To preliminarily evaluate the genetic diversity of the Iranian diploid Triticum L. gene pool, in this study, a total of 176 individuals belonging to T. monococcum L. ssp. aegilopoides (Link) Thell. and T. urartu Thum. ex Gandil. were pre-screened using single-strand conformation polymorphism (SSCP) analysis of the Acc-1 and Pgk-1 loci. A selected set of 76 DNA samples corresponding to the observed SSCP variants were sequenced for both loci and evaluated for nucleotide diversity associated with the taxonomic groups and geographical regions. We found three haplotypes, including one that was new for Iran, at each locus. Population structure and analysis of molecular variation results proved that the collection evaluated could be genetically divided into two distinct groups, which to a great extent was in accordance with the taxonomic classification. A genetic leakage from T. monococcum ssp. aegilopoides into T. urartu was observed during structure analysis, which was inferred on the basis of occasional outcrossing, despite their inbreeding nature. The results revealed that there was no variation within the populations belonging to T. urartu, while a meaningful variation was found between the geographical regions for T. monococcum ssp. aegilopoides. The median-joining networks revealed a conflict between morphology and haplotype variation, which was interpreted on the basis of introgressive hybridization, recombination signature and rapid speciation. In conclusion, we suggest that SSCP analysis is a useful tool in regions where thorough sequencing of an enormous number of DNA samples is time consuming and not affordable.

To investigate the genetic diversity and structure of Jatropha curcas L. oilseed plant, in this study, native populations from Chiapas, Mexico, were evaluated, using microsatellite DNA markers. A total of 93 representative samples were selected from seven sites in two regions in the state of Chiapas grouped by geographical proximity, where leaf samples were collected to isolate the genomic DNA. Individual polymerase chain reactions were carried out with ten pairs of specific oligonucleotides for the microsatellites of J. curcas, separating the products of amplification by acrylamide electrophoresis. Twenty-seven fragments were detected (77% polymorphic) with which heterozygous individuals were distinguished. The most informative microsatellite was Jcps20 (nine alleles, polymorphic index content 0.354). The average polymorphism per population was 58%. The Hardy–Weinberg tests revealed a reproductive pattern of non-random mating. The diversity descriptors and the analysis of molecular variance revealed that the populations were structured and moderately differentiated (FST 0.087) and that this differentiation was not due to isolation by distance, as the Mantel test was not significant (P= 0.137), but rather due to allopatry. Bayesian analysis revealed that the accessions belonged to only four genetic groups and confirmed the differentiation between the regions. Because some loci were in Hardy–Weinberg disequilibrium, it is proposed that differentiation is due to the clonal reproduction of J. curcas practised by farmers in Chiapas, along with the anthropogenic dispersion at regional levels. The results of this study reveal that J. curcas in Chiapas has genetic diversity that is greater than that reported in other parts of the world, which represents a potential germplasm pool for the selection of genotypes.

Plant genetic resources are conserved by genebanks mainly in the form of seeds. In most of the cases, the dried seeds can be stored for a considerable period of time, but eventually seed deterioration results in the inability to generate healthy seedlings. Prolonging seed longevity during storage reduces the frequency of regeneration, which is beneficial from a genetic as well as a management point of view. To reduce the rate of deterioration, cool and dry storage conditions are usually practised for long-term seed storage. In spite of the growing body of evidence that seed deterioration is predominantly caused by oxidative processes, the importance of seed storage under anoxic conditions has received little attention from the genebank community. Herein, we report on the effects of anoxia on seed viability, the oxygen uptake by dry seeds in closed containers and the permeability for oxygen of various seed storage containers. Our results confirm that the ageing of dry seeds is accelerated by the presence of oxygen in the storage environment. Therefore, we recommend that genebanks store dry seeds under anoxic conditions to prolong their longevity during ex situ conservation. To reduce the initial rate of viability loss, we further recommend that the period of temporary storage after seed harvest be minimized and also that the seeds are kept during this period under controlled conditions, including anoxia.

In this study, the genetic constitution of wild grape populations distributed in the Zagros Mountains in the north-west part of Iran was investigated to assess their risk of extinction and to identify the most suitable conservation strategy. A total of 65 wild grapevine samples from five different populations were analysed using 23 SSR loci. Consistent allelic richness was detected in all the analysed populations (from 4.01 to 5.35). The observed heterozygosity and expected heterozygosity were high with mean values of 0.67 and 0.69, respectively. A modest heterozygosity deficiency was detected only in the Piranshahr and Sardasht-Shalmash populations. The neighbour-joining dendrogram clustered the accessions into three groups corresponding to the geographical distribution of the populations. Molecular data combined with field evaluation revealed that an ex situ conservation approach is the most suitable strategy for preserving the genetic richness of Iranian wild grape populations with consistent rare alleles (about 20%). We propose in situ preservation only in the case of the Sardasht-Ghasmarash population to ensure that evolutionary dynamic forces continue to influence plant adaptation and survival in response to environmental alterations.

Millions of farmers depend on the use of local crops and varieties for their food and livelihood. These resources constitute a reservoir of alternative traits and characteristics, which allow us to diversify crops, foods and farming methods and provide material for targeted plant breeding. Still, many countries lag behind in providing support to farming communities for the maintenance and use of plant genetic resources for food and agriculture (PGRFA). A global survey was conducted among a wide range of stakeholders to gain insights into the state of on-farm management (OFM) as a strategy for enhancing the maintenance and sustainable use of PGRFA. The survey showed that a wide range of stakeholders provide de facto support to OFM and that the practices they consider critical are focused on building capabilities in local communities. This supports the fact that the management of crop diversity on farm can be promoted in a variety of ways, depending on the specific context, and that local solutions are needed to successfully support OFM. Partnerships and networks should be considered as one of the critical means to promote OFM, as they involve a diversity of stakeholders working towards common goals. The survey further showed that many respondents currently contribute to existing networks relevant to OFM, but that these networks are mainly nationally or internationally oriented and might therefore exclude crucial local stakeholders, such as community-based organizations. Therefore, mechanisms should be put in place to strengthen the collaboration between stakeholders and networks, especially at the local level.

In this study, genetic diversity in 340 finger millet accessions from Kenya, Tanzania and Uganda and 15 minicore accessions was assessed using 23 single-sequence repeat markers and five qualitative traits. Nineteen markers were polymorphic with a mean polymorphic information content value of 0.606 and a range of 0.035–0.889, with allele size ranging from 148 to 478. A total of 195 alleles were detected (range of 3–23 and average of 10.3 alleles per locus), with 57.7% being rare and 17.4% being private. Differentiation between the accessions of the three countries was weak, with most of the genetic diversity being explained by variability within the countries and subregions than by that among the countries and subregions. The highest genetic diversity was observed in the Kenyan accessions (0.638 ± 0.283) and the least in the Ugandan accessions (0.583 ± 0.264). The highest differentiation based on Wright's fixation index was observed between the Ugandan and Tanzanian accessions (FST= 0.117; P< 0.001). There was no association between the morphological traits assessed and the genetic classes observed. The low variability between the countries could be attributed to a shared gene pool, as the crop originated from the East African region. Farmers' selection for adaptation and end use could have contributed to the high diversity within the countries. Concerted efforts need to be made to characterize the large germplasm stocks in East Africa for their effective conservation and utilization. The lack of representation of accessions from the three countries in all global minicore diversity clusters points to the need to explore the East African germplasm to identify the diversity not captured earlier to be included in the global repository.

To maximize heterosis, it is important to understand the genetic diversity of germplasm and associate useful phenotypic traits such as fertility restoration for hybrid rice breeding. The objectives of the present study were to characterize genetic diversity within a set of rice germplasm groups using coefficient of parentage (COP) values and 58 simple sequence repeat (SSR) markers for 124 genotypes having different attributes such as resistance/tolerance to various biotic and abiotic stresses. These lines were also used for identifying prospective restorers and maintainers for wild abortive-cytoplasmic male sterile (CMS) line. The mean COP value for all the lines was 0.11, indicating that the genotypes do not share common ancestry. The SSR analysis generated a total of 268 alleles with an average of 4.62 alleles per locus. The mean polymorphism information content value was 0.53, indicating that the markers selected were highly polymorphic. Grouping based on COP analysis revealed three major clusters pertaining to the indica, tropical japonica and japonica lines. A similar grouping pattern with some variation was also observed for the SSR markers. Fertility restoration phenotype based on the test cross of the 124 genotypes with a CMS line helped identify 23 maintainers, 58 restorers and 43 genotypes as either partial maintainers or partial restorers. This study demonstrates that COP analysis along with molecular marker analysis might encourage better organization of germplasm diversity and its use in hybrid rice breeding. Potential restorers identified in the study can be used for breeding high-yielding stress-tolerant medium-duration rice hybrids, while maintainers would prove useful for developing new rice CMS lines.

The capitate glandular trichomes of wild sunflowers (Helianthus spp.) are considered to be effective defence components that act against some herbivorous insects, but cultivated sunflowers are reportedly deficient in glandular trichomes. To investigate whether glandular trichomes have a role in the protection of cultivated sunflowers against insects, in the present study, Helianthus annuus L. accessions were grown to quantify glandular trichome density in wild and cultivated germplasm types and assess potential anti-insect effects of terpenoids in the glandular trichomes of cultivated sunflowers. Evaluation revealed that capitate glandular trichomes are often abundant in cultivated sunflowers; relative to wild H. annuus, inbred maintainer (HA) lines have similar numbers of glandular trichomes per floret, while commercial hybrids have only ≈ 20% fewer trichomes when compared with wild sunflowers. In the laboratory assay, it was found that glandular trichome extracts increased the mortality rates of sunflower moth, Homoeosoma electellum (Hulst), larvae exposed from the neonatal stage to 9 d. In the surviving larvae, the extracts significantly reduced larval mass and head capsule width. Though there are limitations to the value of glandular trichomes for host plant resistance, the feeding deterrent or toxic effects of sesquiterpene lactones and diterpenes in sunflower glandular trichomes are not limited to sunflower moth larvae, suggesting a potential for resistance to other sunflower insect pests. Additional research is required to understand the inheritance and value of glandular trichomes in commercial sunflower germplasm and how the composition of terpenoids in the glandular trichomes of wild H. annuus may differ from that in cultivated material.

Crop biofortification is increasingly being recognized as a cost-effective and sustainable approach to address the widespread micronutrient malnutrition arising from Fe and Zn deficiencies. Pearl millet as a cereal crop species has higher Fe density than all other major cereals. Earlier studies in pearl millet have shown that breeding lines, hybrid parents, improved populations and composites having high Fe and Zn densities were often based largely or entirely on iniadi pearl millet germplasm. In an attempt to identify additional sources of high Fe density in this group of germplasm, 297 accessions were screened using Perl's Prussian Blue staining, of which 191 accessions (118 from Togo, 62 from Ghana and 11 from Burkina Faso) were re-evaluated during the 2010 rainy and 2012 summer seasons using the inductively coupled plasma atomic emission spectroscopy method. On the basis of the mean performance over the two seasons (environments), large variability was observed for both Fe (51–121 mg/kg) and Zn (46–87 mg/kg) densities. There was a highly significant and positive correlation between the two micronutrients (r= 0.77, P< 0.01). Of these re-evaluated accessions, 49% had higher Fe density than the high-Fe control commercial cultivar ICTP 8203 (81 mg/kg), and most of these accessions also had Zn density ≥ 61 mg/kg (59 mg/kg for ICTP 8203). A total of 27 accessions (20 from Togo and seven from Ghana) having a Fe density of 95–121 mg/kg (1 standard error of difference above that for ICTP 8203) and a Zn density of 59–87 mg/kg were selected as a valuable germplasm resource for genetic improvement of these two micronutrients in pearl millet.

Monitoring and protecting germplasm in genebanks using in situ collections while preserving its original genetic integrity is a priority of germplasm curation. Many germplasm accessions need to be regenerated due to their demand and/or seed condition. The regeneration of wild Helianthus (sunflower) species poses several challenges due to the diversity of 53 wild species. Fatty acid composition of sunflower oil is an important quality factor for the crop. Since oil quality is environmentally influenced, and evaluation of this trait is usually performed on oil from achenes from the original accessions of wild sunflower species, we conducted a study on 72 accessions of eight annual and four perennial taxa of wild sunflower species to compare the oil quality of the original accessions and those regenerated for genebank maintenance. The results showed that the fatty acid composition profiles of achenes from the original and regenerated accessions are not the same. It seems that selection for specific fatty acids in several species will require the analysis of both populations to identify germplasm accessions for use in breeding programmes. It should be borne in mind that accessions of wild species are open-pollinated segregating populations, so one would expect some variability in each succeeding generation. While there may be differences between the original and regenerated accessions, the interrelationships of fatty acids are generally similar in wild and cultivated sunflower species, so there should be no detrimental effects on oil quality when using the wild species for other traits. As more regenerated accessions become available, a more precise relationship between the original and regenerated accessions should emerge.

Genebanks are important suppliers of genetic resources to the genomics research community, and access to the resulting information will allow traditional genebank users to better select genetic material for their breeding and scientific programmes. We discuss herein a possible solution to interconnect these data automatically based on semantic web technology.