Efficiency of different marker systems for molecular characterization of subtropical carrot germplasm

2010 ◽  
Vol 148 (2) ◽  
pp. 171-181 ◽  
Author(s):  
T. JHANG ◽  
M. KAUR ◽  
P. KALIA ◽  
T. R. SHARMA

SUMMARYGenetic variability in carrots is a consequence of allogamy, which leads to a high level of inbreeding depression, affecting the development of new varieties. To understand the extent of genetic variability in 40 elite indigenous breeding lines of subtropical carrots, 48 DNA markers consisting of 16 inter simple sequence repeats (ISSRs), 10 universal rice primers (URPs), 16 random amplification of polymorphic DNA (RAPD) and six simple sequence repeat (SSR) markers were used. These 48 markers amplified a total of 591 bands, of which 569 were polymorphic (0·96). Amplicon size ranged from 200 to 3500 base pairs (bp) in ISSR, RAPD and URPs markers and from 100 to 300 bp in SSR markers. The ISSR marker system was found to be most efficient with (GT)n motifs as the most abundant SSR loci in the carrot genome. The unweighted pair group method with arithmetic mean (UPGMA) analysis of the combined data set of all the DNA markers obtained by four marker systems classified 40 genotypes in two groups with 0·45 genetic similarity with high Mantel matrix correlation (r=0·92). The principal component analysis (PCA) of marker data also explained 0·55 of the variation by first three components. Molecular diversity was very high and non-structured in these open-pollinated genotypes. The study demonstrated for the first time that URPs can be used successfully in genetic diversity analysis of tropical carrots. In addition, an entirely a new set of microsatellite markers, derived from the expressed sequence tags (ESTs) sequences of carrots, has been developed and utilized successfully.

Horticulturae ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 143
Author(s):  
Lei Zhu ◽  
Huayu Zhu ◽  
Yanman Li ◽  
Yong Wang ◽  
Xiangbin Wu ◽  
...  

Simple sequence repeats (SSRs) are widely used in mapping constructions and comparative and genetic diversity analyses. Here, 103,056 SSR loci were found in Cucurbita species by in silico PCR. In general, the frequency of these SSRs decreased with the increase in the motif length, and di-nucleotide motifs were the most common type. For the same repeat types, the SSR frequency decreased sharply with the increase in the repeat number. The majority of the SSR loci were suitable for marker development (84.75% in Cucurbita moschata, 94.53% in Cucurbita maxima, and 95.09% in Cucurbita pepo). Using these markers, the cross-species transferable SSR markers between C. pepo and other Cucurbitaceae species were developed, and the complicated mosaic relationships among them were analyzed. Especially, the main syntenic relationships between C. pepo and C. moschata or C. maxima indicated that the chromosomes in the Cucurbita genomes were highly conserved during evolution. Furthermore, 66 core SSR markers were selected to measure the genetic diversity in 61 C. pepo germplasms, and they were divided into two groups by structure and unweighted pair group method with arithmetic analysis. These results will promote the utilization of SSRs in basic and applied research of Cucurbita species.


2019 ◽  
Vol 18 (6) ◽  
pp. 57-65
Author(s):  
Naushad Ali ◽  
Sardar Ali ◽  
Naqib Ullah Khan ◽  
Sohail Ahmad Jan ◽  
Malik Ashiq Rabbani ◽  
...  

A total of 96 indigenous Brassica rapa accessions were collected from different locations of Khyber Pakhtunkhwa, Pakistan. Simple Sequence Repeats (SSR) markers were used to identify the most diverse genotypes among the collected lots. Twenty six (26) different SSR primers were used for (genetic) variability among collected genotypes. These primers were selected from literature based on their previous results. These primers produced 135 scorable bands of which 75 were polymorphic, with an average of 55.5% polymorphic loci, and reflected the broader genetic background of the collected genotypes. An average 2.88 polymorphic bands with an average PIC value of 0.49 was recorded. Unweighted Pair Group Method with Arithmetic Mean (UPGMA) divided all genotypes into three main groups. Group one contained three clusters, while group two and three had four and two clusters each. Based on the UPGMA dendrogram, genotypes collected from Kohat, Bannu, Swat and Haripur showed considerable amount of variation. From the present study, it is concluded that SSR markers can be proved as the best tool for the genetic variability of other local and exotic B. rapa genotypes.


2001 ◽  
Vol 126 (3) ◽  
pp. 309-317 ◽  
Author(s):  
O. Gulsen ◽  
M.L. Roose

Inter-simple sequence repeats (ISSR), simple sequence repeats (SSR) and isozymes were used to measure genetic diversity and phylogenetic relationships among 95 Citrus L. accessions including 57 lemons [C. limon (L.) Burm. f.], related taxa, and three proposed ancestral species, C. maxima (Burm.) Merrill (pummelo), C. medica L. (citron), and C. reticulata Blanco (mandarin). The ancestry of lemons and several other suspected hybrids was also studied. Five isozyme and five SSR loci revealed relatively little variation among most lemons, but a high level of variation among the relatively distant Citrus taxa. Eight ISSR primers amplified a total of 103 polymorphic fragments among the 83 accessions. Similarity matrices were calculated and phylogenetic trees derived using unweighted pair-group method, arithmetic average cluster analysis. All lemons, rough lemons, and sweet lemons, as well as some other suspected hybrids, clustered with citrons. Most lemons (68%) had nearly identical marker phenotypes, suggesting they originated from a single clonal parent via a series of mutations. Citrons contributed the largest part of the lemon genome and a major part of the genomes of rough lemons, sweet lemons, and sweet limes. Bands that characterize C. reticulata and C. maxima were detected in lemons, suggesting that these taxa also contributed to the pedigree of lemon.


2008 ◽  
Vol 88 (2) ◽  
pp. 313-322 ◽  
Author(s):  
S. C. Debnath ◽  
S. Khanizadeh ◽  
A. R. Jamieson ◽  
C. Kempler

The goal of this study was to determine the level of genetic diversity and relatedness among 16 strawberry (Fragaria H ananassa Duch.) cultivars and 11 breeding lines developed in Canada, using Inter Simple Sequence Repeat (ISSR) markers. Seventeen primers generated 225 polymorphic ISSR-PCR bands. Cluster analysis by the unweighted pair-group method with arithmetic averages (UPGMA) revealed a substantial degree of genetic similarity among the genotypes ranging from 63 to 77% that were in agreement with the principal coordinate (PCO) analysis. Geographical distribution for the place of breeding program explained only 1.4% of total variation as revealed by analysis of molecular variance (AMOVA). The ISSR markers detected a sufficient degree of polymorphism to differentiate among strawberry genotypes, making this technology valuable for cultivar identification and for the more efficient choice of parents in current strawberry breeding programs. Key words: Fragaria × ananassa, DNA fingerprinting, multivariate analysis, breeding, genetic similarity


2019 ◽  
Vol 31 (1) ◽  
pp. 101-116
Author(s):  
Fatih Hanci

AbstractThe aim of this study was to identify the molecular and morphological characteristics of Turkish pea accessions (Pisum sativum L.). The genetic diversity among 130 Turkish landraces and 2 commercial varieties in a total of 132 pea accessions was assessed with 14 simple sequence repeat (SSR) markers. Forty-eight (48) polymorphic alleles were identified using 14 SSR markers. The pairwise Dice coefficients of similarity between accessions ranged from 0.091 to 0.960. The polymorphism information content (PIC) value ranged from 0.585 to 0.861. Overall, 50 morphological traits were evaluated. Cluster analysis was carried out on a matrix of Euclidean distances. The accessions were divided into three main groups. Principal component analysis (PCA) was used to identify the weight of each morphological characteristic. According to the results, the highest eigenvalue was observed in PC-I (13.88) followed by PC-II (11.42), and PC-III (7.32). The first fifteen PCs with eigenvalues > 1 explained 74.08% of the variability. The results showed that the molecular markers were useful and polymorphic, sufficient to allocate all the evaluated accessions. This research has provided significant insights into the genetic variability of Turkish pea accessions.


2007 ◽  
Vol 132 (3) ◽  
pp. 357-367 ◽  
Author(s):  
P. Escribano ◽  
M.A. Viruel ◽  
J.I. Hormaza

Cherimoya (Annona cherimola Mill.) is an underused fruit crop with a clear niche for expansion in subtropical climates. In this study, 16 simple sequence repeat (SSR) loci were used to find molecular polymorphisms among 279 cherimoya accessions from a worldwide ex situ field germplasm collection. A total of 79 amplification fragments were amplified with 16 pairs of SSR primers, with an average of 4.9 bands/SSR. Mean expected and observed heterozygosities averaged 0.53 and 0.44, respectively. The total value for the probability of identity was 4.34 × 10−8. The SSRs studied resulted in 267 different fingerprinting profiles, of which 258 were unique genotypes; the rest were putative cases of synonymies or mislabeling errors. Unweighted pair group method with arithmetic averages (UPGMA) cluster analysis indicated the relationships among the analyzed accessions, showing some specific groups related to their geographical origins. Analysis of molecular variance (AMOVA) was performed to examine the distribution of genetic variation of the 148 accessions collected from putative cherimoya origin areas in Ecuador and Peru, showing that the major variations occurred within valleys in each country. The results confirmed the usefulness of microsatellites for identification of genetic diversity and geographic origin of cherimoya and are discussed in terms of their implications for ex situ conservation of cherimoya genetic resources.


Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 175 ◽  
Author(s):  
Domenico Aiello ◽  
Nicoletta Ferradini ◽  
Lorenzo Torelli ◽  
Chiara Volpi ◽  
Joep Lambalk ◽  
...  

Fennel (Foeniculum vulgare) is a species belonging to the Apiaceae family, well known for its nutritional and pharmacological properties. Despite the economic and agricultural relevance, its genomic and transcriptomic data remain poor. Microsatellites—also known as simple sequence repeats (SSRs)—are codominant markers widely used to perform cross-amplification tests starting from markers developed in related species. SSRs represent a powerful tool, especially for those species lacking genomic information. In this study, a set of primers previously designed in Daucus carota for polymorphic SSR loci was tested in commercial varieties and breeding lines of fennel in order to: (i) test their cross-genera transferability, (ii) look at their efficiency in assessing genetic diversity, and (iii) identify their usefulness for marker-assisted selection (MAS) in breeding programs. Thirty-nine SSR markers from carrot were selected and tested for their transferability score, and only 23% of them resulted suitable for fennel. The low rate of SSR transferability between the two species evidences the difficulties of the use of genomic SSR in cross-genera transferability.


HortScience ◽  
2016 ◽  
Vol 51 (3) ◽  
pp. 232-235 ◽  
Author(s):  
Xinyi Zhang ◽  
Li Liao ◽  
Yang Liu ◽  
Zhiyong Wang ◽  
Jianxiu Liu

Chrysopogon aciculatus (Retz.) Trin. is a perennial turfgrass for its low management and resistance. To develop simple sequence repeat (SSR) markers for C. aciculatus, we used four Roche 454 pyrosequencing, combined with the magnetic bead enrichment method FIASCO (fast isolation by amplified fragment length polymorphism of sequences containing repeats) to isolate from the C. aciculatus. A total of 66,198 raw sequencing reads were obtained with 4289 sequences (6.48%) were fit for primer pair design. One hundred microsatellite loci were selected to test the primer amplification efficiency in 20 accessions, and out of these, 11 loci were polymorphic. The amount of observed alleles ranged from three to six, with an average of 3.64. Nei’s genetic diversity values ranged from 0.085 to 0.493, with an average of 0.293. Shannon’s information index values ranged from 0.141 to 0.686, with an average of 0.428. Twenty accessions were clustered into three groups by unweighted pair-group method with arithmetic means (UPGMA). These SSR markers will provide an ideal marker system to assist with gene targeting, cultivar variety or species identification, and marker-assisted selection in C. aciculatus species.


2016 ◽  
Vol 154 (7) ◽  
pp. 1254-1269 ◽  
Author(s):  
A. SINGH ◽  
H. K. DIKSHIT ◽  
D. SINGH ◽  
N. JAIN ◽  
M. ASKI ◽  
...  

SUMMARYExpressed sequence tag-simple sequence repeat (EST-SSR) markers were used to analyse genetic diversity among three Lens species. The SSR loci amplified successfully in wild species, with 94·82% transferability in Lens culinaris subsp. orientalis, 95·4% in Lens nigricans, 98·81% in L. culinaris subsp. odemensis, 94·82% in L. culinaris subsp. tomentosus and 96·55% in Lens ervoides. Ninety-nine alleles (average 3·41 alleles/locus) were detected by 29 SSR markers. Based on the unweighted pair group method with arithmetic mean cluster analysis, all the genotypes were grouped into three clusters at a similarity level of 0·30. The diversity analysis indicated no species-specific clustering of the wild and cultivated species. Wild species L. nigricans and L. culinaris subsp. odemensis, L. culinaris subsp. orientalis and L. ervoides were grouped in Cluster I, whereas the Mediterranean land races of L. culinaris subsp. culinaris and L. culinaris subsp. tomentosus formed a separate group in Cluster II A. Cluster II B comprised L. ervoides, L. culinaris subsp. orientalis and L. culinaris subsp. culinaris. Clusters II C, II D and II F included cultivated Indian lentil genotypes. Cluster II E comprised Indian and Mediterranean germplasm lines. Cluster II F included three early maturing germplasm lines, whereas Cluster III included only two germplasm lines. The functional annotation of SSR-containing unigenes revealed that a majority of genes were involved in an important transport-related function or were a component of metabolic pathways. A high level of polymorphism of EST-SSRs and their transferability to related wild species indicated that these markers could be used for molecular screening, map construction, comparative genomic studies and marker-assisted selection.


2021 ◽  
Vol 19 (1) ◽  
pp. 1-13
Author(s):  
MI Haque ◽  
S Ishtiaque ◽  
MM Islam ◽  
TA Mujahidi ◽  
MA Rahim

The molecular characterization of chilli germplasm was done based on estimation of genetic diversity among the germplasm by using SSR markers. Forty chilli germplasms were analyzed using eight SSR primers. The SSR primers produced 30 SSR loci with an average value of 3.75 alleles per SSR locus. The similarity index matrix ranged from zero to 2.74. Polymorphic information content (PIC) of the SSR primers ranged from 0.543 to 0.735 with an average value of 0.658. The highest number (five) of allele was observed in primer CAMS-647, whereas the primers CAMS-864, CAMS-880 and CAMS-885 showed lowest number (three) of allele. The smallest allele was found in case of primer CAMS- 236 (176 bp), while the longest allele was detected for the primer CAMS- 864 (288 bp). Based on similarity matrix using the un-weighed Pair Group Method of Arithmetic Means (UPGMA) dendrogram, chilli germplasms were grouped into four main clusters. SSR markers showed genetic variability in the studied chilli germplasm.  SAARC J. Agric., 19(1): 1-13 (2021)


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