Ampelomyces quisqualis Ces. Ex Schlecht., A Hyperparasite of the

Asparagus Bean Powdery Mildew Pathogen Erysiphe Polygoni in Taiwan

Jwu-Guh Tsay and Bor-Kai Tung

 

Tsay, J. G., and Tung, B. K. 1991. Ampelomyces quisqualis Cex. ex Schlecht., a hyperparasite of the asparagus bean powdery mildew pathogen Erysiphe polygoni in Taiwan. Trans. mycol. Soc. R.O.C. 6(2):55-58.

[Key words] Erysiphe polygoni DC., Ampelomyces quisqualis Ces. ex Schlecht.

 

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1 Department of Plant Protection, National Chia-Yi, Institute of Agriculture,

Chia-Yi, Taiwan, R.O.C.

瓣ミ古竡笰穨盡厩从玂臔, 古竡カ, 籓芖, い地チ瓣

 

Ampelomyces quisqualis Ces. ex Schlecht.(syn. Cicinnobolus cesatii de Bary) was a well known parasite of powdery mildews widely distributed throughout the world(5). The hyphae of A. quisqualis grow through the mycelium of the host fungus and inhibit conidial production and cleistothecial development(3). A. quisqualis was not host specific and some strains of it were slightly pathogenic to cucumber(1). These hyperparasitic fungi were classified in genus Cicinnobolus until 1959(1). Early taxonomy and occurrences of Ampelomyces were reviewed by Emmons(2). These species of Cicinnobolus have been recognized mainly according to the different species of Erysiphales on which they occur.

 

Cicinnobolus nicotiana Saw. was reported in Taiwan in 1933 by Sawada on the powdery mildew (Erysiphe nicotiana Saw.) on Nicotiana longiflora collected from Kanagawa, Japan(4). However, no any species of Ampelomyces has been recorded from Taiwan previously. In May of 1990, A. quisqualis, a hyperparasite of the asparagus bean(Vigna sesquipedalis L.) powdery mildew pathogen Erysiphe polygoni DC. was collected at Shikoou and Chiayi, Taiwan(Table 1). Mycelium of A. quisqualis was superficial or immersed, hyaline, branched, septate. Conidiomata were pycnidial 40 - 90m long X 30 - 60m wide, in the hyphae of E. polygoni, separate, globose or elongated to pyriform, unilocular, wall 1-celled thick, of pale brown angular textured(Fig. 1). No distinct ostiole was present and dehisced by apical rupture of pycnidium. Conidiophores were absent. Conidia were 5 - 10 X 2.5 - 3.8m, very pale brown, aseptate, thin-walled, smooth, guttulate, straight or curved, cyclindrical to fusiform. Cultures of A. quisqualis were isolated from Erysiphe polygoni on asparagus bean. At 25 and 12-hr cycle of fluorescent illumination, single-spore culture grew slowly on patato-dextrose agar but sporulated profusely(Fig. 2).

 

LITERATURE CITED

1.Cook, R. J., and Baker, K. F. 1983. The nature and practice of biological control of plant pathogens. pp.318. APS, Minnesota, 539p.

2.Emmons, C. W. 1930. Cicinnobolus cesatii, a study in host parasite relationships. Bull. Torrey Bot. Club 57: 421 - 441.

3.Rogers, D. P. 1959. On Cicinnobolus. Mycologia 51: 96 - 98.

4.Sawada, K. 1933. Cicinnobolus nicotiana Saw. n. sp. Descriptive Catalogue of Formosan Fungi 6: 71.(in Japanese)

5.Sutton, B. C. 1980. The coelomycetes fungi, imperfecti with pycnidia, acervuli and stromata. pp. 368 - 369. CMI, Kew, Surrey, 696p.

 

籓芖愚ěフ痜颠贺禬盚ネ颠

讲λ㏕  担秨

[篕璶]籓芖, 愚ěフ痜颠フ盚ネ颠1990 5る匪古竡愚ě腑璉祇瞷フ盚ネ颠颠捣盚ネ盚颠捣ずだネ蘒竟(琡催)睱脚︹匆次瑅冰┪耭耤40 - 90 X 30 - 60mだネ蘒睱脚︹虫璏蛾旦┪ 5 - 10 2.5 - 3.8m 皑筧力覆靛蚌緄膀セ颠颠捣ネ絯篊秖玻蘒

[闽龄粂] 愚ěフ痜颠フ盚ネ颠

 

Table 1. Investigation of hyperparasitism of Ampelomyces quisqualis on the asparagus bean powdery mildew pathogen Erysiphe polygoni

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Date                       Location           Hyperparasitism()

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571990      Shikoou(匪)                   100

5181990    Tsyhtorng(踠)                     0

5291990    Chiayi (古竡)                         60

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Fig. 1. Pycnidium of Ampelomyces quisqualis formed parasitically within conidiophore of Erysiphe polygoni. bar = 25m.

 

 

Fig. 2. The colonies of Ampelomyces quisqualis grow on PDA medium at 25 for 40 days.