剑麻茎腐病病原生物学特性的研究

BIOLOGY OF PATHOGEN OF BOLE ROT ON AGAVE H.11648

对剑麻茎腐病病原黑曲霉菌(Aspergillus niger Van.Teigh)生物学特性的研究结果表明,在培养基上,该菌菌丝生长的温度范围为15—39℃,最适32℃,产生分生孢子的温度范围为16—39℃,最适32℃,分生孢子萌发的温度范围为16—44℃,最适36℃;菌丝和分生孢子在60℃的水浴中处理10分钟即可致死。分生孢子必须在空气相对湿度≥92％的条件下才能萌发。光照对分生孢子的产生和萌发无影响。在pH4—9范围内菌丝可以生长,分生孢子能很好萌发,但较酸的条件(pH4—5)较有利于菌丝生长。分生孢子必须在营养较丰富的条件下才能萌发良好。K,Ca,S含量与菌丝生长和分生孢子产生及荫发关系不大。在离体剑麻叶片上,侵染成功的温度范围为20—42℃,最适于侵染的温度为36℃。空气相对湿度对侵染成功率及病斑扩展的影响不大。接种体数量对侵染成功率无影响,单个孢子也可以接种成功,但接种体数量较大则症状较早表现。多菌灵和灭病威杀菌剂在体外测验能很好地抑制菌丝生长和分生孢子萌发,且耐雨水冲刷,但灭病威的抑制作用比多菌灵强。

Biological studies revealed that the effective and optimum temperature for the pathogen of bole rot (Aspergillus niger Van. Teigh) on Agave ranged between 15-39 and 32℃ for hyphal growth, 16-39 and 28-32℃ for sporogenesis, and 15-44 and 32-36℃ for spore germination respectively. The conidia and hyphae were lifeless after treated in water baths at 60℃ for about 10 minutes. The conidia germinated under the relative humidity≥92%. The sporogenesis and spore germination were not affected by light. The hyphae grew and the conidia germinated well under pH4-g, but the hyphae grew better at pH4-5. The conidia germinated well under better nutrient environment of which the contents of K, Ca, S were not so related to sporogenesis, spore germination and hyphae growth. In vitro, the pathogen infected the leaves of Agave at 20-42℃, but the optimum temperature was 32-36℃. The relative humidity only had a little to do with the disease incidence and lesion expansion. A large amount of inocula could result in earlier lesion appearance, but which didn't lead corresponding to higher disease incidence, and a single conidium could infect the leaves successfully. While both the carbendizim and earbendizin-sulphur could strongly inhibit the hyphae and conidia of the pathogen in vitro and resist rain wash on leaves, the latter had a stronger inhibiting ability than the former.