CSIRO PUBLISHING www.publish.csiro.au/journals/app Australasian Plant Pathology, 2005, 34, 619–620 DISEASE NOTES OR NEW RECORDS First report of spring black stem and leaf spot in fenugreek (Trigonella foenum-graecum) caused by Phoma pinodella in Australia T. W. Bretag A,C and J. H. Cunnington B A Primary Industries Research Victoria, Department of Primary Industries, Private Bag 260, Horsham, Vic. 3401, Australia. B Primary Industries Research Victoria, Department of Primary Industries, Knoxfield, Private Bag 15, Ferntree Gully Delivery Centre, Vic. 3156, Australia. C Corresponding author. Email: trevor.bretag@dpi.vic.gov.au Abstract. A high incidence of black stem and leaf spot in a fenugreek (Trigonella foenum-graecum) crop was observed at Rupanyup in the Wimmera region of Victoria in 2004. Phoma pinodella was consistently isolated from diseased plants and shown to be the causal agent by Koch’s postulates. This is the first record of P. pinodella in fenugreek in Australia. Fenugreek (Trigonella foenum-graecum) is a minor legume field crop in Victoria, grown to produce seed for the spice market and also as a green manure crop. There appears to be considerable potential for expansion of the industry, especially following the recent selection of better genotypes with increased grain yield and higher biomass production (McCormick 2004). In September 2004, an unidentified disease occurred in isolated patches within a crop of fenugreek (accession 150118), which was undergoing seed multiplication at Rupanyup in the Wimmera region of Victoria. The disease seriously retarded plant growth and was estimated to have affected approximately 10% of the plants within the crop. Most infected plants were stunted with mild chlorosis and had elongated black lesions on the taproot. When the disease was severe, the lesions completely girdled and sometimes severed the taproot. On the leaves, petioles and stems, there were numerous small (3–4 mm long), irregularly shaped dark brown to black leaf lesions, sometimes with a small chlorotic area surrounding the lesion. Where the disease was severe, many leaves turned completely yellow and withered before falling to the ground. To determine the causal organism, 40 plants (20 diseased and 20 apparently healthy) were removed from the affected crop on 30 September 2004 (approximately 12 weeks after emergence), when they were 15–20 cm tall and had developed four to five leaves. Individual plants were removed by digging to a depth of 20 cm, then washed to remove soil from the roots. To isolate directly from fenugreek plants, infected segments (approximately 1 cm long) of the stem and taproot were removed from each plant, split longitudinally, then surface sterilised (1 min in 0.5% NaOCl) and plated onto V8 agar. The same isolation procedure was used for infected leaf segments (approximately 1 cm 2 area). Apparently healthy segments were also taken from plants with no disease symptoms. Plates were incubated at room temperature (20 ± 2.5 ◦ C) for seven to ten days under continuous illumination provided by a Phillips TLD 36W/33 ‘white light’. Fungi growing from stem and leaf pieces were transferred to fresh plates of V8 agar and grown at room temperature under continuous illumination (as above), then identified. The fungus most frequently isolated from diseased plants was Phoma pinodella (syn. P. medicaginis var. pinodella). Morphological characters agreed well with those given by Boerema et al. (2004): ‘Pycnidia more or less globose, glabrous, 150–200 μm diam., with a single ostiole. Conidia hyaline, ovoid to ellipsoid, usually aseptate (approx. 6 × 2.5 μm), occasionally 1-septate (approx. 9 × 3 μm). Chlamydospores brown, globose to ellipsoidal, single or in short (1–4) chains, intercalary or terminal’. Dendritic crystals were formed on malt extract agar after seven days in the dark at 21 ◦ C. Three isolates have been lodged in the VPRI (Victorian Department of Primary Industries) herbarium under accessions 32171, 32172 and 32176. The rDNA ITS regions of two of these isolates were sequenced, along with a P. pinodella isolate from Pisum sativum (VPRI 32177). All three sequences were identical, and have been lodged in GenBank under accessions DQ087400–DQ087402. Blast searching of GenBank revealed the sequences to be most © Australasian Plant Pathology Society 2005 10.1071/AP05072 0815-3191/05/040619