马铃薯炭疽病菌的生物学特性及培养性状研究

Biological and culture characteristics of Colletotrichum coccodes

对马铃薯炭疽病菌(Colletotrichum coccodes)生物学特性及不同碳、氮源的利用能力等进行了研究。结果表明,马铃薯炭疽病菌菌丝在5～40℃均能生长,最适生长温度为30℃;分生孢子在25℃时萌发率显著高于其他温度,在液态水中萌发率显著高于其他相对湿度,pH6.7时萌发率显著高于其他pH条件(P<0.05);薯块浸提液中萌发率显著高于马铃薯根、茎、叶和土壤浸提液(P<0.05);分生孢子萌发对光不敏感,在有无光照条件下都能萌发,且差异不显著。除D-阿拉伯糖和氯醛糖外在其他碳源培养基上菌落直径显著高于对照(P<0.05);硝酸铵对该菌生长有显著促进作用(P<0.05),而碳酸铵、L-谷氨酸、尿素、大豆蛋白胨、L-组氨酸、L-精氨酸、亮氨酸、蛋白胨和甘氨酸有显著抑制作用(P<0.05);不同培养基对该菌生长影响不同,在PDA培养基上生长最快,在水琼脂培养基上生长最慢,且在不同培养基上菌落形态有差异。

The biological and culture characteristics of Colletotrichum coccodes were studied. The results showed that mycelium of C. coccodes could grow from 5 ℃ to 40 ℃, and the optimum temperature was 30 ℃. At 25 ℃, the conidial germination ratio was significantly higher than that at other temperatures. The liquid water was the most advantageous for the conidial germination （P〈0.05）. The germination ratio at pH6.7 was significantly higher than that at other pH values （P〈0.05）. In tuber extract, the germination ratio was significantly higher than that in extracts of roots, stems, leaves and soil. Conidial germination was not sensitive to light, with or with out light conditions were able to germinate, but not significantly. Carbon sources could significantly promote the growth of C. coccodes except D-arabinose and chloralose （P〈0.05）. Ammonium nitrate also significantly promo ted the growth of C. coccodes, but ammonium carbonate, L-glutamic acid, urea, soybean peptone, L-histidine, L-arginine, glycine, leucine and peptone significantly inhibited its growth （P^0.05）. The effects of different media on C. coccodes were different and the best growth medium was PDA, whereas the worst medium was water agar medium. C. coccodes on different media showed different colony characteristics.