阳春砂仁(Amomum villosum Lour.)叶枯病病原及寄主范围研究

砂仁是我国著名南药之一。砂仁叶枯病是一种新近描述的导致植株枯萎和大量减产的严重病害。症状有叶枯型、斑枯型、星斑型和叶鞘病斑四种。据病原菌形态、培养性状、致病性和奇主范围,鉴定为围小丛壳菌(Glomerella cingulata(Stonem.)Spauld.et Schrenk),分生孢子阶段为盘长孢状刺盘孢(Colletotrichum gloeosporioides(Penz.)Sacc.)。病菌在马铃薯葡萄糖琼脂(PDA)培养基上生长较好,而燕麦(OMA)和葡萄糖酵母膏(DYEA)培养基上较有利于产孢。连续日光灯和试验室散光处理促进孢子形成,而紫外灯照射则抑制孢子产生。分生孢子可以串生方式产生。在供试的23科39种植物中,有9科15种植物发病。该菌田间存活期长达16个月以上。

A STUDY ON THE PATHOGEN AND HOST RANGE OF LEAF BLIGHT IN AMOMUM VILLOSUM

Amomum villosum is one of the famous medical plants in South China.The fungal leaf blight in A.villosum is a newly described serious disease which causes the plants drooping and reduces the production severely.There were four types of symptoms observed in this study:leaf blight,spot,star-mottling and sheath blight,and the first one was the most common symptom.The symptoms developed very rapidly and could extend downward/inward in the leaves 3 to 10mm daily when the conditions were suitable. The pathogen was identified as Glomerella cingulata(Stonem.)Spauld.et Schrenk according to its morphology,cultural properties and host range,and conidium stage as Colletotrichum gloeosporioides(Penz.)Sacc.. The best medium for the growth of the fungus was PDA and the best medium for its sporulation was OMA.Continuous fluorescent light and natural light in laboratory treat- ments favoured its sporulation,and ultraviolet light inhibited sporulation. Among 39 plant species of 23 families inoculated,15 species distributed in 9 families were infected by the fungus.Survival of the pathogen was 16 months more in the field.