Molecular characterization of phytoplasma associated with four important ornamental plant species in India and identification of natural potential spread sources

Abstract

Phytoplasma suspected symptoms of phyllody, witches' broom, leaf yellowing, stunting and little leaf were observed in and during survey of flower nurseries and experimental ornamental fields at Delhi, Maharashtra, Tamil Nadu and Karnataka from 2014 to 2016. Pleomorphic bodies typical to phytoplasma structures were observed in the phloem sieve elements of ultrathin sections of all the four symptomatic ornamental plants (stem tissue) in transmission electron microscope. Amplification of 1.8 and 1.2 kb phytoplasma DNA products was observed in all the four test plants in PCR assays using universal primer pairs P1/P7 followed by nested primer pair R16F2n/R16R2, respectively. Pairwise sequence comparison, phylogeny and virtual RFLP analysis of 16S rDNA sequences confirmed the association of two phytoplasma subgroups (16SrI-B and 16SrII-D) in four ornamental plant species. '' subgroup D (16SrII-D) was found associated with chrysanthemum phyllody and leaf yellowing at Delhi and Tamil Nadu, bougainvillea little leaf and yellowing at Delhi and Chinese aster phyllody at Bengaluru, Karnataka. However, jasmine little leaf and yellowing at Bengaluru, Karnataka and chrysanthemum stunting at Pune were found to be associated with '. ' subgroup B-related strains (16SrI-B). The identification of 16SrII-D subgroup phytoplasma infecting bougainvillea and 16SrI-B subgroup infecting jasmine are the new reports to the world. Besides weed species, showing witches' broom in jasmine fields at Bengaluru and showing witches' broom symptoms in chrysanthemum fields at Delhi were identified to be caused by phytoplasma strains classified under subgroups 16SrI-B and 16SrII-D, respectively, by PCR assays and 16Sr DNA sequence comparison analysis. Among the three major leafhopper species identified, only was identified positive for 16SrI-B and 16SrII-D subgroups of phytoplasmas from chrysanthemum fields at Delhi and jasmine fields at Bengaluru, respectively. The identity of similar phytoplasma strains infecting ornamental species in leafhopper and the weed species in the present study suggested that and weeds may act as potential natural sources for secondary spread of the identified phytoplasma strains.

Stolbur and Clover Proliferation Phytoplasma Infections in Tomato from Bingöl province, Turkey

“…TEM imaging, ELISA assays, and DNA based methodology such as (polymerase chain reaction, hybridization) are frequently used diagnostic methods (Kanatiwela- de Silva et al, 2019;Gopala and Rao, 2018). To date, especially the 16s rRNA gene highly conserved in prokaryotes was used to distinguish the phytoplasma group/subgroup as a conventionally marker gene in numerous research.…”

Genetic diversity of phytoplasma strains infecting chrysanthemum varieties in India and their possible natural reservoirs

“…The identification of 16SrVI group of phytoplasma strain in H. phycitis and in two chrysanthemum varieties, Jaya and Johan Webber, in same field suggest it as vector, which needs further confirmation through transmission assays. This leafhopper species has already been reported as vectors for 16SrI and 16SrII phytoplasma groups in India (Nabi et al 2015 ; Gopala and Rao 2018 ), which indicates its potentiality to transmit different phytoplasma strains. In India, many crops are being cultivated in parallel with other agricultural crops in different seasons.…”

First report of ‘Candidatus Phytoplasma australasia’‐related strains associated with disease of Jasminum multiflorum in India

“…P. oryzae’) and 16SrI (‘Ca. P. asteris’) groups have been reported previously affecting J. sambac in Oman and India (Al‐Zadjali et al , 2007; Madhupriya et al , 2015; Gopala & Rao, 2018). However, this is the first report of the association of ‘ Ca.…”