Identification and Distribution of Two Fungal Species Causing Sclerotial Disease on Mulberry Fruits in Korea

Abstract

A total of 520 overwintered sclerotia were collected from surface of soil under mulberry trees in six locations in Korea during February in 2006 and 2007. The collected sclerotia were tested for their germination in vitro and identified based on their morphological characteristics. Out of all sclerotia tested, 52.3% of the sclerotia germinated and produced two types of apothecia. The two types of fungi occurred from the sclerotia at the ratio of 49.8 vs. 50.2. The fungal type with cup-shaped apothecia was identified as Ciboria shiraiana and another type of fungus with club-shaped apothecia as Scleromitrula shiraiana. Taxonomy and distribution of the two sclerotial fungi were described and discussed.

Mulberry popcorn disease occurrence in Korea region and development of integrative control method

“…The disease in other countries has been known as popcorn disease, swollen fruit disease. (Sultana et al, 2013;Hong et al, 2007a, Kishi, 1998Kohn and Nagasawa, 1984;Whetzel and Wolf, 1945). Mulberry farms have been collectivized over recent years, mulberry popcorn disease, which damages mulberry production most severely, has increasingly occurred every year to cause considerable damages to farmers.…”

“…Mulberry farms have been collectivized over recent years, mulberry popcorn disease, which damages mulberry production most severely, has increasingly occurred every year to cause considerable damages to farmers. In Korea, Ciboria shiraiana and Scleromitrula shiraiana, have been reported to be pathogens for mulberry popcorn disease (Sultana et al, 2013;Cho and Shin, 2004;Hong et al, 2007a). Swollen fruit disease of mulberry tree in Asia including China and Japan was reported as C. shiraiana (Ling, 1948;Kishi, 1998) and S.…”

“…shiraiana was first identified from sclerotia of mulberry fruits in Korea (Hong et al, 2007a). In the spring, when mulberries are flowering, the sclerotia produce cup-like apothecia from which spores are released into the air to infect developing fruit.…”

Breeding of mulberry variety "Shimgang" showing resistance to popcorn disease

“…Infected fallen fruits turn into mummified black sclerotia, a compact mass of hardened fungal mycelia, that can remain dormant for at least two years in the soil. Overwintered sclerotia germinated in the soil and induced apothecia to form encased ascospores within the ascus (Hong et al, 2007a;Hu et al, 2011). is a serious disease for the production of mulberry fruits, if the tree is being cropped for commercial purposes; however, it does no harm to the overall health of the trees Table 5 shows the occurrence of sclerotial disease known on mulberry fruits during local adaptability test at four local places.…”

“…The disease is known to be caused by sclerotial fungal pathogens such as Ciboria shiraiana (Hong et al, 2007b;Liang, 2009), Scleromitrula shiraiana (Kishi, 1998), and Ciboria carunculoides (Hong et al, 2007a;Hu et al, 2011;Siegler & Jenkins, 1923;Sultana et al, 2013). In particular, C. variety was 2.1%, which was 66.7% decreased compared to control variety 'Shimheung' 6.3%.…”