Characterization of Species ofCladobotryumwhich Cause Cobweb Disease in Edible Mushrooms Grown in Korea

Abstract

Four Cladobotryum isolates were collected from four different commercially grown mushroom types infected with cobweb disease in Cheongdo-gun and Chilgok-gun of Gyeongbuk Province, Korea in 2010. The isolates were identified as C. mycophilum from Agaricus bisporus and Pleurotus eryngii, C. varium from Flammulina velutipes and Hypsizygus marmoreus. The cultural characteristics of the four isolates were investigated using potato dextrose agar (PDA) media under nine different temperatures ranging from 5~32℃. Rapid growth of the isolates to colony diameters of 47~82 mm was observed at conditions of 18~22℃. No growth was observed at 32℃. C. mycophilum produced a yellowish red pigment while C. varium produced a cream colored pigment after cultivation for 25 days on PDA. Phylogenetic analysis of the internal transcribed spacer region and partial 28S rDNA from the four isolates confirmed they were C. mycophilum and C. varium. Cross pathogenicity tests revealed that the two isolates of C. mycophilum were highly pathogenic toward three mushroom types, but not toward H. marmoreus. The two isolates of C. varium were less pathogenic than those of C. mycophilum, but were pathogenic toward all mushroom types evaluated.

Cobweb, a serious pathology in mushroom crops: A review

“…As soon as a primary cobweb outbreak is located over the casing or carpophores, it must be treated before sporulation, covering the infected area with thick damp paper to avoid the release of conidia and disease dispersion (Pyck & Grogan, 2015). (Back et al, 2012;Kim et al, 2014;Chakwiya et al, 2015;Carrasco et al, 2016a;Zuo et al, 2016). However, several other species have been reported as causing this pathology in commercial mushroom crops.…”

“…does not secrete aurofusarin. The species has been described as a causal agent of cobweb disease in Korean edible mushroom crops (F. velutipes, H. marmoreus, P. eryngii) (Back et al, 2012;Kim et al, 2012). C. varium was also reported as pathogenic to A. bisporus in cross pathogenicity tests (Back et al, 2012).…”

“…C. asterophorum has also recently been identified on beech mushrooms in Korea. This species was pathogenic against H. marmoreus, F. velutipes and P. eryngii (Back et al, 2012).…”

“…has been reported as infecting different species of cultivated edible mushroom, among them: Agaricus bisporus (Gea et al, 2012;Carrasco et al, 2016a), Agaricus bitorquis (Potočnik et al, 2008), Agaricus blazei (Geösel, 2011), Auricularia mesenterica (Eicker et al, 1990), Coprinus comatus (Wang et al, 2015), Flammulina velutipes (Kim et al, 1999), Ganoderma tsugae (Kirschner et al, 2007), Ganoderma lucidum (Zuo et al, 2016), Hypsizygus marmoreus (Back et al, 2012), Pleurotus eryngii (Gea et al, 2011, Pleurotus ostreatus and Pleurotus pulmonarius (Mignucci et al, 2000).…”

“…Among them cobweb is considered one of the most serious diseases for white button mushroom [Agaricus bisporus (Lange) Imbach] cultures, the most widely cultivated species (Royse, 2014). Other edible cultivated mushrooms may also develop the harmful pathology (Gea et al, 2011Back et al, 2012;Kim et al, 2012). Its occurrence in commercial crops results in reductions in yield and quality, mainly due to cap spotting, a lesser surface area that can be used for cultivation and to the need for early crop termination when the disease becomes epidemic (Adie, 2000;Adie et al, 2006).…”