Black Mold on Tomato Fruits Caused by Alternaria alternata in Korea

Wan-Gyu Kim1,,2,*   Jae-Taek Ryu2   Hyo-Won Choi3   

1Global Agro-Consulting Corporation, Hwaseong 18330, Korea
2Bunong Seed Corporation, Suwon 16372, Korea
3Crop Protection Division, National Institute of Agricultural Sciences, Wanju 55365, Korea

Abstract

Black mold was frequently observed on tomatoes grown in a greenhouse in Suwon, Korea in July 2018. The incidence of the disease was 5.0-25.0% (average 12.3%) and 2.0-7.0% (average 3.7%) in the context of tomato and cherry tomato fruits, respectively. Sixteen single-spore isolates of Alternaria sp. were obtained from the diseased fruits and investigated for their morphological characteristics. Among the isolates, eight were used for sequencing analysis. All of the isolates were identified as Alternaria alternata based on their morphological and molecular characteristics. The pathogenicity of four isolates of A. alternata was investigated using three varieties each of tomato and cherry tomato via artificial inoculation. All of the isolates induced black mold symptoms on the inoculated tomato fruits. Notably, the symptoms were similar to those observed in the greenhouse. However, the pathogenicity tests revealed that different tomato varieties presented distinct patterns of susceptibility to the isolates. This is the first report of A. alternata causing black mold on tomato fruits in Korea.

Figures & Tables

Fig. 1.Symptoms of black mold on fruits of tomatoes observed in the greenhouse. A and B, symptoms produced on tomato fruits; C and D, symptoms produced on cherry tomato fruits.