Aphanomyces cochlioides

HOST-SPECIFIC ZOOSPORE ATTRACTANTS OF THE FUNGUS APHANOMYCES COCHLIOIDES, THE CAUSE OF SPINACH ROOT ROT... 

The compatibility of Aphanomyces cochlioides with several higher plants has been investigated by Ui and Nakamura [59], According to their results, the pathogen was highly compatible with Chenopodiaceae... 

Table 7. Results of a Preliminary Screening Test for Zoospore Attractants in Roots of Species Compatible and Incompatible with Aphanomyces cochlioides...

Table 10. Attractant Effect of Cochliophilin A (6) on of Aphanomyces cochlioides...

Twelve flavones (1, 6,10, 53-55, 57-59, 77-79) including cochliophilin A (6), and a chromone (64), were chemically prepared in order to compare their attractant effects on zoospores of Aphanomyces cochlioides. 

We thank Professors R. Yokosawa, F. Tomita, and M. Fujimura for kindly supplying the fungal strains, Aphanomyces cochlioides, Cladosporium herbarum, and Neurospora crassa, respectively. Much of the research on which this review is based, has been carried out by the following students, Masters Y. Matsukura, N. Toda, and H. Katsuta (benzimidazole antidotes), and by Dr. T. Horio Masters T. Takayama, H. Kikuchi, K. Ohkawa, and M. Mizutani (zoospore attractants). 

Host plant Chenopodium album Oomycete Aphanomyces cochlioides... 

Fig. (3). Response of Aphanomyces cochlioides zoospores toward spinach roots. A. Photomicrograph (dark field) of aggregated zoospores (docs dose to root surface) jusi behind rooi cap of spinach root tip. B. A mass of cystospores (arrow) on spinach rooi (11],...

Table 1 Responses of zoospores toward the extracts of plants belonging to different families and varying levels of compatibility with Aphanomyces cochlioides ...

Fig. (4). Morphological changes (developmental transitions) of Aphanomyces cochlioides zoospores triggered by a host-specific plant signal, cochliophilin A (3). White bars 1 jjM.

Table 3. Activities of Some Nonhost Plant Extracts3 toward Aphanomyces cochlioides Zoospores...

We are thankful to Prof. R. Yokosawa, Health Science University of Hokkaido for kindly providing Aphanomyces cochlioides strain AC-5 and Mr. Toshiaki Ito, Laboratory of Electron Microscopy, Hokkaido University for his support in electron microscopy. The first author is thankful to the Japan Society for the Promotion of Science (JSPS) for his Postdoctoral fellowship. The financial support from MEXT (to S. T Grant-in-Aid for Scientific Research, No. 14206013) is also acknowledged. 

Secondary Metabolites with Diverse Activities toward Phytopathogenic Zoospores of Aphanomyces cochlioides in Host and Nonhost Plants... 

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