作物根际和叶围中产几丁质酶微生物的分布及其抑制真菌作用

从几十种作物的根际和叶围分离获得３５０株微生物，其中细菌和放线菌分别为２００株和１５０株。对所有这些分离物进行了抑制真菌试验和几丁质酶活性测定。在抑菌试验中，以棉花枯萎病菌、棉花黄萎病菌、黄瓜枯萎病菌，及西瓜枯萎病菌作为供试病原菌，有９６个分离物对其中的一种或一种以上的病原菌有抑制作用，其中１８个分离物对这４种病原菌都具有强烈的抑制作用。在几丁质酶活性方面，１０％的细菌和４０％的放线菌都能不同程度地产生几丁质酶。有些菌株几丁质酶活性强，抑菌作用也明显，有些菌株几丁质酶活性弱，抑菌作用弱或无作用，少数菌株几丁质酶活性强，但却无抑菌作用。用几丁质酶液处理病原菌孢子，其萌发率和芽管长度比对照显著降低

STUDIES ON THE CHITINASE PRODUCING MICROORGANISMS AT CROP RHIZOPSPHERE AND PHYLLOSPHERE AND THEIR ANTIFUNGAL ACTIVITIES

Three hundred and fifty isolates of bacteria and actinomyces were obtained from the rhizosphere and phyllosphere of various crops.Of them,96 showed inhibiting a ctivity to the growth of several crop pathogenic fungi in the laboratory bass.Th e percent of the isolated bacteria and 40% of the actinomyces produced chitinase on chitin plate.The chitinase activity appeared to be related to certain degree to the antifungal ability of the isolates.Treatment of spores of the pathogens with a solution of the chitinase produced by some isolates resulted in reduction s of the spore germination rate and length of the germ tubes.