Mungbean yellow mosaic virus (MYMV) is a disastrous pathogen of mungbean. It is widespread in most of southern India and no complete resistance has been identified among its commercial cultivars. Two isolates of MYMV, representing its diversity, were used to assess and characterize the susceptibility reaction of all the three species of Vigna. The seeds were agroinoculated with the virus and the presence of the viral DNA was confirmed after 12 d by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis after which the plants were monitored for the expression of symptoms. All of the 20 accessions of Vigna radiata and ten accessions of Vigna mungo were systemically infected with MYMV, and they all produced typical symptoms. On the other hand, the 24 accessions of Vigna umbellata were found to be resistant to both the isolates. For additional affirmation, three representative accessions of V. radiata and V. mungo and all the accessions of V. umbellata were agroinoculated, and quantitative RT-PCR was performed for the quantitative detection of the MYMV. The mRNA transcripts of MYMV were detected in V. radiata and V. mungo plants but not in the V. umbellata plants. Researching the molecular basis of the resistance in V. umbellate against MYMV might definitely be very constructive for developing resistant varieties of mungbean on a commercial scale. This genetic quality offering resistance to MYMV could also be incorporated into V. radiata/V. mungo by means of interspecific crosses.

The antimalarial drug artemisinin (ART) is commercially extracted from the medicinal plant Artemisia annua L. Here, we report the screening of 70 A. annua plants representing 14 diverse germplasm accessions sourced from around the world, and identify lines containing >2% ART. These extremely high-yielding individuals have been maintained as vegetative clones, and they represent promising germplasm resources for future A. annua breeding programmes.

In this paper, Shannon–Weaver diversity indices were employed to examine the phenotypic diversity in 271 Ethiopian tetraploid wheat accessions in relation to characters, regions of origin and altitude. Moreover, review of genetic diversity studies in Ethiopian tetraploid wheat was made to explore breeding opportunities. The diversity index varied widely across regions. Among the four altitudinal classes, the highest (0.72) and lowest (0.61) mean diversity indices were observed in altitude classes II and IV, respectively. The diversity index (H′) showed that most traits are polymorphic. The partitioning of the total phenotypic diversity into within- and among-region diversity indicated that 71% of the total variation was attributed to the within-region diversity. Principal component analysis was computed to examine the regional and altitudinal patterns of variation. On regional bases, the first four axes, whose eigenvalues are greater than 1, explained about 82% of the observed phenotypic diversity in the 271 tetraploid wheat accessions. On altitudinal bases, however, only the first two principal components explained 89.7% of the total variation. In general, phenotypic diversity showed considerable differences for each trait in different geographical regions and altitudinal classes which could be utilized in wheat improvement programmes. Breeding opportunities and strategies are suggested.

The water lotus, genus Nelumbo, contains two species, the sacred (Nelumbo nucifera) and American lotuses (Nelumbo lutea). Hundreds of flowering lotus cultivars are currently known. However, their classification is unclear. For the classification of Nelumbo cultivars, in addition to 35 simple sequence repeat (SSR) markers recently developed, we have developed 17 and 16 of new Nelumbo SSR markers from SSR-enriched genomic libraries and expressed sequence tag (EST) data, respectively. Out of these 68 SSRs, along with SSRs recently published by others, 52 showed clear polymorphisms in 98 Nelumbo samples. A total of 300 alleles were observed, ranging from 2 to 11 alleles per locus, with an average of 5.77. Alleles specific for the American lotus-derived cultivars and a cluster of the American lotus-derived cultivars on a neighbour-joining tree confirmed genetic differences between N. lutea and N. nucifera. In addition, a possible differentiation between Chinese and Japanese cultivars was also suggested. Parentage analysis using the SSR markers confirmed four known parentages and predicted currently-unknown parentages of six cultivars. The present data have demonstrated that site-specific, co-dominant SSR markers enable more accurate classification, identification and comparison of Nelumbo species.

Heat stress greatly limits the productivity of wheat in many regions. Knowledge on the degree of genetic diversity of wheat varieties along with their selective traits will facilitate the development of high yielding, stress-tolerant wheat cultivar. The objective of this study were to determine genetic variation in morpho-physiological traits associated with heat tolerance in 30 diverse wheat genotypes and to examine genetic diversity and relationship among the genotypes varying heat tolerance using molecular markers. Phenotypic data of 15 traits were evaluated for heat tolerance under non-stress and stress conditions for two consecutive years. A positive and significant correlation among cell membrane stability, canopy temperature depression, biomass, susceptibility index and grain yield was shown. Genetic diversity assessed by 41 polymorphic simple sequence repeat (SSR) markers was compared with diversity evaluated for 15 phenotypic traits averaged over stress and non-stress field conditions. The mean polymorphic information content for SSR value was 0.38 with range of 0.12–0.75. Based on morpho-physiological traits and genotypic data, three groups were obtained based on their tolerance (HHT, MHT and LHT) levels. Analysis of molecular variance explained 91.7% of the total variation could be due to variance within the heat tolerance genotypes. Genetic diversity among HHT was higher than LHT genotypes and HHT genotypes were distributed among all cluster implied that genetic basis of heat tolerance in these genotypes was different thereby enabling the wheat breeders to combine these diverse sources of genetic variation to improve heat tolerance in wheat breeding programme.

The purpose of the study was to support the selection process of the most valuable currant and gooseberry accessions cultivated in Northern Europe, in order to establish a decentralized core collection and, following the selection, to ensure sufficient genetic diversity in the selected collection. Molecular analyses of the material from nine project partners were run at seven different laboratories. The results were first analysed for each partner separately, and then combined to ensure sufficient genetic diversity in the core collection.

More than 3200 new mutant varieties have been bred and used by millions of farmers, which has significantly contributed to world food security. A lot more mutants have also served as tools for gene discovery and functional analysis. Recent genomic approaches including TILLING (Targeting Induced Local Lesions In Genome) have enabled screening of mutations at the molecular level. This review describes the molecular nature of chemically and physically induced mutations and their repercussions. Analyses of TILLING reports indicate that chemically induced mutations are mostly nucleotide substitutions, but that mutation frequencies fluctuate among plant species ranging from one DNA lesion per 300 kbp in Arabidopsis to one DNA lesion per 30 kbp in bread wheat, which reciprocate with an increase in ploidy levels. The majority (>95%) of chemically induced DNA lesions are silent or missense mutations. Mutations induced by physical mutagens seem to be more diverse, including single-nucleotide substitutions, insertions, inversions and translocations, although short deletions ( < 15 bp) are relatively more predominant. The proportion of complex mutations (translocation, inversions, etc.) may increase with an increase in the linear energy transfer of radiations. In addition, the implications of these findings for the roles of induced mutants in breeding and gene function analysis are briefly discussed.

Pepper (Capsicum sp.) is important in human diets in many parts of the world and a major source of several antioxidants, including carotenoids, ascorbic acid, tocopherols and phenolics. More information on genetic diversity within Capsicum for antioxidant (AO) content and antioxidant activity (AOA) could contribute to improved human health. We evaluated 46 Capsicum accessions from AVRDC—the World Vegetable Center Capsicum core collection for content of nine AO (five carotenoids, ascorbic acid, tocopherols α and γ, and total phenolics) and two AOA assays for 2 years in south Taiwan. Ample genetic diversity exists within C. annuum to increase AO content. Based on dry weight values, non-pungent C. annuum entries as a group were significantly greater than pungent entries for contents of β-cryptoxanthin (36%), ascorbic acid (65%), total phenolics (36%) and α-tocopherol (11%). Group means of the brown-fruited entries exceeded the means of red-fruited entries for capsanthin (34%), zeaxanthin (37%), lutein (36%), β-cryptoxanthin (71%), β-carotene (82%), ascorbic acid (19%) and α-tocopherol (40%). Red-fruited C. annuum entries ‘Verdano Poblano’ and ‘Guajillo Ancho’ from Mexico ranked among the entries highest for all carotenoids, ascorbic acid and α-tocopherol. The inhibition of lipid peroxidation (ILP) assay could be adopted for AOA characterization or selection because of high variation among entries and consistent entry performance over years. ILP was positively correlated with phenolics (r=0.72**) and ascorbic acid (r=0.58**) contents. Significant positive correlations were detected between most carotenoids as well as a significant positive correlation between ascorbic acid and total phenolics contents (r=0.78**).

Eighty-six chickpea (Cicer arietinum L.) genotypes, including 44 Kabuli type and 42 Desi type, were evaluated for their phenological, physicochemical and cooking quality traits. There were significant differences among the genotypes for days to 50% flowering (34–81 d), days to maturity (85–122 d), number of pods per plant (13–66), number of seeds per plant (15–85), 100-seed weight (10.5–58.6 g), seed yield (561–1852 kg/ha), hydration capacity (0.11–0.68 g water/seed), hydration index (0.80–1.21), swelling capacity (0.11–0.7 ml/seed), seed volume (0.1–0.52 ml/seed) and cooking time (38–125 min). The Desi and Kabuli types of chickpea differed significantly from each other for all the traits except for hydration index, swelling index and cooking time. High heritability coupled with high genetic advance was recorded for 100-seed weight, hydration capacity, swelling capacity and seed volume in both Desi and Kabuli genotypes. Seed size (100-seed weight and seed volume) showed significant positive correlations with hydration capacity and swelling capacity. Cooking time did not show any significant positive or negative correlation with any of the traits studied, including seed size, indicating that other additional factors may be involved in controlling cooking time. The results of this study indicate that it is possible to develop cultivars with faster cooking time in both Kabuli and Desi types and in all seed size categories.

This paper shows the results of the investigation on some ecological aspects and on the sanitary status of the wild Euroasiatic native grapevine (Vitis vinifera L. ssp. sylvestris (Gmelin) Hegi) in Georgia (South Caucasus). This taxon is seriously endangered by human activities such as forest cleaning and setting fires. Moreover, invasive Vitaceae of the North American origin, imported after phylloxera (Daktulosphaira vitifoliae Fitch) when vineyards were being replanted, increase the risk to lose these spontaneous vines. The survey includes collection of data on the population structure, the plant sex ratio, the main botanical supporters of the vines and the associated flora, the presence of invasive vines of the North American origin and the incidence of phytophagous arthropods and pathogens. The phytosanitary study showed that monophagous eriophyid mites and exotic fungal diseases, such as downy (Plasmopara viticola (Berkeley and Curtis) Berlease and de Toni) and powdery mildews (Erysiphe necator –(Schweinitz) Burrill), cause symptoms on all the observed populations. The absence of symptoms caused by phylloxera, root-knot nematodes and root rot is remarkable. However, the level of detected injuries caused by these parasitic organisms does not seem to be a real problem for the survival of the populations.

In order to describe the phenotypic diversity in a core collection of grasspea, 47 progenies of single plants (pure lines) selected from 25 accessions were evaluated. Sixteen morpho-agronomic characters including seed 3-(β-N-oxalyl)-l-2,3 diaminopropionic acid (β-ODAP) content were studied. Univariate and multivariate analyses (principal component analysis and cluster analysis) were performed to estimate differences between progenies. Some high-yielding lines could be used directly for cultivation as new varieties and/or as parental lines in crossing programmes. Seed β-ODAP concentration varied from 0.24% to 0.64%. However, a medium to high seed β-ODAP level was recorded for most of the lines, and no significant correlation was observed between this and other morphological traits.

Rice is a salt-sensitive species with enormous genetic variation for salt tolerance hidden in its germplasm pool. The EcoTILLING technique allows us to assign haplotypes, thus reducing the number of accessions to be sequenced, becoming a cost-effective, time-saving and high-throughput method, ideal to be used in laboratories with limited financial resources. Aiming to find alleles associated with salinity tolerance, we are currently using the EcoTILLING technique to detect single nucleotide polymorphisms (SNPs) and small indels across 375 germplasm accessions representing the diversity available in domesticated rice. We are targeting several genes known to be involved in salt stress signal transduction (OsCPK17) or tolerance mechanisms (SalT). So far, we found a total of 15 and 23 representative SNPs or indels in OsCPK17 and SalT, respectively. These natural allelic variants are mostly located in 3′-untranslated region, thus opening a new path for studying their potential contribution to the regulation of gene expression and possible role in salt tolerance.

Millefolii herba is one of the oldest and most important drugs in Lithuania, used both in folk and official medicine. The raw material is usually gathered from spontaneous populations. It would be reasonable to develop methods to identify the populations which produce high plant biomass and accumulate high levels of proazulenes. The quantitative variation of proazulenes and their relationships with phytosociological dependence and morphological characters of Achillea millefolium from wild populations has been examined. The vegetation records were made at 140 growing sites of A. millefolium. The species was found in 29 types of community representing different growing habitats. The resources of milfoils prevailed in dry grasslands of Arrhenatheretalia communities and ruderal habitats of Dauco-Meliliotion. The data on productivity and morphological characters were subjected to multivariate statistical analysis. A hierarchical cluster analysis indicated that higher productivity of A. millefolium populations was associated with their dependence on ruderal and segetal communities. The testing of A. millefolium plants revealed high variation for proazulenes in different communities. The proazulene-containing plants have been identified in 38% of all analysed cases. In the highest segetal and wasteland communities of Agropyretalia repentis, Sisybietalia, Digitario-Setarion, Aperion spicae-venti, Senecion fluviatilis only proazulene-free plants were found. Results of the ANOVA showed the proazulene-containing and proazulene-free plants significantly differed (P<0.05) for width of leaves and number of nodes. The presence of nodes in high number and narrow leaves in high proazulene-containing plants distinctly marked them from the proazulene-free plants. The study raised the possibility that selection based on the two morphological marker traits (node number and leaf width) and proazulene distribution in the populations would be effective for rapid identification of highly productive population(s) of pharmaceutical importance.

To date, very limited molecular knowledge and molecular tools are available on grass pea (Lathyrus sativus L.). Herein, we present a genetic diversity analysis of 20 grass pea accessions collected from various regions of Ethiopia by means of seven newly developed Lathyrus expressed sequence tag-derived simple sequence repeat (EST-SSR) markers and four cross-transferable EST-SSRs derived from Medicago truncatula L. Forty-five alleles were detected among all the analyzed accessions. The number of alleles/locus ranged from two to seven with an average of four alleles/locus. The observed heterozygosity (Ho) ranged from 0.320 to 0.504, while the expected heterozygosity (He) ranged from 0.354 to 0.470. FST values estimated by analysis of molecular variance were 0.01, 0.15 and 0.84 for among regions, among accessions and within accessions, respectively, indicating that most of the variation (84%) resides within accession. The model-based cluster analysis grouped the accessions into three clusters grouping accessions, irrespective of their collection regions.

The allelic diversity within oil palm populations (45 native ones from 10 African countries, three breeding populations and one collection of semi-wild material) was determined using 16 microsatellite markers. A total of 209 alleles were detected, with a mean number of 13.1 alleles per locus. The mean effective number of alleles per locus (Ae) was 3.3 ± 1.3. Although the Duncan's multiple range test only separated the group of populations from Madagascar from the rest on the basis of Ae, the presence of unique and rare alleles and high values of Ae suggest that 23 of the African populations should be conserved to secure allelic diversity.

Here we review the potential of ILB 938 (IG 12132 – doi: 10.18730/60FD2), a unique faba bean accession originating from the Andean region of Colombia and Ecuador, maintained at ICARDA – International Center for Agricultural Research in the Dry Areas, with resistance to multiple biotic and abiotic stresses and carrying some useful morphological markers. It has been used as a donor of leaf-related drought adaptation traits and chocolate spot (Botrytis fabae) resistance genes in faba bean breeding programmes worldwide. From generated populations of recombinant inbred lines, quantitative traits loci associated with these useful traits have been mapped. Other markers, such as a lack of stipule-spot pigmentation and clinging pod wall, show the presence of unusual changes in biochemical pathways that may have economic value in the future.

The dwarfing wheat (Triticum aestivum L.) breeding has promoted a dramatic increase in yields. Since the utilized dwarfing genes in wheat are very limited, identification of novel dwarfing genes is necessary for improving the genetic diversity of wheat. In this study, more than 300 dwarfing wheat lines from induced mutation were screened by kompetitive allele-specific PCR and gibberellin (GA) treatment. The 17.49% of Rht-D1b and 1.37% of Rht-B1b dwarfing mutants were identified in this mutant group. Additionally, Rht-D1b mutants showed more effective in reduction of plant height and higher 1000-grain weight comparing with that of Rht-B1b mutants. By combing with comparison of yield components and expression profile of GA biosynthetic genes with wild-type, the GA-responsive mutant dm15 without directly involvement in GA metabolism, significantly increased 1000-grain weight but no change of other yield components in two locations of field experiments. Meanwhile, another elite mutant dm11 with change of GA biosynthetic genes expression was also identified. These mutants will be promising candidates for dwarfing wheat breeding.

The primary mission of germplasm collections is to preserve genetic diversity, but germplasm is preserved so that it can be used. Historically, the standard practice is that all germplasm accessions should be maintained as collected, so that even self-pollinated accessions are maintained as heterogeneous seed lots. In theory, this seems like an ideal strategy for preserving genetic diversity, but in practice, it is simply not workable. Heterogeneous accessions are in constant risk of change and loss. It is possible to mitigate the risk factors, but they can only be lessened and not eliminated. Maintaining pure-lined accessions for self-pollinated species not only eliminates the problems associated with genetic drift and natural selection, but also enhances the accuracy of the evaluations and fosters effective germplasm utilization. Neither the current potential to characterize entire germplasm collections with tens of thousands of DNA markers nor the future potential of whole genome sequencing to completely characterize the diversity of all accessions in collections can be fully realized for self-pollinated species unless accessions are homogeneous and homozygous. In this manuscript, the case is made for pure-lining self-pollinated germplasm accessions using the USDA Soybean Germplasm Collection, which has maintained pure-lined accessions for over 50 years, as an example. There is also an analysis of the extensive seed distribution from this collection to indicate the value of a diverse collection of genotypes.

Variety registration is an important area of plant genetic resource characterization and utilization. Within the European Union, varieties must be included on a National List (NL) of a member state or on the Common Catalogue (a compilation of the NLs of the member states) before seed can be sold. This requires a series of tests and trials which assess if the variety is distinct, uniform and stable (DUS) and if it has sufficient value for cultivation and use (VCU). The same DUS criteria are also used world-wide for the granting of Plant Breeders' Rights (PBR), an intellectual property protection system. Both DUS and VCU are currently assessed primarily using field-based trials. However, the potential use of biochemical and molecular markers for DUS purposes is being actively investigated and such markers could have an important role to play in maintaining the quality and scope of PBR in an environment where the increasing number of countries involved in DUS testing and the number of variety comparisons to be made are causing logistical difficulties. More recently, given firstly the increase in the availability of markers from expressed regions of the genome, and secondly the possibilities raised by detailed DNA sequencing programmes and the association of markers (particularly single nucleotide polymorphisms, SNPs) with specific genes, the prospects for a more molecular approach to VCU are also being discussed. This paper reviews the current situation with regard to the use of molecular markers for DUS and VCU testing and considers future prospects for variety registration in the 21st century, ‘-omics’, era.

Production of summer squash, Cucurbita pepo, can be severely limited by viral pathogens and powdery mildew. Resistance has been introgressed from Cucurbita moschata, and resistant hybrids have been commercially deployed. Our objective was to assess genetic affinities of such hybrids with susceptible, open-pollinated cocozelle and zucchini cultivars, and two disease-resistant lines derived from six generations of backcrossing to a susceptible zucchini cultivar. Amplified fragment length polymorphism (AFLP) EcoRI/MseI primer combinations were employed and, based on the resulting polymorphic bands, genetic similarities were estimated, and an unweighted pair group method using arithmetic average (UPGMA) cluster analysis was conducted. The open-pollinated cocozelle cultivars clustered with the resistant hybrids. The hybrids had greater similarities with one another than did the open-pollinated cultivars. The zucchini cultivars and their resistant backcross lines formed their own exclusive cluster. However, the resistant backcross lines showed less than 0.80 similarity with their recurrent parent. As the chromosome number of Cucurbita is high (2n = 2x = 40) and the resistances are inherited monogenically and oligogenically, these results, after six generations of backcrossing, cannot be explained by classical genetic linkage.