Microsatellite DNA fingerprinting, differentiation, and genetic relationships of clones, cultivars, and varieties of six poplar species from three sections of the genus Populus.

Accurate identification of Populus clones and cultivars is essential for effective selection, breeding, and genetic resource management programs. The unit of cultivation and breeding in poplars is a clone, and individual cultivars are normally represented by a single clone. Microsatellite DNA markers of 10 simple sequence repeat loci were used for genetic fingerprinting and differentiation of 96 clones/cultivars and varieties belonging to six Populus species (P. deltoides, P. nigra, P. balsamifera, P. trichocarpa, P. grandidentata, and P maximowiczii) from three sections of the genus. All 96 clones/cultivars could be uniquely fingerprinted based on their single- or multilocus microsatellite genotypes. The five P. grandidentata clones could be differentiated based on their single-locus genotypes, while six clones of P. trichocarpa and 11 clones of P. maximowiczii could be identified by their two-locus genotypes. Twenty clones of P. deltoides and 25 clones of P. nigra could be differentiated by their multilocus genotypes employing three loci, and 29 clones of P. balsamifera required the use of multilocus genotypes at five loci for their genetic fingerprinting and differentiation. The loci PTR3, PTR5, and PTR7 were found to be the most informative for genetic fingerprinting and differentiation of the clones. The mean number of alleles per locus ranged from 2.9 in P. trichocarpa or P. grandidentata to 6.0 in P. balsamifera and 11.2 in 96 clones of the six species. The mean number of observed genotypes per locus ranged from 2.4 in P. grandidentata to 7.4 in P. balsamifera and 19.6 in 96 clones of the six species. The mean number of unique genotypes per locus ranged from 1.3 in P. grandidentata to 3.9 in P. deltoides and 8.8 in 96 clones of the six species. The power of discrimination of the microsatellite DNA markers in the 96 clones ranged from 0.726 for PTR4 to 0.939 for PTR7, with a mean of 0.832 over the 10 simple sequence repeat loci. Clones/cultivars from the same species showed higher microsatellite DNA similarities than the clones from the different species. A UPGMA cluster plot constructed from the microsatellite genotypic similarities separated the 96 clones into six major groups corresponding to their species. Populus nigra var. italica clones were genetically differentiated from the P. nigra var. nigra clones. Microsatellite DNA markers could be useful in genetic fingerprinting, identification, classification, certification, and registration of clones, clultivars, and varieties as well as genetic resource management and protection of plant breeders' rights in Populus.     

Cross-species transfer of nuclear microsatellite markers: potential and limitations

Molecular ecologists increasingly require 'universal' genetic markers that can easily be transferred between species. The distribution of cross-species transferability of nuclear microsatellite loci is highly uneven across taxa, being greater in animals and highly variable in flowering plants. The potential for successful cross-species transfer appears highest in species with long generation times, mixed or outcrossing breeding systems, and where genome size in the target species is small compared to the source. We discuss the implications of these findings and close with an outlook on potential alternative sources of cross-species transferable markers.     

Eighteen microsatellite loci in Salix arbutifolia (Salicaceae) and cross-species amplification in Salix and Populus species

Salix arbutifolia is a riparian dioecious tree species that is of conservation concern in Japan because of its highly restricted distribution. Eighteen polymorphic loci of dinucleotide microsatellites were isolated and characterized. Among these, estimates of the expected heterozygosity ranged from 0.350 to 0.879. Cross-species amplification was successful at 9-13 loci among six Salix species and at three loci in one Populus species.     

Sequence-based identification of species belonging to the genus Debaryomyces

In the present study we assessed the identification by sequence analysis of the 15 species belonging to the genus Debaryomyces. We found that the following species can be identified both quickly and correctly by direct sequence comparison of the ribosomal 5.8S-ITS region: D. carsonii, D. etchelsii, D. maramus, D. melissophilus, D. occidentalis and D. yamadae. In contrast, the species D. castellii, D. coudertii, D. hansenii, D. nepalensis, D. polymorphus, D. pseudopolymorphus, D. robertsiae, D. udenii and D. vanrijiae showed high sequence similarity in ribosomal regions with one or several species. In these cases, sequence comparison of the ACT1 gene is proposed to ensure unequivocal strain designation.     

Pollen morphology of some species belonging to Codonoprasum and Allium sections of Allium (Liliaceae-Alliaceae) genus

Pollen morphology of 14 Allium L. species grown in Turkey, that belong to the sections Codonoprasum and Allium, were investigated under LM (light microscopy) and by SEM (scanning electron microscopy). However, the pollens of 5 species were investigated under TEM (transmission electron microscopy). Detailed pollen morphological characteristics are given for Allium in the family on the basis of the results presented here together with data from the literature. The genera Allium homogeneous in both aperture type and exine ornamentation. It is suggested that some palynological characters, such as aperture type and the presence of an operculum, could be of taxonomic value at the section level.     

Comparative genomic analysis of isolates belonging to the six species of the genus Thermus using pulsed-field gel electrophoresis and ribotyping

Fifty isolates belonging to the six validly described species of the genus Thermus (T. aquaticus, T. filiformis, T. thermophilus, T. scotoductus, T. brockianus, and T. oshimai) isolated from hot springs of different geographical areas were compared using macrorestriction analysis of genomic DNA and ribotyping. With the exception of presumed clones, the macrorestriction patterns of isolates obtained with EcoRI or NdeI were distinct. However, isolates belonging to the same species exhibited similar profiles particularly when they were isolated from the same hot spring. The estimated genomic size of strains of the Thermus spp. varied between approximately 1.8 and 2.5 Mbp. Ribotyping with BamHI and HindIII produced 30 and 35 distinct ribotypes, respectively. In spite of the variability of the hybridization patterns produced, the ribotypes obtained for isolates belonging to the same species also shared, in general, several fragments of identical size, and these fragments were similar when isolates originated from the same spring. Received: 7 October 1996 / Accepted: 10 March 1997     

Population genetic diversity and species relationships in the genus Rhinanthus L. based on microsatellite markers

The genus Rhinanthus L. is complex, containing many taxonomically unresolved taxa. In this paper we studied genetic variation and species relationships in 15 populations of six Rhinanthus species from three sections. For this purpose, we developed new microsatellite primers for R. osiliensis and used them to investigate genetic variation in two narrow endemics (R. osiliensis, R. javorkae) and in four widespread species (R. rumelicus R. wagneri, R. angustifolius and R. minor). Species‐specific private alleles were found in all species except R. osiliensis and R. angustifolius. The Bulgarian endemic R. javorkae showed the lowest genetic variation, followed by widespread R. minor and Estonian endemic R. osiliensis. Rhinanthus javorkae and R. minor were genetically most differentiated. Section Cleistolemus is weakly structured genetically, indicating close affinity between R. osiliensis, R. rumelicus, R. wagneri and R. angustifolius.     

Redescriptions and reestablishments of some species belonging to the genus Prionospio (Polychaeta,Spionidae) and descriptions of three new species

Available type material of Prionospio heterobranchia Moore, 1907, P. (Prionospio) texana Hartman, 1951, P. spongicola Wesenberg-Lund, 1958 and P. (P.) newportensis Reish, 1959, as well as newly collected material from the Southern Gulf of Mexico and Chetumal Bay in the Caribbean Sea, was examined. Several important differences were found between P. heterobranchia, P. (Prionospio) texana, P. spongicola and P. (P.) newportensis, and as a result, these three species are removed from synonymy with P. heterobranchia Moore, 1907, and redescribed and reinstated as valid species. In addition, three new species were identified and described: P. caribensis sp. nov., P. rosariae sp. nov. and P. jamaicensis sp. nov. A key to all species of Prionospio with five pairs of branchiae is provided.     

Clonal fingerprinting in the genus <Emphasis Type="Italic">Populus</Emphasis> L. by nuclear microsatellite loci regarding differences between sections,species and hybrids

Reliable methods for clone identification are desired to characterise and distinguish breeding products within the genus Populus L. (Salicaceae). Ten nuclear microsatellite loci (PMGC14, PMGC456, PMGC2163, PTR2, PTR7, WPMS05, WPMS09, WPMS14, WPMS15 and WPMS20) were applied on a clone collection with several species and hybrids belonging to the sections Tacamahaca (balsam poplars), Aigeiros (black poplars, cottonwoods) and Populus (white poplars and aspens) and intersectional hybrids between black and balsam poplars. The members of the different sections and species do not always share their allelic ladders. Some shifts of one or two nucleotides in allele length were observed for several loci. This could be explained by nucleotide sequence differences in the flanking regions of loci in diverse taxonomic groups. Such shifts of allelic ladders result in irregular patterns in hybrid genotypes. The set of loci should have a sufficient amount of variation for a differentiation between clones, even if they are full siblings originating from crossing experiments.     

High degree of conservation of nuclear microsatellite loci in the genus Clusia.

In plants, microsatellites and their flanking DNA are rarely conserved across a whole genus, let alone other genera in the same family. Therefore, the possibility of using microsatellite primers developed for a species across a large number of plant species in the same genus is often limited. Remarkably, dinucleotide nuclear microsatellites developed for Clusia minor and for Clusia nemorosa amplified homologous microsatellites in species across the whole genus Clusia. In this present study, we report on the DNA sequence variation across the genus of 3 microsatellite loci with varying levels of variation. Compared over the species, there was a correlation between the lengths of the microsatellite loci. Interrupts occurred multiple times and did not seem to lead to the death of the microsatellite. These highly conserved markers will be useful for studying the variable reproductive systems in the genus Clusia.     

Dense genetic linkage maps of three Populus species (Populus deltoides, P. nigra and P. trichocarpa) based on AFLP and microsatellite markers

Populus deltoides, P. nigra, and P. trichocarpa are the most important species for poplar breeding programs worldwide. In addition, Populus has become a model for fundamental research on trees. Linkage maps were constructed for these three species by analyzing progeny of two controlled crosses sharing the same female parent, Populus deltoides cv. S9-2 x P. nigra cv. Ghoy and P. deltoides cv. S9-2 x P. trichocarpa cv. V24. The two-way pseudotestcross mapping strategy was used to construct the maps. Amplified fragment length polymorphism (AFLP) markers that segregated 1:1 were used to form the four parental maps. Microsatellites and sequence-tagged sites were used to align homoeologous groups between the maps and to merge linkage groups within the individual maps. Linkage analysis and alignment of the homoeologous groups resulted in 566 markers distributed over 19 groups for P. deltoides covering 86% of the genome, 339 markers distributed over 19 groups for P. trichocarpa covering 73%, and 369 markers distributed over 28 groups for P. nigra covering 61%. Several tests for randomness showed that the AFLP markers were randomly distributed over the genome.     

Protein polymorphisms in six species of the genus Calanus

Isoelectric focusing was used to study total protein patterns and allozyme variations of six species of the genus Calanus. Each species could be characterized by total protein patterns. The results of the allozyme study indicated, in agreement with previous morphological studies, that the six Calanus species belong to three different groups: the C. finmarchicus group C. finmarchicus, C. glacialis and C. marshallae the C. helgolandicus group (C. helgolandicus, C. pacificus), and C. hyperboreus, which stands apart. There is no indication that there are more loci coding for the proteins studied in species with larger genome sizes. Nor is the degree of enzyme polymorphism related to genome size in these species.     

Isolation of microsatellite loci and cross‐species amplifications in three gobiid fish of the genus Pomatoschistus

Gobiids of the genus Pomatoschistus are increasingly being investigated as models for adaptation to coastal environments and for mating system studies. Among the dozen currently analysed species, microsatellite primers have been characterized only for Pomatoschistus minutus. This paper describes seven new polymorphic loci isolated from Pomatoschistus marmoratus and Pomatoschistus microps, two species that hybridize. Cross‐species amplification was tested for these new loci, together with seven already published P. minutus loci. Systematic amplification of samples of each of the three species provided a first indication of their polymorphism.     

Brunneocorticium pyriforme, a new corticioid fungal genus and species belonging to the euagarics clade

Evidence derived from molecular studies in recent years has revealed that corticioid fungal genera are present in all major clades of Homobasidiomycetes. Brunneocorticium pyriforme, a corticioid fungus is proposed as a new species and placed in a new genus belonging to the euagarics clade. This fungus has been collected in subtropical-tropical Taiwan and southern Yunnan Province, China. Basidiocarps often occur on bark of living Murraya spp. (Rutaceae). Basidiocarps of B. pyriforme are resupinate with a smooth hymenial surface, a dimitic hyphal system, with nodose-septate generative hyphae and abundant yellowish brown skeletal hyphae, and leptocystidia. It has 2-sterigmate basidia and pear-shaped basidiospores. Phylogenetic analysis based on sequence data derived from LSU rDNA included Brunneocorticium in the euagarics clade of Homobasidiomycetes, allied to the agaricoid genera Marasmiellus, Campanella, etc. The molecular analysis indicated that the Brunneocorticium was independent from other corticioid genera with similar morphological features.     

A comparison of the karyotypes of six species of the genus Macaca and a species of the genus Cercocebus

Karyotypes from 72-hour whole blood cultures were compared for six species of macaques (Macaca arctoides, M. fascicularis, M. mulatta, M. nemestrina, M. nigra, and M. radiata) and one species of mangabey (Cercocebus atys). G-bands, sequential C-bands, and late replication patterns were studied. Results showed a variation in a single chromosome pair which differentiated C. atys from the macaques. Heteromorphic variation in silver stained nucleolar organizing regions was seen between and within individuals. This data supports previous work showing the highly conserved nature of the chromosomes of the subfamily Cercopithecus.