CSIRO PUBLISHING www.publish.csiro.au/journals/apdn Australasian Plant Disease Notes, 2009, 4,70–71

First report of anthracnose of Acacia in Australia

H. Golzar

Department of Agriculture and Food Western Australia, Bentley Delivery Centre, WA 6983, Australia. Email: [email protected]

Abstract. In May 2009, anthracnose symptoms were observed on Acacia seedlings, in the south-west of Western Australia. Based on morphological characteristics of the isolated , disease symptoms and pathogenicity tests, acutatum J.H. Simmonds was identified as the causal agent of anthracnose of Acacia. This is the first report of Anthracnose (C. acutatum)onAcacia both in Australia and worldwide.

The genus Colletotrichum contains a large number of plant causes the disease commonly pathogenic species which cause significant economic damage. known as anthracnose on a wide range of plants, including It has a wide range of hosts in tropical, subtropical, and temperate , , small and perennial crops. The regions (Bailey and Jeger 1992). Colletotrichum gloeosporioides disease can occur on leaves, stems and fruits of plants. (teleomorph Glomerella cingulata) and C. acutatum are the most (Dyko and Mordue 1979; Peres et al. 2005; Sergeeva et al. 2008). common species causing anthracnose on a wide range of plant Acacia species are woody perennial belong to the family species (Mordue 1971; Dyko and Mordue 1979). In Florida, Mimosaceae commonly known as wattle in Australia. Acacia C. gloeosporioides has caused anthracnose of Acacia (Barnard microbotrya, A. acuminata and A. saligna species are of interest and Schroeder 1984); however, there is no record of C. acutatum for commercial utilisation in agroforestry plantings in Western on Acacia internationally. Australia (Byrne and Broadhurst 2003). The anthracnose symptoms were observed on the Acacia seedlings in the south-west of Western Australia which experiences a Mediterranean climate. Typical symptoms

Fig. 1. Anthracnose symptoms on severely infected leaves and young stem Fig. 2. Orange conidial masses of C. acutatum produced on infected leaf of Acacia acuminata caused by C. acutatum. Bar = 1 cm. tissues of Acacia acuminata. Bar = 1 cm.

Australasian Plant Pathology Society 2009 10.1071/DN09030 1833-928X/09/010070 Anthracnose of Acacia in Australia Australasian Plant Disease Notes 71

(a)(b)

Fig. 3. C. acutatum, Conidia (a); conidia with germ tubes and appressoria (b). Bars = 10 mm. appeared as brown sunken circular to irregular lesions, Acknowledgements progressing to larger necrotic areas. The fungus produced The author would like to thank Ms Paula Mather for her technical assistance, erumpent, mucilaginous, orange masses under high Dr Sarah Collins for reviewing of the manuscript and Matthew Rumenos for humidity conditions (Figs 1 and 2). providing Acacia samples. Pieces of infected stems and leaves were surface-sterilised by immersion in a 1.25% aqueous solution of sodium hypochlorite for 1 min, rinsed in sterile water and dried in a References laminar flow cabinet. Specimens were selected randomly and Bailey JA, Jeger MJ (1992) Colletotrichum: Biology, Pathology and Control. either: (a) placed on potato dextrose agar (PDA), incubated at CAB International. Wallingford, UK. 22 Æ 3C, and after 5 days emerged fungal colonies were sub- Barnard EL, Schroeder RA (1984) Anthracnose of Acacia in Florida: cultured on PDA and pure cultures obtained using the ‘single occurrence and fungicidal control. Proceeding of the Florida State – spore method’; or (b) placed in trays on the moist filter paper Horticultural Society 97, 244 247. and incubated at 25C with a 12 : 12 h light : dark cycle. Byrne M, Broadhurst L (2003) Genetic diversity and the utilisation of Acacia species complexes in agroforestry in Western Australia. Colletotrichum sp. was consistently isolated from the diseased Australian Systematic Botany 16,49–55. doi: 10.1071/SB01037 specimens. Growth rate, colony morphology and morphological Dyko BJ, Mordue JEM (1979) Colletotrichum acutatum. CMI characteristics of the isolated fungus were determined and (Commonwealth Mycological Institute) Description of Pathogenic C. acutatum was identified as the causal agent of the Fungi and Bacteria. No. 630. anthracnose symptoms (Fig. 3). Lubbe CM, Denman S, Lamprecht SC, Crous PW (2006) Pathogenicity of Pathogenicity of the fungus isolates was tested on Acacia Colletotrichum species to Protea cultivars. Australasian Plant Pathology acuminata cv. acuminata seedlings in a glasshouse experiment. 35,37–41. doi: 10.1071/AP05097 Seedlings were inoculated (leaves and stems) by either wounding Mordue JEM (1971) Glomerella cingulata. CMI (Commonwealth or non-wounding. Controls were inoculated using sterilised Mycological Institute) Description of Pathogenic Fungi and Bacteria. water (Lubbe et al. 2006). Plants were placed under mist for No. 315. Peres NA, Timmer LW, Adaskaveg JE, Correll JC (2005) Lifestyles of 48 h and then moved to the growth room chamber at – Æ  Colletotrichum acutatum. Plant Disease 89, 784 796. doi: 10.1094/ 22 1 C. Disease symptoms were observed 6 days post- PD-89-0784 ’ fi inoculation. Koch s postulates were ful lled by reisolation of Sergeeva V, Nair NG, Spooner–Hart R (2008) Evidence of early flower the C. acutatum. A culture of C. acutatum has been deposited infection in olives (Olea europaea) by Colletotrichum acutatum and in the WA culture collection as WAC 13265. C. gloeosporioides causing anthracnose disease. Australasian Plant To our knowledge, this is the first report of anthracnose of Disease Notes 3,81–82. Acacia caused by C. acutatum in Australia. Acacia is a new host for C. acutatum and it has not previously been reported worldwide. Manuscript received 23 June 2009, accepted 30 June 2009

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