Archivio Journal of Plant Pathology

Abstract:

Justicia gendarussa Burm.f. (family Acanthaceae) is a shade-loving, quick-growing evergreen ornamental hedge plant mostly found in moist areas. It is believed to be native to China and is distributed widely across India, Sri Lanka and Malaysia. Witches’ broom and little leaf symptoms were observed on J. gendarussa plants in Shahjahanpur district, Uttar Pradesh, India in 2013-14 with 2% incidence. Three symptomatic and one symptomless plants were analyzed by nested PCR with using primer pairs P1/P6 (Deng and Hiruki, 1991) and R16F2n/R2 (Gundersen and Lee, 1996), which yielded products ca.1.2 kbp in size only in nested PCR assays from symptomatic samples. All three amplicons were directly sequenced from both directions and one sequence was submitted to the GenBank (accession No. KT365865). In pairwise sequence comparison, 100% sequence identity was observed with members of the ‘Candidatus Phytoplasma cynodontis’ taxon (16SrXIV group) reported from various parts of the world, which was confirmed upon analysis of a phylogenetic tree constructed by neighbor-joining method. The iPhyClassifier virtual RFLP analysis (Zhao et al., 2009) using 17 restriction enzymes revealed that the J. gendarussa phytoplasma produced RFLP profiles identical to those of the reference strain of ’Ca. P. cynodontis’ (KM220612) classified in the 16Sr XIV-A subgroup. To the best of our knowledge, J. gendarussa is a new host of a phytoplasma belonging to the 16Sr XIV-A subgroup in India.