scholarly journals Genetic structure and diversity of a collection of Brassica rapa subsp. rapa L. revealed by simple sequence repeat markers

2011 ◽  
Vol 149 (5) ◽  
pp. 617-624 ◽  
Author(s):  
P. SOENGAS ◽  
M. E. CARTEA ◽  
M. FRANCISCO ◽  
M. LEMA ◽  
P. VELASCO

SUMMARYBrassica rapa subsp. rapa L. includes three different crops: turnips (roots), turnip greens (leaves) and turnip tops (inflorescences). A collection of B. rapa subsp. rapa from north-western Spain is currently kept at ‘Misión Biológica de Galicia’ (a research centre of the Consejo Superior de Investigaciones Científicas (CSIC), Spain). This collection has been characterized based on morphological and agronomical traits. A better understanding of the genetic diversity present in the collection is necessary in order to optimize its use and maintenance. The objectives of the present work were to assess the genetic diversity present in the B. rapa subsp. rapa collection, to establish genetic relationships among populations and to study the genetic structure of the collection. Eighty populations were analysed based on 18 simple sequence repeats (SSRs). Populations showed a broad range of genetic diversity, thus offering good potential for further genetic improvement. Most of the variability was found within the population level, probably due to high rates of allogamy, to migration and/or interchange of seed among local growers. Populations showed a low level of differentiation, grouping in just one cluster, and therefore they can be considered as samples of a highly variable metapopulation that can be used for B. rapa breeding programmes.

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Qian You ◽  
Liping Xu ◽  
Yifeng Zheng ◽  
Youxiong Que

Sugarcane is the most important sugar and bioenergy crop in the world. The selection and combination of parents for crossing rely on an understanding of their genetic structures and molecular diversity. In the present study, 115 sugarcane genotypes used for parental crossing were genotyped based on five genomic simple sequence repeat marker (gSSR) loci and 88 polymorphic alleles of loci (100%) as detected by capillary electrophoresis. The values of genetic diversity parameters across the populations indicate that the genetic variation intrapopulation (90.5%) was much larger than that of interpopulation (9.5%). Cluster analysis revealed that there were three groups termed as groups I, II, and III within the 115 genotypes. The genotypes released by each breeding programme showed closer genetic relationships, except the YC series released by Hainan sugarcane breeding station. Using principle component analysis (PCA), the first and second principal components accounted for a cumulative 76% of the total variances, in which 43% were for common parents and 33% were for new parents, respectively. The knowledge obtained in this study should be useful to future breeding programs for increasing genetic diversity of sugarcane varieties and cultivars to meet the demand of sugarcane cultivation for sugar and bioenergy use.


2014 ◽  
Vol 12 (3) ◽  
pp. 278-285 ◽  
Author(s):  
Yassine Yahia ◽  
Hédia Hannachi ◽  
Antonio Jose Monforte ◽  
James Cockram ◽  
Mohamed Loumerem ◽  
...  

Faba bean (Vicia faba L.) is one of the most important legumes in the world. Little is known about the genetic resources of faba bean in Southern Tunisia. In the present study, genetic diversity within Tunisian faba bean germplasms was investigated using 16 simple sequence repeat markers. In total, 50 alleles were detected. The number of alleles per marker ranged from 2 to 6, with an average of 3. Genetic diversity and polymorphism information content values averaged, respectively, 0.43 (range 0.34–0.51) and 0.36 (range 0.28–0.43). The mean heterozygosity value was 0.27. A model-based structure analysis based on neighbour-joining tree and factorial correspondence analysis revealed the presence of two subpopulations, consistent with the clustering based on genetic distance (GD). The overall Fis value was 0.36, indicating the importance of selfing in these populations. Analysis of molecular variance revealed that the within-population genetic variance component was much higher than the between-population or between-subpopulation variance component. The genetic relationships based on Nei's GD revealed that AGD (Aguadulce) and SAG (Super Aguadulce) and TF1 and TF2 (Tafartassa-Gafsa) were the most closely related populations. Assessment of genetic variation within faba bean populations will be informative for the conservation of germplasms and the implementation of effective breeding programmes in Tunisia.


2012 ◽  
Vol 10 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Kim Banni ◽  
Kyaw Thu Moe ◽  
Yong-Jin Park

Red bean, also known as azuki bean [Vigna angularis (Willd.) Ohwi & Ohashi], belongs to a group of legumes (family Fabaceae). The name azuki is a transliteration of the native Japanese name from the Chinese word Shōzu, which means small bean. In Korea, it is known as pat. In total, 178 red bean accessions were taken to analyse the genetic diversity, population structure and gene flow using 39 polymorphic simple sequence repeat markers. A total of 431 alleles were detected, with an average of 11 alleles per locus, among the 178 tested red bean accessions. Forty-six specific alleles were identified with 20 loci. Locus CEDG090 had the highest number (n = 22) of alleles, whereas only two alleles were observed at loci CEDG144 and CEDC018. The proportion of different alleles for microsatellite loci was analysed using a microsatellite toolkit. In locus CEDG029, one allele was shared in all the three groups of varieties and species, and three alleles were shared between the wild ancestors and cultivated varieties, while in locus CEDG090, one allele was shared in all the three groups and 12 alleles were shared between the wild ancestors and cultivated varieties. Our findings describe the genetic relationships and population structure of the red bean in Korea and will be useful for designing effective breeding programmes and broadening the genetic base of commercial varieties. Moreover, the results demonstrate substantial gene flow from the red bean to nearby wild relatives in a given region.


2005 ◽  
Vol 3 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Sally L. Dillon ◽  
Peter K. Lawrence ◽  
Robert J. Henry

The Sorghum genus is extremely diverse both morphologically and geographically, however, relatively few of the 25 recognized species have been evaluated genetically. The apparent lack of basic knowledge pertaining to the levels of genetic diversity both within and between the 17 Australian wild species is a major obstacle to both their effective conservation and potential use in breeding programmes. Twelve Sorghum bicolor-derived simple sequence repeat (SSR) markers were evaluated for cross-species amplification in all 25 Sorghum species. The SSR markers were highly polymorphic, with diversity indices ranging from 0.59 to 0.99 with mean of 0.91. Five markers combined were able to differentiate 24 of the 25 Sorghum species, with intra-species polymorphism apparent. Sorghum bicolor-derived SSRs have proven to be an efficient source of markers for genetic diversity studies of the relatively poorly characterized Australian indigenous Sorghum species.


2020 ◽  
Author(s):  
Brenda G. Díaz ◽  
Maria I. Zucchi ◽  
Alessandro. Alves-Pereira ◽  
Caléo P. de Almeida ◽  
Aline C. L. Moraes ◽  
...  

AbstractAcrocomia (Arecaceae) is a genus widely distributed in tropical and subtropical America that has been achieving economic interest due to the great potential of oil production of some of its species. In particular A. aculeata, due to its vocation to supply oil with the same productive capacity as the oil palm even in areas with water deficit. Although eight species are recognized in the genus, the taxonomic classification based on morphology and geographic distribution is still controversial. Knowledge about the genetic diversity and population structure of the species is limited, which has limited the understanding of the genetic relationships and the orientation of management, conservation, and genetic improvement activities of species of the genus. In the present study, we analyzed the genomic diversity and population structure of seven species of Acrocomia including 117 samples of A. aculeata covering a wide geographical area of occurrence, using single nucleotide Polymorphism (SNP) markers originated from Genotyping By Sequencing (GBS). The genetic structure of the Acrocomia species were partially congruent with the current taxonomic classification based on morphological characters, recovering the separation of the species A. aculeata, A. totai, A. crispa and A. intumescens as distinct taxonomic groups. However, the species A. media was attributed to the cluster of A. aculeata while A. hassleri and A. glauscescens were grouped together with A. totai. The species that showed the highest and lowest genetic diversity were A. totai and A. media, respectively. When analyzed separately, the species A. aculeata showed a strong genetic structure, forming two genetic groups, the first represented mainly by genotypes from Brazil and the second by accessions from Central and North American countries. Greater genetic diversity was found in Brazil when compared to the other countries. Our results on the genetic diversity of the genus are unprecedented, as is also establishes new insights on the genomic relationships between Acrocomia species. It is also the first study to provide a more global view of the genomic diversity of A. aculeata. We also highlight the applicability of genomic data as a reference for future studies on genetic diversity, taxonomy, evolution and phylogeny of the Acrocomia genus, as well as to support strategies for the conservation, exploration and breeding of Acrocomia species and in particular A. aculeata.


2012 ◽  
Vol 39 (No. 4) ◽  
pp. 149-157 ◽  
Author(s):  
J. Patzak ◽  
F. Paprštein ◽  
A. Henychová ◽  
J. Sedlák

Genetic diversity and genetic relationships of Czech apple cultivars were evaluated. Trees of 33 Czech apple cultivars and 97 reference foreign cultivars were analysed using the set of 10 SSR (simple sequence repeat) primer pairs. The total of 89 polymorphic alleles were amplified, while the number of alleles per locus ranged from 4 to 14. The SSR dendrogram, based on the Jaccard’s similarity coefficient, divided apple cultivars into three major groups: Cox’s Orange Pippin, McIntosh and Golden Delicious ancestries. The clustering highly depended on pedigree and origin of apple cultivars. Spontaneous mutated cultivars were identical with their progenitors. We proved that microsatellite markers were useful for evaluation of genetic resources, collection management and cultivar identification.  


Genome ◽  
2005 ◽  
Vol 48 (5) ◽  
pp. 802-810 ◽  
Author(s):  
Muwang Li ◽  
Li Shen ◽  
Anying Xu ◽  
Xuexia Miao ◽  
Chengxiang Hou ◽  
...  

To determine genetic relationships among strains of silkworm, Bombyx mori L., 31 strains with different origins, number of generations per year, number of molts per generation, and morphological characters were studied using simple sequence repeat (SSR) markers. Twenty-six primer pairs flanking microsatellite sequences in the silkworm genome were assayed. All were polymorphic and unambiguously separated silkworm strains from each other. A total of 188 alleles were detected with a mean value of 7.2 alleles/locus (range 2–17). The average heterozygosity value for each SSR locus ranged from 0 to 0.60, and the highest one was 0.96 (Fl0516 in 4013). The mean polymorphism index content (PIC) was 0.66 (range 0.12–0.89). Unweighted pair group method with arithmetic means (UPGMA) cluster analysis of Nei's genetic distance grouped silkworm strains based on their origin. Seven major ecotypic silkworm groups were analyzed. Principal components analysis (PCA) for SSR data support their UPGMA clustering. The results indicated that SSR markers are an efficient tool for fingerprinting cultivars and conducting genetic-diversity studies in the silkworm.Key words: silkworm, Bombyx mori L., microsatellites, simple sequence repeat (SSR), genetic diversity.


2009 ◽  
Vol 7 (03) ◽  
pp. 244-251 ◽  
Author(s):  
Didiana Gálvez-López ◽  
Sanjuana Hernández-Delgado ◽  
Maurilio González-Paz ◽  
Enrique Noe Becerra-Leor ◽  
Miguel Salvador-Figueroa ◽  
...  

Genetic diversity and relationships among 112 mango (Mangifera indica) plants native to 16 states of Mexico and four controls [three mango cultivars (Ataulfo, Manila and Tommy Atkins) and one accession ofMangifera odorata] were evaluated based on amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) molecular markers. Mango germplasm shows broad dispersion through Mexico and genetically similar germplasm from different agroecological regions has previously been found by our group. Both AFLP and SSR analyses indicated high genetic similarity among mango populations that were clustered in two major groups: mangos from Gulf of Mexico coastline and mangos from Pacific Ocean coastline and locations far away from the sea. The highest genetic diversity was found within plants from each state, and significant genetic differentiation (FST = 0.1921, AFLPs and 0.1911, SSRs) was also observed among mango populations based on geographical origin and genetic status (cultivars versus landraces). Heterozygosity values ranged from low (0.38) to moderate (0.68), and no heterozygote deficits were found. The highest genetic variability was found in mango populations from Tabasco, Michoacán and Oaxaca. Data suggested that mangoes are subjected to natural or induced pollination, so segregation as well as genetic recombination plays major roles on genetic diversification of Mexican mangos. AFLP analysis was more robust than SSR for determining the genetic relationships among mango landraces from Mexico.


2008 ◽  
Vol 6 (1) ◽  
pp. 11-21 ◽  
Author(s):  
S. I. Warwick ◽  
T. James ◽  
K. C. Falk

Information on genetic diversity and genetic relationships among taxa of Brassica rapa (n = 10, AA genome) is currently limited. Grown for oil, vegetable and fodder use in Europe and Asia, previous studies have indicated western and eastern groups corresponding to independent centres of origin. This study evaluated patterns and levels of genetic diversity in 93 accessions [includes 25 Agriculture and Agri-Food Canada (AAFC) breeding lines (BL)] of B. rapa based on 307 amplified fragment length polymorphisms (AFLP), testing subspecific separateness and the affiliation of four previously unassigned AA genome species (B. perviridis, B. purpuraria, B. ruvo and B. septiceps). AFLP data revealed three main clusters (I, II, III) corresponding to European (I), Indian (III), and a mixed Asian/European/Indian (II) purported origins of the taxa, with several subclusters observed in I and II. Mean AFLP polymorphism levels for Asian, European, Indian and AAFC-BL accessions were 79, 74, 66 and 62%, respectively. Few of the subspecies formed unique clusters and some, particularly subspecies chinensis and pekinensis, were assigned to several clusters. AFLP-based genetic distance information can be used by breeders to select diverse genotypes for cultivar development and fingerprinting of genotypes/cultivars. For example, a single AFLP primer pair was sufficient to uniquely identify all breeding lines in the AAFC B. rapa breeding programme.


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