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Genetic maps facilitate an understanding of genome organization and the mapping of genes and QTLs for traits of interest. Our objective was to develop a high-density genetic map of Jatropha and anchoring scaffolds from genome assemblies. We developed two ultra-high-density genetic linkage maps of Jatropha curcas × Jatropha intergerrima using a backcross (BC1) population using SNP, AFLP and SSR markers. First, SNPs were identified through genotyping-by-sequencing (GBS). The polymorphic SNPs were mapped to 3267 Jat_r4.5 scaffolds and 484 Wu_JatCur_1.0 scaffolds, and then these genomic scaffolds were mapped/anchored to the genetic linkage groups along with the AFLP and SSR markers for each genome assembly separately. We successfully mapped 7284 polymorphic SNPs, and 54 AFLP and SSR markers on 11 linkage groups using the Jat_r4.5 genomic scaffolds, resulting in a genome length of 1088 cM and an average marker interval of 0.71 cM. We mapped 7698 polymorphic SNPs, and 99 AFLP and SSR markers on 11 linkage groups using the Wu_JatCur_1.0 genomic scaffolds, resulting in a genome length of 870 cM and an average marker interval of 1.67 cM. The mapped SNPs were annotated to various regions of the genome, including exon, intron and intergenic regions. We developed two ultra-high-density linkage maps anchoring a high number of genome scaffolds to linkage groups, which provide an important resource for the structural and functional genomics as well as for molecular breeding of Jatropha while also serving as a framework for assembling and ordering whole genome scaffolds. [ABSTRACT FROM AUTHOR]

Genetic linkage maps are important for quantitative trait locus (QTL) and marker-assisted selection breeding. The wolfberry (Lycium spp.) is an important food and traditional medicine in China. However, few construction genetic linkage maps have been reported because of the lack of genomic and genetic resources. In this study, a population of 89 F1 seedings was derived from a cross between two heterozygous parents, L. chinense var. potaninii ‘BF-01’ (female) and L. barbarum var. auranticarpum ‘NH-01’ (male), in order to construct a genetic linkage map using simple sequence repeat (SSR) and amplified fragment length polymorphism (AFLP) markers based on the double pseudo-test cross mapping strategy. The resulting genetic map consisted of 165 markers (74 AFLPs and 91 SSRs) distributed across 12 linkage groups and spanned a total length of 557.6 cM with an average distance of 3.38 cM between adjacent markers. The 12 linkage groups contained 3 to 21 markers and ranged in length from 8.6 to 58.3 cM. Twenty-nine segregated markers distributed in the map were mainly located on LG4 and LG9 linkage groups at P

Sugarcane mosaic disease (SMD) caused by sugarcane mosaic virus, is one of the main diseases in sugarcane production areas in Brazil. Thus, the identification of new sources of resistance for use in future introgression crosses is key for reliable economic gains. Here, we aimed to screen a diversity panel of 98 sugarcane genotypes for SMD under natural infection conditions, to investigate virus-specific amplicons from SCMV coat protein gene (CP), and identify marker-trait associations via association mapping using Amplified Fragment Length Polymorphism (AFLP) and Simple Sequence Repeats (SSR). The highest SMD incidence (26.53%) was observed eight months after planting, with significant differences (p<0.01) among genotypes and a means-based broad-sense heritability of 62.49% with a noticeable contribution of Saccharum spontaneum to SMD resistance. The CP sequence analysis revealed no variation among the four selected plant samples, which phylogenetic analysis revealed clustering with the RIB-1 strain while putative amino acid substitutions indicate a new SCMV isolate. From a subset of 135 SSR and 663 AFLP markers, selected after quality control, 91 markers were associated with response to SCMV (p <0.05) by simple linear regression, and 24 were significant at p <0.01. Four out these 24 fit in a stepwise regression at p <0.05, all contributing for the resistance to SMD, and are present in thirteen genotypes showing no SMD symptoms. These four markers collectively explain 29.95% of trait variation, while individually explain from 5.51 to 14.02%, and may correspond to new genomic regions conferring genetic resistance to SMD which investigation is worthwhile. [ABSTRACT FROM AUTHOR]

Given the significant impact of molecular markers on the genetic diversity assessment, understanding genetic diversity pattern across diverse marker types in a comparative manner is of great importance. In Korea, within the last 10 years population genetics studies of wild plants have drawn much attention as varying DNA markers have developed. To investigate the pattern of among-population and within-population level genetic diversity of wild plants in Korea, we reviewed the extent of population genetic parameters across four DNA markers (RAPD, AFLP, ISSR, SSR). We compiled 73 data sets from research papers published between 2010 and 2019. ISSR markers were the most frequently used in population genetics studies conducted on Korean wild plants. Overall, genetic diversity patterns greatly varied across the different marker types. On average, endangered species exhibited low within-population genetic variation and high among-population genetic diversity. Species with wide geographic distribution showed greater within-population diversity values than the ones residing in a restricted area except for AFLP data. Populations were genetically less differentiated in long distance dispersal species with wide geographic ranges. Our review indicates that the studies on the genetic diversity of wild plants may be improved by expanding the scope and increasing the sample sizes.

Safflower (Carthamus tinctorius L.), an oilseed crop, is severely affected by Fusarium oxysporum f. sp. carthami (Foc), a fungus causing Fusarium wilt (FW) resulting in up to 80% yield loss. In the present study, we used a panel of 84 diverse accessions from the composite core collection to perform association mapping for FW-resistance. Hydroponics-based screening resulted in categorization of 84 accessions as 31 immune, 19 highly resistant, 9 moderately resistant, 4 moderately susceptible, and 21 highly susceptible. Genotyping with a combination of 155 AFLP and 144 SSR markers revealed substantial genetic differentiation and structure analysis identified three main subpopulations (K = 3) with nearly 35% of admixtures in the panel. Kinship analysis at individual and population level revealed absence of or weak relatedness between the accessions. Association mapping with General Linear Model and Mixed Linear Model identified 4 marker-trait associations (MTAs) significantly linked with the FW-resistance trait. Of these, 3 robust MTAs identified in both the models exhibited phenotypic variance ranging from 4.09 to 6.45%. Locus-128 showing a low P-value and high phenotypic variance was identified as a promising marker-trait association that will facilitate marker-assisted breeding for FW-resistance in safflower. [ABSTRACT FROM AUTHOR]

Genetic variation was investigated in fifteen single, eighteen three-way, and nine double hybrid crosses and their parents along with nine elite commercial cucumber hybrids. Six lines (NS5, NS9, NS17, NS29, NS31, and NS33) were used to develop these cross hybrids. Based on AFLP and SSR analysis, the studied cucumber genotypes have a narrow genetic base. The results also showed genetic differentiation compared to commercial varieties. Out of 1352 bands produced from 12 AFLP primer pairs, only 47 were polymorphic. Similarly, out of 26 SSR primers, only one primer was polymorphic. The highest heterozygosity index (0.6044), polymorphic information content value (0.5392), and marker Index (0.6044) were observed with M-CTT_E-AAG AFLP primer combination, while the highest effective multiplex ratio (2.8246) and resolving power (4.8421) were observed with M-CTC_E-AGC AFLP primer combination. Genetic distance estimation revealed clear distinctiveness of the studied genotypes with the control varieties. The cluster analysis by UPGMA showed two main clusters covering 84% of the studied genotypes grouped. This research shows that double and three-way hybrid crosses can be used in cucumber hybrid breeding. [ABSTRACT FROM AUTHOR]

Genotyping is an essential procedure for identifying agronomically useful genes and analyzing population structure. Various types of genetic marker systems have been developed in common buckwheat (Fagopyrum esculentum Moench). In the 1980s, morphological and allozyme markers were used to construct linkage maps. Until the early 2000s, allozyme markers were widely used in population genetics studies. Such studies demonstrated that cultivated common buckwheat likely originated in the Sanjiang area of China. In the late 1990s and early 2000s, advances in PCR technology led to the development of various DNA marker systems for use in linkage mapping. However, PCR-based markers did not completely cover the genome, making genetic analysis of buckwheat challenging. The subsequent development of next generation sequencing, a game-changing technology, has allowed genome-wide analysis to be performed for many species. Indeed, 8,884 markers spanning 756 loci were recently mapped onto eight linkage groups of common buckwheat; these markers were successfully used for genomic selection to increase yield. Furthermore, draft genome sequences are now available in the Buckwheat Genome DataBase (BGDB). In this review, I summarize advances in the breeding and genetic analysis of common buckwheat based on contemporary genetic marker systems. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum L.) is an important staple food and economic crop in many countries. China has led world potato production in recent years. To understand the genetic diversity of potato germplasms and to enrich the current gene pool for potato improvement, we made a global collection consisted of 288 potato germplasms from eight countries and the International Potato Center (CIP). Using SSR and AFLP techniques, we evaluated the genetic diversity and population structure of these 288 potato accessions. A total of 190 alleles on 20 SSR loci were detected and all of the SSR alleles were polymorphic among these potato germplasms with an average of 9.5 alleles per SSR locus ranging from 2 to 23. The effective number of alleles per locus (Ne*), Nei's genetic diversity (H*), and Shannon's information index (I*) was from (0.1709±0.3698) to (1.6166±0.3414), (0.076±0.1388) to (0.3812±0.1886), and (0.1324±0.1970) to (0.5347±0.1440), respectively, and the mean polymorphic information content (PIC) value was 0.7312. A total of 988 AFLP alleles were detected by 10 AFLP primer combinations with 983 polymorphic alleles, and 99.49% alleles was polymorphic with an average of 98.3 polymorphic alleles per primer combination ranging from 91 to 116. The values of Ne*, H* and I* were from (1.5162±0.311) to (1.6423±0.3278), (0.3114±0.145) to (0.3675±0.1121), and (0.4761±0.1792) to (0.547±0.1322), respectively, and the average PIC value was 0.9871. Bayesian analysis discriminated the accessions into seven subgroup and an admix group. The majority of accessions from CIP and China were assigned into SG1, SG5, SG6, SG7 and admix group. Accessions in SG3 were mainly from CIP and two small groups SG2 and SG4 were mainly from northeastern China. In general, the results obtained from Bayesian statistical analysis, cluster analysis and principal coordinate analysis consistently revealed the lack of geographical differentiation among country-wide collections, indicating germplasm introduction was common for the countries out of potato origin center. The polymorphic markers and the differentiate genetic lineages found in this study provide useful information for potato improvement and conservation programs.

Penstemon caryi is a narrow-range endemic angiosperm found primarily on sparsely vegetated limestone outcrops in the Bighorn and Pryor Mountains of north-central Wyoming and south-central Montana. A former candidate for listing under the Endangered Species Act, and currently a species of concern in these states, P. caryi is potentially threatened by habitat loss due to encroaching anthropogenic activities, such as limestone quarrying and road construction. In an effort to assess the capacity of P. caryi to withstand habitat loss and degradation, we used simple sequence repeats (SSRs) and amplified fragment length polymorphism (AFLP) markers to examine genetic diversity and differentiation of P. caryi populations from the Pryor Mountains of Montana and the southern Bighorn Mountains of Wyoming. Our analyses revealed overall moderate to high levels of genetic diversity in P. caryi, but with relatively lower levels of diversity in populations from the Pryor Mountains. There are fewer known individuals of Penstemon caryi in Montana, and because the examined populations from Montana exhibited less genetic diversity than those from Wyoming, populations from Montana may face an increased risk of population decline and extirpation. Both the AFLP and SSR data sets found population structure between different regions (Montana vs. Wyoming), while AFLP markers identified further subdivision between Wyoming populations. Despite moderate to high levels of genetic diversity, P. caryi is still a species at risk due to impending environmental stresses such as global climate change and human encroachment, which may be especially troublesome given its narrow distribution and the specificity of its habitat preferences. [ABSTRACT FROM AUTHOR]

The production of African nightshade is below its potential due to a lack of superior varieties. The development of varieties through breeding programmes has been initiated in order to supply farmers with quality seeds. However, systematic studies on the agronomic performance of African nightshade germplasm have been started only recently, and publications in this area are very scarce. In this study, we analysed morphological traits relevant for the agronomic performance of 54 entries comprising two species: Solanum villosum and S. scabrum. In addition, AFLP markers and newly developed SSR markers were used to assess genetic diversity and differentiation in the African nightshade entries. An analysis of molecular variance showed higher variation within than among entries. A cluster analysis grouped the entries into two clusters representing the two species. The analysis of agronomic traits revealed significant differences among entries. The genetic diversity of the released cultivars and accessions was comparable to but lower than that of the local cultivars. Additionally, the local cultivars had higher allelic richness and a larger number of unique alleles than did the developed cultivars and could serve as a useful gene pool for future breeding of superior germplasm. [ABSTRACT FROM AUTHOR]

Barley (Hordeum vulgare L.), an important food and fodder crop, is potentially tolerant to salinity. To identify quantitative trait loci (QTLs) controlling salt tolerance, the population of 162 recombinant inbred lines (RILs) derived from F8 generation of Arigashar (an extremely salt tolerant Iranian six-rowed barley landrace) crossed with Igri (a salt semi-sensitive two-rowed cultivar) were evaluated. The growth of shoots, roots, and coleoptiles, and root numbers are four important growth characteristics severely affected by salt stress at seedling growth stages. A linkage map was constructed using 106 AFLP and SSR markers spanning six barley chromosomes including 2(2H), 3(3H), 4(4H), 7(5H), 6(6H), and 1(7H). Out of totally 26 detected QTLs, 17 QTLs were found effective for salt tolerance at 250 and 350 mM NaCl which localized on chromosomes 2H, 3H, 4H, 6H, 7H, and linkage group L1, whereas considering equivalent overlapped QTLs with a pleiotropic effect led to detection of totally 9 distinctive QTLs (QClgH2.1b, QSdgH2.1b, QSlgH2.1c, QNrgH2.1b, QTwgH2.2c, QSdg3Hb, QSlg4Hb1, QClg4Hb, and QSlg6Hc2) effective for salinity tolerance. 2(2H), 4(4H), and 6(6H) were major chromosomes harboring QTLs which effectively controlled salt tolerance in the Igri×Arigashar population. An interesting QTL, QTwg4Hc, was localized on chromosome 4H in the XE41-M61 marker distance that controls several traits including shoot and coleoptile lengths and shoot fresh mass under salt stress. A dense marker cluster around a resistance gene could offer a starting point for positional cloning.

Globe artichoke (Cynara cardunculus var. scolymus) is a cross-pollinated, highly heterozygous species, which is conventionally propagated vegetatively. A scheme is described here which combines phenotypic with genotypic selection to fast track the development of a seed-propagated variety. The scheme was tested by making three selections, on a phenotypic basis, from a Brazilian seed-propagated variety showing an high phenotypic variation. The genetic relatedness as well as the heterozygosity of the material in study, in respect to standard variety representatives, was initially assessed with a wide set of microsatellite markers. Afterwards, an AFLP-based selection demonstrated to provide a practical and cheap means of conducting marker assisted breeding, which can be easily adopted also in laboratories of small seed companies. The selection approach described here could be readily adopted also to convert current vegetatively propagated landraces into seed-propagated varieties. [ABSTRACT FROM AUTHOR]

For a long time, mites mainly rely on the morphological characteristics in the systematic study. DNA markers are DNA fragments which can reflect the characteristics of the genome between individual species or species. Recently, the application of DNA markers has become more and more important in the systematic study of mites. The present situation and prospect of DNA markers, RAPD (Random Amplified Polymorphic), RFLP (Restriction Fragment Length Polymorphism), SSR (Simple Sequence Repeat), DNA Sequence Analysis, AFLP (Amplified Fragment Length Polymorphism) and DALP (Direct Amplification of Length Polymorphism), used in the systematic study of mites are described here, which will be helpful for research on acarolog [ABSTRACT FROM AUTHOR]

Natural introgression can cause negative effects where rare species experience genetic assimilation and invade by their abundant congeners. Quercus austrocochinchinensis and Q. kerrii (subgenus Cyclobalanopsis) are a pair of closely related species in the Indo-China area. Morphological intermediates of the two species have been reported in this region. In this study, we used AFLP, SSR and two key leaf morphological diagnostic traits to study the two Q. austrocochinchinensis populations, two pure Q. kerrii and two putative hybrid populations in China. Rates of individual admixture were examined using the Bayesian clustering programs STRUCTURE and NewHybrids, with no a priori species assignment. In total, we obtained 151 SSR alleles and 781 polymorphic loci of AFLP markers. Population differentiation inferred by SSR and AFLP was incoherent with recognized species boundaries. Bayesian admixture analyses and principal coordinate analysis identified more hybrids and backcrossed individuals than morphological intermediates in the populations. SSR inferred a wide genetic assimilation in Q. austrocochinchinensis, except for subpopulation D2 in the core area of Xi-Shuang-Ban-Na Nature Reserve (XSBN). However, AFLP recognized more Q. austrocochinchinensis purebreds than SSR. Analysis using NewHybrids on AFLP data indicated that these hybridized individuals were few F2 and predominantly backcrosses with both parental species. All these evidences indicate the formation of a hybrid swarm at XSBN where the two species co-exist. Both AFLP and SSR recognized that the core protected area of XSBN (D2) has a high percentage of Q. austrocochinchinensis purebreds and a unique germplasm. The Hainan population and the other subpopulations of XSBN of the species might have lost their genetic integrity. Our results revealed a clear genetic differentiation in the populations and subpopulations of Q. austrocochinchinensis and ongoing introgression between Q. austrocochinchinensis and Q. kerrii at the disturbed contact areas. Combining the results from genetic and morphological analyses, the conservation of subpopulation D2 should be prioritized. Conservation and restoration of the integrity of tropical ravine rainforest is an important long-term goal for the successful conservation of Q. austrocochinchinensis. The fine-scale landscape might play an essential role in shaping the spatial patterns of hybridization. Further studies are needed to evaluate these patterns and dynamics. [ABSTRACT FROM AUTHOR]

Cupressus sempervirens L. is a keystone species for Mediterranean ecosystems. It appears in two varieties according to its crown form, C. sempervirens var. horizontalis and C. sempervirens var. pyramidalis. A progeny of 382 F individuals was screened using Amplified Fragment Length Polymorphism (AFLP) and simple sequence repeats (SSR) markers for constructing genetic maps of the horizontalis and pyramidalis varieties used as parents, as well as a consensus map covering all chromosomes of the cypress genome. Out of the 1340 AFLP and SSR loci generated, 1271 variable loci segregated in 1:1, 3:1, 1:1:1:1, and 1:2:1 ratios and were used for linkage mapping. Segregation distortion was relatively high, but comparable to that reported in other Cupressaceae. The consensus C. sempervirens map (LOD = 6, θ = 0.30) consisted of 11 linkage groups and covered 2.105.65 cM. The consensus map was used for QTL detection regarding crown form, resistance to the fungus Seiridium cardinale, height, and diameter. A QTL for crown form architecture was found in linkage group 11 (LOD = 3.30). The long-term mapping population employed permits future map enrichment with more molecular markers, as well as more detailed records of quantitative traits at future ontogenetic stages. This is the first report of a consensus linkage map in a cypress species. [ABSTRACT FROM AUTHOR]

European hazelnut ( Corylus avellana L.), cultivated in several areas of the world including Europe, Anatolia, and the USA, is an economically important nut crop due to its high mineral, oleic acid, amino acid, and phenolic compound content and pleasant flavor. This study examined molecular genetic diversity and population structure of 54 wild accessions and 48 cultivars from the Slovenian national hazelnut collection using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Eleven AFLP primer combinations and 49 SSR markers yielded 532 and 504 polymorphic fragments, respectively. As expected for a wind-pollinated, self-incompatible species, levels of genetic diversity were high with cultivars and wild accessions having mean dissimilarity values of 0.50 and 0.60, respectively. In general, cultivars and wild accessions clustered separately in dendrogram, principal coordinate, and population structure analyses with regional clustering of the wild material. The accessions were also characterized for ten nut and seven kernel traits and some wild accessions were shown to have breeding potential. Morphological principal component analysis showed distinct clustering of cultivars and wild accessions. An association mapping panel composed of 64 hazelnut cultivars and wild accessions had considerable variation for the nut and kernel quality traits. Morphological and molecular data were associated to identify markers controlling the traits. In all, 49 SSR markers were significantly associated with nut and kernel traits [ P < 0.0001 and LD value ( r ) = 0.15-0.50]. This work is the first use of association mapping in hazelnut and has identified molecular markers associated with important quality parameters in this important nut crop. [ABSTRACT FROM AUTHOR]

Sustaining and developing of genetic diversity in winter wheat germplasm is one of the main prerequisite for success in future winter wheat breeding programs. Selection of diverse parents is essential for creation of superior new varieties. Danger of genetic erosion specially exists in smaller breeding programs and selection for limited production area with similar growing conditions. Croatian winter wheat breeding has a long tradition but it is relatively small compared to countries with bigger growing areas. Use of molecular markers in evaluating genetic diversity of winter wheat varieties is limited in Croatian breeding programs. Therefore, aim of this study was to evaluate genetic diversity of Croatian winter wheat varieties using SSR and AFLP markers as a powerful tool for assessing genetic diversity. Forty winter wheat varieties, from three Croatian breeding centres and foreign centres were included in the study. A set of 26 microsatellite primers were used, covering three wheat genomes and 42 chromosomes by 0.66 average genetic distance. The largest calculated distance was between the varieties Zlatna Dolina and Lela (dij=0.98), while most similar varieties were Super Žitarka and Barbara with the distance value of dij=0.21. Four AFLP marker combinations generated 108 polymorphic bands with average of 34 specific bands per primer combination. On the average 27 polymorphic bands were generated with average PIC value of 0.34. Specific polymorphic bands were discriminant for the three varieties Žitarka, Super Žitarka and Barbara, which, therefore, can be used for their identification. Grouping of varieties was in accordance with their origin (breeding centre) and pedigree data.

For the first time, the durum wheat Graziella Ra was compared to four Italian durum wheat varieties (Cappelli,Grazia, Flaminio and Svevo) and to Kamut in order to preliminary characterize its genome and to investigategenetic diversity among and within the accessions by Amplified Fragment Length Polymorphisms (AFLPs),Simple Sequence Repeats (SSRs) and α-gliadin gene sequence analysis. The main aim of the study was anattempt to determine the relationship between the historic accession Graziella Ra and Kamut which isconsidered an ancient relative of the durum subspecies. In addition, nutritional factors of Graziella Ra werereported. Obtained results showed that (i) both AFLP and SSR molecular markers detected highly congruentpatterns of genetic diversity among the accessions showing nearly similar efficiency; (ii) for AFLPs,percentage of polymorphic loci within accession ranged from 6.57% to 19.71% (mean 12.77%) and, for SSRs,from 0% to 57.14% (mean 28.57%); (iii) principal component analysis (PCA) of genetic distance amongaccessions showed the first two axes accounting for 58.03% (for AFLPs) and 61.60% (for SSRs) of the totalvariability; (iv) for AFLPs, molecular variance was partitioned into 80% (variance among accessions) and 20%(within accession) and, for SSRs, into 73% (variance among accessions) and 27% (within accession); (v)cluster analysis of AFLP and SSR datasets displayed Graziella Ra and Kamut into the same cluster; and (vi)molecular comparison of α-gliadin gene sequences showed Graziella Ra and Kamut in separate clusters. Allthese findings indicate that Graziella Ra, although being very similar to Kamut, at least in the little part of thegenome herein investigated by molecular markers, may be considered a distinct accession showing appreciablelevels of genetic diversity and medium-high nutritional qualities.

Forty-four soybean genotypes with different photoperiod response were selected after screening of 1000 soybean accessions under artificial condition and were profiled using 40 SSR and 5 AFLP primer pairs. The average polymorphism information content (PIC) for SSR and AFLP marker systems was 0.507 and 0.120, respectively. Clustering of genotypes was done using UPGMA method for SSR and AFLP and correlation was 0.337 and 0.504, respectively. Mantel's correlation coefficients between Jaccard's similarity coefficient and the cophenetic values were fairly high in both the marker systems (SSR = 0.924; AFLP = 0.958) indicating very good fit for the clustering pattern. UPGMA based cluster analysis classified soybean genotypes into four major groups with fairly moderate bootstrap support. These major clusters corresponded with the photoperiod response and place of origin. The results indicate that the photoperiod insensitive genotypes, 11/2/1939 (EC 325097) and MACS 330 would be better choice for broadening the genetic base of soybean for this trait.

O objetivo deste trabalho foi avaliar a produtividade de híbridos simples de milho obtidos de cruzamentos dialélicos entre linhagens divergentes, estimar a capacidade de combinação das linhagens e confirmar se a divergência genética entre as linhagens, obtida por marcadores moleculares, é correlacionada com a heterose dos híbridos simples no campo. Trinta e seis híbridos resultantes do dialelo parcial e as 12 linhagens parentais foram avaliadas em Campinas em blocos ao acaso, com três repetições e duas testemunhas. A capacidade de combinação das linhagens foi estimada de acordo com o modelo 4 de Griffing. Estimaram-se a correlação matricial, mediante a estatística de Mantel, entre heterose, produtividade e capacidade específica de combinação com divergência genética por AFLP e SSR. Destacou-se o híbrido PM518 x L111 e as linhagens PM518, IP4035 e L111 apresentaram efeitos positivos da capacidade geral de combinação. As estimativas de heterose variaram de 927 a 6.698 kg ha-1. Houve correlação entre heterose e divergência genética por AFLP e SSR. No entanto, a divergência genética não foi suficiente para determinar a capacidade específica de combinação nem a produtividade dos híbridos.The objective of this work was to evaluate grain yield of maize single cross hybrids obtained from diallel crosses among contrasting lines, to estimate the combining ability of the lines, and finally to confirm if the genetic diversity among those lines assessed by molecular markers is correlated with single cross hybrids heterosis. The 36 single cross hybrids resulting from partial diallel and 12 parental lines were evaluated in Campinas in randomized block design, with three replicates and two control lines checks. General combining ability of the lines was estimated according to Griffing model 4. Correlations among matrices were estimated through Mantel statistics, considering heterosis, yield and specific combining ability with genetic divergence assessed by AFLP and SSR. The hybrids PM518 x L111 exhibited an outstanding yield and the lines PM518, IP4035 and L111 showed positive general combining ability. The estimate heterosis ranged from 927 to 6,698 kg ha-1. A positive and significant correlation was observed in parental lines between heterosis and genetic diversity assessed by AFLP and SSR. The genetic divergence, however, was not enough to determine the specific combining ability and the hybrids yield.

The Andean blackberry belongs to the genus Rubus, the largest of the Rosaceae family and one of the mostdiverse of the plant kingdom. In Colombia Rubus glaucus Benth, known as the Andean raspberry or blackberry, is one of thenine edible of the genus out of forty-four reported species. In this study wild and cultivated genotypes, collected in the CentralAndes of Colombia were analyzed by AFLP and SSR markers. Sexual reproduction seems to play an important role inmaintaining the genetic variability in R. glaucus, and the viability of using the SSR of Rubus alceifolius to characterizeColombian Rubus species was clearly demonstrated. All species evaluated produced very specific banding patterns,differentiating them from the others. Both AFLP and SSR produced bands exclusive to each of the following species: R.robustus, R. urticifolius, R. glaucus, and R. rosifolius. The SSR markers differentiated diploid and tetraploid genotypes of R.glaucus.

Perennial ryegrass (Lolium perenne L.) is the most important grass species used in temperate grassland agriculture. Our objective was to obtain an overview of the genetic relationships between 20 individual genotypes of perennial ryegrass of diverse origins, using amplified fragment length polymorphism (AFLP), inter-simple sequence repeat (ISSR), random amplified polymorphic DNA (RAPD) and two sets of simple sequence repeat (SSR) markers. All 20 individuals were uniquely fingerprinted by all four marker systems and comparisons were made on the basis of 85 markers each. Mean genetic similarities were estimated at 0.31, 0.43, 0.23 and 0.15 for AFLPs, ISSRs, RAPDs and SSRs, respectively. Cophenetic values resulted in good (AFLP and SSR-B = 0.88) to moderately good fits (ISSR = 0.76, RAPD = 0.70, and SSR-A = 0.79). Comparing the four marker systems to each other, AFLP and SSR-A were correlated best (r = 0.57). All other comparisons revealed rather low correlation coefficients in the Mantel Z test. With twice as many markers cophenetic values increased to a very good fit for AFLPs (0.90) and SSRs (0.92).

The genetic diversity of Saccharina japonica inhabiting the Hokkaido coastline and the surrounding area was investigated by AFLP and SSR analyses. A STRUCTURE analysis based on the AFLP data identified two clusters in the species, although a few local populations with genetic structures different from that of the neighboring populations were detected. The two clusters could be identified even within each current variety. In the SSR analysis, genetic variation in nucleotide sequences in all samples was located in four DNA regions (MS10, MS11, MS16, and MS29), and it is thought that these regions can be used as markers to detect individual-level variation in S. japonica. The STRUCTURE analysis of the SSR data identified four clusters in the species. Since the geographical distribution of these four different clusters does not correspond exactly to the currently recognized varieties in this species, it will be necessary to re-evaluate the distribution of the varieties of S. japonica. [ABSTRACT FROM AUTHOR]

Background: Neonectria ditissima is one of the most important fungal pathogens of apple trees, where it causes fruit tree canker. Information about the amount and partitioning of genetic variation of this fungus could be helpful for improving orchard management strategies and for breeding apple cultivars with high levels of genetically determined resistance. In this study single-spore Neonectria isolates originating from both the same and from different perithecia, apple cultivars and apple orchards in Sweden and Belgium, were evaluated for AFLP- and SSR-based genetic similarity and for mating system. Results: Seven SSR loci produced a total of 31 alleles with an average of 4 alleles per locus, while 11 AFLP primer combinations produced an average of 35 fragments per primer combination and 71 % polymorphic fragments. An AFLP-based analysis of molecular variance (AMOVA) revealed that 89 % of the variation was found within orchards and 11 % between orchards. Genetic similarity among the studied isolates was illustrated with a principal coordinate analyseis (PCoA) and a dendrogram. AFLP-based Jaccard's similarity coefficients were the highest when single-ascospore isolates obtained from the same perithecium were compared, medium-high for isolates from different perithecia on the same tree, and lowest when isolates from different trees were compared. Conclusions: Based on the results of PCoA and AMOVA analysis, isolates from the same or geographically close orchards did not group together. Since AFLP profiles differed also when single-ascospore isolates from the same perithecium were compared, the mating system of N. ditissima is most likely heterothallic. [ABSTRACT FROM AUTHOR]

Genetic diversity of 70 Mediterranean lentil ( Lens culinaris ssp. culinaris Medicus) landraces was assessed using simple sequence repeats (SSRs) and amplified fragment length polymorphisms (AFLPs). These landraces were also assessed for variation in root and shoot traits and drought tolerance as estimated by relative water content (RWC), water losing rate (WLR) and wilting score (WS). Genetic diversity and clear differentiation of Moroccan landraces from those from northern Mediterranean regions (Italy, Turkey and Greece) were found. High genetic variation in root and shoot traits and traits related to drought tolerance was also observed. No relationship was found between drought tolerance of landraces and their geographic origin. Landraces with higher dry root biomass, chlorophyll content and root-shoot ratio were drought tolerant as evidenced by higher RWC and lower WLR and wilting severity. Kruskal-Wallis non-parametric test (K-W) was used to find SSRs and AFLPs associated with RWC, WLR and WS. Regression analysis showed six SSR and AFLP alleles explaining the highest phenotypic variation of RWC, WLR and WS (ranging from 21 to 50 % for SSRs and from 14 to 33 % for AFLPs). Functional genetic diversity analysis showed relationships between drought response of landraces and linked SSR and AFLP alleles to RWC, WLR and WS according to K-W test using canonical discriminant analysis. Our results confirm the feasibility of using association mapping to find DNA markers associated with drought tolerance in larger numbers of lentil landraces. [ABSTRACT FROM AUTHOR]

Genetic diversity and genealogical relationships among individuals of eight aspen demes in a common garden experiment were studied using microsatellite (SSR) and amplified fragment length polymorphism (AFLP) markers. Moderate to high levels of genetic diversity were observed within all demes for the SSR and AFLP markers. The Shannon index for the AFLP markers was positively and significantly correlated with the average observed heterozygosity for the SSR markers across the demes. Comparative analysis of the numbers of the full-sibling groups inferred by different algorithms suggested that the 2-allele algorithm was more accurate than the other methods used in the study. However, in general, significant correlations were found in the numbers of the full-sibling groups inferred by some other algorithms, such as a heuristic algorithm, the 2-allele algorithm, and the Simpson, modified Simpson and pairwise score algorithms. Among demes, the USA and Swiss demes had the highest and lowest numbers, respectively, of full-sibling groups. This combined approach for sibship reconstruction can also be applied to infer the number of paternal or maternal parents in forest tree plantations when no parental information is available; this approach can improve our understanding of family structure and the extent of genetic diversity within forest tree plantations when no diversity, origin, or parental genotypes information is available. [ABSTRACT FROM AUTHOR]

Fusarium head blight (FHB) is a barley disease, which occurs every year in various areas of barley cultivation all over the world and the increasing incidence has been confirmed in the Czech Republic also during the last years. We aimed to emply AFLP (Amplified fragment length polymorphism) and SSR (Single sequence repeats) markers to describe diversity among breeding lines with a sufficient level of resistance towards FHB and to find marker(s) associated with the analysed traits. The number of eight accessions including five expected resistance donors and three sensitive lines were tested in the field and laboratory. The field values and the amount of deoxynivalenol were positively correlated (r = 0.92). The laboratory test and content DON manifested also a high correlation (r = 0.73). Several DH lines developed from androgenetic barley progenies of the F1 hybrids between the susceptible line PI 383933 and resistant line PEC 210 or the susceptible line PI 383933 and resistant cultivar Chevron were found resistant towards Fusarium infection in both the field and laboratory tests. Low infestation was found at line DH 37 from combination Chevron × PI 383933 and lines DH48, DH49, DH50 and DH55 from the combination PEC 210 × PI 383933. Cluster analyses based on 68 AFLP and 18 SSR markers demonstrate a genetic relationship among parental genotypes and DH lines.Some DH lines combined a sufficient degree of resistance against FHB and extract content (basic parameters malting quality). Statistically significant differences in malt-extract values were observed between groups of the DH lines possessing and not possessing the AFLP marker CAA/AGC 341bp. The markers will be further evaluated and optionally used for MAS.

In recent years, molecular markers have been developed based on the more detailed knowledge of genome structure. Considerable emphasis has been laid on the use of molecular markers in practical breeding and genotype identification. This review attempts to give an account of different molecular markers currently available for genome mapping and for tagging different traits - restriction fragment length polymorphisms (RFLPs), random amplified polymorphic DNAs (RAPDs), amplified fragment length polymorphisms (AFLPs) and microsatellites. Other markers, expressed sequence tags (ESTs) and single nucleotide polymorphisms (SNPs) are also mentioned. The importance of structural, functional genomic and comparative mapping is also discussed.

Different genetic markers are used for estimation of breeding material, its characteristics and potential for ultimate aim - heterosis of hybrids. They also point out to the qualitative seed traits at the level of linkage with genes responsible for desirable agronomic traits. This program encompasses testing methodologies for the new seed technology. Genetic analysis of breeding material during certain phases is comprised of isozymic gene expression and degrees of their variability, but it is continued (in order to be evaluated) until determination of presence or absence of some genes existing or introduced for certain traits. Using combination of different molecular methods such as PCR, RAPD and AFLP based on polymorphism of DNA fragments, the definite aim - identification of newly created products of improvement is achieved. Testing of traits of breeding material, its genetic variability and diversity is the first stage in analysis of the maize genome. It is also the condition for determination of presence of certain genes, used for obtaining the ultimate aim - attest of identity of the genotype.

Zucchini yellow mosaic virus (ZYMV) is one of the most important pathogens that cause significant yield losses in many cucurbit crops including cucumber (Cucumis sativus L). ZYMV resistance in cucumber is inherited by a single recessive gene. The purpose of this study was to identify molecular markers linked to the gene conferring ZYMV resistance in cucumber. We developed a population of 188 F2 plants derived from inbred cucumber lines. Individual F2 plants were self-pollinated to generate F3 populations. Ten randomly selected plants from each F3 population were tested for ZYMV resistance. We used a bulk segregant analysis method to identify putative molecular markers linked to ZYMV resistance. Using bulked DNA samples with parental lines and F1, a total of 170 sequence-related amplified polymorphism (SRAP), 586 simple sequence repeat (SSR), and 308 amplified fragment length polymorphism (AFLP) primer combinations were screened. Neither polymorphic SRAP nor SSR markers were linked with ZYMV resistance. Among the 308 AFLP primer combinations tested, an AFLP marker in the E-ACA/MCA primer combination showed significant association among parental lines, F1, and resistant and susceptible plants. The combination of E-ACA/M-CA was achieved on parental lines, F1, and 188 F2 individuals for confirmation of the marker segregation on the F2 population. We found that the combination of E-ACA/M-CA was linked to the zym locus with 6.91 cM. [ABSTRACT FROM AUTHOR]

Populations of polyploid apomictic dandelions consist of a mixture of clonal genotypes that are nearly phenotypically and genetically uniform. Some apomictic taxa are widespread, but many other taxa occur locally or at a single locality. Additionally, certain Central European dandelion populations consist of both diploid sexuals and polyploid apomicts, and the gene flow expected in mixed populations obscures clear genetic and morphological borders among apomictic taxa. In the present study, we investigated genotypic diversity among seven apomictic microspecies coexisting in Central Europe. Using microsatellites, amplified fragment length polymorphism and chloroplast DNA markers, we focused on the clonal structure of apomictic taxa, i.e., whether the studied apomictic taxa are represented by one or a few related genotypes or whether they are represented by many different and unrelated genotypes. The pattern of genotypic diversity within the studied microspecies suggests both intra- and inter-specific genetic diversification. At the intra-specific level, the studied apomictic taxa consist of several related genotypes, and difference among these genotypes is the result of somatic mutations and/or the consequence of repeated origin from different lineages or recent hybridisation. The inter-specific genetic diversity is greater and may reflect a different evolutionary origin of apomictic taxa. Our results show that despite their increased genetic diversity, apomictic dandelions form definable clusters that may be characterised by both molecular markers and morphology. [ABSTRACT FROM AUTHOR]

In this paper, we report the estimates of outcrossing rates using open-pollinated progeny arrays of 40 BC individuals of Jatropha developed as a result of interspecific hybridization between J. curcas and J. integerrima. For analysis PCR-based dominant AFLP and codominant SSR markers were used. The multilocus outcrossing rate (t) estimated from AFLP markers (0.892 ± 0.112) are almost in the same range with SSR (0.884 ± 0.293) markers which indicate a high level of heterozygosity. A low value of inbreeding coefficient (F) also points out to the fact that outcrossing was the prevalent mode of reproduction in Jatropha and suggests maintenance of adequate genetic variability within families. [ABSTRACT FROM AUTHOR]

A number of Pacific oyster ( Crassostrea gigas) with golden shell background color were obtained which show great potential to develop a niche market. To improve the selective breeding progress of true-breeding strains with complete golden oysters, research was conducted to identify genetic markers linked to the shell color locus. An F-segregating population was obtained by crossing two oysters with golden shell and white shell. Genomic DNA from eight progenies with golden shell and eight progenies with white shell were equally pooled for amplified fragment length polymorphism (AFLP) screening. In bulked segregant analysis, six out of 225 selective primer pair combinations produced seven polymorphic fragments tightly linked to shell color across the segregating population. The seven AFLP markers were all derived from the golden dam and mapped onto a single linkage group flanking the shell color locus. In conversion of the AFLPs into single-locus PCR-based markers, a sequence-characterized amplified region (SCAR) marker, named SCARJ8-2, a single nucleotide polymorphism (SNP) marker, named SNPL2-4, and a simple sequence repeat (SSR) marker, named SSRO11-2, were obtained. These markers obtained in this study will be useful for marker-assisted selection of the Pacific oyster. [ABSTRACT FROM AUTHOR]

The stalk sugar content in silage maize plays an important role in improving its forage quality and palatability. In this study, we reported a dynamic quantitative trait loci (QTL) analysis of stalk sugar content at different growth stages in maize. A recombinant inbred line (RIL) population with 202 lines derived from a cross of YXD053 × Y6-1 was used to identify the dynamic QTL for stalk sugar content (Brix) in maize. The Brix of RILs were measured at four stages in two environments. Twenty-two QTLs affecting maize stalk sugar content (Brix) were detected by unconditional mapping method. Fifteen QTLs were identified using conditional mapping approach. No QTL was detected at all sampling stages. Six QTL, qSSC-2.1, qSSC-2.2, qSSC-2.3, qSSC-5.1, qSSC-9.1 and qSSC-9.4, were detected by both unconditional and conditional mapping. One major QTL qSSC-2.1 flanked by markers bnlg1909 and umc1635 on chromosome 2 had a relatively high net effects of gene expression from anthesis stage to 20 days after anthesis. A total of six pairs of QTL with significant epistatic effects were identified at different developmental stages. No significant QTL × environment interactions were observed. Stalk sugar content is controlled by a complex genetic mechanism, and the QTL detected at different development stages might be important contributors to stalk sugar content in maize. [ABSTRACT FROM AUTHOR]

Somatic hybridization is a biotechnological tool, which allows the transfer of multiple resistance genes from sexually incompatible Solanum species into cultivated potato. Here we report the effect of the recipient commercial tetraploid potato cultivar on the genetic make-up of the somatic hybrids (SHs) with an accession of the incongruent diploid species Solanum bulbocastanum Dun. The SHs were produced by mesophyll protoplast electrofusion. The analysis of ploidy by flow cytometry was first used to select hexaploid putative SH shoots but SSR and AFLP markers, DAPI staining and later flow cytometry evaluation of ploidy reveals symmetric and asymmetric SH plants regeneration in proportions that depend on the potato cultivar. The growth and fertility of the SHs support the effect of recipient cultivar. Out of five different fusion combinations, the highest number of SHs and tuberosum morphology was recorded for the combinations: blb41 (+) 'Delikat' 235 SHs (104 symmetric and 131 asymmetric) and blb41 (+) 'Rasant' 33 SH plants (22 symmetric, 11 asymmetric). There were fertile SHs of these combinations and BC and BC progenies were obtained. Less successful were the combinations: blb41 (+) 'Quarta' 64 SHs (57 symmetric and 7 asymmetric), blb41 (+) 'Baltica' 25 SHs (16 symmetric and 9 asymmetric), which were infertile and blb41 (+) 'Agave' with only one highly asymmetric non-viable SH plant. The production of a large number of SHs with diverse commercial cultivars is a prerequisite for further selection of useful pre-breeding material. The causes of nuclear constitution asymmetry and somatic incompatibility of the two species are also discussed. [ABSTRACT FROM AUTHOR]

Understanding the population structure and genetic diversity in sugarcane (Saccharum officinarum L.) accessions from INTA germplasm bank (Argentina) will be of great importance for germplasm collection and breeding improvement as it will identify diverse parental combinations to create segregating progenies with maximum genetic variability for further selection. A Bayesian approach, ordination methods (PCoA, Principal Coordinate Analysis) and clustering analysis (UPGMA, Unweighted Pair Group Method with Arithmetic Mean) were applied to this purpose. Sixty three INTA sugarcane hybrids were genotyped for 107 Simple Sequence Repeat (SSR) and 136 Amplified Fragment Length Polymorphism (AFLP) loci. Given the low probability values found with AFLP for individual assignment (4.7%), microsatellites seemed to perform better (54%) for STRUCTURE analysis that revealed the germplasm to exist in five optimum groups with partly corresponding to their origin. However clusters shown high degree of admixture, FST values confirmed the existence of differences among groups. Dissimilarity coefficients ranged from 0.079 to 0.651. PCoA separated sugarcane in groups that did not agree with those identified by STRUCTURE. The clustering including all genotypes neither showed resemblance to populations find by STRUCTURE, but clustering performed considering only individuals displaying a proportional membership > 0.6 in their primary population obtained with STRUCTURE showed close similarities. The Bayesian method indubitably brought more information on cultivar origins than classical PCoA and hierarchical clustering method. [ABSTRACT FROM AUTHOR]

Barley ( Hordeum vulgare L.), an important food and fodder crop, is potentially tolerant to salinity. To identify quantitative trait loci (QTLs) controlling salt tolerance, the population of 162 recombinant inbred lines (RILs) derived from F8 generation of Arigashar (an extremely salt tolerant Iranian six-rowed barley landrace) crossed with Igri (a salt semi-sensitive two-rowed cultivar) were evaluated. The growth of shoots, roots, and coleoptiles, and root numbers are four important growth characteristics severely affected by salt stress at seedling growth stages. A linkage map was constructed using 106 AFLP and SSR markers spanning six barley chromosomes including 2(2H), 3(3H), 4(4H), 7(5H), 6(6H), and 1(7H). Out of totally 26 detected QTLs, 17 QTLs were found effective for salt tolerance at 250 and 350 mM NaCl which localized on chromosomes 2H, 3H, 4H, 6H, 7H, and linkage group L1, whereas considering equivalent overlapped QTLs with a pleiotropic effect led to detection of totally 9 distinctive QTLs ( QClgH2.1b, QSdgH2.1b, QSlgH2.1c, QNrgH2.1b, QTwgH2.2c, QSdg3Hb, QSlg4Hb1, QClg4Hb, and QSlg6Hc2) effective for salinity tolerance. 2(2H), 4(4H), and 6(6H) were major chromosomes harboring QTLs which effectively controlled salt tolerance in the Igri×Arigashar population. An interesting QTL , QTwg4Hc, was localized on chromosome 4H in the XE41-M61 marker distance that controls several traits including shoot and coleoptile lengths and shoot fresh mass under salt stress. A dense marker cluster around a resistance gene could offer a starting point for positional cloning. [ABSTRACT FROM AUTHOR]

Until now, only a few genetic and physical maps had been constructed for durum wheat, mostly from the gene pools of only few geographic regions. The Fertile Crescent, particularly southeastern Turkey, is thought to be the primary center of wheat domestication and diversity. In spite of the importance of the genetic diversity from this area, a severe lack of information on the genetic structure of the durum wheat gene pool from this region is evident. For example, thus far, no efforts have been made to understand the genetic structure of the Anatolian durum wheat gene pool, despite its importance in durum wheat breeding. This study aimed to provide a new insight into the genetic structure of the durum wheat from Anatolia. The present study represents the first genetic linkage map of durum wheat from Anatolia, containing one famous Turkish local cultivar Kunduru-1149. The genetic linkage map was constructed using a population of 141 recombinant inbred lines (RILs) derived from a cross between the Turkish cultivar Kunduru-1149 and ICARDA cultivar Cham1. Linkage analysis resulted in a final linkage map spanning 4853.8 cM, which comprised 395 polymorphic marker loci (213 simple sequence repeats [SSRs], 146 amplified fragment length polymorphisms [AFLPs], and 36 seed storage proteins [SSPs]). The detected loci were distributed over 15 linkage groups on 14 whole chromosomes of durum wheat. Most of the markers (70.7 %) used in this map segregated according to Mendelian laws. This linkage map represents a key starting point toward understanding the genome structure of Anatolian durum wheat to genetically evaluate important agromorphological and qualitative characteristics. [ABSTRACT FROM AUTHOR]

To enrich the source of germplasm of cultivated olive ( Olea europaea subsp. europaea L.), inter-subspecific hybrid plants have been produced by experimental crosses between several varieties of cultivated olive and Asian and African accessions of the wild related subspecies cuspidata. Germination of putative hybrid seeds was enhanced by using in vitro embryo culture. The genetic make-up of germinated seedlings was assayed with the aid of both AFLP and SSR molecular markers and their hybrid nature was proved by the presence of male-specific alleles in their molecular patterns. Most of the parent specific alleles showed segregation among F progenies indicating high heterozygosity content of the parental lines. The majority of the hybrids derived from crosses in which an African accession of cuspidata was used as female parent. The overall morphological aspect of hybrids resembled that of the female parent. The production of inter-subspecific hybrid plants in Olea is discussed in relation to the genetic improvement of cultivated olive. [ABSTRACT FROM AUTHOR]

Series Crocus comprises ten autumn-flowering species, including the cultivated Crocus sativus, Saffron-Crocus. Interspecific genetic variation was examined in all species of the series, except for C. naqabensis. Intraspecific genetic and morphological variation was considered in the three Greek endemics, C. cartwrightianus, C. hadriaticus and C. oreocreticus. Genetic variation was evaluated based on amplified fragment length polymorphism and simple sequence repeats analyses, including 94 and 233 specimens, respectively. Analysis of molecular variance demonstrated significant genetic variation within populations, compared with low genetic variation between populations suggesting substantial gene flow between populations. In Neighbour-Net analysis, C. hadriaticus samples from mainland Greece were separated from Peloponnesian samples; C. cartwrightianus, C. hadriaticus and C. oreocreticus generally were grouped with C. sativus samples. Pollination and maintenance of genetic variation are discussed. The large intraspecific variation found within the three specifically studied species reflects dynamic population structures with potential to meet future ecological fluctuations. It emphasises a large gene pool which should be considered by including a larger number of accessions in genetic diversity studies. [ABSTRACT FROM AUTHOR]

Application of molecular markers, have now been increasingly adopted to address the problems in Citrus taxonomy. Compared to morphological data, molecular tools provide abundant information, highly efficient and are insensitive to environmental factors. Molecular markers has provided an ideal means for identifying genotypes, estimation of relatedness between different accessions and following inheritance of economically important characters. In Citrus, a wide variety of DNA based markers has been used in order to study their genetic variation as well as phylogenic and taxonomic relationship among different genera. RAPD markers provide a fast and easy approach for taxonomic classification and cultivar-typing of Citrus fruits. SSR have proven to be the marker of choice in Citrus breeding research, because of their variability, ease of use, accessibility of detection and reproducibility. ISSR, SRAP, CAPS-SNP, AFLP are also used to study the genetic diversity of Citrus throughout the world. In addition, cpDNA is especially useful in phylogenetic analyses due to its evolutionary conservatism, relative abundance in plant tissue, small size and pre dominant uniparental inheritance. [ABSTRACT FROM AUTHOR]

There is an ample genetic diversity of plants with medicinal importance around the globe and this pool of genetic variation serves as the base for selection as well as for plant improvement. Thus, identification, characterization and documentation of the gene pool of medicinal plants are essential for this purpose. Genomic information of many a medicinal plant species has increased rapidly since the past decade and genetic resources available for domestication and improvement programs include genome sequencing, expressed sequence tags sequencing, transcript profiling, gene transmit, molecular markers in favor of mapping and breeding. In recent years, multiple endeavors have been undertaken for genomic characterization of medicinal plant species with the aid of molecular markers for sustainable utilization of gene pool, its conservation and future studies. Recent advancement in genomics is so fast that only some researches have been published till date and to a large extent documentation is restricted to electronic resources. Whole genome profiling of the identified medicinal plant species, carried out by several researchers, based on the DNA fingerprinting, is well documented in the present review. This review will facilitate preparing a database of the widely used, economically important medicinal plant species, based on their genomic organization. [ABSTRACT FROM AUTHOR]