Host range ofErwinia psidiiand genetic resistance ofEucalyptusandCorymbiaspecies to this pathogen

Abstract

Dieback caused by Erwinia psidii is currently one of the most important emerging diseases in eucalypt plantations in Brazil. However, little is known in terms of the host range of this pathogen or the potential sources of resistance against the disease it causes. In this study, we inoculated plants of species from nine families to gain insight into the host range of E. psidii. Plants of all inoculated species of Myrtaceae except Acca sellowiana exhibited disease symptoms and therefore represent potential hosts for the pathogen under natural conditions. In addition, the response of four Corymbia species, 29 Eucalyptus species and three interspecific Eucalyptus hybrids to inoculation with E. psidii was evaluated. All Corymbia henryi, Corymbia maculata, Eucalyptus thozetiana, Eucalyptus cloeziana, Eucalyptus viminalis, Eucalyptus dalrympleana and Eucalyptus pilularis plants were highly resistant to the pathogen, whereas differential disease resistance was observed in the other species. This study provides important information on sources of resistance to Erwinia psidii with potential use in the development of clones with enhanced resistance in eucalypt species of economic importance.

Improved evaluation of the genetic variability of Brazilian strains of Erwinia psidii with newly developed microsatellite markers

“…This information could be pivotal for improvement of the effectiveness of plant genetic resistance selected in breeding programmes. Although sources of resistance to E. psidii have recently been identified in some eucalypt species (Caires et al, 2019), screening of germplasm must continue in order to identify resistance effective against both guava and eucalypt strains. The methods used in our study could also contribute to investigations of the impact of the E. psidii haplotypic variation on disease epidemiology and the development of strategies for efficient deployment of plant resistance.…”

“…Although sources of resistance to E . psidii have recently been identified in some eucalypt species (Caires et al, 2019), screening of germplasm must continue in order to identify resistance effective against both guava and eucalypt strains. The methods used in our study could also contribute to investigations of the impact of the E .…”

“…psidii was detected in Malaysia affecting papaya (Chai et al, 2017). Currently, the measures adopted in Brazil to control the disease in guava and eucalypt are cultural practices and genetic resistance (Caires et al, 2019).…”

Phylloplane as a potential Erwinia psidii inoculum reservoir

“…From a practical standpoint, pitanga and guava plants near eucalyptus forests may serve as potential sources of bacterial inoculum for epidemic outbreaks of bacterial blight. In addition to E. psidii existing in the resident (epiphytic) phase, it can also be in the pathogenic phase, causing symptoms in these fruit trees (Rodrigues-Neto et al 1987; Caires et al 2019). This is critical because, without the eradication of these fruit trees, E. psidii can persist inde nitely in both epiphytic and pathogenic phases, causing the inoculum to increase in eucalyptus forests.…”

Stakeholders' views on the global guidelines for the sustainable use of non‐native trees

“…Several NNTs are also charismatic and aesthetically pleasing in their new habitats (Dickie et al, 2014;Jarić et al, 2020). Moreover, many NNTs used in forest plantations have faster growth rates, broader climate tolerance and better resistance to pathogens and pests than native species (Seidl et al, 2018), and some have been hybridized and artificially selected to improve these attributes (Caires et al, 2019;Rubilar et al, 2020). For these reasons, NNTs are widely introduced and planted and contribute significantly to the world economy (Bastin et al, 2019;Brockerhoff et al, 2008;Martin et al, 2021).…”