Abstract
Imported carambolas in Shanghai market frequently suffer from brown rot disease, causing severe loss of commercial values. To clarify the causal pathogens, market disease surveys were conducted and the possible fungal pathogens were isolated from infected carambolas imported from Taiwan district, USA and Thailand. A new disease symptom has been found on USA carambolas, that is dark brown decay spot between peduncle and pedicel, with white molds attached and brown areas formed on the edge of the fruits. The isolated pathogen was named EXYL-1 and further identified via morphological and molecular characteristics. The aerial mycelium of EXYL-1 appeared white, produced some reddish to purple pigment and adhered to microconidium. Optimal temperature for the hyphal growth was 20-25°C. Together with the nucleotide sequences of ribosomal DNA internal transcribed spacer regions and specific gene sequences, this pathogen EXYL-1 has been identified as Fusarium proliferatum.
