Genetic diversity analysis of grapevine rupestris stem pitting-associated virus from grapevine by colony PCR-SSCP and -RFLP.

We have developed methods for detecting the genetic diversity of grapevine rupestris stem pitting-associated virus (GRSPaV) based on restriction fragment length polymorphism (RFLP) and single stranded conformational polymorphism (SSCP) in the 905 nt 3' sequence. The amplicons were cloned from six grapevine cultivars, and colony polymerase chain reaction (colony PCR) using recombination bacteria was subsequently analyzed by RFLP and SSCP. Four haplotypes of SSCP and six haplotypes of Sac I RFLPs were defined. The two methods had a 40% discrepancy rate in showing the degree of diversity. All clones were sequenced and were used to construct a phylogenetic tree with seven previously reported GRSPaV sequences. In the tree, all the newly acquired sequences were divided into three clusters, I, II, and III, which corresponded to haplotypes I, II, and III of SSCP, respectively. Haplotype IV of SSCP was grouped into cluster II. A recombination analysis showed that haplotype IV has undergone a recombination event. Together, these results indicate that the SSCP assay is useful for the rapid identification of genetic diversity of GRSPaV. This is the first report of an analysis of the large fragment of GRSPaV by colony PCR-SSCP. Keywords: grapevine; grapevine rupestris stem pitting-associated virus (GRSPaV); RFLP; SSCP; genetic diversity analysis.

Molecular characterizations of two grapevine rupestris stem pitting-associated virus isolates from China.

The complete nucleotide sequences of two isolates of grapevine rupestris stem pitting-associated virus (LSL and JF) collected from grapevine of Xingcheng in Liaoning Province, China, were determined. The genomes of both LSL and JF were found to contain five open reading frames (ORFs). Sequence alignments showed that the genomic sequences of JF were 76.1 %-83.5 % identical to the other ten GRSPaV isolates that have been reported previously and that the nucleotide sequence identity of isolate LSL to other isolates was no more than 78 %. Phylogenetic analysis based on the complete genome sequence indicated that JF belongs to group III and that LSL belongs to a new group (group IV). The average genetic distances of the new genetic lineage from groups I, II and III were 0.34, 0.32 and 0.33, respectively.

Self-Assembly of [3]Catenane and [4]Catenane Based on Neutral Organometallic Scaffolds.

Transition metal-mediated templating and self-assembly have shown great potential to construct mechanically interlocked molecules. Herein, we describe the formation of the bimetallic [3]catenane and [4]catenane based on neutral organometallic scaffolds via the orthogonality of platinum-to-oxygen coordination-driven self-assembly and copper(I) template-directed strategy of a [2]pseudorotaxane. The structures of these bimetallic [3]catenane and [4]catenane were characterized by multinuclear NMR {1H and 31P} spectroscopy, electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), and PM6 semiempirical molecular orbital theoretical calculations. In addition, single-crystal X-ray analyses of the [3]catenane revealed two asymmetric [2]pseudorotaxane units inside the metallacycle. It was discovered that tubular structures were formed through the stacking of individual [3]catenane molecules driven by the strong π-π interactions.