Persistence of ‘Candidatus Phytoplasma asteris’ in marigold plants showing virescence in Eastern Uttar Pradesh, India

Marigold is an economically important ornamental crop widely cultivated across India. The present study reports the molecular detection and identification of phytoplasmas associated with virescence symptoms, including flower green structures and abnormal development in marigold from Gorakhpur, Uttar Pradesh, India. With PCR and nested PCR assays the presence of phytoplasmas in symptomatic samples was confirmed. The obtained 1.25 kb amplicon was sequenced and showed 98.87% identity with ‘Candidatus Phytoplasma asteris’ reference strain. RFLP analysis further confirmed that the strain belongs to the 16SrI-B subgroup. Although this subgroup has previously been reported from marigold in the same region in plants showing flat stem, little leaf and witches’ broom symptoms, the present study confirms its occurrence also in the presence of virescence symptoms. This indicates the persistence and epidemiological stability in marigold of ‘Ca. P. asteris’ strains in eastern Uttar Pradesh region. The study also underscores the potential role of ornamental plants as reservoirs for phytoplasmas, contributing to disease persistence and spread in agro-ecosystems and emphasizing the need for continuous monitoring and integrated management strategies.