Relationship between Susceptibility to Anthracnose Disease and Antifungal Compounds Content in Fruit Latex of Thai Mango W. Kumpoun Postharvest Technology Innovation Center Science and Technology Research Institute Chiang Mai University Chiang Mai Thailand D. Boonyakiat Department of Horticulture Faculty of Agriculture Chiang Mai University Chiang Mai Thailand Keywords: anthracnose, postharvest disease, mango, latex, antifungal compound Abstract Mango has a different degree of susceptibility to Anthracnose disease. In the previous study, it was found that latex contained some antifungal compounds which had an effect to control Anthracnose disease caused by Colletotrichum gloeosporioides. Eight commercial mango cutivars, namely ‘Nam Dokmai #4’, ‘Rad’, ‘Kaew’, ‘Kaew Juk’, ‘Keaw Sawaey’, ‘Chok Anan’, ‘Keaw Moragot’ and ‘Mahajanaka’, were studied for susceptibility to Anthracnose disease. The relationship between susceptibility to Anthracnose disease and antifungal compounds content in fruit latex were investigated. Crude extract of latex was separated and tested. It was found that antifungal compounds presented only in water insoluble fraction. Most of the antifungal compounds were found in ‘Kaew’ which was the least susceptible to Anthracnose disease whereas ‘Nam Dokmai #4’ had the least antifungal compounds and it showed the most susceptible to Anthracnose disease. The cultivar showing greater susceptibility to Anthracnose disease had a lower antifungal compounds fraction content in the fruit latex. The amount of antifungal compound in the fruit latex in each mango cultivar varying from low to high level was ‘Nam Dokmai #4’, ‘Rad’, ‘Keaw Moragot’, ‘Mahajanaka’, ‘Kaew Juk’, ‘Keaw Sawaey’, ‘Chok Anan’ and ‘Kaew’, respectively. The result showed that antifungal compounds played an important role in controlling Anthracnose disease. INTRODUCTION Mango is one of the important fruit in Thailand. It is produced in large amounts in all parts of the country for local consumption and export. The major postharvest deterioration of mango fruit produced in Thailand is the infection of Anthracnose disease, which is caused by Colletotrichum gloeosporioides (Johnson et al., 1991). Usually, many kinds of fungicides were applied to fruits after harvesting in order to prevent this deterioration. Recently, the fungicides have become unacceptable by the consumer. The researches on natural antifungal compounds from plants, especially in fruit become hot issues. There are many reports revealing that peels of many kinds of unripe fruit contain antifungal compounds, such as avocado, citrus, pomelo, and mango (Prusky et al., 1983; Cojocaru et al., 1986; Ben-Yehoshua et al., 1992; Kumpoun et al., 1993, 1997). Kumpoun et al. (2005) reported that the latex of ‘Nam Dokmai See Thong’, Thai mango cultivars, contained an antifungal compound, which has a greater activity of antifungal compound than in the peel. There are more than 100 cultivars of mango in Thailand. Only about 20 cultivars are produced commercially. Each cultivar has a different degree of susceptibility to Anthracnose disease. In a previous study, it was found that latex contained some antifungal compounds which had an effect to control Anthracnose disease caused by C. gloeosporiodes. Antifungal compounds presented only in water insoluble fraction (Kumpoun et al., 2005). The amount of the water insoluble fraction was different among mango cultivars (Kumpoun and Boonyakait, 2007). The largest amount of water insoluble fraction was found at the mature green stage (98-105 -day) (Kumpoun et al., 2008). The 1501 Proc. 6 th International Postharvest Symposium Eds.: M. Erkan and U. Aksoy Acta Hort. 877, ISHS 2010