[show abstract][hide abstract] ABSTRACT: Cucumber green mottle mosaic virus (CGMMV) is the first-known cucurbit-infecting tobamovirus. To analyse its biological and molecular diversities, 36 isolates of CGMMV were collected from watermelon (Citrullus vulgaris) and cucumber (Cucumis sativus) plants in Korea. The cDNAs of coat protein (CP) and partial movement protein genes of the isolates were synthesized by reverse transcription and polymerase chain reaction (RT-PCR) and subjected to single-strand conformation polymorphism (SSCP) analysis with 530 bp-synthesized RT-PCR products. CGMMV isolates were categorized into three subgroups by SSCP analysis, designated types I, II and III. All watermelon isolates of CGMMV belonged to types I and II, whereas cucumber isolates were subgrouped into types II and III. These three type isolates of CGMMV were divided by RT-PCR-restriction fragment length polymorphism (RFLP) using full-length cDNAs of three types of CGMMV. Biological properties of each subgroup-type of CGMMV isolates were determined by mechanical inoculation of common host plants of CGMMV. Among the virus isolates, isolate NW-1, belonging to type I, did not infect cucumber (cv. Baegbong), whereas all CGMMV isolates (types II and III) infected the same host species. In addition, all isolates of CGMMV types could infect Nicotiana debneyii, except that isolate KC1-2, subgrouped into type III, failed to infect. Nucleotide and predicted amino acid sequences of CP gene of CGMMV isolates were compared to those of reported CGMMVs and other cucurbit-infecting tobamoviruses. In phylogenetic tree analyses between CGMMV isolates and other cucurbit-infecting tobamoviruses, CGMMV was subgrouped as a cluster and no remarkable molecular diversity was found among the CGMMV isolates.
[show abstract][hide abstract] ABSTRACT: The genetic diversity and relationship between Paphiopedilum and Phragmipedium species and cultivars was determined by randomly amplified polymorphic DNA (RAPD) analysis. Twenty-one species and 13 varieties of these two orchids genera were analyzed and the similarity values ranged from 0.629, between P. kolosand and Paphiopedilum koloparkngii, to 0.882, between P. koloparkingii and Phragmipedium ‘Hanne Popow’. The analysis included both total and polymorphic band scores. The orchids examined could be separated into two major subgroups. The first major subgroup, subgroup I, included 28 species, which was composed of all Paphiopedilum species and 8 Phragmipedium species. Subgroup II was comprised of six species. These two subgroups could be further divided into two minor clusters. In this study Paphiopedilum and Phragmipedium were successfully differentiated by RAPD and the results were in good agreement with morphological based classifications. Therefore, our results suggest that the phylogenetic information could be obtained using molecular markers to address the interspecies genetic relationships of Paphiopedilum and Phragmipedium.
[show abstract][hide abstract] ABSTRACT: A novel virus we call zucchini green mottle mosaic virus (ZGMMV) was isolated from zucchini squash and its properties were determined. The size and shape of its virions, and other properties suggest that the virus is a tobamovirus. The coat protein (CP) genes of ZGMMV and kyuri green mottle mosaic virus (KGMMV), which also infects zucchini squash plants, were cloned and their nucleotides sequences were determined. The CP genes of ZGMMV and KGMMV are composed of 161 amino acid residues, and they share 77.6% amino acid identity. Western blot analysis showed that the two viruses are serologically related but not identical. Comparison of the sequences with those of sixteen other tobamoviruses revealed that the two viruses had much higher identity to cucumber green mottle mosaic virus (CGMMV), another tobamovirus infectious to cucurbit plants, than other tobamoviruses. The nucleotide and amino acid sequences of ZGMMV were from 29.5 to 78.4% and from 29.3 to 77.6% identical, respectively, to those of other tobamoviruses. The predicted virion assembly origins of the two tobamoviruses were located in the CP region of the genomic RNAs, and the predicted secondary structures were more similar to that of CGMMV than those of other tobamoviruses. The seventeen tobamo-viruses could be classified into three main subgroups based on the phylogenetic tree analysis on the CP gene, and ZGMMV and KGMMV formed a third subgroup together with CGMMV and sunn-hemp mosaic virus (SHMV). These results show that ZGMMV is a previously unknown member of the Tobamovirus genus.
Archives of Virology 02/2000; 145(11):2325-33. · 2.03 Impact Factor