First Report of Anthracnose Caused by Colletotrichum gloeosporioides on Gueroba in Brazil.

Gueroba (Syagrus oleracea (Mart.) Becc.), a member of the family Arecaceae, is an important native palm tree in central Brazil and has great potential as a cultivated crop and ornamental plant (1). In July 1999, anthracnose symptoms were observed on several gueroba plants growing in a field in Planaltina, Federal District. Leaves showed spots or small circular to irregular, brown-to-black necrotic lesions, which generally coalesced as symptoms progressed. Tissue sections from leaves with symptoms were plated aseptically on potato dextrose agar (PDA). A fungus was consistently isolated from leaves of symptomatic plants and was identified as Colletotrichum gloeosporioides (Penzig) Penzig & Sacc. by P. F. Cannon of CABI Bioscience, Egham, UK, where a culture (IMI 384186) has been deposited. An isolate was tested for pathogenicity by inoculating 20 plants at the two-leaf stage by placing a mycelial PDA plug from a 10-day-old fungal culture on a previously wounded leaf. Noninoculated plants served as controls. Plants were enclosed in a plastic bag and incubated for 4 days at 26 ± 2°C and ≈100% relative humidity. Ten days after inoculation, plants developed leaf lesions similar to those observed in the field. Symptoms did not develop on the control plants. C. gloeosporioides was reisolated from 95% of the inoculated leaves, completing Koch's postulates. The pathogenicity test was repeated with the same results. To our knowledge, this is the first report of C. gloeosporioides causing anthracnose on gueroba in Brazil. Reference: (1) H. Lorenzi. Page 288 in: Árvores Brasileiras. Plantarum. Nova Odessa, Brazil 1998.

First Report of Anthracnose of Cagaita Caused by Colletotrichum gloeosporioides in Brazil.

Cagaita (Eugenia dysenterica Mart. Ex DC.), family Myrtaceae, is an important wild perennial fruit crop in Central Brazil (1). Anthracnose symptoms were observed on cagaita leaves in a field in Brasília, Federal District (S 15° 36' 16″ W 47° 42' 42″), in August 2000. A fungus was consistently isolated from infected leaves and grown on potato dextrose agar (PDA) and its identification was made by P. F. Cannon of CABI Bioscience as Colletotrichum gloeosporioides (Penzig) Penzig & Sacc. (IMI 384184). Pathogenicity tests were performed on 16 cagaita seedlings by placing mycelial PDA plugs on leaves previously wounded with a sterile needle. Control plants were inoculated with plugs without mycelia. After inoculations, the plants were placed in a dew chamber maintained at 25°C for 72 h and later transferred to the greenhouse. Necrotic leaf spots developed on 100% of the inoculated plants 4 days later. Koch's postulates were fulfilled by consistently reisolating C. gloeosporioides from inoculated plants. Control plants remained symptomless. Inoculations were repeated twice with the same results. To the authors' knowledge, this is the first report of anthracnose caused by C. gloeosporioides of cagaita in Brazil. Reference: (1) S. P. Almeida et al. 1998. Pages 182-186 in: Cerrado: espécies vegetais úteis. Embrapa Cerrados.