First Record of Phytoplasma Associated with Yellowing and Decline Symptoms of Pomegranate Trees

Abstract

Pomegranate (Punica granatum L.) is an economically important fruit crop cultivated widely in tropical and subtropical regions due to its nutritional and medicinal value. During recent field surveys, severe yellowing, leaf chlorosis, stunted growth, branch dieback, and gradual decline symptoms were observed in pomegranate orchards, indicating the possible association of a phytoplasma infection. The present study was undertaken to identify and characterize the phytoplasma associated with yellowing and decline symptoms in pomegranate trees. Symptomatic and asymptomatic leaf samples were collected from affected orchards and subjected to molecular diagnosis using polymerase chain reaction (PCR) assays targeting the 16S rRNA gene of phytoplasmas. Amplified PCR products were sequenced and analyzed through BLAST and phylogenetic approaches to determine the taxonomic relationship of the detected pathogen. The results confirmed the presence of phytoplasma infection exclusively in symptomatic plants, while healthy samples tested negative. Sequence analysis revealed high similarity with members of the ‘Candidatus Phytoplasma’ group, confirming the association of phytoplasma with the observed disease symptoms. Phylogenetic analysis further demonstrated a close relationship between the detected isolate and previously reported phytoplasma strains infecting economically important horticultural crops. This investigation represents the first report of phytoplasma associated with yellowing and decline disease of pomegranate trees in the studied region. The findings provide valuable insights into the etiology of the disease and highlight the potential threat posed by phytoplasma infections to pomegranate cultivation. Early detection and continuous surveillance are therefore essential for effective disease management and for minimizing economic losses in pomegranate production systems.