Fingerprinting, structure, and genetic relationships among selected accessions of blue honeysuckle (Lonicera caerulea L.) from European collections.

Due to its value and economic importance, the genome of Lonicera caerulea L. has been widely studied in various fields of science. In this study the genetic structure and relationships between 24 accessions of L. caerulea of different origins were assessed. A total of 692, 814, and 258 loci were amplified using 43 RAPD (random amplified polymorphic DNA), 40 ISSR (intersimple sequence repeat), and 20 R-ISSR (RAPD+ISSR) primers, respectively. Among the amplified loci, 66-78% were polymorphic and 12-20% were private. Selected R-ISSR sequences were detected in Lonicera japonica transcripts. Cluster and STRUCTURE analyses performed for each of the techniques revealed the existing differences and unknown similarities between the genotypes. The r-factor values calculated in the Mantel test indicated highly significant positive correlations between the Nei distance matrices, similar to the F ST values (F ST_RAPD = 0.223, F ST_ISSR = 0.279, F ST_R-ISSR = 0.363) determined in the analysis of molecular variance. It was found that 78%, 72%, and 64% of the genetic variations were related to the differences observed within the populations, which suggest that the variations are mainly reflected in the differences among the genotypes. The principal coordinate analysis showed greater differences between the mean distances of the Lonicera genotype pair and the actual distances of the same pairs on the Nei matrix compared to multidimensional scaling. These differences were 45%, 56%, and 42% higher for RAPD, ISSR and R-ISSR, respectively.

Three new species of arbuscular mycorrhizal fungi discovered at one location in a desert of Oman: Diversispora omaniana, Septoglomus nakheelum and Rhizophagus arabicus.

Three new species of arbuscular mycorrhizal (AM) fungi (Glomeromycota) were isolated from soil samples collected from a hyperarid sandy plain of South Arabia. Morphological characteristics of the spores clearly differentiated them from closely related AM species. Molecular analyses were performed on rDNA sequences obtained from single spores including a ~1700 bp region comprising partial SSU, ITS, partial LSU and the ~600 bp ITS region only. The phylogenetic trees based on these regions showed that the three species belong to well described genera but are clearly distinct from known species. Consequently, we describe them here as Diversispora omaniana, Septoglomus nakheelum and Rhizophagus arabicus spp. nov. D. omaniana and R. arabicus were isolated from the native, arid habitat, while S. nakheelum was isolated from a nearby irrigated date palm plantation. The discovery of three new species of AM fungi from this location suggests that a number of additional undescribed AM taxa may be present in such desert ecosystems. Further work to understand the diversity and functional significance of these new AM taxa may offer new opportunities for conservation, re-vegetation, and sustainable agriculture in extremely arid environments.

Septoglomus fuscum and S. furcatum, two new species of arbuscular mycorrhizal fungi (Glomeromycota).

Two new arbuscular mycorrhizal fungal species, (Glomeromycota) Septoglomus fuscum and S. furcatum, are described and illustrated. Spores of S. fuscum usually occur in loose hypogeous clusters, rarely singly in soil or inside roots, and S. furcatum forms only single spores in soil. Spores of S. fuscum are brownish orange to dark brown, globose to subglobose, (20-)47(-90) µm diam, rarely ovoid, 21-50 × 23-60 µm. Their spore wall consists of a semi-persistent, semi-flexible, orange white to golden yellow, rarely hyaline, outer layer, easily separating from a laminate, smooth, brownish orange to dark brown inner layer. Spores of S. furcatum are reddish brown to dark brown, globose to subglobose, (106-) 138(-167) µm diam, rarely ovoid, 108-127 × 135-160 µm, usually with one subtending hypha that is frequently branched below the spore base, or occasionally with two subtending hyphae located close together. Spore walls consists of a semipermanent, hyaline to light orange outermost layer, a semipermanent, hyaline to golden yellow middle layer, and a laminate, smooth, reddish brown to dark brown innermost layer. None of the spore-wall layers of S. fuscum and S. furcatum stain in Melzer's reagent. In the field, S. fuscum was associated with roots of Arctotheca populifolia colonizing maritime dunes located near Strand in South Africa and S. furcatum was associated with Cordia oncocalyx growing in a dry forest in the Ceará State, Brazil. In single-species cultures with Plantago lanceolata as host plant, S. fuscum and S. furcatum formed arbuscular mycorrhizae. Phylogenetic analyses of the SSU, ITS and LSU nrDNA sequences placed the two new species in genus Septoglomus and both new taxa were separated from described Septoglomus species.