Diverse phytoplasmas associated with maize bushy stunt disease in Peru

Abstract

Corn plants showing symptoms of midribs chlorosis, and leaf reddening, short internodes, ear proliferation, and plant growth reduction were collected in Peru from fields in nine localities in the provinces of Huancayo, Chupaca, and Jauja in the Junín region, and tested to verify phytoplasma presence and identity. Primers amplifying the phytoplasma ribosomal 16S and ribosomal protein genes were used. The phytoplasma presence was detected in symptomatic samples from all the surveyed areas. The sequencing of the obtained amplicons indicated the presence of ‘Candidatus Phytoplasma asteris’ and ‘Ca. P. pruni’-related strains. A BLASTn search of sequenced genes showed that the two ‘Candidatus Phytoplasma’ strains identified in corn shares 100% and 99.82% identity with the ‘Ca. P. asteris’ strains from maize and 99.92% and 99.55% with ‘Ca. P. pruni’-related strains, respectively. The RFLP analyses allowed to enclose these phytoplasma strains in the 16SrI-B and 16SrIII-J subgroups; however, the two phytoplasmas were, in some cases, present in mixed infection. The 16SrIII-J phytoplasma is for the first time reported associated with the maize bushy stunt disease and this represent a relevant information for the disease epidemiology towards its appropriate management in the affected area.

Detection and molecular identification of a 16SrI group phytoplasma associated with sisal purple leafroll disease

“…According to the previous report, the phytoplasma causing these symptoms belongs to seven 16SrRNA groups and 21 subgroups, including 16SrI (-A, -B, -C, -E, -F, -M), 16SrII (-A, -C, -D), 16SrIII (-B, -J, -F), 16SrXII (-A, -B, -E, -I), 16SrVII (-B), 16SrV (-A, -C, -D), 16SrX (-A) (Rao et al 2018). The 16SrI-B are common in aster (Seemüller et al 1994), apple (Jomantiene & Davis 2005), tomato (Holguín-Peña et al 2007), potato (Girsova et al 2008), grapevine (Babaei et al 2019), rice (Jonson et al 2020), and maize (Gamarra et al 2022); among these, the symptoms of purple margins, leafroll, and yellowing have been observed in tomato (Holguín-Peña et al 2007), potato (Girsova et al 2008), grapevine (Babaei et al 2019), and maize (Gamarra et al 2022). In this study, a phytoplasma 16SrI-B was verified to be present in sisal, and it was associated with SPLD in different provinces in Southern China from 2018-2021.…”

“…The symptoms of SPLD, including purple margins and yellowing and rolling of the leaves, are simi-lar to several other plant diseases caused by viruses (Trenado et al 2011;Li et al 2012;Chen et al 2018;Byarugaba et al 2020), phytoplasmas (Holguín-Peña et al 2007;Sabaté et al 2014;Babaei et al 2019;Gamarra et al 2022), or nutrient deficiency (Yoneda et al 1997;Ariraman et al 2020). In 1964, a disease called "purple leaf tip roll" with similar symptoms to SPLD was reported in sisal in Tanzania; it was suggested to be caused by manganese deficiency (Muller 1964).…”

Development of a Specific Nested PCR Assay for the Detection of 16SrI Group Phytoplasmas Associated with Sisal Purple Leafroll Disease in Sisal Plants and Mealybugs

“…From symptom analysis, it was found that SPLD had similar symptoms to some other plant diseases caused by viruses [ 6 , 7 , 8 ], phytoplasma [ 9 , 10 , 11 ], or nutrient deficiency [ 12 , 13 , 14 ]. Over the past several years, our attempts to study the aetiology of SPLD focusing on viruses and nutrient deficiency have yielded only minor results.…”