First report of a 16SrVI ‘Candidatus Phytoplasma trifolii’ isolate infecting Norfolk Island pine (Araucaria heterophylla) in India

Abstract

Mung bean is an important source of food for humans and animals in tropical and subtropical countries, and is also used for green manure. During spring 2008, mung bean plants in Faisalabad, Pakistan, showed severe symptoms of phyllody, virescence and a bushy appearance. Stem, leaf and stalk phloem sections from plants with and without symptoms were examined under a light microscope (CXRII, Labomed, CA, USA) using Dienes' stain. Regularly distributed dark blue areas were observed only in the phloem cells from plants with symptoms, and not in other plant tissues nor in the phloem of healthy plants, indicating the presence of a phytoplasma. Four week-old greenhouse-potted mung bean plants were grafted, and developed phyllody symptoms 25-30 days after grafting, similar to those observed in the field, whilst no symptoms developed in non-grafted control plants.To determine the 16Sr group of the phytoplasma associated with mung bean phyllody, total DNA was extracted from eight symptom-bearing plants, and amplified by nested PCR using universal 16S rDNA phytoplasma primers, P1 ⁄ P7 followed by R16F2n ⁄ R16R2. No symptomless plants were tested. All samples from plants with symptoms yielded a 1250bp PCR product, and identical RFLP profiles using the enzymes AluI and HpaII.

Molecular Identification of Phytoplasmas Infecting Diseased Pine Trees in the UNESCO-Protected Curonian Spit of Lithuania

“…Phytoplasma pruni-related strains have been found associated with diseases of gymnosperms in Europe [36]. In India, a phytoplasma of group 16SrVI was identified from Norfolk Island pine [37]. In North America, a new subgroup 16SrIX-E, Ca.…”

New natural host plants of ‘Candidatus Phytoplasma pini’ in Poland and the Czech Republic

“…The disease symptoms in Norfolk Island pine have been associated with ‘ Ca. Phytoplasma trifolii’ group 16SrVI infection (Gupta et al. , 2009), while symptoms in Western juniper have been associated with infection by the new phytoplasma subgroup 16SrIX‐E (‘ Ca.…”

Molecular characterization of phytoplasmas of ‘Clover proliferation’ group associated with three ornamental plant species in India

“…In India, 16SrVI group of phytoplasmas was earlier reported to be associated with several diseases of plants, viz. Araucaria little leaf (Gupta et al 2009), brinjal little leaf (Azadvar and Baranwal 2012), Withania little leaf (Zaim and Samad 1995; Samad et al 2006), Portulaca little leaf (Samad et al 2008), Datura little leaf (Raj et al 2009; Singh et al 2012), Croton leaf yellows (Madhupriya et al 2016), and Calotropis gigantea leaf yellows (Madhupriya et al 2010). However, 16SrVI-D subgroup of phytoplasma was only reported with brinjal little leaf (Azadvar and Baranwal 2012) and Catharanthus roseus little leaf (Bertaccini 2015).…”