Ferrugem do eucalipto

Abstract

<abstract language="eng">On surroundings of a branch of the C.N.E.P.A. situated at Km 47 of the Rio-S. Paulo road (Rio de Janeiro) it was reported a rust attacking young plants of Eucalyptus citriodora Hk. in seed-plot and in transplanting boxes. Teliospores not observed in that occasion, showed up later and were found to belong to Puccinia psidii Winter. This species was hitherto unknown to this host. The Uredo sp. found by Gonçalves in the State of Espírito Santo, in 1932, on Eucalyptus sp. was considered the first known Uredinales attacking the plant afore mentioned. Later, the same fungus was found on Eucalyptus in two districts in the state Pernambuco. After examining several herbarium material and consulted with the diagnoses of thirteen Puccinia species recorded upon Myrtacex, twelve from them were found to be morphologicaly identical to the rust on Eucalyptus. Specimen of Eucalyptus rust was sent to prof. G. C. Cummins, Purdue University, and he identified it as P. psidii Wint. His classification was confirmed also by Dr. F. Kern, of Pennsylvania State College, U.S.A. P. psidii is commonly found in several regions of Brazil upon Myrtacex. As a parasite of Eucalyptus it appears on leaves, petioles, and new stem tissues; the rust injuries seedlings making them improper for planting. The rust was not found on other species of cultivated eucalypti in the same site and climate conditions in which E. citriodora was found

A new race of Puccinia psidii defeats rust resistance in eucalypt

“…However, two clones (BA6021 and G21) were found to be resistant to isolate UFV-2, but susceptible to isolate EUBA-1 (Table 1). This result further confirms the existence of physiologic difference within P. psidii populations (Aparecido et al 2003;Castro et al 1983;Coelho et al 2001;Coutinho and Figueiredo 1984;Ferreira 1981;Joffily 1944;Maclachlan 1938). Three P. psidii races have been previously reported in Brazil (Xavier 2002); however, the isolate EUBA-1 represents a fourth pathogen race in Brazil, based on our results.…”

“…Several cross-inoculation studies using Myrtaceae species have indicated the physiologic differences among P. psidii populations (Maclachlan 1938;Joffily 1944;Ferreira 1981;Castro et al 1983;Coutinho and Figueiredo 1984;Coelho et al 2001;Aparecido et al 2003),. Considering that P. psidii is a biotrophic pathogen that is capable of infecting different Myrtaceae species across a wide geographic range, it appears reasonable that hostspecific virulence genes could have been selected within the pathogen populations.…”

The Myrtle rust pathogen, Puccinia psidii, discovered in Africa

“…It was first described from native guava ( Psidium guajava ) in Brazil in 1884 and gained notoriety when it was found to infect various other members of the Myrtaceae , an unusual feature for most rust fungi (Coutinho et al 1998, Glen et al 2007, Carnegie et al 2010a, Morin et al 2012). Puccinia psidii became particularly prominent in the literature when it was found causing disease on non-native Eucalyptus species in Brazil (Jollify 1944) and it was rapidly considered as a significant threat to the commercial production of Eucalyptus species globally (Coutinho et al 1998). It was also feared to threaten the survival of native Myrtales in countries such as Australia where this order represents a mega-diverse group of plants (Glen et al 2007, Morin et al 2012).…”

Puccinia psidii infecting cultivated Eucalyptus and native myrtaceae in Uruguay

“…Psidium pomiferum L.) in Brazil (Winter 1884) and was discovered on non-native eucalypts (Corymbia citriodora (Hook) Hill & Johnson syn: Eucalyptus citriodora Hook), in the same country in 1944 (Joffily 1944). This was the first record of the rust having undergone a host jump from a native to a non-native tree (De Castro et al 1983).…”