稻瘟病菌粗毒素的制备及其对水稻毒性的测定

PO_9稻瘟病原菌的菌丝悬浮液和孢子悬浮液,经无菌滤取和高压灭菌制备成稻瘟病菌粗毒素。采用浸根处理、心叶注射、叶肉注射、穗苞注射和叶面喷布5种方法,测定所制备的2种粗毒素对水稻的毒性。结果表明,本试验制备的粗毒素对水稻的根、叶、穗的幼嫩组织有较强的毒性;粗毒素经高温高压后,毒性略有减低;不同材料制备的粗毒素对水稻的毒性以菌丝悬浮液的较强。文中还讨论了稻瘟病菌毒素的毒性、制备及应用等。

PREPARATION OF CRUDE EXTRACTS OF PYRICULARIA ORYZAE CAV. AND DETERMINATION OF THEIR TOXICITY ON RICE

Crude toxin extracts from mycelia or spore of Pyricularia oryzae Cav. were prepared by sterile filtration and damp-heat sterilization. To determine the toxicity of these extracts, they were used to soak rice seedlings, to spray leaf blades, or were injected into mesophyll tissues or into the sheaths of emerging tender leaves or panicle buds. The extracts obtained from two materials by two methods were all highly toxic to the tender tissues of rices plants (root, leaf and panicle bud). They could induce black root, seedling wilt, leaf necrosis or chlorosis and white ears. They also could be absorbed into the rice seedling through roots and induce rice seedling toxicosis. Application of the extracts on mechanically wounded rice leaves produced necrotic lesions closely resembling those of blast diseases caused by P. oryzae. The toxins extracted from spore suspensions could induce chlorotic lesions on the treated leaves or emerged blades, but could not permeate through the epidermal tissue. It was considered that the toxins bad been extracted from different materials by two methods having variant toxicity and it was expressed the highest toxicity extracted the toxin from mycelia suspension by sterile filtration. Some problems about the toxins had been discussed.