Studies On Diseases Species Of Major Medicinal Plants In Sichuan And Anthracnose (Colletotrichum Spp.) Of Ophiopogon Japonicus

This paper reported the investigation results on diseases species of major medicinal plants in Sichuan and anthracnose oi Ophiopogon japonicus. 1. The disease species of major medicinal plants in SichuanIn 2003~2004, we made a field survey of the major medicinal plants diseases in Sichuan province. The diseased samples were collected and isolated the pathogens to identify the species of pathogens. One hundred and thirty-six species of diseases were found in thirty-eight species of major medicinal plants in Sichuan. Among them twenty-sixspecies of diseases were new domestic records. According to the investigation results, a listof diseases in these medicinal plants was made.2. The investigation on anthracnose of Ophiopogon japonicusThe samples of anthracnose of Ophiopogon japonicus were collected from Santai, Mianyang and Ya'an. The fungi caused the disease were isolated from samples and identified for the species of colletotricum spp. .The results showing that the anthrocnose of Ophiopogon japonicus was caused by two species of colletotricum. They are Colletotrichum liliacearum (West.) Duke. and Colletotrichum gloeosporioides (Penz.) Penz. et Saccado. The biological characteristics of the two pathogens were investigated by agar plate and glass slide methods. The results indicated that there were some differences in biological characteristics (the effect of temperature, humidity, pH value, illumination and nutrition on mycelial growth, sporvilation and germination of conidia) between the two pathogens. The range and lethal temperature of mycelia and conidia were determined.The anthracnose pathogens of Ophiopogon japonicus could overwinter in diseased leaves of plants under field condition as a primary infection source.The five fungicides were tested in laboratory to determine the effect of these fungicides on mycelial growth and germination of conidia, and the EC50.. The results showed that five fungicides had inhibition on the mycelial growth and germination of conidia. Carbendazim was the best fungicide to inhibit the mycelial growth, but it was not good to inhibit the germination of conidia. Mancozeb was the worst fungicide of inhibiting the mycelial growth, while it was the best to inhibite the germination of conidia of C. liliacearum. Thiram & ziram & urbacide was better fungicide to inhibit the mycelial growth, while it was the best to inhibite the germination of conidia of C.gloeosporioides. Thiophanate-methyl and chlorothalonil (TPN) were good fungicides on the inhibition of mycelial growth and germination of conidia.