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Simple Sequence Repeat (simple + sequence_repeat)
Terms modified by Simple Sequence Repeat Selected AbstractsSimple sequence repeat-based diversity in elite pigeonpea genotypes for developing mapping populations to map resistance to Fusarium wilt and sterility mosaic diseasePLANT BREEDING, Issue 2 2010R. K. Saxena With 1 figure and 3 tables Abstract In order to maximize polymorphism in the mapping populations for mapping loci for Fusarium wilt (FW) and sterility mosaic disease (SMD) resistance in pigeonpea, a set of 32 pigeonpea lines were screened for polymorphism with 30 microsatellite or simple sequence repeat markers. A total of 23 marker loci showed polymorphism with 2,4 alleles and the polymorphism information content for these markers ranged from 0.12 to 0.65 with an average of 0.43 per marker. High number of polymorphic markers, higher genetic dissimilarity coefficient and contrasting phenotypic data taken into consideration and five parental combinations were identified and crosses initiated for developing five genetically diverse mapping populations. Of these crosses, one cross segregates for FW resistance, two for SMD resistance and the remaining two crosses segregate for resistance to both FW and SMD. Development of mapping populations is in progress for mapping loci for resistance to FW and SMD in pigeonpea. [source] Characterization of simple sequence repeat variants linked to candidate genes for behavioral phenotypes,,HUMAN MUTATION, Issue 1 2006Zoë Prichard Abstract Simple sequence repeats (SSRs) have traditionally been used as markers in gene mapping studies and typing for forensic purposes. Recently there has been some speculation that this type of genetic variation also plays a more direct role in influencing gene expression and hence complex phenotypic outcomes such as human behavior. For this reason it is interesting to investigate SSRs linked to candidate genes for various complex phenotypes. An economical multiplex PCR-based assay was designed to simultaneously genotype individuals at 15 loci across 10 candidate genes for human behavioural phenotypes, including seven loci previously unreported in Caucasians (five unreported in any population). All loci were tested for Hardy-Weinberg equilibrium and for two-locus Linkage Disequilibrium. Ewens-Watterson neutrality testing indicated possible selection at a previously unreported DRD2 locus. © 2005 Wiley-Liss, Inc. [source] Isolation and characterization of polymorphic microsatellites for assessment of genetic variation of hops (Humulus lupulus L.)MOLECULAR ECOLOGY RESOURCES, Issue 2 2004A. M. Hadonou Abstract Hop (Humulus lupulus L.) cultivars are vegetatively propagated and it is difficult to differentiate them during the process of propagation. Fingerprinting with molecular markers based on DNA could be a useful means of identifying different cultivars. Simple sequence repeats, or microsatellite markers, are the most suitable marker for genetic fingerprinting because they are multi-allelic and co-dominant. For this purpose, we have developed primers for 10 new polymorphic microsatellite loci that are suitable for genetic fingerprinting in hop. [source] Hybridization between perennial ryegrass and Italian ryegrass in naturalized Japanese populationsGRASSLAND SCIENCE, Issue 2 2008Hiroyuki Tobina Abstract Introduced Lolium species, including perennial ryegrass (Lolium perenne) and Italian ryegrass (Lolium multiflorum), have been widely utilized in Japan for forage, turf and soil conservation. These ryegrasses have escaped from cultivated areas and become naturalized, and this has become a serious issue in recent years. Interspecific hybrids between perennial ryegrass and Italian ryegrass have often been found in naturalized populations. It has also been suggested that hybridization between plant species might serve as a stimulus for the evolution of invasiveness. We surveyed the genetic structure of naturalized ryegrass populations in Japan using genetic markers that distinguished perennial ryegrass and Italian ryegrass. Of the 55 naturalized populations surveyed, 41 exhibited morphological traits of Italian ryegrass. DNA analysis using simple sequence repeat and chloroplast DNA markers characterized 20 of these 41 populations as Italian ryegrass, with the remaining populations as interspecific hybrid derivatives. Approximately half of the naturalized ryegrasses populations in Japan were inferred to include interspecific hybrids. [source] Cross-species amplification of Lolium microsatellites in Poa sspGRASSLAND SCIENCE, Issue 3 2006Bryan Kindiger Abstract Cross-species amplification of 47 Lolium ssp. microsatellite primers were evaluated across eight Poa species or subspecies. Of the 47 evaluated Lolium simple sequence repeat (SSR) primer pairs examined, 18 generated one or more amplification products. Of these, only two resulted in the identification of Poa ssp. microsatellite motifs, of which only one was complementary to the microsatellite motif identified in Lolium. Though few Poa ssp. microsatellite regions were identified, several of the amplification products were polymorphic within and across the Poa ssp. and could be utilized as markers in Poa ssp. intergeneric hybrid studies. Results of the research suggest the use of Lolium microsatellite derived primers to identify complementary SSR regions in Poa is not an effective approach for the development of microsatellite markers in Poa. [source] SSR based linkage and mapping analysis of C, a yellow cocoon gene in the silkworm, Bombyx moriINSECT SCIENCE, Issue 5 2008Yun-Po Zhao Abstract The yellow color of the cocoon of the silkworm Bombyx mori is controlled by three genes, Y (Yellow haemolymph), I (Yellow inhibitor) and C (Outer-layer yellow cocoon), which are located on linkage groups 2, 9 and 12, respectively. Taking advantage of a lack of crossing over in females, reciprocal backcrossed F1 (BC1) progeny were used for linkage analysis and mapping of the C gene using silkworm strains C108 and KY, which spin white and yellow cocoons, respectively. DNA was extracted from individual pupae and analyzed for simple sequence repeat (SSR) markers. The C gene was found to be linked to seven SSR markers. All the yellow cocoon individuals from a female heterozygous backcross (BC1 F) showed a heterozygous profile for SSR markers on linkage group 12, whereas individuals with light yellow cocoons showed the homozygous profile of the strain C108. Using a reciprocal heterozygous male backcross (BC1 M), we constructed a linkage map of 36.4 cM with the C gene located at the distal end, and the closest SSR marker at a distance of 13.9 cM. [source] Microsatellite markers application on domesticated silkworm and wild silkwormINSECT SCIENCE, Issue 6 2005LIE ZHANG Abstract Twenty-seven sets of simple sequence repeat (SSR) primers were developed through hybridizing of (CA)n, (CT)n and (GT)n and sequencing the positive clones in libraries constructed by using p50 silkworm strain. Of those primer pairs, 26 sets of SSR primers amplified well in two regional wild silkworm strains. Ten domesticated silkworm strains and two regional wild silkworm strains were used for comparing the polymorphisms and for constructing a phylogenetic tree employing the UPGAM method. The result showed that the genetic distances within Japanese strains are closer than those of Chinese strains. And this result also implies that Japanese strains diverged from domesticated silkworm later than Chinese strains. According to the clustering result, the domesticated silkworm is firstly clustered in one class, but could be classified into two groups. Within a strain, the individual polymorphism of wild silkworm was significantly higher in abundance than those of domesticated silkworm. The S SR primers of domesticated silkworm could be used in genetic studies for wild silkworm. [source] A Genetic Map Constructed Using a Doubled Haploid Population Derived from Two Elite Chinese Common Wheat VarietiesJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 8 2008Kun-Pu Zhang Abstract Genetic mapping provides a powerful tool for the analysis of quantitative trait loci (QTLs) at the genomic level. Herein, we report a new genetic linkage map developed from an F1 -derived doubled haploid (DH) population of 168 lines, which was generated from the cross between two elite Chinese common wheat (Triticum aestivum L.) varieties, Huapei 3 and Yumai 57. The map contained 305 loci, represented by 283 simple sequence repeat (SSR) and 22 expressed sequence tag (EST)-SSR markers, which covered a total length of 2141.7 cM with an average distance of 7.02 cM between adjacent markers on the map. The chromosomal locations and map positions of 22 new SSR markers were determined, and were found to distribute on 14 linkage groups. Twenty SSR loci showed different chromosomal locations from those reported in other maps. Therefore, this map offers new information on the SSR markers of wheat. This genetic map provides new opportunities to detect and map QTLs controlling agronomically important traits. The unique features of this map are discussed. [source] Genetic Diversity and Association Analysis for Salinity Tolerance, Heading Date and Plant Height of Barley Germplasm Using Simple Sequence Repeat MarkersJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 8 2008Lilia Eleuch Abstract The objective of this study was to investigate the genetic diversity of barley accessions. Additionally, association trait analysis was conducted for grain yield under salinity, heading date and plant height. For this purpose, 48 barley genotypes were analyzed with 22 microsatellite simple sequence repeat (SSR) markers. Four of the 22 markers (Bmac316, scssr03907, HVM67 and Bmag770) were able to differentiate all barley genotypes. Cluster and principal coordinate analysis allowed a clear grouping between countries from the same region. The genotypes used in this study have been evaluated for agronomic performance in different environments. Conducting association analysis for grain yield under salinity conditions using TASSEL software revealed a close association of the marker Bmag749 (2H, bin 13) in two different environments with common significant alleles (175, 177), whereas the HVHOTR1 marker (2H, bin 3) was only significant in Sakhar_Egypt with alleles size being 158 and 161. Heading date also showed an association with scssr03907 through the common significant specific allele 111 and EBmac0415 markers in three different agro climatic locations, whereas HVCMA, scssr00103 and HVM67 were linked to heading date in the Egyptian environment only. The plant height association analysis revealed significant markers Bmag770 via the significant allele 152 and scssr09398. [source] Molecular Tagging and Mapping of Quantitative Trait Loci for Lint Percentage and Morphological Marker Genes in Upland CottonJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 3 2006Wang-Zhen Guo Abstract Using 219 F2 individuals developed by crossing the genetic standard line TM-1 and the multiple dominant marker line T586 in Gossypium hirsutum L., a genetic linkage map with 19 linkage groups was constructed based on simple sequence repeat (SSR) markers. Compared with our tetraploid backboned molecular genetic map from a(TM-1 × Hai 7124) × TM-1 BC1 population, 17 of the 19 linkage groups were combined and anchored to 12 chromosomes (sub-genomes). Of these groups, four morphological marker genes in T586 had been mapped into the molecular linkage map. Meanwhile, three quantitative trait loci for lint percentage were tagged and mapped separately on the A03 linkage group and chromosome 6. (Managing editor: Li-Hui Zhao) [source] Extensive spatial genetic structure revealed by AFLP but not SSR molecular markers in the wind-pollinated tree, Fagus sylvaticaMOLECULAR ECOLOGY, Issue 5 2007ALISTAIR S. JUMP Abstract Studies of fine-scale spatial genetic structure (SGS) in wind-pollinated trees have shown that SGS is generally weak and extends over relatively short distances (less than 30,40 m) from individual trees. However, recent simulations have shown that detection of SGS is heavily dependent on both the choice of molecular markers and the strategy used to sample the studied population. Published studies may not always have used sufficient markers and/or individuals for the accurate estimation of SGS. To assess the extent of SGS within a population of the wind-pollinated tree Fagus sylvatica, we genotyped 200 trees at six microsatellite or simple sequence repeat (SSR) loci and 250 amplified fragment length polymorphisms (AFLP) and conducted spatial analyses of pairwise kinship coefficients. We re-sampled our data set over individuals and over loci to determine the effect of reducing the sample size and number of loci used for SGS estimation. We found that SGS estimated from AFLP markers extended nearly four times further than has been estimated before using other molecular markers in this species, indicating a persistent effect of restricted gene flow at small spatial scales. However, our SSR-based estimate was in agreement with other published studies. Spatial genetic structure in F. sylvatica and similar wind-pollinated trees may therefore be substantially larger than has been estimated previously. Although 100,150 AFLP loci and 150,200 individuals appear sufficient for adequately estimating SGS in our analysis, 150,200 individuals and six SSR loci may still be too few to provide a good estimation of SGS in this species. [source] Fine-scale genetic structure and gene dispersal inferences in 10 Neotropical tree speciesMOLECULAR ECOLOGY, Issue 2 2006OLIVIER J. HARDY Abstract The extent of gene dispersal is a fundamental factor of the population and evolutionary dynamics of tropical tree species, but directly monitoring seed and pollen movement is a difficult task. However, indirect estimates of historical gene dispersal can be obtained from the fine-scale spatial genetic structure of populations at drift,dispersal equilibrium. Using an approach that is based on the slope of the regression of pairwise kinship coefficients on spatial distance and estimates of the effective population density, we compare indirect gene dispersal estimates of sympatric populations of 10 tropical tree species. We re-analysed 26 data sets consisting of mapped allozyme, SSR (simple sequence repeat), RAPD (random amplified polymorphic DNA) or AFLP (amplified fragment length polymorphism) genotypes from two rainforest sites in French Guiana. Gene dispersal estimates were obtained for at least one marker in each species, although the estimation procedure failed under insufficient marker polymorphism, limited sample size, or inappropriate sampling area. Estimates generally suffered low precision and were affected by assumptions regarding the effective population density. Averaging estimates over data sets, the extent of gene dispersal ranged from 150 m to 1200 m according to species. Smaller gene dispersal estimates were obtained in species with heavy diaspores, which are presumably not well dispersed, and in populations with high local adult density. We suggest that limited seed dispersal could indirectly limit effective pollen dispersal by creating higher local tree densities, thereby increasing the positive correlation between pollen and seed dispersal distances. We discuss the potential and limitations of our indirect estimation procedure and suggest guidelines for future studies. [source] SHORT COMMUNICATION: Do farmers reduce genetic diversity when they domesticate tropical trees?MOLECULAR ECOLOGY, Issue 2 2005A case study from Amazonia Abstract Agroforestry ecosystems may be an important resource for conservation and sustainable use of tropical trees, but little is known of the genetic diversity they contain. Inga edulis, a widespread indigenous fruit tree in South America, is used as a model to assess the maintenance of genetic diversity in five planted vs. five natural stands in the Peruvian Amazon. Analysis of five SSR (simple sequence repeat) loci indicated lower allelic variation in planted stands [mean corrected allelic richness 31.3 (planted) and 39.3 (natural), P = 0.009]. Concerns regarding genetic erosion in planted Amazonian tree stands appear valid, although allelic variation on-farm is still relatively high. [source] Fifteen polymorphic simple sequence repeat markers from expressed sequence tags of Liriodendron tulipiferaMOLECULAR ECOLOGY RESOURCES, Issue 3 2006MENG XU Abstract We developed and evaluated simple sequence repeat (SSR) markers derived from expressed sequence tags (ESTs) of Liriodendron tulipifera. Characteristics of 15 EST-SSR loci were investigated using 33 L. tulipifera individuals. The number of alleles per locus ranged from two to five. The expected and observed heterozygosities ranged from 0.216 to 0.751 and from 0.182 to 0.97, respectively. These loci were further tested for their cross-species transferability to Liriodendron Chinense. Because of their high level of polymorphism and transferability, our 15 single-locus EST-SSR markers will be valuable tools for research on mating system, population genetics and systemic evolution of Liriodendron. [source] Development of simple sequence repeat (SSR) markers and their use in identification of Dendrobium varietiesMOLECULAR ECOLOGY RESOURCES, Issue 3 2006G. H. YUE Abstract The aim of this study was to develop simple sequence repeat (SSR) markers for Dendrobium varieties/species, many of which have medicinal and horticultural values. Two genomic DNA libraries of Dendrobium Sonia enriched with GA repeats and CA repeats were constructed. Fourteen polymorphic SSR markers were identified when screened against 42 popular commercial Dendrobium hybrids. The average allele number was 12.0 ± 1.9 and the observed heterozyosity was averaged at 0.70. All 42 hybrids tested, except for two tissue culture mutants, were uniquely identified with the markers used. Sibling hybrids were closely clustered. Hybrids were also closer to parents. These SSR markers can be used for molecular ecology research, genetic mapping and marker-assisted breeding. They can also help protection for new Dendrobium varieties. [source] Characterization of microsatellite markers for rough fescue species (Festuca spp.)MOLECULAR ECOLOGY RESOURCES, Issue 3 2006YONG-BI FU Abstract One major challenge in genetic diversity analysis of minor grass species is the lack of informative molecular markers. A set of 210 simple sequence repeat (SSR) markers developed from wheat and barley were evaluated for their transferability to three rough fescue species [Festuca altaica Trinius, F. campestris (Rydb.) and F. hallii (Vassey) Piper]. Twelve SSR primer pairs displayed scorable polymorphism among and within the species. The number of alleles per primer pair ranged from three to 17 with an average of 8.3 for all the species and greatly varied for each species. About 82% of SSR variation resided within the species. Festuca hallii was genetically most distinct among the three species. [source] Development of DNA microsatellite markers in tropical yam (Dioscorea sp.)MOLECULAR ECOLOGY RESOURCES, Issue 1 2006S. TOSTAIN Abstract We developed new simple sequence repeat (SSR) markers in different species of yam (Dioscorea sp.). A microsatellite-enriched bank was created from Dioscorea alata, Dioscorea abyssinica and Dioscorea praehensilis. Sixteen polymorphic loci were characterized. Several of these markers are transferable to species of other Dioscorea sections. [source] Development and characterization of microsatellite markers for the fungus Ceratocystis fimbriataMOLECULAR ECOLOGY RESOURCES, Issue 2 2004J. Steimel Abstract Ceratocystis fimbriata is a serious fungal pathogen on a wide range of plants, but many cryptic species within C. fimbriata are apparently host-specialized. Anchor polymerase chain reaction (PCR) and simple sequence repeat (SSR) enriched libraries were used to develop 16 microsatellite markers for C. fimbriata. All markers were polymorphic when tested against isolates from four host-specialized lineages of the pathogen. These markers will be valuable for phylogenetic and population genetic studies, as well as for tracking accidental introductions of host-specialized forms of the pathogen. [source] A set of polymorphic microsatellites for Vochysia ferruginea, a promising tree for land reclamation in the NeotropicsMOLECULAR ECOLOGY RESOURCES, Issue 3 2002A. J. Lowe Abstract Vochysia ferruginea Mart. (Vochysiaceae) is a gap colonist of Neotropical forest. Because of its high tolerance of low-nutrient acidic conditions and high aluminium and iron concentrations, and its high potential seed and pollen dispersal, it is a promising timber species for commercial development as reclaimed forest on degraded land. We present here primer sequences for 10 polymorphic simple sequence repeat (SSR) loci for use with V. ferruginea to assess fine scale genetic structure and gene flow dynamics. [source] Development and characterization of SSR markers in Ribes speciesMOLECULAR ECOLOGY RESOURCES, Issue 3 2002R. Brennan Abstract Eleven microsatellite loci were identified and characterized in blackcurrant (Ribes nigrum L.) and related species. An enriched library was constructed and screened with simple sequence repeat (SSR) oligonucleotides. Positive clones were sequenced and primers were designed flanking the repeat motifs. These 11 microsatellites produce amplification products polymorphic across a range of Ribes germplasm, predominantly from the Eucoreosma section of the genus. The number of alleles varied from 2 to 18 with levels of diversity ranging from 0.18 to 0.91. [source] Development of novel polymerase chain reaction (PCR) based microsatellite markers in Armillaria gallica by cross-species amplification and species-specific cloningMOLECULAR ECOLOGY RESOURCES, Issue 2 2002J.-B. Lefrancois Abstract Cross-species PCR amplification of Armillaria mellea group taxa with previously reported A. ostoyae microsatellite markers, indicative of flanking sequence conservation, was exploited for the species-specific isolation of simple sequence repeat (SSR) motifs from A. gallica. Six SSR motifs were sequence characterized from cloned PCR fragments generated with primers previously developed from A. ostoyae. Five novel primer pairs, designed from motif flanking regions, allowed for improved, efficient amplification in this species. One original A. ostoyae primer pair was used directly. Polymorphims were observed at wide geographical levels only. Relative cross-species amplification intensities generally supported the currently accepted molecular phylogeny of this group. [source] Development of simple sequence repeat (SSR) markers for the assessment of gene flow and genetic diversity in pigeonpea (Cajanus cajan)MOLECULAR ECOLOGY RESOURCES, Issue 4 2001M. J. Burns Abstract Pigeonpea (Cajanus cajan) is an important subsistence crop in India where traditional landraces and improved hybrids are grown alongside each other. Gene flow may result in genetic erosion of these landraces and their wild relatives, whilst transgene escape from future genetically engineered varieties is another potential hazard. To assess the impact of these factors gene flow needs to be measured. A set of 10 simple sequence repeat markers have been developed, which exhibit polymorphism across a range of pigeonpea varieties. Use of these markers also offers an efficient system for the assessment of genetic diversity within populations of pigeonpea. [source] Quantitative trait loci and epistatic interactions in barley conferring resistance to net type net blotch (Pyrenophora teres f. teres) isolatesPLANT BREEDING, Issue 4 2010S. Gupta With 2 figures and 5 tables Abstract Net type net blotch (NTNB) is an important barley disease in Australia and elsewhere, with significant yield reduction. This trait is important in selection along with other traits of quality and agronomic value. Two-hundred doubled-haploid lines were generated through anther culture from a cross between ,Pompadour' and ,Stirling'. Quantitative trait loci (QTL) were identified against five isolates of Pyrenophora teres f. teres, which represent virulences across Australia. QTL were mapped on chromosomes 3H and 6H using simple sequence repeat (SSR) markers. The resistance locus on 6H was detected with all isolates while the 3H locus was detected with two isolates. The 6H QTL from ,Pompadour' contributed resistance to isolates 97NB1, 95NB100 and NB81, whereas 6H QTL from ,Stirling' contributed resistance to isolates NB50 and NB52B. The 3H QTL from ,Pompadour' contributed resistance to NB50 and NB52B. Significant epistatic interactions were detected between QTL on 3H and 6H. These resistance QTL are a useful resource and identifying closely linked SSR markers with allelic combinations will facilitate in marker-assisted selection to develop NTNB resistant breeding lines. [source] Genetic analysis and gene mapping of a rice recessive male sterile mutantPLANT BREEDING, Issue 3 2010J. B. Chen With 3 figures and 2 tables Abstract Male sterility of rice is one of the major genetic tools used for hybrid rice production. In this study, a spontaneous male sterile mutant, SC-ms-2, was obtained from the F4 progeny of the cross D 297B × Changfeng B. Microscopic observation revealed that the microspores were developed abnormally and the tapetum cells were incrassated during microsporogenesis. Genetic analysis indicated that male sterility of SC-ms-2 was controlled by a single recessive gene. By using bulked segregant analysis on two F2 populations developed from crossing SC-ms-2 with Hua B and ,Nipponbare', this gene was finely mapped between two simple sequence repeat (SSR) markers on chromosome 9, RM24451 and RM7048, with genetic distance of 0.3 cM and 0.6 cM respectively, and the approximate physical distance was 172 kb. Our results showed that this gene was distinguished from all the other male sterility genes in rice reported and it was designated ms92(t), temporally. Moreover, candidate genes in the region of 172kb, including the rice homologue to the Arabidopsis MALE STERILITY1 (MS1) gene, were surveyed and discussed. [source] Novel SSR Markers for Polymorphism Detection in Pigeonpea (Cajanus spp.)PLANT BREEDING, Issue 2 2010R. K. Saxena With 1 figure and 4 tables Abstract With an objective to expand the repertoire of molecular markers in pigeonpea (Cajanus cajan), 36 microsatellite or simple sequence repeat (SSR) loci were isolated from a SSR-enriched genomic library. Primer pairs were designed for 23 SSR loci, of which 16 yielded amplicons of expected size. Thirteen SSR markers were polymorphic amongst 32 cultivated and eight wild pigeonpea genotypes representing six Cajanus species. These markers amplified a total of 72 alleles ranging from two to eight alleles with an average of 5.5 alleles per locus. The polymorphic information content for these markers ranged from 0.05 to 0.55 with an average of 0.32 per marker. Phenetic analysis clearly distinguished all wild species genotypes from each other and from the cultivated pigeonpea genotypes. These markers should be useful for genome mapping, trait mapping, diversity studies and assessment of gene flow between populations in pigeonpea. [source] Molecular mapping of a fertility restorer gene for cytoplasmic male sterility in soybeanPLANT BREEDING, Issue 1 2010Y. Wang With 2 figures and 2 tables Abstract In this study, we report the mapping of the Rf locus in soybean by microsatellite simple sequence repeat (SSR) genetic markers. A cross was made between cytoplasmic male sterility (CMS) line JLCMS82A and restorer line JIHUI 1 based on the DNA polymorphisms revealed by 109 SSR markers. A F2 population derived from a single F1 plant containing 103 individuals was used for mapping the Rf locus. The Rf gene of JIHUI 1 gametophytically restores male fertility to JLCMS82A. Fertile and semi-fertile DNA bulks and parental DNAs were screened with 219 SSR markers, and Satt215 which was previously mapped to soybean LG J, was found linked to the Rf gene. Five additional polymorphic SSR markers from LG J were used for analysis and a regional linkage map around the Rf locus was established. SSR markers, Sctt011 and Satt547, flanked the Rf locus at 3.6 cM and 5.4 cM, respectively. The availability of these SSR markers will facilitate the selection of restorer lines in hybrid soybean breeding. [source] Molecular diversity and association of SSR markers to rust and late leaf spot resistance in cultivated groundnut (Arachis hypogaea L.)PLANT BREEDING, Issue 1 2010S. Mondal With 1 figure and 2 tables Abstract Molecular diversity and association of simple sequence repeat (SSR) markers with rust and late leaf spot (LLS) resistance were detected in a set of 20 cultivated groundnut genotypes differing in resistance against both diseases. Out of 136 bands amplified from 26 primers, 104 were found polymorphic (76.5%). Cluster analysis (UPGMA) revealed two main clusters separated at 52% Jaccard's similarity coefficient according to disease reaction to rust and LLS. Based on the Kruskal,Wallis one-way anova and simple regression analysis three and four SSR alleles were found associated with rust and LLS resistance, respectively. [source] Genetic linkage map of cassava (Manihot esculenta Crantz) based on AFLP and SSR markersPLANT BREEDING, Issue 1 2010S. Kunkeaw With 1 figure Abstract To generate a genetic linkage map of cassava (Manihot esculenta Crantz), 58 F1 progenies from a cross between Rayong 90 (female) and Rayong 5 (male) were examined in amplification fragment length polymorphism (AFLP) and simple sequence repeat (SSR) analyses. A total of 469 polymorphic markers consisting of 378 AFLPs generated from 76 primer combinations and 91 SSRs were identified. These markers were analyzed using the joinmap®3.0 package program to construct a genetic linkage map. A total of 33 linkage groups of a common map were constructed from 119 AFLPs and 18 SSRs, spanning 1095 cM with an average of 7.99 cM between markers. The genetic linkage map generated in this study will be useful for genetic studies in cassava particularly for the identification of genetic markers linked to traits of interest, although the complex cassava genome suggests that maybe a long term objective. [source] Isolation and characterization of microsatellite markers from guineagrass (Panicum maximum) for genetic diversity estimate and cross-species amplificationPLANT BREEDING, Issue 1 2010A. Chandra With 1 figure and 1 table Abstract Guineagrass (Panicum maximum Jacq.) is one of the major forage grasses in tropical and semitropical regions, largely apomictic and predominantly exist as tetraploid. Non-availability of polymorphic molecular markers has been a major limitation in its characterization and improvement. We report isolation and characterization of microsatellites in P. maximum and cross-species results with other five Panicum species. Based on microsatellite-motifs, 15 functional and polymorphic simple sequence repeat (SSR) primer-pairs were designed, validated and employed in estimating genetic relationship among 34 guineagrass accessions. Thirteen primer-pairs amplified single locus and remaining two generated more than two loci with an average of 3.57 bands per locus amounts to 63 bands with 34 guineagrass accessions. Average expected heterozygosity (HE) of 0.35 (maximum 0.97) and observed heterozygosity (HO) of 0.37 (maximum 0.91) established the efficiency of developed markers for discriminating guineagrass accessions. Dice's similarity coefficients-based unweighted pair group with arithmetic average method-clustering supported with high bootstrap values (,40) indicated its significance and distinguished all accessions except IG97-93 and IG97-6. Utility of these new SSR loci in genetic diversity study of P. maximum and other cross,amplified species is discussed. [source] Molecular mapping of genic male-sterile genes ms15, ms5 and ms6 in tetraploid cottonPLANT BREEDING, Issue 2 2009D. Chen Abstract Two genic male sterile (GMS) lines, Lang-A conditioned by ms15 and Zhongkang-A conditioned by ms5ms6 duplicate recessive genes in Gossypium hirsutum L., were chosen to map GMS genes. These two lines were crossed with Gossypium barbadense cv. ,Hai7124' to produce segregating populations. The ms15 gene was mapped on chromosome 12, and was flanked by two simple sequence repeat (SSR) markers, NAU2176 and NAU1278, with a genetic distance of 0.8 and 1.9 cM respectively. The ms5 and ms6 genes were mapped to one pair of homoeologous chromosomes, ms5 on chromosome 12 flanked by three SSR markers, NAU3561, NAU2176 and NAU2096, with genetic distances of 1.4, 1.8 and 1.8 cM, respectively, and ms6 on chromosome 26 flanked by two SSR markers, BNL1227 and NAU460, with a genetic distance of 1.4 and 1.7 cM respectively. These tightly linked markers with the ms15, ms5 and ms6 genes can be used in the marker-assisted selection among segregating populations in a breeding programme, and provide the foundation for gene isolation by map-based cloning for these three genes. [source] | |||||||||||||||||||