scholarly journals Gene flow among wild and cultivated common walnut (Juglans regia) trees in the Qinling Mountains revealed by microsatellite markers

Author(s):  
Huijuan Zhou ◽  
Peng Zhao ◽  
Keith Woeste ◽  
Shuoxin Zhang

AbstractPatterns of gene flow and gene introgression can be used to assess the risk of genetic pollution of wild forest trees from widespread cultivated trees. A comprehensive understanding of the genetic relationships and levels of gene flow among wild and cultivated common walnut (Juglans regia) has become an urgent issue. Using twelve microsatellite markers, we investigated the genetic diversity and gene flow between cultivated and wild trees of J. regia in the Qinling Mountains, China. A high level of genetic variation was detected in both cultivated and wild trees. The mean number of alleles per locus was 17.5. Observed heterozygosity (HO) and expected heterozygosity (HE) were 0.777 and 0.800, respectively. Pollination of mother trees was not by nearest neighbors, and a paternity of 60.7% of offspring evaluated could not be assigned to a local, sampled tree. Pollen flow from cultivated trees to wild trees was infrequent (5.4%), and selfing rates ranged from zero to 25.0%. Male parents were located from 0 to 1005 m from their female partners, with an average pollination distance of 285.1 m. These results are discussed in light of the cultivated species' diversity, outlining the frequent spontaneous genetic contributions from the wild to the cultivated compartment. In addition, the pollen flow parameters provide useful information about the dynamics of pollen movement within J. regia populations.

2021 ◽  
Vol 3 (4) ◽  
pp. 77-96
Author(s):  
O. Yu. Antonova ◽  
N. S. Klimenko ◽  
D. A. Rybakov ◽  
N. A. Fomina ◽  
V. V. Zheltova ◽  
...  

The N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) is developing new approaches to documentation of national cultivars, taking into account recommendations of the International Code of Nomenclature for Cultivated Plants in parallel with methods of genetic certification. The nomenclatural standard of a particular cultivar represented by a herbarium specimen can be used as a reference for verifying authenticity and uniformity of cultivar specimens obtained from various sources. The verification requires fast and reliable methods for cultivar genotyping. This paper presents protocols for modified methods of DNA extraction, PCR-analysis and SSR-genotyping, which allow potato cultivars identification without the use of expensive reagent kits. A set of ten chromosome-specific microsatellite markers was used to study polymorphisms in 66 modern Russian potato cultivars, as well as in 11 pre-cultivars and breeding clones, represented by nomenclatural standards and voucher specimens, respectively. This subset of 77 specimens has demonstrated a high level of polymorphism in ten studied microsatellite loci. The SSR analysis identified 73 alleles; 7.3 alleles per locus were observed on average, the number of which varied from 3 (STG0025 locus) to 11 (locus StI046). The PIC values varied from 0.544 (STG0025 locus) to 0.836 (StI046 locus). The alleles, unique for this subset, were found at six studied loci. The high level of polymorphism at the SSR loci made it possible to unambiguously identify almost every cultivar, with the exception of the expected coincidence of microsatellite profiles of two cultivars, which are somaclonal variants. Using an optimized set of eight microsatellite markers, the genetic relationships of modern Russian potato cultivars were studied.


2006 ◽  
Vol 131 (3) ◽  
pp. 352-359 ◽  
Author(s):  
Innocenzo Muzzalupo ◽  
Nicola Lombardo ◽  
Aldo Musacchio ◽  
Maria Elena Noce ◽  
Giuseppe Pellegrino ◽  
...  

Genetic diversity studies using microsatelite analysis were carried out in a set of 39 accessions of Olea europaea L., corresponding to the majority of the regional autochthon germplasm in Apulia. Samples of olive leaves were harvested from plants growing in the olive germplasm collection of the Consiglio per la Ricerca e Sperimentazione in Agricoltura (C.R.A.) - Istituto Sperimentale per l'Olivicoltura at Rende in Cosenza Italy. Herein, we evaluated the extent to which microsatellite analysis using electrophoresis was capable of identifying traditional olive cultivars. In addition, the DNA sequence of all amplicons was determined and the number of repeat units was established for each sample. Using five loci, electrophoretic analysis identified 24 genotype profiles, while DNA sequence analysis detected 28 different genotype profiles, identifying 54% of cultivars. The remaining 46% were composed of seven different accession groups containing genetically indistinguishable cultivars, which are presumably synonyms. This study demonstrates the utility of microsatellite markers for management of olive germplasm and points out the high level of polymorphisms in microsatellite repeats when coupled with DNA sequence analysis. The establishment of genetic relationships among cultivars in the Apulian germplasm collection allows for the construction of a molecular database that can be used to establish the genetic relationships between known and unknown cultivars.


Genetics ◽  
2000 ◽  
Vol 154 (3) ◽  
pp. 1309-1321 ◽  
Author(s):  
Frédéric Austerlitz ◽  
Stéphanie Mariette ◽  
Nathalie Machon ◽  
Pierre-Henri Gouyon ◽  
Bernard Godelle

Abstract Tree species are striking for their high within-population diversity and low among-population differentiation for nuclear genes. In contrast, annual plants show much more differentiation for nuclear genes but much less diversity than trees. The usual explanation for this difference is that pollen flow, and therefore gene flow, is much higher for trees. This explanation is problematic because it relies on equilibrium hypotheses. Because trees have very recently recolonized temperate areas, they have experienced many foundation events, which usually reduce within-population diversity and increase differentiation. Only extremely high levels of gene flow could counterbalance these successive founder effects. We develop a model to study the impact of life cycle of forest trees, in particular of the length of their juvenile phase, on genetic diversity and differentiation during the glacial period and the following colonization period. We show that both a reasonably high level of pollen flow and the life-cycle characteristics of trees are needed to explain the observed structure of genetic diversity. We also show that gene flow and life cycle both have an impact on maternally inherited cytoplasmic genes, which are characterized both in trees and annual species by much less diversity and much more differentiation than nuclear genes.


Author(s):  
V. Dodokhov ◽  
N. Pavlova ◽  
T. Rumyantseva ◽  
L. Kalashnikova

The article presents the genetic characteristic of the Chukchi reindeer breed. The object of the study was of the Chukchi reindeer. In recent years, the number of reindeer of the Chukchi breed has declined sharply. Reduced reindeer numbers could lead to biodiversity loss. The Chukchi breed of deer has good meat qualities, has high germination viability and is adapted in adverse tundra conditions of Yakutia. Herding of the Chukchi breed of deer in Yakutia are engaged only in the Nizhnekolymsky district. There are four generic communities and the largest of which is the agricultural production cooperative of nomadic tribal community «Turvaurgin», which was chosen to assess the genetic processes of breed using microsatellite markers: Rt6, BMS1788, Rt 30, Rt1, Rt9, FCB193, Rt7, BMS745, C 143, Rt24, OheQ, C217, C32, NVHRT16, T40, C276. It was found that microsatellite markers have a wide range of alleles and generally have a high informative value for identifying of genetic differences between animals and groups of animal. The number of identified alleles is one of the indicators of the genetic diversity of the population. The total number of detected alleles was 127. The Chukchi breed of deer is characterized by a high level of heterozygosity, and the random crossing system prevails over inbreeding in the population. On average, there were 7.9 alleles (Na) per locus, and the mean number of effective alleles (Ne) was 4.1. The index of fixation averaged 0.001. The polymorphism index (PIC) ranged from 0.217 to 0.946, with an average of 0.695.


2011 ◽  
Vol 46 (9) ◽  
pp. 1035-1044 ◽  
Author(s):  
Patrícia Coelho de Souza Leão ◽  
Sérgio Yoshimitsu Motoike

The objective of this work was to analyze the genetic diversity of 47 table grape accessions, from the grapevine germplasm bank of Embrapa Semiárido, using 20 RAPD and seven microsatellite markers. Genetic distances between pairs of accessions were obtained based on Jaccard's similarity index for RAPD data and on the arithmetic complement of the weighted index for microsatellite data. The groups were formed according to the Tocher's cluster analysis and to the unweighted pair‑group method with arithmetic mean (UPGMA). The microsatellite markers were more efficient than the RAPD ones in the identification of genetic relationships. Information on the genetic distance, based on molecular characteristics and coupled with the cultivar agronomic performance, allowed for the recommendation of parents for crossings, in order to obtain superior hybrids in segregating populations for the table grape breeding program of Embrapa Semiárido.


2011 ◽  
Vol 59 (6) ◽  
pp. 515 ◽  
Author(s):  
Tian Tang ◽  
Lian He ◽  
Feng Peng ◽  
Suhua Shi

Hibiscus tiliaceus L. (Malvaceae) is a pantropical coastal tree that extends to the tidal zone. In this study, the retrotransposon sequence-specific amplified polymorphism (SSAP) technique was used in order to understand the genetic variation between four population pairs of H. tiliaceus from repeated estuarine and inland habitat contrasts in China. The estuarine populations were consistently more genetic variable compared with the inland ones, which may be attributed to extensive gene flow via water-drifted seeds and/or retrotransposon activation in stressful estuarine environments. An AMOVA revealed that 8.9% of the genetic variance could be explained by the habitat divergence within site, as compared with only 4.9% to geographical isolation between sites, which indicates significant habitat differentiation between the estuarine and inland populations. The estuarine populations were less differentiated (ΦST = 0.115) than the inland (ΦST = 0.152) implying frequent gene interchange in the former. Accordingly, the principal coordinate analysis of genetic distance between individuals revealed that genetic relationships are not fully consistent with the geographic association. These results suggest that despite substantial gene flow via sea-drifted seeds, habitat-related divergent selection could be one of the primary mechanisms that drive habitat differentiation in H. tiliaceus at a local ecological scale.


2005 ◽  
Vol 1 (4) ◽  
pp. 174-183 ◽  
Author(s):  
Yoshinari Moriguchi ◽  
Naoki Tani ◽  
Sinji Itoo ◽  
Fuminori Kanehira ◽  
Kouji Tanaka ◽  
...  

2018 ◽  
Author(s):  
Bruce F Murray ◽  
Michael A Reid ◽  
Shu-Biao Wu

Duma florulenta and Acacia stenophylla are two ecologically important but understudied species that naturally occur on the floodplains and riverbanks of Australia’s arid and semi-arid river systems. This paper describes the discovery and characterization of 12 and 13 polymorphic microsatellite markers for D. florulenta and A. stenophylla respectively. The number of alleles per locus for D. florulenta ranged from 2-12 with an average of 6.1. Across all samples, observed and expected heterozygosities ranged from 0.026 to 0.784 and 0.026 to 0.824 respectively and mean polymorphic information content was equal to 0.453. For A. stenophylla, the number of alleles per locus ranged between 2 and 8 with an overall mean of 4.8. Across all samples, observed and expected heterozygosities ranged from 0.029 to 0.650 and 0.029 to 0.761 respectively and mean polymorphic information content was 0.388. The developed suites of 12 and 13 microsatellite markers for D. florulenta and A. stenophylla respectively provide opportunity for novel research into mechanisms of gene flow, dispersal and breeding system and how they operate under the extreme variability these species are exposed to in the environments in which they live.


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