三七根腐病病原研究

【目的】三七根腐病是三七的重要病害，是限制三七种植业发展的严重障碍。【方法】在田间进行系统的三七根腐病害观察、调查和采样；在室内进行病原分离、鉴定和室内致病性测定，并进行田间人工接种试验。【结果】发现三七根腐病的主要症状表现有黄腐型、干裂型、髓烂型、急性青枯型、湿腐型和茎基干枯型等，但以黄腐型和急性青枯型较为常见，其中干裂型、髓烂型和茎基干枯型是新发现的三七根腐病症状表现。分离和鉴定结果表明，引起三七根腐病的病原真菌类群主要包括Cylindrocarpon destructans、C. didynum、Fusarium solani、F. oxysporum、Phytophthora cactorum、Phoma herbarum、Rhizoctonia solani等。室内致病性测定结果表明C. didynum、C. destructans、P. cactorum、P. herbarum和R. solani均能导致块根不同程度的腐烂。田间人工接种以P. cactorum和P. herbarum的致病性较强，发病率分别为48.4%和50.0%。C. destructans和C. didynum的致病力虽然较弱（C. destructans为23.5%，两株C. didynum分别为28.0%和15.2%），但在田间分布范围广，分离频率高（Cylindrocarpon属真菌最高组织分离频率为100%），且可导致典型的黄腐型症状。【结论】C. destructans和C. didynum是田间三七根腐病的重要病原真菌。

The Causal Microorganisms of Panax notoginseng Root Rot Disease

Objective] Panax notoginseng, cultivated in Yunnan, China, is an important medicinal herb. Rot root disease is the most serious problem limiting the production of the herb. Method] Panax notoginseng root rot disease was surveyed and sampled in the field. The pathogens of the root rot was isolated and identificated. Pathogenecity tests in vitro and in field were carded out. Result] A survey on the disease indicated that the symptoms of the disease are expressed as dry chap rot, medullary tissue rot, slowly yellow rot, stem base dry rot, suddenly wilt rot and wet rot. Among them, slowly yellow rot and suddenly wilt wet rot were the most popular ones. Dry chap rot, medullary tissue rot and stem base dry rot are new records for symptoms of the disease. Cylindrocarpon destructans, C. didynum, Fusarium solani, Phytophthora cactorum, Phoma herbarum, Monilia sp., Verticillium sp., Trichoderma sp., Rhizoctonia solani were involved in the disease. In vitro pathogenecity tests demonstrated that C. destructans, C. didynum, P cactorum, P. herbarum and R. solani could result in the disease at different levels. Field inoculation tests showed that P cactorum and P herbarum were the most pathogenic fungi, leading to disease incidences at 48.4% and 50.0%, respectively. Conclusion] However, C. destructans and C. didynum were considered as two of the most important fungi causeing Panax notoginseng root-rot diseases because of their wide distribution, high frequency of isolation, and close relationship with dominant symptom.