First report of Xanthomonas citri Subsp. Citri causing citrus canker on grape fruit (Citrus paradisi), washington naval (Citrus sinensis), kaghzi limon (Citrus aurantifolia Swingle), lemon (Citrus lim

Abstract

Citrus fruit production is largely affected by different bacterial and fungal pathogens. In Pakistan bacterial diseases like citrus bacterial canker (CBC) pose severe risk to citrus economy. Diagnoses of such diseases could be helpful to avoid the epidemics in nurseries or orchids. In 2011-12, citrus canker symptoms i.e., callus-like outgrowths on leaves and fruits of grape fruit (Citrus paradisi), Washington naval (Citrus sinensis), Kaghzi Limon (Citrus aurantifolia swingle), lemon (Citrus Limon) and pomelo (Citrus maxima) were noticed in Sargodha district of Punjab, Pakistan. Bacteria i.e., yellow mucoid, Xanthomonas- like isolates, were isolated from these lesions. Bacteria isolated from these lesions were cultured and total DNA was isolated. A diagnostic fragment of 581 bp based on rpf genes of Xanthomonas citri pv. citri was amplified, cloned and completely sequenced. BLAST and evolutionary analysis revealed that these isolates show 100% sequence similarity and group with Xanthomonas citri subsp. citri from Argentina (CP023285) and Reunion (CP018858), (CP018854). To our knowledge, this is the first formal report of X. campestris pv. citri pathotypes A on Citrus paradise, Citrus sinensis, Citrus maxima, Citrus Limon and Citrus aurantifolia swingle in Pakistan