黄瓜枯萎病病株残茬对黄瓜的化感效应

Allelopathy of diseased survival on cucumber Fusarium wilt

采用生长速率法、孢子萌发法、胚根生长抑制法、电导率法等方法，研究不同发病程度的黄瓜残茬腐解物对黄瓜枯萎病菌菌丝生长和孢子萌发、黄瓜种子萌发、胚根生长、根部细胞膜通透性、苗期生长性状以及苗期枯萎病的影响。结果表明，黄瓜枯萎病发病越重，其残茬腐解物对黄瓜枯萎病菌孢子的促进作用越强，高浓度健株、轻病株和重病株残茬的产孢量分别比对照增加了27．29％、50．05％和44．88％；健株残茬可使黄瓜枯萎病病菌孢子萌发率提高15．91％～38．94％；不同浓度黄瓜残茬腐解液可影响黄瓜胚根生长，并减少须根6．15％～27．10％；重病株不同浓度残茬腐解液可使黄瓜幼苗细胞膜透性增加76．03％～89．96％；高浓度重病株残茬腐解物可使黄瓜出苗率降低53．15％，同时枯萎病病株率增加55．11％。

We studied on the effect of decaying substances on Fusarium oxysporum mycelia growth, spore emergence, seed emergence, radicle growth, characters of seedling and Fusarium wilt, through method of plate growth test, spore germination test, radicle growth inhibition test, conductivity method and pot experiment. The results showed that the much higher cucumber wilt disease incidented, the more significantly the diseased survival inhibited growth of the next decaying stubble. Compared with CK, quantity of spores of healthy plants, mild diseased plants and severe diseased plants increased 27.29% , 50.05% and 44.88%, respectively. Spore emergence ratio increased 15.91% -38.94% under treatments of healthy plants＇ decaying substances. Cucumber decaying substances of different concentrations influenced radicle growth, and fibres decreased 6. 15% -27.10%. Cell membrane permeability increased 76.03% -89.96% under treatments of decaying substances of heavy diseased plants, which concentrations were different. Decaying substances of heavy diseased plants those concentration were high, de- creased emergence of cucumber 53.15%, while ratio of diseased plants increased 55.11%. Therefore, allelopathy of diseased roots＇ decaying substances might be important reason of serious disease of cucumber continuous cropping.