ABSTRACT
Cathranthus roseus also known as periwinkle, an ornamental plant contains several medicinal values, was found with the symptoms of little leaf and witches' broom at Shahjahanpur location with the incidence of up to 8%. The phytoplasma etiology was confirmed through scanning electron microscopy examination in all the four-leaf samples. Molecular analysis through PCR with universal primer pairs P1/P6 followed by nested PCR with R16F2n/R16r2 primers yielded ~1.2kbp amplicons in all the four symptomatic leaf samples. One amplicon was eluted, purified, sequenced, and used in BLASTn searches, which showed maximum identity of periwinkle isolate with several isolates of 16SrIX group of phytoplasma. Further, phylogenic analysis and in silico RFLP confirmed the association of 16SrIX-C subgroup phytoplasma in little leaf and witches broom plants which is the first report from India.
Subject(s)
Vinca , Phytoplasma DiseaseABSTRACT
Abstract Phytoplasmas (class Mollicutes) are causal agents of plant diseases with an economic impact on crops or threatening local biodiversity. A survey was conducted from 2012 to 2016 on infected Catharanthus roseus plants that exhibited symptoms reminiscent of phytoplasma infection throughout Costa Rica. A total of 73 plants were collected exhibiting symptoms such as virescence, phyllody, axillary proliferation, little leaf, leaf malformation, chlorosis, or yellowing. All samples were tested by nested PCR using phytoplasma universal and specific primer pairs. Phytoplasma infection was detected in 52 (71.2 %) of the plants collected. Phytoplasmas of six subgroups belonging to 16Sr groups I, III, IX, XIII and XV were identified based on sequencing and in silico RFLP analyses. 'Candidatus Phytoplasma asteris' (16SrI) was the predominant group among the positive samples (n = 30) showing variety of symptoms and wide distribution from sea level to ca. 1 400 m.a.s.l. in six of the seven Costa Rican provinces. Group 16SrIII was the second most abundant (14 samples); and the remaining three groups were seldom found in C. roseus (8 samples). Moreover, group 16SrXIII phytoplasma was detected for the first time in the country. To the best of our knowledge, this is the first report of natural infection of C. roseus with phytoplasma subgroups 16SrI-B, 16SrI-P, 16SrIII-F, 16SrIX-F, 16SrXIII-A, and 16SrXV-B in Costa Rica and Central America.
Resumen Los fitoplasmas (clase Mollicutes) son agentes causales de enfermedades de plantas que provocan pérdidas económicas o amenazan la biodiversidad local. Una recolecta de plantas de Catharanthus roseus que mostraban síntomas de posible infección con fitoplasmas se realizó en diferentes lugares de Costa Rica desde 2012 a 2016. Un total de 73 plantas fueron recolectadas con síntomas tales como viriscencia, filodia, brotación axilar múltiple, reducción foliar, deformación foliar, clorosis, y amarillamiento. Todas las muestras fueron evaluadas mediante PCR anidado usando los pares de imprimadores universales y específicos para fitoplasmas. Infección por fitoplasmas se detectó en 52 (71.2 %) de las muestras. Fitoplasmas de seis subgrupos dentro de los grupos 16Sr I, III, IX, XIII y XV fueron identificados basados en secuenciación del ADN y análisis de polimorfismos de restricción (RFLP) in silico. El grupo predominante encontrado en las muestras positivas (n = 30) fue el 16SrI ('CandidatusPhytoplasma asteris'), éste mostró variedad de síntomas y amplia distribución desde el nivel del mar hasta casi los 1 400 m.s.n.m. en seis de las siete provincias de Costa Rica. El grupo 16SrIII fue el segundo más abundante (14 muestras); y los restantes tres grupos se encontraron en pocas muestras de C. roseus (8 muestras). Además, fitoplasmas del grupo 16SrXIII se detectaron por primera vez en el país. De acuerdo a nuestro conocimiento, este es el primer informe de infección natural de C. roseus con fitoplasmas de los subgrupos 16SrI-B, 16SrI-P, 16SrIII-F, 16SrIX-F, 16SrXIII-A y 16SrXV-B en Costa Rica y Centroamérica.
Subject(s)
RNA, Ribosomal, 16S/analysis , Polymerase Chain Reaction/instrumentation , Vinca , Biodiversity , Infections/diagnosisABSTRACT
Catharanthus roseus is a perennial, evergreen herb in the family Apocynaceae, which is used as ornamental and for popular medicine to treat a wide assortment of human diseases. This paper describes a new potyvirus found causing mosaic symptom, foliar malformation and flower variegation in C. roseus. Of 28 test-plants inoculated mechanically with this potyvirus, only C. roseus and Nicotiana benthamiana developed systemic mosaic, whereas Chenopodium amaranticolor and C. quinoa exhibited chlorotic local lesions. The virus was transmitted by Aphis gossypii and Myzus nicotianae. When the nucleotide sequence of the CP gene (768nt) was compared with other members of the Potyviridae family, the highest identities varied from 67 to 76 %. For the 3' UTR (286nt), identities varied from 16.8 to 28.6 %. The name Catharanthus mosaic virus (CatMV) is proposed for this new potyvirus.
ABSTRACT
Catharanthus roseus is a perennial, evergreen herb in the family Apocynaceae, which is used as ornamental and for popular medicine to treat a wide assortment of human diseases. This paper describes a new potyvirus found causing mosaic symptom, foliar malformation and flower variegation in C. roseus. Of 28 test-plants inoculated mechanically with this potyvirus, only C. roseus and Nicotiana benthamiana developed systemic mosaic, whereas Chenopodium amaranticolor and C. quinoa exhibited chlorotic local lesions. The virus was transmitted by Aphis gossypii and Myzus nicotianae. When the nucleotide sequence of the CP gene (768nt) was compared with other members of the Potyviridae family, the highest identities varied from 67 to 76 %. For the 3' UTR (286nt), identities varied from 16.8 to 28.6 %. The name Catharanthus mosaic virus (CatMV) is proposed for this new potyvirus.