- Volume 65, Issue Pt_8, 2015

Strawberry red leaf phytoplasma was found in strawberry plants from production fields in Lules (Tucumán province) and Bella Vista (Corrientes province), Argentina. Characteristic strawberry red leaf symptoms were stunting, young leaves with yellowing at the edges, mature leaves which curled and were reddish at the abaxial face, flower and fruit deformation and death. The pathogen was detected with phytoplasma-universal primer pairs P1/P7 followed by R16F2n/R16R2 as nested primers in 13 diseased plants. Based on RFLP and sequence analysis of the amplified 16S rRNA gene, the phytoplasma was related to the 16SrXIII group (Mexican periwinkle virescence). In silico the RFLP profile of all the samples analysed revealed the presence of a unique pattern, showing that the novel phytoplasma is different from all the phytoplasmas currently composing the 16SrXIII group. The phylogenetic analysis was consistent with RFLP analysis as the strawberry red leaf phytoplasma was grouped within the 16SrXIII group, but formed a particular cluster. On this basis, the Strawberry red leaf phytoplasma associated with strawberry red leaf disease was assigned to a new subgroup, 16SrXIII-F.

Erigeron sp. plants showing symptoms of witches' broom and stunting were found near orchards of passion fruit in São Paulo state, Brazil. These symptoms were indicative of infection by phytoplasmas. Thus, the aim of this study was to detect and identify possible phytoplasmas associated with diseased plants. Total DNA was extracted from symptomatic and asymptomatic plants and used in nested PCR conducted with the primer pairs P1/Tint and R16F2n/16R2. Amplification of genomic fragments of 1.2 kb from the 16S rRNA gene confirmed the presence of phytoplasma in all symptomatic samples. The sequence identity scores between the 16S rRNA gene of the phytoplasma strain identified in the current study and those of previously reported ‘Candidatus Phytoplasma fraxini’-related strains ranged from 98 % to 99 % indicating the phytoplasma to be a strain affiliated with ‘Candidatus Phytoplasma fraxini’. The results from a phylogenetic analysis and virtual RFLP analysis of the 16S rRNA gene sequence with 17 restriction enzymes revealed that the phytoplasma strain belongs to the ash yellows phytoplasma group (16SrVII); the similarity coefficient of RFLP patterns further suggested that the phytoplasma represents a novel subgroup, designated 16SrVII-D. The representative of this new subgroup was named EboWB phytoplasma (Erigeron bonariensis Witches' Broom).

The aim of this study was to reclarify the taxonomic status of strain Bacillus invictae Bi.FFUP1 T by performing comparative analyses with the other four type strains within the Bacillus pumilus group. The digital DNA–DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strains B. invictae Bi.FFUP1 T ( = DSMZ 26896T = MCCC 1A07089T), B. altitudinis 41KF2bT ( = DSMZ 21631T = MCCC 1A06452T), B. safensis FO-36bT ( = DSMZ 19292T = MCCC 1A6451T), B. pumilus ATCC 7061T ( = DSMZ 27T = MCCC 1A06453T) and B. xiamenensis HYC-10T ( = MCCC 1A00008T) were, respectively, 82.90  % and 98.10  %, which are greater than the thresholds for bacterial species delineation, suggesting that they should belong to the same species, while the dDDH and ANI values between strain B. invictae DSMZ 26896T and the other three type strains within the B. pumilus group were below the respective thresholds of 70  % and 95  %. Meanwhile, B. invictae DSMZ 26896T and B. altitudinis 41KF2bT shared 98.7  % gyrB gene sequence similarity based on resequencing, whereas strain B. invictae DSMZ 26896T shared low similarities ( < 95  %) with the other three type strains. In addition, in comparison with those from the other three type strains, phenotypic data of B. invictae DSMZ 26896T and B. altitudinis 41KF2bT, including API 20NE, API ZYM, Biolog GN2 and API 50CHB tests, showed slight differences. The data from these combined genotypic and phenotypic analyses suggest that Bacillus invictae Branquinho et al. 2014 should be regarded as a later heterotypic synonym of Bacillus altitudinis Shivaji et al. 2006 .