangladesh Journal of Medical Science Vol.20(4) 2021 p.848-854





Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1067
Author(s):  
Aalap Dixit ◽  
Thomas Kolb ◽  
Owen Burney

Ponderosa pine (Pinus ponderosa Lawson & C. Lawson var. scopulorum Engelm.) forests of the southwestern US are threatened by climate change and deforestation. Information about geographic patterns of provenance variation in budburst phenology is needed to make decisions about selecting seed sources for future planting. In this study, provenance variation in the budburst phenology of ponderosa pine seedlings was examined using common garden studies. Seedlings from 21 provenances, representing an elevational gradient in Arizona and New Mexico, were planted in July 2018 at a ponderosa pine-dominated field site in northern Arizona. Field budburst was monitored weekly on all seedlings in the spring of 2019. Field budburst was compared with budburst timing of the same provenances measured under greenhouse conditions. The hypotheses for this study were that (1) budburst varies among provenances, with earlier budburst in low-elevation provenances, and (2) differences in budburst timing among provenances are consistent for seedlings grown in greenhouse and field environments. Field results show that provenances vary in budburst date and that low- and middle-elevation provenances break bud sooner than high-elevation provenances. Field budburst date had a moderate, positive correlation with provenance mean annual precipitation (r = 0.522) and a moderate, negative trend with latitude (r = −0.413). Budburst date of provenances in the greenhouse had a moderate, positive trend with budburst date in the field (r = 0.554), suggesting application of greenhouse results to field plantings. Such information about provenance variation and environmental and geographic trends in budburst timing will be useful for developing species-specific seed transfer guidelines and effective assisted migration strategies in a changing climate.



2012 ◽  
Vol 22 (1) ◽  
pp. 51-58 ◽  
Author(s):  
M.E. Hoque ◽  
M.M. Hasan

Random Amplified Polymorphic DNA (RAPD) markers were used to study the molecular genetic diversity analysis among six BARI released lentil varieties viz. BARI masur-1, BARI masur-2, BARI masur-3, BARI masur-4, BARI masur-5 and BARI masur-6. PCR amplified products were visualized on 1.0% agarose gel and the band for each primer were scored. Ten RAPD markers were used in this study. Out of them 7 primers showed amplification of 53 DNA fragments with 60.37% of them being polymorphic. The highest number of polymorphic loci was noticed in the variety BARI masur-3. The same variety also showed maximum Nei’s gene diversity value (0.0552). The highest Nei’s genetic distance (0.5002) was observed in BARI masur-1 vs. BARI masur-5 whereas, the lowest genetic distance (0.0692) was found in BARI masur-1 vs. BARI masur-2. The unweighted pair group method of arithmetic mean (UPGMA) dendrogram based on Nei’s genetic distance grouped the six cultivars into two main clusters. BARI masur-1, BARI masur-2 and BARI masur-3 were in cluster I and BARI masur-4, BARI masur-5 and BARI masur-6 were in cluster II. The cultivar BARI masur-4 was closest to the cultivar BARI masur-6 with the lowest genetic distance (0.0972) and the highest genetic distance (0.5002) was found between BARI masur-1 and BARI masur-5. The RAPD markers were found to be useful in molecular characterization of lentil varieties which could be utilized by the breeders for the improvement of lentil cultivars. DOI: http://dx.doi.org/10.3329/ptcb.v22i1.11260 Plant Tissue Cult. & Biotech. 22(1): 51-58, 2012 (June)



2007 ◽  
Vol 55 (3) ◽  
pp. 375-382 ◽  
Author(s):  
S. Mamo ◽  
A. Ayana ◽  
T. Tesso

A study on the extent and pattern of genetic variability in late-maturing sorghum [ Sorghum bicolor (L.) Moench] landraces collected from the Wello and Hararge areas of Ethiopia was conducted using random amplified polymorphic DNA (RAPD) markers for 70 individuals representing 14 populations. Four oligonucleotide primers generated a total of 55 polymorphic bands with 13–19 bands per primer and a mean of 16 bands across the 70 individuals. The value of the Shannon diversity index among the populations (0.26) and between the two regions (0.24) was low to moderate, despite the high degree of polymorphic bands per primer. The mean genetic distance (0.25) between the populations was found to be low. The low genetic variation may be due to the reduced population size of late-maturing sorghum landraces in the two regions of Ethiopia because of farmers’ decisions in the process of planting, managing, harvesting and processing their crops. Partitioning of the genetic variation into variation between and within the population revealed that 92.9% and 7.10% of the variation was found to be between and within the populations, respectively. Cluster analysis of genetic distance estimates further confirmed a low level of differentiation in late-maturing sorghum populations both between and within the regions. The implications of the results for genetic conservation purposes are discussed.



Sign in / Sign up

Export Citation Format

Share Document