Puccinia psidii infecting cultivated Eucalyptus and native myrtaceae in Uruguay

Abstract

Eucalyptus or guava rust caused by Puccinia psidii is a serious disease of Eucalyptus and other Myrtaceae. In Uruguay, it has been previously found on Eucalyptus globulus and Psidium brasiliensis. Almost nothing is known regarding the occurrence of this pathogen on other Eucalyptus species or native Myrtaceae in that country. In this study, we determined the presence of P. psidii on Eucalyptus species and native Myrtaceae trees in Uruguay and evaluated the pathogenicity of specimens from native myrtaceous hosts on E. globulus and E. grandis. Phylogenetic analyses based on the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA operon were used to confirm pathogen identity. Comparisons of ITS sequences confirmed the identity of P. psidii on Eucalyptus globulus, E. grandis, Myrcianthes pungens, and Myrrhinium atropurpureum var. octandrum. This is the first report of P. psidii on M. atropurpureum var. octandrum. Pathogenicity tests showed that isolates from native Myrtaceae could infect both Eucalyptus species tested, indicating a strong biological relationship between both introduced and native Myrtaceae. This study supplies relevant field data, morphological information, molecular phylogenetic analyses and infection studies that contribute to a better understanding of an important and little studied pathogen.

Unexpected genetic diversity revealed in the Eucalyptus canker pathogen Teratosphaeria gauchensis

“…From this study we can conclude that T. gauchensis in all likelihood has a mixed mode of reproduction and has asexual and sexual reproductive structures similar to the most closely related Mycosphaerella spp. (Cortinas et al 2010;(Cortinas et al 2004;Cortinas et al 2006a;Cortinas et al 2006b;Hunter et al 2008;Pérez et al 2010a;Pérez et al 2010b;Pérez et al 2010c)). …”

“…have been planted as exotics (Wingfield 2003;Glen et al 2007) Many of these examples are from South America including Uruguay (Pérez 2008). The most recent examples are Quambalaria eucalypti (Pérez et al 2008), Neofusicoccum eucalyptorum (Pérez et al 2009b), Puccinia psidii (Pérez et al 2010a) and members of Botryosphaeriaceae (Pérez et al 2010b). It would not be unusual for T. gauchensis to have behaved in a similar fashion.…”

Species richness, taxonomy and peculiarities of the neotropical rust fungi: are they more diverse in the Neotropics?

“…One may therefore hypothesize initially that rust fungi with a reportedly broad host range could comprise unresolved aggregates of species with narrower host ranges. On the other hand, there are examples that show that rusts originally described as separate species may in fact belong to a few plurivorous species like Puccinia lagenophorae, P. lantanae, P. xanthii, and P. psidii (Laundon 1963;Pérez et al 2010;Scholler et al 2011;Seier et al 2009). …”

Characterization of Eucalyptus maidenii Timber for Structural Application: Physical and Mechanical Properties at Two Moisture Conditions

“…This species occurs naturally in high-quality closed forests on sheltered slopes and gullies in good soils [1], among latitudes 34 and 39 S in altitudes from 230 to 915 meters, and its origin is along the Australian regions of southern New South Wales and northeastern Victoria [1,3]. Maiden's Gum species is also found in Brazil [4,5], Uruguay [6,7], New Zealand [8][9][10], India [11], Portugal [5], Italy, Iberian Peninsula, Kenya, Malawi, Burundi [1], Tanzania [12], Uganda [13], Rwanda [14], etc. Eucalyptus maidenii is a tall to very tall forest tree usually 30 to 45 meters in height with a diameter of up to 2.5 meters, whose bark is smooth, whitish or cream, decorticating in strips to ground level, or sometimes with a short stocking of undecorticated rough bark [15].…”