重寄生菌对花棒锈病的抑制作用

Inhibitory Effect of Hyperparasite on Uromyces onobrychidis

花棒（Hedysarum scoparium Fisch. et Mey）是优良的固沙先锋树种，花棒锈病（Uromyces onobrychidis （Desm．）Lév．）是花棒的常见病害之一，在一些地区严重制约了花棒的先锋固沙作用。本文对花棒锈病菌上的重寄生菌菌种来源、温度和碳源对重寄生菌菌丝生长及产孢的影响、室内接种试验、花棒锈病菌的重寄生现象及对花棒锈病的自然抑制力进行了研究。研究发现，花棒锈病菌的重寄生菌寄生于花棒锈病菌的夏孢子堆和冬孢子堆上，被重寄生菌寄生后，夏孢子堆南橙黄色变为灰白色，冬孢子堆南棕褐色变为灰色，后期夏孢子失去萌发力，孢子堆原基处只存有重寄生菌的分生孢子器。重寄生菌在20～25℃ PDA培养基上产孢量大。重寄生菌为Sphaerellopsis sp．，是一种自然重寄生现象，并对花棒锈病有很强的抑制作用，如果充分利用这一生物链，人工干预这一现象的早发和多发，可以有效提高花棒固沙能力的发挥，其潜质意义很大，是以菌治病、以菌哺林的新资源。

Hedysarum scoparium Fisch. et Mey. is an excellent pioneer tree species tor sandtlxatlon. Uromyces onobrychidis（Desm.）L v. is one of the common disease on H. scoparium and in some areas it restrict the sandfixation effect of H. scoparium seriously. This paper reported the source of hyperparasite strains, effect of temperature and carbon sources on mycelia growth and sporogensis, inoculation experiment in laboratory and the natural inhibition of hyperparasitism on H. scoparium It was found out that the hyperparasite parasitized on the uredinia and telia of the rust of H. scoparium. When they were parasitized by hyperparasite, the color of uredinia changed from orange yellow to white and that of telia changed from chocolate-brown to pale-brown. At later stage, the uredinia lost their germinating ability, and hyperparasite conidia only occurred at uredinia base. The hyperparasite grew well on PDA and in the temperature of 20-25℃. It was a natural hyperparasitism, the hyperparasite was identified as Sphaerellopsis sp., it has strong inhibitory effect on rust of H. scoparium. If we use the bio-chain sufficiently and artificially interfere the occurrence of this phenomenon early and more, it can improve the sandfixation ability of H. scoparium effectively, its latent meaning is great and it is also a new resource to control tree diseases and to foster forest with fungi.