Eucalypt powdery mildew caused by Podosphaera pannosa in Brazil

Abstract

Eucalypt powdery mildew is an important disease in greenhouses and clonal hedges of Eucalyptus spp. in Brazil, which can cause leaf and shoot distortion, shoot discoloration, and growth reduction that results in production losses. Because reliable information regarding the causal agent of the disease is lacking, this study used ITS and 28S rDNA sequencing and morphological analyses to identify the powdery mildew pathogen that occurrs in eucalypt nurseries within different regions in Brazil. Based on the results of morphological characteristics and phylogenetic analyses, the pathogen isolates were identified as Podosphaera pannosa, also known as the rose powdery mildew pathogen. Cross inoculations with pathogen isolates from rose and eucalypt demonstrated that P. pannosa can infect both host species. The ITS sequence-based phylogeny showed that 42 sequences generated in this study were comprised within a single clade containing P. pannosa, which was supported by a posterior probability of 88%. Identical ITS sequences were obtained from all 42 pathogen isolates, which suggests a clonal population. Keywords Eucalyptus. Rosa. Bayesian analysis. Cross inoculation. Erysiphales. ITS rDNA. 28S rDNA * Acelino C.

Transcriptome analysis of a powdery mildew pathogen (Podosphaera pannosa) infecting Eucalyptus urophylla: De novo assembly, expression profiling and secretome prediction

“…Powdery mildews are diseases on the economically important eucalypt crop in South America, but little is known about the pathogen, which was only recently identified as P. pannosa (Fonseca et al, 2017). The transcriptome sequencing of P. pannosa produced more than 178 million reads, de novo assembled into ~200,000 transcripts.…”

“…), powdery mildew is a nursery disease causing leaf and shoot distortion, shoot discoloration and reduction in growth, which consequently reduces mini-cutting production (Alfenas, Zauza, Mafia, & Assis, 2009;Keane, Kile, Podger, & Brown, 2000). de Bary (1870) was the cause of powdery mildew on eucalypt in Brazil (Fonseca, Guimaraes, Pires, Klopfenstein, & Alfenas, 2017). (1902) or generically as Oidium sp.…”

“…Recently, studies based on ITS and 28S rDNA sequences concluded that Podosphaera pannosa (Wallr.:Fr.) de Bary (1870) was the cause of powdery mildew on eucalypt in Brazil (Fonseca, Guimaraes, Pires, Klopfenstein, & Alfenas, 2017). However, studies on the powdery mildew pathosystem are limited, and definitive information is needed to develop technologies for managing the disease.…”

Erysiphe alphitoides causes powdery mildew on Eucalyptus gunnii

“…Eucalyptus citriodora) from Korea (Cho, Park, Lee, Lee, & Shin, 2016) and P. pannosa on Eucalyptus spp. from Brazil ( Fonseca, Guimarães, Pires, Klopfenstein, & Alfenas, 2017).Our study provides detailed information on the first finding of E. alphitoides on a Eucalyptus tree worldwide and reports the host range expansion of E. alphitoides to the genus Eucalyptus for the first time.This information might be helpful for eucalyptus breeding, planting and gardening.…”

“…Eucalyptus citriodora ) from Korea (Cho, Park, Lee, Lee, & Shin, ) and P. pannosa on Eucalyptus spp. from Brazil (Fonseca, Guimarães, Pires, Klopfenstein, & Alfenas, ). Our study provides detailed information on the first finding of E .…”