First report of Uredo crepidis-japonicae and Septoria crepidis on Crepis japonica in Brazil

Primeito relato de Uredo crepidis-japonicae e Septoria crepidis em Crepis japonica no Brasil

NOTAS FITOPATOLÓGICAS / PHYTOPATHOLOGICAL NOTES

FIRST REPORT OF Uredo crepidis-japonicae AND Septoria crepidis ON Crepis japonica IN BRAZIL

OLINTO L. PEREIRA¹, JOSÉ R. P. CAVALLAZZI¹ & ROBERT W. BARRETO²

¹Departamento de Microbiologia, Universidade Federal de Viçosa, 36571-000, Viçosa, MG; ²Departamento de Fitopatologia, Universidade Federal de Viçosa, 36571-000, Viçosa, MG, e-mail: [e-mail]

(Accepted for publication on 29/01/2002)

Corresponding author: Robert W. Barreto

RESUMO

Primeito relato de Uredo crepidis-japonicae e Septoria crepidis em Crepis japonica no Brasil

Dois fungos fitopatogênicos foram encontrados atacando Crepis japonica em Viçosa, MG. Os fungos foram identificados como Uredo crepidis-japonicae e Septoria crepidis. Este é o primeiro relato desses fitopatógenos em C. japonica no Brasil.

Crepis japonica Benth is a herbaceous plant native from China and Japan which was recently introduced into Brazil, where it is disseminating rapidly and already has become an important weed in nurseries (Plantas Daninhas do Brasil, 3^a ed., pg.146, 2000). In July 2000 a leaf rust was observed on C. japonica growing in a citrus (Citrus sp.) nursery situated in Viçosa, Minas Gerais State, Brazil. The fungus was identified as Uredo crepidis-japonicae Lindroth which has been reported only from Australia, Continental China, Formosa (Taiwan) and Japan (Rept. Tottori Mycol. Inst., n.08, pg.1, 1980). Irregularly oval shaped leaf lesions were dark-brown due to the presence of a powdery mass of uredospores (Figure 1A). Severely infected leaves were clorotic. Morphological features for this fungus were: uredia, 0.3 to 0.5 mm diam; uredospores spherical, 14 to 20 mm diam, pale brown, with 3 to 4 germ pores, and walls 1mm thick. U. crepidis-japonicae is the uredial stage of Puccinia crepidisjaponicae Dietel, but no teliospores were found in the material examined (VIC 22136). However, size and shape of uredospore alone suffices for distinguishing this species from other rust fungi on Crepis spp. (Table 1).

In January 2001 another foliar disease on young and old leaves was also observed on C. japonica, at a different site in Viçosa. The inciting agent was identified as Septoria crepidis Vestrerg. (Syll. Fung., XIV, pg. 974, 1899) known from USA, Europe and Asia. Lesions were necrotic, irregular, pale-brown, 1 to 8mm diam. The fungus had immersed, globose pycnidial conidiomata (Figure 1B), 60 to 70 mm diam, pale-brown, ostiolate, conidiophores were absent; conidia were hyaline, filiform, multiseptate, 25 to 35 mm x 1.0 to 1.5 mm (VIC 22137).

These are the first reports of occurrence of these fungi in Brazil. Both fungi were probably introduced into Brazil together with their host and may be playing a significant role as biocontrol agents for this potentially damaging weed.

Publication Dates

• Publication in this collection
  20 Aug 2002
• Date of issue
  June 2002