First report of Thielaviopsis paradoxa causing palm fruit rot of Butia capitata in Uruguay.
Butia capitata palms are endemic to southern Brazil and eastern Uruguay, but the original palm forests that covered extensive areas are disappearing due to lack of regeneration in areas used for cattle, rice or other agricultural purposes. The fruit is consumed fresh or processed by the local inhabitants to supplement their incomes. Research is being carried out in an effort to conserve this natural resource by increasing its commercial utility. In April 2011, ripe fruit was harvested near Castillos in southeastern Uruguay and stored at different temperatures. After 7 days at 20°C and 90% relative humidity, 24% had rotted with 80% rotten after 21 days. The fruit lost their yellow-orange colour, becoming brown, and then black and shrivelled due to loss of moisture. At high relative humidity they were covered by white mycelium that became black with age. Based on morphological characteristics, the pathogen was identified as Thielaviopsis paradoxa anamorph of Ceratocystis paradoxa, which was confirmed by sequencing the internal transcribed spacers (ITS1, 5.8S, ITS2) region of rDNA with ITS1/ITS4 primers, and pathogenicity test. This is thought to be the first report of C. paradoxa in Uruguay and the first identification of this pathogen causing disease on Butia sp. palms.