First report of Trichothecium ... - Springer

CSIRO PUBLISHING 

www.publish.csiro.au/journals/apdn Australasian Plant Disease Notes, 2008, 3, 103--104 

First report of Trichothecium roseum causing postharvest fruit rot 

of tomato in Argentina 

G. Dal Bello 

Centro de Investigaciones de Fitopatología, Facultad de Ciencias Agrarias y Forestales, UNLP, 

Comisión de Investigaciones Científicas de la Provincia de Buenos Aires, 60 y 119, La Plata 1900, 

Buenos Aires, Argentina. Email: dalbello@speedy.com.ar 

Abstract. Postharvest fruit rot caused by Trichothecium roseum on tomato fruit is recorded for the first time in Argentina. 

The fungus was consistently isolated from diseased fruits and shown to be the causal agent according to Koch’s Postulates. 

Although the economic impact of the disease is minimal, T. roseum is known as a producer of mycotoxins. Therefore, its 

presence on vegetables and fruits decreases the quality of those food products and causes a risk to the consumers. 

The presence of microorganisms is one of the most important 

factors in the depreciation in quality of fresh fruits. Commercial 

value of fruit decreases due to different pathogens, especially 

(a) (b) 

(c) (d ) 

fungi, which manifest their destructive action during storage 

(Puia et al. 2003). Furthermore, contamination of foodstuffs 

with moulds such as Trichothecium spp. causes a real risk to 

Fig. 1. Symptoms of pink rot on tomato fruit artificially inoculated with Trichothecium roseum (a, b, c). 

Controls remained healthy (d). 

Ó Australasian Plant Pathology Society 2008 10.1071/DN08041 1833-928X/08/010103

104 Australasian Plant Disease Notes G. Dal Bello 

the health of consumers because these fungi are producers of 

mycotoxins (Lugauskas et al. 2005). In particular, tomatoes are 

susceptible to numerous fruit decays, from the field through 

postharvest handling. 

During the summer of 2008, postharvest fruit rot was found on 

fresh-market tomatoes (Lycopersicon esculentum Mill.) at 

storage facilities in La Plata city (34 55 0 S; 57 57 0 W). 

Symptoms started as circular, water-soaked lesions, which 

enlarged and coalesced into a soft rot covered with white to 

pinkish powdery mycelium (Fig. 1). The fruit became watery and 

emitted a sour smell. The pathogen was readily isolated by 

transferring conidia from diseased tissue onto potato dextrose 

agar (PDA) amended with 250 mg/L of chloramphenicol. Isolates 

were incubated with a 12/12 h light/dark cycle using cool white 

fluorescent and near ultraviolet light, at a temperature of 20 2 C 

for 7 days. After 4--5 days, the fungus produced abundant septate 

mycelia, white at first, then pale rosy pink as the conidia 

developed; conidiophores long, slender, simple and septate 

with conidia which were borne apically and singly, attached in 

groups or chains; conidia hyaline or brightly coloured, 2-celled, 

ovoid, 12--22 5--10 mm (Fig. 2), appearing in basipetal 

succession from the tip of the conidiophore. Based on the 

morphological structures after single-conidium cultures were 

established on PDA, the causal agent was identified as 

Trichothecium roseum (Pers.) Link (Howard et al. 1994). 

Pathogenicity was tested by inoculating surface-sterilised 

healthy, ripe tomato fruits with a 20 mL drop of aqueous 

conidial suspension (10 5 conidia/mL) which was injected to a 

depth of ~1 mm. Fruits inoculated in the same way using sterilised 

water were kept as a control. Inoculated fruit were placed in a 

sterilised plastic container at room temperature (21--25 C). Spots 

similar to those observed on naturally infected fruits developed on 

inoculated tomatoes within 5 days; whereas control fruits 

remained healthy (Fig. 1c). Trichothecium roseum was 

successfully reisolated from the lesions, fulfilling Koch’s 

Postulates. 

The fungus has been cited causing fruit rot on many crops 

including tomato (Welch et al. 1975; Farr et al. 2007). To our 

knowledge, this is the first report of T. roseum causing pink mould 

rot on tomato in Argentina. 

References 

http://www.publish.csiro.au/journals/apdn 

Fig. 2. Conidia of Trichothecium roseum isolated from fruit lesions 

(bar = 20 mm). 

Farr DF, Rossman AY, Palm ME, McCray EB (2007) Fungal databases, 

systematic botany and mycology laboratory, ARS, USDA. Available at 

http://nt.ars-grin.gov/fungaldatabases/ [Verified 10 July 2008] 

Howard RJ, Garland JA, Seaman WL (Eds) (1994) ‘Diseases and pests of 

vegetablecrops in Canada.’ (The Canadian Phytopathological Society and 

The Entomological Society of Canada) 

Lugauskas A, Raudonienè V, Šveistytè L (2005) Toxin producing 

micromycetes on imported products of plant origin. Annals of 

Agricultural and Environmental Medicine 12, 109--118. 

Puia CE, Popovici EJ, Viorel F (2003) The evolution of the fitosanitary status 

of the stored apples in natural conditions. Journal of Central European 

Agriculture 4(4), http://www.agr.hr/jcea/issues/jcea4-4/pdf/jcea44-6.pdf 

[Verified 10 July 2008] 

Welch AW Jr, Jenkins SF Jr, Averre CW (1975) Trichothecium fruit rot on 

greenhouse tomatoes in North Carolina. Plant Disease Reporter 59, 

255--257. 

Manuscript received 20 April 2008, accepted 8 July 2008

First report of Trichothecium ... - Springer

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