【摘要】 利用改进的MS液体培养基,通过改变碳、氮源组合,分别在振荡培养小麦全蚀病菌7,14,21 d时(26℃,150 r/min),用3,5-二硝基水杨酸(DNS)比色法测定培养滤液中的β-1,3-葡聚糖酶活性。结果表明,培养基中分别以小麦茎秆、叶片,玉米茎秆、叶片和根系为碳源与不同氮源组合,培养滤液中β-1,3-葡聚糖酶活性有明显差异,其中以小麦叶片为碳源时酶活性最高,以玉米根系为碳源时酶活性较低,但两者之间酶活性无明显差异。培养基中加入有机氮时酶活性均明显高于加入无机氮,但两种有机氮培养基中的酶活性变化趋势完全不同。以牛肉膏为氮源时,在小麦全蚀病菌培养7 d时培养滤液中的酶活性最高,且酶活性随病菌培养时间的延长而逐渐下降;以蛋白胨为氮源时酶活性则呈上升趋势,在病菌培养21 d时最高。以上结果表明,供试各组合中以牛肉膏为氮源、小麦叶片为碳源的组合为最佳组合,7 d时有相对较高的酶活性。更多还原

【Abstract】 The pathogenic fungi Gaeumannomyces graminis var.tritici(Ggt) was cultured in modified MS medium(26 ℃,150 r/min) with different combinations of carbon and nitrogen sources.The enzyme activity in the culture filtrate was detected by 3,5-dinitrosalicylic acid(DNS) in 7,14,21 d after culturing the fungus.The results showed the enzyme activities were obviously different in the culture filtrate with wheat stalks,wheat leaves,maize stalks,maize leaves and maize roots as carbon source combined with different nitrogen sources.The highest enzyme activities were detected in the culture filtrate with wheat leaves as the carbon source and the lowest enzyme activities were in the culture filtrate with maize roots as the carbon source.The enzyme activities were not significantly different in the culture filtrate with wheat tissues as compared with that with maize tissues.Comparing 4 nitrogen sources,the enzyme activities were obviously higher in the culture filtrate with organic nitrogen than that with inorganic nitrogen.The highest enzyme activities were detected in the culture filtrate with beef extract as nitrogen source 7 d after culturing the fungus.The enzyme activities detected in the culture filtrate with peptone were low and reached the peak 21 d after culturing the fungus.The enzyme activities in the culture filtrate with beef extract decreased gradually during the culture stage.The best carbon and nitrogen combination in the medium for enzyme activities was beef exact and wheat leave detected 7 d after culturing the fungus.更多还原