Characterization of wild germplasm provides essential information on genetic diversity that breeders utilize for crop improvement. The potential of the sequence-related amplified polymorphism (SRAP) technique, which preferentially amplifies gene-rich regions, was evaluated to assess the genetic relationships among members of the Saccharum species. A panel of 31 SRAP primer combinations were used to score 30 genotypes of Saccharum officinarum, Saccharum spontaneum, Saccharum robustum, Saccharum sinense, Saccharum barberi and sugarcane hybrids, with Miscanthus and Erianthus included as outgroups. The amplifications produced 1364 DNA fragments for an average of 44 per primer combination, with 83% (1135) being polymorphic and 8.7% (119) being species specific. Based on the Dice index, all 30 genotypes were differentiated from each other with genetic similarity (GS) estimates ranging from 0.60 to 0.96 (mean = 0.79). Both the dendrogram [obtained by the unweighted pairgroup method with arithmetic mean or (UPGMA)] and the non-metric multidimensional scaling method grouped the genotypes according to their phylogenetic relationships. Erianthus and Miscanthus were separated as two outgroups (at GS levels of 0.56 and 0.72, respectively) into two major clusters: cluster I separated the S. robustum, S. sinense, S. barberi and hybrids as different subgroups with each one including some S. officinarum clones, while cluster II included the S. spontaneum clones, exclusively. A S. officinarum–S. spontaneum sequence comparison of some of the monomorphic and polymorphic bands revealed 65–90% homology with rice, corn or sugarcane sequences deposited in databases. The high discriminatory power coupled with the possibility that most of the amplicons may be amplifying gene-rich regions of the genome makes SRAP a potentially robust tool for genetic mapping aimed at marker-assisted introgression in sugarcane.

Germplasm accessions of wild Lactuca species are maintained worldwide in ex situ collections as gene reservoirs for quality and disease resistance traits for cultivated lettuce. Accessions of 12 Lactuca species from 6 genebanks were compared via morphological characterization and AFLP (Amplified Fragment Length Polymorphism)-based profiling to estimate the extent of duplication. A method of assessing redundancy within very similar, but not identical accessions, is proposed, based on 352 polymorphic AFLP products. Seven duplication groups showed a high level of AFLP similarity, and one pair of Lactuca saligna accessions displayed identical AFLP profiles. In several cases, the morphological assessment indicated that a taxonomic reclassification of accessions was necessary. Candidate duplicates were identified using population parameters and inter- and intra-accession variability. The implications of these findings on the conservation of wild species are discussed.

Microsatellite markers (SSRs) were used to screen and analyse the genetic diversity among clonal genotypes of date palm (Phoenix dactylifera L.) derived by somatic embryogenesis in Oman. Twenty-one palms, representing 14 Omani, five Bahraini, one Iraqi and one Moroccan genotype, were screened with ten microsatellite markers. All primer pairs produced an amplification product in the expected size range and detected high levels of polymorphism among the analysed samples. Correspondence analysis revealed that the genotypes from Bahrain and Iraq showed a close relationship with accessions already grown in Oman. The genotype from Morocco (Medjool) appeared distinct from the rest of the material. Three independent clonal lines derived from a single Khalas Aldahra genotype were found to give identical genetic fingerprints. The value of this work for date palm production and conservation in Oman is discussed.

Brinjal (Solanum melongena L.) is an important solanaceous vegetable in many countries of Asia and Africa. It is a good source of minerals and vitamins in the tropical diets. Assessment of genetic resources is the starting point of any crop improvement programme. In India, the National Bureau of Plant Genetic Resources is the nodal institute for management of germplasm resources of crop plants and holds more than 2500 accessions of brinjal in its genebank. In the present study, morphological diversity in a set of 622 accessions, comprising 543 accessions from indigenous sources and 79 accessions of exotic origin, was assessed. Wide range of variations for 31 descriptors, 13 quantitative and 18 qualitative, were recorded. The wide regional variations for plant, flower and fruit descriptors revealed enough scope for improvement of yield characters by selection. The genetic differences among the landraces are potentially relevant to breeding programmes in that the variability created through hybridization of the contrasting forms could be exploited.

Hayachine-usuyukiso (Leontopodium hayachinense) is an alpine plant native to Mt Hayachine. This unique chrysanthemum is listed as an endangered plant by the Department of Conservation, Iwate Prefecture, and as a threatened plant by the Ministry of the Environment, Japan. We successfully cryopreserved the shoot tips from in vitro-grown L. hayachinense shoots using a vitrification protocol. Cold-hardened shoot tips were excised and pre-cultured on a solidified Murashige–Skoog medium containing 0.3 M sucrose for 1 d at 5°C. The shoot tips were then treated with loading solution for 20 min at 25°C, dehydrated in plant vitrification solution 2 for 120 min at 25°C and immersed in liquid nitrogen. The survival rate of the vitrified shoot tips was 63.3% after 30 d of regrowth. This protocol appears to be a promising technique for the cryopreservation of in vitro-grown shoots of this endangered plant.

Sets of microsatellites extracted from both a genomic library (gSSRs) and from expressed sequence tag sequence (eSSRs), and single nucleotide polymorphisms (SNPs) were applied to assess the levels of genetic diversity in a sample of 70 barley accessions, originating from 28 countries in Asia, Africa, the Middle East and Europe. The eSSR assays detected a mean of 9.5 alleles per locus, and the gSSRs only 5.7 alleles per locus, but the polymorphism information content values for the two assay types were indistinguishable. Strong and statistically significant correlations were observed between the eSSR and gSSR (r = 0.86, P < 0.05), the eSSR and SNP (r = 0.74, P < 0.05) and the gSSR and SNP genotypes (r = 0.67, P < 0.05). Accessions originating from the Middle East and Asia had the highest levels of genetic diversity. Pairwise genetic similarity ranged from 0.16 to 0.87 (mean 0.43), indicating that the sample was genetically diverse. When clustered on the basis of genotype, Asian and African accessions tended to be grouped together, but those originating from the Middle East were not concentrated in any particular cluster.