ANTHRACNOSE OF PITAYA (HYLOCEREUS SPP.) CAUSED BY COLLETOTRICHUM SPP., A NEW POSTHARVEST DISEASE IN TAIWAN
Pitaya (Hylocereus undatus, H. polyrhizus, and H. costaricensis) has been widely planted as a fruit crop in Taiwan in the past three decades. Field survey in pitaya orchards during 2009 to 2013 showed that anthracnose of pitaya caused by Colletotrichum spp. was one of the major postharvest diseases in Taiwan. Disease symptoms encompassed brown colored sunken spots with or without water-soaked necrosis on the harvested fruits skin after storing at room temperature for 5–10 d, which apparently shortening the marketable period and reducing the price of the harvested fruits. Based on morphological characteristics and ITS region sequences, at least three species of Colletotrichum isolated from diseased fruits of pitaya collected from orchards in Taiwan were identified, including C. truncatum and 2 species within each respective C. gloeosporioides and C. boninense species complex, with isolation frequencies of 21.8, 73.4, and 4.8%, respectively, during 2009 to 2013. However, to precisely discriminate the Collectotrichum species within each respective C. gloeosporioides and C. boninense species complex, further multi-locus phylogenetic analyses are mandatory in the future. This is the first report of anthracnose caused by Colletotrichum spp. as an important postharvest disease of pitaya in Taiwan.
Chu-Ping Lin, Pao-Jen Ann, Hung-Chang Huang, Jay-Ting Chang, Jyh-Nong Tsai
Taiwan Agriculture Research Institution