| multilocus sequences confirm the close genetic relationship of four phytoplasmas of peanut witches'-broom group 16srii-a. | four witches'-broom diseases associated with arachis hypogaea (peanut), crotalaria pallida, tephrosia purpurea, and cleome viscosa were observed in hainan province, china during field surveys in 2004, 2005, and 2007. in previously reported studies, we identified these four phytoplasmas as members of subgroup 16srii-a, and discovered that their 16s rrna gene sequences were 99.9-100% identical to one another. in this study, we performed extensive phylogenetic analyses to elucidate relationships am ... | 2014 | 23686459 |
| phylogenetic analysis of "candidatus phytoplasma australiense" reveals distinct populations in new zealand. | abstract the phytoplasma "candidatus phytoplasma australiense" has been reported from new zealand and australia, where it has been associated with a range of host plants, especially since the 1970s. partial tuf gene sequences of 36 new zealand (nz) isolates from four different host genera revealed nine different variants, which clustered into two distinct groups without any obvious correlation with host or geographic region. phylogenetic analysis of these sequences, together with those available ... | 2006 | 18943748 |
| "candidatus phytoplasma americanum", a phytoplasma associated with a potato purple top wilt disease complex. | potato purple top wilt (ppt) is a devastating disease that occurs in various regions of north america and mexico. at least three distinct phytoplasma strains belonging to three different phytoplasma groups (16sri, 16srii and 16srvi) have been associated with this disease. a new disease with symptoms similar to ppt was recently observed in texas and nebraska, usa. two distinct phytoplasma strain clusters were identified. one belongs to the 16sri phytoplasma group, subgroup a, and the other is a n ... | 2006 | 16825635 |
| comparative analysis of the plasmids from two isolates of "candidatus phytoplasma australiense". | two plasmids from the plant-pathogenic mollicute "candidatus phytoplasma australiense" were completely sequenced from two isolates derived from different plant hosts. plasmid ppaph2 (3607bp) was obtained from phormium showing phormium yellow leaf symptoms and ppasb11 (3635bp) from strawberry showing strawberry lethal yellows symptoms. the plasmids varied in their copy number and nucleotide sequence yet contained the same four open reading frames (orfs). the deduced amino acid sequence derived fr ... | 2006 | 16620976 |
| phylogenetic positions of phytoplasmas associated with dieback, yellow crinkle and mosaic diseases of papaya, and their proposed inclusion in 'candidatus phytoplasma australiense' and a new taxon, 'candidatus phytoplasma australasia'. | dna extracted from three papaya (carica papaya l.) plants, individually affected by dieback, yellow crinkle or mosaic diseases, was subjected to pcr using phytoplasma-specific primers to amplify the 16s rrna gene plus 16s-23s rrna intergenic spacer region. near-complete dna sequences obtained for the three pcr amplimers were subjected to phylogenetic analyses and direct sequence comparison with other phytoplasma 16s rdna and 16s-23s spacer region dna sequences. the papaya yellow crinkle (ppyc) a ... | 1998 | 9734050 |
| "candidatus phytoplasma australiense," a new phytoplasma taxon associated with australian grapevine yellows. | a phytoplasma was detected in naturally diseased 'chardonnay' grapevines exhibiting symptoms of australian grapevine yellows disease. the use of pcr designed to amplify phytoplasma dna resulted in detection of phytoplasma dna in all of the diseased plants examined; no phytoplasma dna was detected in healthy seedling grapevines. the collective restriction fragment length polymorphism (rflp) patterns of amplified 16s ribosomal dna differed from the patterns described previously for other phytoplam ... | 1997 | 9103609 |
| comparative genome analysis of "candidatus phytoplasma australiense" (subgroup tuf-australia i; rp-a) and "ca. phytoplasma asteris" strains oy-m and ay-wb. | the chromosome sequence of "candidatus phytoplasma australiense" (subgroup tuf-australia i; rp-a), associated with dieback in papaya, australian grapevine yellows in grapevine, and several other important plant diseases, was determined. the circular chromosome is represented by 879,324 nucleotides, a gc content of 27%, and 839 protein-coding genes. five hundred two of these protein-coding genes were functionally assigned, while 337 genes were hypothetical proteins with unknown function. potentia ... | 2008 | 18359806 |
| optimizing phytoplasma dna purification for genome analysis. | genome analysis of uncultivable plant pathogenic phytoplasmas is hindered by the difficulty in obtaining sufficient quantities of phytoplasma enriched dna. we investigated a combination of conventional enrichment techniques such as cesium chloride (cscl) buoyant gradient centrifugation, and new methods such as rolling circle amplification (rca), suppression subtractive hybridization (ssh), and mirror orientation selection (mos) to obtain dna with a high phytoplasma:host ratio as the major first ... | 2007 | 17496222 |
| extrachromosomal dna isolated from tomato big bud and candidatus phytoplasma australiense phytoplasma strains. | the nucleotide sequences of two extrachromosomal elements from tomato big bud (tbb) and one extrachromosomal element from candidatus phytoplasma australiense (ca. p. australiense) phytoplasmas were determined. both tbb plasmids (3319 and 4092 bp) contained an open reading frame ( approximately 570 bp) with homology to the rolling circle replication initiator protein (rep). this gene was shorter than the rep genes identified from other phytoplasma plasmids, geminiviruses and bacterial plasmids. b ... | 2006 | 16879868 |