Microsatellite Repeat Markers Research Articles

First report of Phytophthora infestans genotype US17 causing late blight on potato and tomato in British Columbia, Canada

Potato and tomato are grown in all Canadian provinces and contribute billions of dollars in exports and sales. Late blight, caused by Phytophthora infestans, is a destructive disease of potato and tomato worldwide and is responsible for millions of dollars in losses annually. Changes in pathogen strains were reported to be associated with late blight epidemics in several regions and pose challenges to late blight management. In British Columbia (BC), diverse strains of P. infestans were reported. Using multiplex microsatellite or simple sequence repeat (SSR) markers, we identified the new genotype US17 of P. infestans from samples of potato and tomato with late blight in BC. All isolates were of the A1 mating type. One, five, and one isolates were sensitive, moderately resistant, and highly resistant to metalaxyl-m, respectively. This is the first report of the occurrence of the US17 genotype in BC and Canada. The US17 strain was also able to cause tuber rot and foliar blight symptoms in potato in pathogen-inoculated assays.

Polymorphism analysis of tri- and tetranucleotide repeat microsatellite markers in Hanwoo cattle

Polymorphism analysis of tri- and tetranucleotide repeat microsatellite markers in Hanwoo cattle

Analysis of genetic diversity and population structure of Magnaporthe grisea, the causal agent of foxtail millet blast using microsatellites.

Foxtail millet blast caused by Magnaporthe grisea is becoming a severe problem in foxtail millet growing regions of India. The genetic diversity and population structure of foxtail millet infecting M. grisea is crucial for developing effective management strategies, such as breeding blast-resistant cultivars. We analyzed thirty-two M. grisea isolates from ten foxtail millet-growing districts in Tamil Nadu, India for genetic diversity using twenty-nine microsatellite or simple sequence repeat (SSR) markers. A total of 103 alleles were identified with a mean of 3.55 alleles/locus. Gene diversity ranged from 0.170 to 0.717, while major allelic frequencies ranged from 0.344 to 0.906. The polymorphism information content (PIC) ranged from 0.155 to 0.680, with a mean value of 0.465. Population structure analysis of the genomic data sets revealed two major populations (SP1 and SP2) with different levels of ancestral admixture among the 32 blast isolates. Phylogenetic analysis classified the isolates into three major clusters. Analysis of molecular variance (AMOVA) showed high genetic variation among individuals and less among populations. Principal Coordinate Analysis (PCoA) revealed 27.16% genetic variation among populations. The present study provides the first report on the genetic diversity and population structure of the foxtail millet-infecting M. grisea population in Tamil Nadu, which could be useful for the development of blast-resistant foxtail millet cultivars.

Characterisation of bell pepper (Capsicum annuum L. var. grossum Sendt.) accessions for genetic diversity and population structure based on agro-morphological and microsatellite markers

Bell pepper (Capsicum annuum L. var. grossum Sendt.) is a leading Solanaceous vegetable crop across the world with immense therapeutic and export potential. Such wide cultivation exposes the crop to various biotic and abiotic stresses. Genetic diversity is one of the major prerequisites for any crop breeding programme. Hence, in this study, an attempt was made to evaluate the genetic diversity and population structure of 24 bell pepper genotypes using 25 agro-morphological [9 distinctness, uniformity and stability (DUS) descriptors; 13 quantitative traits; and 3 quality traits] and 82 microsatellite or simple sequence repeat (SSR) markers. Eight DUS descriptors showed polymorphism with maximum morphological variation (H = 1.29) for fruit shape in longitudinal section. Multivariate analysis using Mahalanobis D2 statistic distinguished the genotypes into 11 clusters. With a mean of 4.08 alleles per locus, a total of 151 alleles were generated from 37 polymorphic SSR primers. The polymorphic information content (PIC) ranged from 0.14 (CAMS 451) to 0.76 (CA 525390) with an average of 0.54. The genotypes were divided into two major clusters based on cluster analysis using the unweighted pair group method with arithmetic mean (UPGMA) algorithm, whereas the cluster tree using the neighbour-joining (NJ) method identified three major groups. The population was classified into three groups based on structure analysis. On comparing agro-morphological and molecular clusters, 11 genotypes viz., BWT-39, BWT-39-BR, BWT-39-DR, BWT-29, BWT-3Y, BWT-3Y-4L, Kandaghat Selection, BWT-48-AC, BWT-49-AC, EC-464107, and EC-464115, were found common. These genotypes also exhibited considerable resistance to bacterial wilt disease. Mantel's test showed a moderate positive correlation between agro-morphological (DUS descriptors) and molecular data. Therefore, a combined approach of agro-morphological and molecular evaluation can facilitate the selection of diverse parental lines followed by subsequent hybridisation between them to introduce new traits in bell pepper.

Development and characterization of EST-SSR markers from Thujopsis dolabrata var. hondae RNA-sequencing data

ABSTRACT Thujopsis dolabrata Siebold et Zucc. var. hondae Makino (hiba), an endemic conifer of Japan, is naturally distributed in northern Honshu and southern Hokkaido. The species is one of the important woody materials for buildings, such as cultural assets, temples, and shrines, because of its long-term durability and has been planted since ancient times in Aomori, Niigata, and Ishikawa Prefectures. A linkage map is an important basis for marker-assisted selection and map-based cloning of desirable genes. In this study, to increase the number of available markers for linkage mapping, we used RNA-sequencing data for two parent individuals of the mapping family in T. dolabrata var. hondae to develop expressed sequenced tag simple sequence repeat (EST-SSR) microsatellite markers. Among 126 designed primer pairs, 62 showed amplifications. Sixteen of the 62 showed clear and stable allele peaks in 32 plus-trees and were used to assess the degree of polymorphism. The number of alleles per locus varied from 2 to 16, and the observed and expected heterozygosity values varied from 0.219 to 0.906 and from 0.242 to 0.897, respectively. All 16 markers developed in this study can be used in future linkage analysis. These EST-SSR markers will be useful for population genetic studies as well as linkage analysis in T. dolabrata var. hondae.

Evaluation of the Genetic Structure of Some Accessions Belonging to Onobrychis spp. Using Microsatellite DNA Markers

Turkey is in a very convenient position for animal husbandry in terms of both natural resources and ecological conditions. Forage crops, which has a very important place in agricultural activities, is the insurance of plant and animal production. Sainfoin is a perennial forage legume species that grown in the northern temperate regions of the world from the Mediterranean region and the Caucasus, and to Central Asia. In this study the genetic diversity of 100 genotypes representing 44 accessions from 18 different Onobrychis species (O. arenaria subsp. arenaria, O. inermis, O. petraea, O. cyri, O. iberica, O. altissima, O. vassilczenkoi, O. conferta subsp. argentea, O. alba subsp. laconica, O. biebersteinii, O. grandis, O. kachetica, O. kemulariae, O. oxyodonta, O. megataphros, O. pallasii, Onobrychis spp., and O. viciifolia) were evaluated using 8 simple sequence repeat (microsatellite) markers. Based on the results, OVK036, OVK094, OVK125, OVM033, OVK161, OVK046, OVM061, and OVK174 loci were polymorphic. The observed number of alleles per SSR locus ranged from 6 to 21 alleles (mean of 11.625). Maximum allele frequency ranged from 0.51 to 0.93 with a mean value of 0.73. The PIC value ranged from 0.124 to 0.244. The mean polymorphism information content of loci was 0.188. Genetic diversity coefficients according to the UPGMA ranged from 0.000 to 0.9375. Cluster analysis divided the 100 sainfoin genotypes into two main groups (Cluster-I and Cluster-II). All diploid genotypes (except for 1 diploid genotype) used in the study formed a separate group within Cluster-I. The results revealed that SSR markers used in this study are useful for molecular characterization and assessing genetic diversity of sainfoin accessions. The obtained SSR alleles and genetic variability in a studied certain loci provided significant information about the genetic structure of sainfoin accessions that could be used as parental lines in sainfoin breeding programs.

Morphological and molecular characterization of flax (Linum usitatissimum L.) accessions obtained from different locations in Turkey

Flax (Linum usitatissimum L.) is one of the most significant industrial crops due to its oil and fiber, which have a plethora of uses. Because of this, the characterization and introduction/adaptation of flax crops are of great interest. For this reason, we aimed to investigate the genetic diversity and patterns of flax cultivars/genotypes (a 63-cultivar/genotype was used) employing single sequence repeat microsatellite markers via 16 strong amplicon loci, and by estimating their morphological attributes. We determined the quality of the flax, in terms of oil content and composition, and its fiber quality using scanning electron microscopy and strength-linked attributes. For assessment, a series of statistical analyses were carried out in order to cluster and scatter the relevant parameters corresponding to the cultivars/genotypes. Of the assayed flax cultivar/genotypes, Eckendorfi was found to have promising agromorphological values. The average polymorphic information content values were recorded (= 0.689), and the smallest and largest loci with allele dimensions were Lu9(2) and Lu19-Lua613(6) respectively. Overall, the agromorphological attributes were consistent with the microsatellite-based markers in decoding the genetic diversity and population structure of the flax germplasm.

Molecular genetics and phenotypic assessment of foxtail millet (Setaria italica (L.) P. Beauv.) landraces revealed remarkable variability of morpho-physiological, yield, and yield-related traits.

Foxtail millet (Setaria italica (L.) P. Beauv.) is highly valued for nutritional traits, stress tolerance and sustainability in resource-poor dryland agriculture. However, the low productivity of this crop in semi-arid regions of Southern India, is further threatened by climate stress. Landraces are valuable genetic resources, regionally adapted in form of novel alleles that are responsible for cope up the adverse conditions used by local farmers. In recent years, there is an erosion of genetic diversity. We have hypothesized that plant genetic resources collected from the semi-arid climatic zone would serve as a source of novel alleles for the development of climate resilience foxtail millet lines with enhanced yield. Keeping in view, there is an urgent need for conservation of genetic resources. To explore the genetic diversity, to identify superior genotypes and novel alleles, we collected a heterogeneous mixture of foxtail millet landraces from farmer fields. In an extensive multi-year study, we developed twenty genetically fixed foxtail millet landraces by single seed descent method. These landraces characterized along with four released cultivars with agro-morphological, physiological, yield and yield-related traits assessed genetic diversity and population structure. The landraces showed significant diversity in all the studied traits. We identified landraces S3G5, Red, Black and S1C1 that showed outstanding grain yield with earlier flowering, and maturity as compared to released cultivars. Diversity analysis using 67 simple sequence repeat microsatellite and other markers detected 127 alleles including 11 rare alleles, averaging 1.89 alleles per locus, expected heterozygosity of 0.26 and an average polymorphism information content of 0.23, collectively indicating a moderate genetic diversity in the landrace populations. Euclidean Ward's clustering, based on the molecular markers, principal coordinate analysis and structure analysis concordantly distinguished the genotypes into two to three sub-populations. A significant phenotypic and genotypic diversity observed in the landraces indicates a diverse gene pool that can be utilized for sustainable foxtail millet crop improvement.

Development of EST-SSR markers for an endangered plant species, Camellia fascicularis (Theaceae)

AbstractThe plant Camellia fascicularis, belonging to family Theaceae, has high ornamental and medicinal value, and rare gene resources for genetic improvement of Camellia crops, but is currently threatened with extinction because of the unique and extremely small wild populations. Molecular markers have clarified the wild plant species’ genetic diversity structure, new gene resources and relationship with crops. This will be beneficial for conservation of these valuable crop-related wild species and crop improvement. In this study, we identified 95,979 microsatellite loci from 155,011 transcriptome unigenes, and developed 14 polymorphic expressed sequence tag-derived simple sequence repeat (EST-SSR) microsatellite markers for C. fascicularis. The number of alleles (Na) per locus was 2–8 with a mean of 4.86. The genetic diversity of 40 individuals from four natural populations of C. fascicularis was analysed using these polymorphic markers. The number of alleles (Na) for EST-SSR ranged from 2 to 5, with the expected heterozygosities (He) and observed heterozygosities (Ho) in all loci ranging from 0.183 to 0.683, and from 0.201 to 0.700, respectively, implying a rich genetic variation present in wild C. fascicularis populations. Moreover, the phylogenetic analysis among four populations, using the 14 EST-SSR markers developed in this study, grouped 40 individuals into three groups, which coincide with their geographic distribution. These results showed that 14 EST-SSR markers are available for the analysis of genetic variation in C. fascicularis populations and genetic improvement of new Camellias cultivars by interspecific hybridization, and are beneficial for conservation of the endangered species.

The Influence of Heavy Metals on Gastric Tumorigenesis.

Objectives This study aimed to observe the relationship among heavy metals concentration, microsatellite instability (MSI), and human epidermal growth factor receptor type 2 (HER2) gene amplification in gastric cancer (GC) patients. Methods The concentrations of 18 heavy metals in the plasma of GC patients and healthy controls were measured by inductive coupled plasma emission spectrometry (ICP-MS). MSI detection was conducted by detecting 5 microsatellite repeat markers by PCR analysis. HER2 gene amplification was detected by fluorescence in situ hybridization (FISH). The relationship among heavy metal elements, tumor biomarkers, HER2 amplification, and MSI status was analyzed by Pearson correlation analysis. Results A total of 105 GC patients and 62 healthy controls were recruited in this study. The concentration of arsenic (As), chromium (Cr), cuprum (Cu), mercury (Hg), manganese (Mn), lead (Pb), stibium (Sb), selenium (Se), stannum (Sn), strontium (Sr), thallium (Tl), vanadium (V), and zinc (Zn) were significantly different between GC patients and controls. Among 105 GC patients, including 87 microsatellite-stable (MSS) samples and 18 MSI samples, the concentration of Ga is significantly higher in the MSI group than that in the MSS group. Meanwhile, in 97 GC patients having detected HER2 gene amplification, 69 of 97 had negative HER2 gene amplification and the rest 28 GC patients had positive HER2 gene amplification. The concentration of Hg, Sn, and Tl is noticeably higher in the HER2 positive group than in the HER2 negative group. Only Sb was positively correlated with MSI, but none of these heavy metals was correlated with HER2 gene amplification. Conclusions The results indicated that Sb has significant positive correlation with the MSI status, which suggests that Sb may cause MSI in GC. However, further research studies are required to elucidate the mechanisms in the near feature.

Microsatellite markers as a tool for active germplasm management and bridging the gap between national and local collections of apple

Simple sequence repeat (SSR) microsatellite markers have been extensively used to identify duplication and analyse genetic diversity in germplasm collections of apple. Here, we present findings from the use of a standard set of SSR loci in the managed repropagation of a significant international germplasm collection: the UK National Fruit Collection (NFC). A subset of eight SSR loci was deemed sufficient to distinguish all apart from the clonal relatives across a sample of 1995 accessions, with a single exception being one pair of full siblings. In total, 99% of accessions were able to be confirmed present and correct after the replacement of trees initially identified to be incorrectly propagated. In parallel to the curation of the collection itself, through an initiative led by the UK local apple enthusiast community, 3373 SSR profiles for apples held in local collections were compared to the NFC holdings. Overall, in both sets of material, diversity remained high with average gene diversity values of 0.800 and 0.812 in the NFC holdings and local collections, respectively. Accessions in local collections were not found to differ in their overall coverage of genetic diversity to that of the NFC collection (FST = 0.0035) although significant numbers of locally valued, and genetically distinguishable individuals were identified, some of which may represent ‘lost’ cultivars.

Development of microsatellite panels for molecular fingerprinting of Napier grass (Cenchrus purpureus) cultivars

Napier grass is a perennial tropical forage that is used in beef and dairy production systems. Despite its significance in animal nutrition, molecular information available, such as microsatellite or simple sequence repeat (SSR) or single nucleotide polymorphism (SNP) markers, is limited. Using an assembled transcriptome, 50 novel SSR markers were developed, of which 21 were found to be polymorphic. These polymorphic markers were tested for DNA fingerprinting of Embrapa cultivars, five of which revealed distinct allele patterns for cultivar identification. SSR markers 05, 17, and 44 identified a unique pattern in the BRS Kurumi cultivar. The BRS Capiaçu cultivar was identified using SSR markers 17, 43, and 44. The Pioneiro cultivar exhibited a rare fragment amplification pattern using SSR marker 46, while SSR marker 44 revealed a distinct allele in the BRS Canará cultivar. SSR marker panels could be utilized as DNA fingerprinting tools to assist in cultivar identification.

Towards a Joint International Database: Alignment of SSR Marker Data for European Collections of Cherry Germplasm.

The objective of our study was the alignment of microsatellite or simple sequence repeat (SSR) marker data across germplasm collections of cherry within Europe. Through the European Cooperative program for Plant Genetic Resources ECPGR, a number of European germplasm collections had previously been analysed using standard sets of SSR loci. However, until now these datasets remained unaligned. We used a combination of standard reference genotypes and ad-hoc selections to compile a central dataset representing as many alleles as possible from national datasets produced in France, Great Britain, Germany, Italy, Sweden and Switzerland. Through the comparison of alleles called in data from replicated samples we were able to create a series of alignment factors, supported across 448 different allele calls, that allowed us to align a dataset of 2241 SSR profiles from six countries. The proportion of allele comparisons that were either in agreement with the alignment factor or confounded by null alleles ranged from 67% to 100% and this was further improved by the inclusion of a series of allele-specific adjustments. The aligned dataset allowed us to identify groups of previously unknown matching accessions and to identify and resolve a number of errors in the prior datasets. The combined and aligned dataset represents a significant step forward in the co-ordinated management of field collections of cherry in Europe.

Identification of Associations between SSR Markers and Quantitative Traits of Maize (Zea mays L.)

Microsatellite or simple sequence repeat (SSR) markers have wide applicability for genetic analysis in crop plant improvement strategies. Marker-assisted selection is an important tool for plant breeders to increase the efficiency of a breeding process, especially for multigenic traits, highly influenced by the environment. In this paper, the relationships between SSR markers and 26 quantitative traits of hybrid maize varieties (Zea mays L.) were analyzed. Association analyses were performed based on 30 SSR primers in a set of thirteen hybrid maize varieties. A total of 112 SSR markers were detected in these genotypes. The number of alleles per locus ranged from 1 to 17, with the average number of alleles per locus equal to 3.7. The number of molecular markers associated with observed traits ranged from 1 (for the number of kernels in row, ears weight and fresh weight of one plant) to 14 (for damage of maize caused by P. nubilalis) in 2016 as well as from 1 (for soil plant analysis development—SPAD, the number of grains in ear and fresh weight of one plant) to 12 (for carotenoids content) in 2017. The sum of statistically significant associations between SSR markers and at least one trait was equal to one hundred sixty in 2016 as well as one hundred twenty-five in 2017. Marker trait associations (MTAs) were found on the basis of regression analysis. The proportion of the total phenotypic variances of individual traits explained by the marker ranged from 24.4% to 77.7% in the first year of study and from 24.3% to 77.9% in 2017. Twenty-two SSR markers performed a significant effect on at least one tested trait in both years of experiment. The three markers (phi021/4, phi036/3, and phi061/2) can be a good tool in marker-assisted selection because they allow simultaneous selection for multiple traits in both years of study, such as the number of kernels in row and the number of grains in ear (phi021/4), the number of plant after germination, the number of plants before harvest, and the number of ears (phi036/3), as well as moisture of grain and length of ears (phi061/2).

Genetic diversity and population structure analyses in the Alpine plum (Prunus brigantina Vill.) confirm its affiliation to the Armeniaca section

In-depth characterization of the genetic diversity and population structure of wild relatives is of paramount importance for genetic improvement and biodiversity conservation, and is particularly crucial when the wild relatives of crops are endangered. In this study, we sampled the Alpine plum (Briançon apricot) Prunus brigantina Vill. across its natural distribution in the French Alps, where its populations are severely fragmented and its population size strongly impacted by humans. We analysed 71 wild P. brigantina samples with 24 nuclear simple sequence repeat (microsatellite) markers and studied their genetic diversity and population structure, with the aim to inform in situ conservation measures and build a core collection for long-term ex situ conservation. We also examined the genetic relationships of P. brigantina with other species in the Prunophora subgenus, encompassing the Prunus (Eurasian plums), Prunocerasus (North American plums) and Armeniaca (apricots) sections, to check its current taxonomy. We detected a moderate genetic diversity in P. brigantina and a Bayesian model–based clustering approach revealed the existence of three genetically differentiated clusters, endemic to three geographical regions in the Alps, which will be important for in situ conservation measures. Based on genetic diversity and population structure analyses, a subset of 36 accessions were selected for ex situ conservation in a core collection that encompasses the whole detected P. brigantina allelic diversity. Using a dataset of cultivated apricots and wild cherry plums (P. cerasifera) genotyped with the same markers, we detected gene flow neither with European P. armeniaca cultivars nor with diploid plums. Similar to previous studies, dendrograms and networks placed P. brigantina closer to the Armeniaca section than to the Prunus section. Our results thus confirm the classification of P. brigantina within the Armeniaca section; it also illustrates the importance of the sampling size and design in phylogenetic studies.

Genetic structure of coast redwood (Sequoia sempervirens [D. Don] Endl.) populations in and outside of the natural distribution range based on nuclear and chloroplast microsatellite markers.

Coast redwood (Sequoia sempervirens) naturally growing in southern Oregon and northern California is one of the few conifer tree species that are polyploid. Despite its unique ecological and economic importance, its population genetic structure is still insufficiently studied. To obtain additional data on its population genetic structure we genotyped 317 samples collected from populations in California (data set C) and 144 trees growing in a provenance trial in France (data set F) using 12 nuclear (five random nuclear genomic nSSRs and seven expressed sequence tag EST-SSRs) and six chloroplast (cpSSRs) microsatellite or simple sequence repeat (SSR) markers, respectively. These data sets were also used as reference to infer the origin of 147 coast redwood trees growing in Germany (data set G). Coast redwood was introduced to Europe, including Germany as an ornamental species, decades ago. Due to its fast growth and high timber quality, it could be considered as a potential commercial timber species, especially in perspective to climate warming that makes more regions in Germany suitable for its growing. The well performing trees in colder Germany could be potential frost resistant genotypes, but their genetic properties and origin are mostly unknown. Within the natural range in southern Oregon and northern California, only two relatively weak clusters were identified, one northern and one southern, separated by the San Francisco Bay. High genetic diversity, but low differentiation was found based on the 12 nuclear SSR markers for all three data sets F, C and G. We found that investigated 147 German trees represented only 37 different genotypes. They showed genetic diversity at the level less than diversity observed within the natural range in the northern or southern cluster, but more similar to the diversity observed in the southern cluster. It was difficult to assign German trees to the original single native populations using the six cpSSR markers, but rather to either the northern or southern cluster. The high number of haplotypes found in the data sets based on six cpSSR markers and low genetic differentiation based on 12 nuclear SSRs found in this study helps us study and better understand population genetic structure of this complex polyploid tree and supports the selection of potential genotypes for German forestry.

Assessing Evolutionary Significant Units (ESU) of the Endangered Freshwater Pearl Mussel (Margaritifera margaritifera) in Southeast Norway on the Basis of Genetic Analysis.

A total of 312 specimens of freshwater pearl mussel (Margaritifera margaritifera) were sampled from 11 populations, located in four different river systems in Southeast Norway, and analyzed for 11 simple sequence repeat (SSR) (microsatellite) markers. All study populations have landlocked brown trout (Salmo trutta) as the only possible host. Several populations had experienced recruitment failure, probably due to low pH (about 6.0) and calcium concentration. STRUCTURE clustering analysis revealed two genetic clusters, of which one cluster occurred mainly in the western river systems, and totally dominated in one population (Fallselva (A-FAL)) that had higher genetic diversity than the others. Cluster 2 completely dominated in the populations of the eastern river systems, and all of them had low genetic diversity. Bottleneck events were indicated in all populations and the inbreeding coefficient FIS was significant in all populations, except for the southernmost population (Sørkedalselva (B-SØR)), which was the only population with genotypes in Hardy–Weinberg equilibrium. FIS were especially high in the populations of the eastern river systems, and maximum shell length was negatively correlated to FIS. If artificially breeding and stocking should become necessary for future preservation, it should be based on single populations; alternatively, the eastern populations should be based on cross-breeding of populations within the cluster to increase their genetic diversity.

Development of novel Quercus rubra chloroplast genome CAPS markers for haplotype identification

Abstract Our main objective was to generate cost-effective chloroplast (cp) DNA markers that are easy to apply and to score. In combination with already published cpSSR markers they should increase haplotype resolution in populations. To discover new cpDNA markers, we sequenced 87-97 % of the entire chloroplast genome (except the second inverted repeat) of 8 trees representing different regions of the Quercus rubra L. natural range with 4,030X-6,297X coverage and assembled the genome sequences using the publicly available chloroplast genome of Quercus rubra L. as a reference. In total, 118 single nucleotide polymorphisms (SNPs) and 107 insertions or deletions (indels) were detected, and 15 cleaved amplified polymorphic sequence (CAPS) markers were developed for Q. rubra. Using these new markers together with five chloroplast microsatellite or simple sequence repeat (cpSSR) markers, we identified 10 haplotypes in our diversity panel of 19 Q. rubra populations. Specifically, two haplotypes based only on the cpSSR markers could now be separated in five haplotypes. These markers are useful to assess haplotype diversity with high resolution and are also transferable to a closely related species, Quercus ellipsoidalis E. J. Hill.

Highly transferable microsatellite markers for the genera Lasiodiplodia and Neofusicoccum

Abstract Population genetic studies play an integral role in understanding the ecology and management of fungal plant pathogens. Such studies for species of Botryosphaeriaceae are hampered by a lack of available markers. Genomic sequences are available for multiple species in this family and they provide excellent resources for the development of population genetic markers. Here we describe highly transferable microsatellite or simple sequence repeat (SSR) markers for species in Lasiodiplodia and Neofusicoccum; two important and globally distributed members of the Botryosphaeriaceae. These were developed by extracting SSR-containing sequences from available genomes. Seventy-seven markers were developed for Lasiodiplodia and 32 markers were developed for Neofusicoccum. Most of these markers were transferable between species within a genus. Twelve markers tested for fragment length polymorphism in 20 isolates of Lasiodiplodia mahajangana identified between two and nine alleles and gene diversities between 0.18 and 0.83. Eleven markers indicated between two and five alleles for 20 isolates of Neofusicoccum parvum and gene diversities between 0.26 and 0.57. The large number and high transferability of the developed markers will facilitate population studies of a wide range of Lasiodiplodia and Neofusicoccum species associated with tree diseases globally.

G6PD A- is the major cause of G6PD deficiency among the Siddis of Karnataka, India

Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human erythroenzymopathy affecting more than 400 million people worldwide. G6PD deficiency was reported in India more than 50 years ago and the prevalence rate varies from 5.7% to 27.9% in different caste and tribal groups.Aim: To study the prevalence of, and the mutations causing, G6PD deficiency among the Siddis of Karnataka.Subjects and methods: A total of 755 individuals were screened using the DPIP dye decolorisation method and the deficiency was further confirmed by quantitative assay. Molecular characterisation was performed by PCR-RFLP method and DNA sequencing. Biochemical characterisation was performed as per WHO criteria.Results: Of the 755 individuals, 71 individuals (9.4%) were found to be G6PD deficient with an enzyme activity ranging from 0.02 to 3.83 IU/gm Hb. Mutational analysis could be performed on 49 G6PD deficient individuals and 45 (91.8%) of them showed the presence of the G6PD A- variant while the remaining 4 (8.2%) had the G6PD Kerala-Kalyan mutation. Microsatellite analysis in G6PD A- individuals showed the presence of 166/195 bp, AC/CTT alleles.Conclusions: G6PD deficiencies among the Siddis are predominantly due to G6PD A- mutation. Furthermore, biochemical parameters and the microsatellite repeat markers in the Siddi A- chromosome confirmed they are African descendants with Indian admixture.