‘Candidatus Phytoplasma australasia’ association with phyllody and purpling diseases of carrot in India

Carrot plants showing suspected phytoplasma symptoms of witches’ broom and purpling at IARI fields, New Delhi and Kushmi Jungle, Gorakhpur, Uttar Pradesh were subjected to nested PCR assay on 16S rRNA and secA genes with specific primer pairs. Amplification of 1.25 kb and 480 bp was achieved from all the symptomatic samples collected from Gorakhpur and New Delhi using 16S rRNA and secA gene primers, respectively. Hshimonus phycitis from Gorakhpur and Empoasca motti from New Delhi and Cannabis sativa and Parthenium hysterophorus in and around carrot fields at Delhi and Kushmi Jungle, Gorakhpur were also detected positive for phytoplasma presence by employing both set of primers. The 16S rRNA and secA gene sequences and virtual RFLP comparison analyses confirmed the presence of ‘Candidatus Phytoplasma australasia’ (16SrII-D) in carrot, leafhoppers and weed samples. This is the first report of the presence of this phytoplasma associated with witches’ broom and purpling disease of carrot in Northern India.