Molecular identification of phytoplasma associated with tomato big bud disease in Guangdong province
In 2022,the suspected tomato big bud diseased plants were found in Lianjiang city,Zhanjiang city,Guangdong province.The related phytoplasma was detected and identified using molecular technology.The 16S rRNA gene fragment(1 430 bp,GenBank accession no.ON102780)of phytoplasma associated with tomato big bud disease in Guangdong province(TBB-GD-2022)was amplified from total DNA of diseased tomato plants using universal primers R16mF2/R16mR1.Sequence similarity based on 16S rRNA gene sequence showed that TBB-GD-2022 had higher similarity(96.82%-100%)with phytoplasmas from 16Sr Ⅱ group,while had highest similarity(100%)with six phytoplasmas belonged to 16SrⅡ-Ⅴ subgroup.Phylogenetic analysis showed that TBB-GD-2022 formed a large evolutionary branch with 16Sr Ⅱ group phytoplasmas,and a small evolutionary branch with 16Sr Ⅱ-Ⅴ subgroup phytoplasmas.iPhyClassifier analysis for 16S rRNA gene showed that the similarity coefficient between TBB-GD-2022 and'Praxelis clematidea'phyllody phytoplasma(GenBank accession no.KY568717)of the reference strain from 16SrⅡ-Ⅴ subgroup was 1.00.These results showed that phytoplasma associated with tomato big bud disease in Guangdong province belonged to the 16SrⅡ-Ⅴ subgroup.In this paper,tomato big bud disease was discovered firstly in Guangdong,and the taxonomic status of its related phytoplasma was further determined.The results provide the scientific basis for controlling tomato big bud disease in Guangdong province.
tomato big bud diseasephytoplasma16S rRNAmolecular identification