The narrow genetic base of existing commercial oil palm cultivars has prompted oil palm breeders to give increased importance to augmenting these genetic resources because the sustainable development of the crop depends largely on the availability of genetic diversity and its use. Therefore, the purpose of this study was to conduct a molecular characterization of an ex situ collection of oil palm Elaeis guineensis Jacq. populations from the Republic of Cameroon using microsatellite molecular markers. Overall, 31 simple sequence repeats were polymorphic, with a total of 223 alleles, 78.4% of which were found at low frequency. The total genetic diversity was relatively high (HT= 0.673). The genetic differentiation between geographical regions was low (GST= 0.023, P= 0.001), and between families it was high (GST= 0.166, P= 0.001), showing greater variation between families than among geographical regions. The molecular data indicate that genetic diversity among the genotypes evaluated is mainly distributed within regions, suggesting that there is no isolation by geographical distance and that all the sampled individuals form a single diverse population. Therefore, it was concluded that a relatively low number of accessions (120 in the analysed case) that includes at least one representative of each family would allow us to efficiently collect almost the entire genetic diversity of Cameroon within the collection studied. This will allow for the efficient use of genetic resources and a reduction in morpho-agronomic characterization costs.

Three hundred and seventeen grape accessions from the National Active Grape Germplasm Site in India were analysed with 25 microsatellite markers. A total of 411 alleles were detected, of which 42% were rare alleles. Unique alleles for 56 genotypes were also identified. The analysis of microsatellite data identified 63 duplicate accessions and only 254 accessions were unique genotypes. Several cases of misnomers, synonymy and homonymy were identified. Parental genotype for a few clonal selections was ascertained. Population structure analysis grouped 254 unique genotypes into four major clusters. The analysis also revealed the presence of admixtures with only 79% of pure ancestry. A core collection comprising 80 genotypes was identified, which represented all the alleles and genetic diversity. A user-friendly and interactive computer application software was developed for storage and the retrieval of molecular data. A molecular database for the 254 genotypes was created. This analysis will help in the rationalization and better management of germplasm. Information on genetic diversity and population structure will form the basis for varietal improvement programmes.

Data on intra-specific variability for seed oil content, physical characteristics and fatty acid composition in Cucurbita moschata and Cucurbita argyrosperma are lacking in the scientific literature. We examined 528 genebank accessions of C. moschata and 166 accessions of C. argyrosperma – which included members of both subsp. argyrosperma and subsp. sororia – for seed oil content, oil physical characteristics and fatty acid composition. The oil of both species had near-identical viscosities, viscosity indices, colour and oxidative stabilities while the oil of C. argyrosperma had a slightly higher pour point, cloud point, percentage of free fatty acids and acid value when compared with C. moschata. Mean oil content values of the two species were similar at 28.7 ± /2.7 and 29.8 ± /2.6% for C. moschata and C. argyrosperma, respectively. The mean seed oil content of C. argyrosperma subsp. argyrosperma var. palmeri (32.1%) was significantly higher than that of the other taxa examined. The average (mean) percentage of total seed weight attributable to the kernel was 77.2% in C. moschata (n= 34) and 74.5% in C. argyrosperma (n= 46). The percentage of total seed weight attributable to the hull was correlated with seed oil content, in both species. Linoleic was the predominant fatty acid in all the samples analysed. Means for individual fatty acids in C. moschata were linoleic 48.5%, oleic 22.6%, palmitic 20.7% and stearic 7.5%. Means for individual fatty acids in C. argyrosperma were linoleic 47.3%, oleic 27.5%, palmitic 16.5% and stearic 8.0%.

Extensive studies of genetic diversity and population structure important for conservation of wild sorghum are yet lacking in Ethiopia, the centre of origin for cultivated sorghum. To assess both genetic diversity and the probability of gene flow between wild and cultivated types, collections of wild Sorghum bicolor were made from regions in Ethiopia where wild and cultivated sorghum coexist. Morphological data were recorded in situ for both quantitative and qualitative characters from 30 populations in five diverse geographical regions and eight agroecologies. High phenotypic diversity was observed among the wild and weedy sorghum populations. The overall standardized Shannon–Weaver diversity index (H′), computed from the frequencies of all qualitative traits, ranged from 0.47 to 0.98 with an average value of 0.76. Moreover, warm semi-arid lowland (SA2) agroecologies, which contain Tigray populations, supported the highest diversity for these traits. Subspecies verticilliflorum and drummondii (the two major subspecies of wild S. bicolor) were observed in diverse habitats throughout northern and central Ethiopia. In some areas, weedy types showed domestication traits including the absence of awns and reduced seed shattering. The existence of morphologically intermediate forms indicates that gene flow between cultivated and wild forms has likely occurred. Deployment of transgenic crop sorghum, therefore, would pose a distinct risk for transgene movement into wild Ethiopian populations.

In order to utilize germplasm resources more efficiently for peanut (Arachis hypogaea L.) genetic improvement, a core collection of 576 accessions and a primary mini core collection of 298 accessions were developed previously from a collection of 6839 cultivated peanut lines stored at the Oil Crops Research Institute of Chinese Academy of Agricultural Sciences at Wuhan. For an efficient evaluation and characterization of the most useful agronomic and disease-resistant traits, an even smaller collection of peanut accessions that represent a spectrum of phenotypes could be more desirable. For this reason, a mini-mini core collection with 99 accessions from the core accessions was developed based on the analysis of 21 morphological traits. It was demonstrated that there were no significant differences between the core and mini-mini core collections in 20 out of the 21 morphological traits studied. Further, the mini-mini core collection captured the ranges of all of the 21 traits displayed in the core collection. The newly developed mini-mini core collection was assessed for resistance to bacterial wilt disease caused by Ralstonia solanacearum. Two accessions showing a high level of resistance to bacterial wilt were identified, demonstrating the usefulness of the mini-mini core collection. The mini-mini-core collection provides a more efficient means of germplasm evaluation and will be resequenced as part of the International Peanut Genome Consortium sequencing project at the UC-Davis Genome Center.

This is the first report of a pasture plant collecting mission to the highlands of Eritrea and a preliminary examination of the potential of species for both Eritrea and southern Australia. In 2004, seeds from 53 legume species were collected from 58 locations in the southern highlands between Keren, Adi Quala and Senafe. Strains of Rhizobium from 18 species were also collected. Seed collections of 11 species with Rhizobium were established in germplasm nurseries at the Medina Research Station, Western Australia between 2005 and 2010. Observations on their growth, flowering and seed production were recorded. Based on a climate match analysis and observations from germplasm nurseries, it was suggested that species with most promise for parts of southern Australia include the annual legume Biserrula pelecinus ssp. leiocarpa and the perennial shrub Colutea abyssinica. The greatest potential, however, is reserved for the highlands of Eritrea where germplasm is well adapted. Species found low in the landscape including from the genera Lotus, Trifolium and Medicago appeared well utilized. Different species found higher in the landscape including from the genera Indigofera, Tephrosia, Crotalaria, Trifolium schimperi, B. pelecinus ssp. leiocarpa and C. abyssinica were much less common, appeared under-utilized and may be under threat from genetic erosion. Animal production on the non-arable dry hillsides of the highlands would benefit from better utilization of these species through replanting some areas, careful grazing management and demonstration of the benefits of increasing the native legume component of these wild pastures.

Crop wild relatives are an increasingly important source of plant genetic resources for plant breeders. Several studies have estimated the effects of climate change on the distribution of crop wild relatives, using species distribution models. In this approach, two important aspects, i.e. species' dispersal capacity and founder effects, are currently not taken into account. Neglecting these aspects can lead to an underestimation of the climate change-induced threat to the size of the species range and the conservation of range-wide levels of genetic diversity. This paper presents two recommendations for the interpretation of the results obtained with these models. The integration of process-based simulation models and statistical species distribution models will facilitate the inclusion of dispersal processes and founder effects in future assessments of the resilience of plant genetic resources under climate change.

Studies to quantify genetic variation in cassava germplasm, available within the national breeding programmes in Africa, have been limited. Here, we report on the nature and extent of genetic variation that exists within 1401 cassava varieties from seven countries: Tanzania (270 genotypes); Uganda (268); Kenya (234); Rwanda (184); Democratic Republic of Congo (DRC; 177); Madagascar (186); Mozambique (82). The vast majority of these genotypes do not exist within a formal germplasm conservation initiative and were derived from farmers' fields and National Agricultural Research Systems breeding programmes. Genotypes were assayed using 26 simple sequence repeat markers. Moderate genetic variation was observed with evidence of a genetic bottleneck in the region. Some differentiation was observed among countries in both cultivars and landraces. Euclidean distance revealed the pivotal position of Tanzanian landraces in the region, and STRUCTURE analysis revealed subtle and fairly complex relationships among cultivars and among landraces and cultivars analysed together. This is likely to reflect original germplasm introductions, gene flow including farmer exchanges, disease pandemics, past breeding programmes and the introduction of cultivars from the International Institute of Tropical Agriculture – Nigeria. Information generated from this study will be useful to justify and guide a regional cassava genetic resource conservation strategy, to identify gaps in cassava diversity in the region and to guide breeding strategies.

A detailed survey along the coastal regions of Southern India revealed the occurrence of seven Pandanus species, viz. P. kaida Kurz., P. odorifer (Forssk.) Kuntz., P. canaranus Warb., P. furcatus Roxb., P. thwaitesii Mart., P. foetidus Roxb and a new species P. palakkadensis Nadaf, Zanan & Wakte. The fragrance of staminate inflorescences of these species was compared with the fragrance of commercial staminate inflorescences of P. odorifer. P. thwaitesii,P. kaida and P. palakkadensis recorded comparable fragrance with that of P. odorifer. The study reveals the fragrance potential of these species, which could be exploited commercially for extraction of essential oil.

Open-pollinated (OPs) and composite populations (CPs) represent a valuable resource for sunflower breeding programmes. However, little is known about the levels and distribution of genetic variation within each of these populations. In this study, quantitative and qualitative traits along with molecular markers were used to evaluate 14 populations from the Instituto Nacional de Tecnología Agropecuaria (INTA) sunflower germplasm collection. These populations were chosen to represent historically important accessions that still play a central role within the INTA sunflower breeding programme due to their extensive variation in diverse agronomically important traits. Nine quantitative and eight qualitative agro-morphological descriptors were recorded and compared with those of a larger set of accessions representative of the phenotypic diversity of the sunflower collection. Molecular characterization was conducted on a total of 311 individuals using 16 microsatellite markers. Overall, the average gene diversity was 0.56 and the average number of alleles per locus was 6.25. No statistically significant differences in genetic diversity were detected between the OPs and CPs. Global estimates of FST revealed very high levels of differentiation among accessions (FST= 0.413, P< 0.05). Population structure analyses were consistent with the observed levels of differentiation and identified two major groups. The results of this work show that high global diversity is preserved within the accessions analysed here. Additionally, this study provides a set of reliable and discriminant markers for the cost-effective molecular characterization of sunflower accessions, along with the guidelines for the delineation of sampling strategies for OPs and CPs, thus aiding the efficient management and exploitation of sunflower germplasm collections.

Grapevine cultivar identification is based mainly on two complementary methodologies: microsatellite (simple sequence repeat (SSR)) DNA analysis and traditional ampelography. Here, we report a direct multiplex PCR approach that allows the simultaneous amplification of 11 SSR loci from crude samples, i.e. bypassing DNA extraction, by using an engineered DNA polymerase improved to tolerate plant PCR inhibitors. Many different plant tissues were successfully amplified: leaf, root, wood, berry flesh and skin, stalk and must, from wine and table grape varieties, and rootstocks. The direct multiplex PCR that we propose is quicker and cheaper than the methodologies used until now, and provides accurate results. Thus, SSR DNA analysis becomes economically more accessible to a larger number of potential users in addition to research institutes.

Anthocyanin indexes, quercetin, kaempferol and myricetin may provide industry with potential new medicines or nutraceuticals. Velvetleaf (Abutilon theophrasti Medik) leaves from 42 plant introductions (PI) were analyzed for anthocyanin indexes while both leaves and fruit were used for quercetin, kaempferol and myricetin concentration analysis by reverse-phase high performance liquid chromatography. Leaf anthocyanin indexes ranged from 6.15 to 11.25 among PI. Leaf quercetin and kaempferol concentrations ranged from 1.50 to 4.79 mg/g and 0.43 to 2.17 mg/g, respectively. Fruit quercetin, kaempferol and myricetin concentrations ranged from 0.061 to 0.266 mg/g, 0.054 to 0.734 mg/g, and 0 to 35.87 μg/g, respectively. Significant differences in leaf weight were also observed. Significant correlations were found between several traits. This information regarding anthocyanin indexes, quercetin, kaempferol and myricetin concentrations will be useful for velvetleaf cultivar development. Breeders and other scientists could use this germplasm that contains high concentrations of anthocyanins, quercetin, kaempferol and myricetin to develop new medicines or nutraceuticals from an extremely useful weedy species.

Vicine and convicine are anti-nutritional compounds that accumulate in the cotyledons of faba beans. When humans consume beans with high levels of these compounds, it can cause a condition called favism in individuals harbouring a deficiency in the activity of their glucose-6-phosphate dehydrogenase. When faba beans are used in animal feeds, there can be effects on performance. These concerns have resulted in increasing interest within plant breeding in developing low vicine and convicine faba bean germplasm. In order to facilitate this objective, we developed a rapid and robust screening method for vicine and convicine, capable of distinguishing between faba beans that are either high (wild type) or low in vicine and convicine. In the absence of reliable commercial reference materials, we report an adaptation of a previously published method where a biochemical assay and spectral data were used to confirm the identity of our analytes, vicine and convicine. This method could be readily adopted in other facilities and open the way to the efficient exploitation of diverse germplasm in regions where faba beans play a significant role in human nutrition. We screened a collection of germplasm of interest to a collaborative plant breeding programme developing between the National Institute for Agricultural Botany in the UK and L'Institut Nationale d'Agronomie de Tunisie in Tunisia. We report the results obtained and discuss the prospects for developing molecular markers for the low vicine and convicine trait.

Morinda reticulata Gamble and Morinda umbellata Linn. (Rubiaceae) are medicinally important climbers distributed as a mixed population in southern Western Ghats of India. A close morphological resemblance of these two species misleads the harvester in the identification of plant parts for preparation of herbal medicines. Though both species contain anthraquinone derivatives and share common medicinal properties for treating stomach disorders, each of these species has unique curative properties for treating selective diseases. Conventional methods are not reliable for identification of these species due to similarities in morphology. Thus, misidentification often leads to the deterioration of the quality of medicines. Thus, authentication utilizing conserved gene sequences in the chloroplast genome of these two Morinda spp. has been attempted for precise identification. Here we report the use of two barcoding genes (maturase kinase and ribulose 1,5-bisphosphate carboxylase large subunit) to distinguish M. reticulata and M. umbellata based on single nucleotide polymorphism. The present findings can be used for authenticating leaf samples of M. reticulata and M. umbellata.

This study was undertaken to analyse the variation in panicle-related traits of 206 sorghum accessions collected from 27 Asian and African countries. Significant differences among the accessions were observed for 18 measured traits. First, we found that the patterns of the observed panicle-related traits reflected the distribution of the accessions of different origins. Second, the distribution of several components of inflorescence architecture in sorghum accessions influenced their yield components. Principal component analysis of the data showed a wide range of variations across the 206 sorghum accessions. Despite their geographical isolation, no distinct separation between the Asian and African accessions was observed. Correlation coefficient and path coefficient analysis indicated that panicle length (PanL), the total number of branches, rachis length (Rac) and panicle width had a positive direct effect on grain yield. Finally, we showed that the variation in the inflorescence architecture of sorghum accessions was dependent not only on the PanL, but also on the total number of branches, the maximum length of primary branches, Rac, panicle diameter and panicle width. Thus, there are major panicle determinants that are strongly associated with grain yield which should be considered in breeding programmes. These results will serve as a starting point for further evaluation of sorghum germplasm via quantitative trait loci analysis and may be useful for improving yield based on careful consideration of trait selection and inflorescence morphology.

The large variation in multifactorial and seemingly non-adaptive kernel colour traits displayed by Native American maize landraces is an evidence of recurring selection for perceptual distinctiveness. Native American farmers selected for colour traits that allowed them to distinguish between and maintain large diversity within maize landraces for traditional uses. Multivariate statistical procedures were employed to quantify the variation and interrelationships between physical traits, C:N ratio, protein content, micro- and macronutrient concentrations with kernel colour traits measured on random kernel samples of Northern flint maize landraces grown for 2 years in a common-garden experiment. The colour traits (L*, a* and b* indicating dark–light, red–green and yellow–blue colour continuum, respectively) were digitally quantified on 590 random kernels from each of 28 accessions in 11 landraces. Accessions within landraces exhibited the largest variation for all colour traits. The variation in the L*a*b*, L*a* and L*b* combinations explained significant variances in 37, 14 and 37% of 120 landrace–trait combinations, respectively; the remaining 12% were explained by L*, a* or b*. On average, 37.5% of the variation in protein content (range 19.2–64.5%) and 36.6% of the variation in the C:N ratio (range 15.7–65.0%) were explained by the combinations of colour traits in different landraces. Slightly larger average variations in K (43.7%), S (43.0%), Fe (42.2%) and P (40.8%) were accounted for by colour traits. A hierarchical and joint clustering procedure of landraces and traits was developed to facilitate the identification of large variation and the selection of single or multiple traits based on kernel colour traits with reasonable certainty.

Common lilac is a popular landscape plant with nearly 2000 cultivars. In the present study, nine novel polymorphic microsatellite markers were developed for common lilac using genome screening with inter-simple sequence repeat primers. Each of the nine markers revealed two to five alleles. The markers were used for genotyping of 75 common lilac shrubs, including 17 accessions that represented named cultivars. A dendrogram, based on the allele profiles of the shrubs, was generally in agreement with the grouping made on the basis of morphological traits, as well as with the pedigree information available. The novel markers appear valuable for differentiation between common lilac cultivars.