松针褐斑病菌毒素的确定及其基本性质研究

以ＭＳ液体培养基培养２０ｄ左右至菌丝大量生长并紧密交织成团时病菌即可大量产生毒素，病菌是否产孢对产毒量大小无显著影响。毒素原液中仅非蛋白质部分具致病活性，经高温高压灭菌１５ｍｉｎ后活性仍不丧失，且有所加强。该毒素在冷冻条件或灭菌后于室温下可保存两个月以上而不失活。毒素粗提液中活性成分为一类极性较大的物质，易溶于水、甲醇、乙醇，可溶于正丁醇，微溶于乙酸乙酯，不溶于苯，可被活性炭吸附并为甲醇所洗脱。毒素粗提液的ｐＨ值为６０，渗透势为－１２２ｋＰａ，经试验确定毒素粗提液的毒性非溶液的酸度或渗透势所致，从而进一步确定了病菌人工培养滤液中存在具致病活性的毒素物质。

Studies on the Determination and the Basic Properties about the Pathogenic Toxin of Brown Spot Needle Blight Fungus(Lecanosticta acicola)

Brown spot needle blight is one of the important pine diseases in south China.MS liquid medium was selected as the most suitable medium producing brown spot needle blight fungus toxin(LA toxin)by comparing with several other culture media.The fungus could produce a large amount of the toxin when it was cultured in MS liquid medium for 20 days.It is not evidently affected on the toxin production amount if the culturing fungus has produced the spores.The nonprotein part in the original toxin liquid possesses the pathogenic activity.The toxin could keep its activity for more than two months after being disinfected under high temperature and pressure for 15 minutes or keeped in refrigerator.The activity part of the toxin extraction liquid is a kind of the substance with a big heteropolarity.It could be melted,easily in water,methyl alcohol and ethanol,generally in nbutanol,less in acetic ester,and not in benzol.It could be absorpted by activated charcoal and then bewashed out.The pH value and the osmotic pressure of the toxin extraction liquid are pH 6.0 and -122 kPa.So the toxinity of the extract liquid isnt induced by itself pH value and osmotic pressure.It is determinated that there are the pathogenic toxin substances in the extract liquid.