Résumé
L'influence de différents facteurs physiques (température, pH, lumière, pression osmotique) et nutritionnels (sels, vitamines, sucres et hydrolysats de protéine) a été étudiée sur la germination des conidies primaires de Conidiobolus obscurus. Les germinations globales les plus élevées sont obtenues à 24 °C, à la lumière sur un milieu gélosé contenant du glucose et des vitamines ou de l'extrait de levure. Une température comprise entre 19 et 24 °C, un pH basique (8–10), l'obscurité et la présence de glucose et/ ou d'hydrolysats de protéine stimulent l'émission de tubes germinatifs. Les souches ont pu être classées en 2 groupes en fonction de leur mode de germination in vitro et de leur agressivité vis-à-vis du puceron du pois.
Abstract
Different physical (temperature, pH, light and osmotic pressure) and nutritional factors (salts, vitamins, sugars and protein hydrolysates) were tested on the germination of primary conidia of Conidiobolus obscurus. The most important total germination levels were obtained at 24 δC, in continuous light on an agar medium containing dextrose and vitamins or yeast extract. Temperatures ranging from 19 to 24°, a basic pH (8–10), darkness and the presence of dextrose and/ or protein hydrolysates stimulated the formation of germ tubes. The strains of C. obscurus studied were classified in 2 groups depending on their aggressivity against the pea aphid and their mode of germination in vitro.
References
Allen, P. J., 1976. Spore germination and its regulation. Control of spore germination and infection structure formation in fungi. In: Encyclopedia of Plant Physiology, Vol. 4. Physiological Plant Pathology (Heitefuss, R. & Williams, P. H., eds.), pp. 53–85. Springer Verlag, Berlin.
Auclair, J. L., 1958. Honeydew excretion in the pea aphid, Acyrthosiphon pisum (Harr.) (Homoptera: Aphididae). J. Ins. Physiol. 2: 330–337.
Ben Ze'ev, I., 1980. Systematics of entomopathogenic fungi of the ‘Sphaerosperma’ group and their prospects for use in biological pest control. Ph.D. Thesis. Univ. Jerusalem.
Callaghan, A. A., 1974. Effect of pH and light on conidium germination in Basidiobolus ranarum. Trans. Br. Mycol. Soc. 63: 13–18.
Callaghan, A. A., 1978. Effect of nutrient level, pH and light on conidial germination in Entomophthoraceous fungi. Trans. Br. Mycol. Soc. 70: 271–275.
Kerwin, J. L., 1982. Chemical control of the germination of asexual spores of Entomophthora culicis, a fungus parasitic on Dipterous. J. Gen. Microbiol. 128: 2179–2186.
Latgé, J. P., 1975. Croissance et sporulation de 6 espèces d'Entomophthorales. 1. Influence de la nutrition carbonée. Entomophaga 20: 201–207.
Latgé, J. P., 1981. Comparaison des exigences nutritionnelles des Entomophthorales. Ann. Microbiol. (Inst. Pasteur) 132B: 299–306.
Latgé, J. P., 1983. Conidiobolus obscurus et les Entomophthorales pathogènes de pucerons. Thèse Doctorat d'Etat, Université Paris XI-Orsay, 7 mars 1983, 2 vols.
Latgé, J. P., Papierok, B. & Sampedro, L., 1982. Agressivité de Conidiobolus obscurus vis-à-vis du puceron du pois. I. Comportement des conidies sur la cuticule avant la pénétration du tube germinatif dans l'insecte. Entomophaga (sous presse).
Latgé, J. P., Sampedro, L. & Brey, P., 1982. Physiological study of the pathogenicity of Conidiobolus obscurus. Invertebrate Pathology and Microbial Control. Abstr. Offered papers. 3rd int. coll. Brighton, 6–10 September 1982, p. 109.
Page, R. M. & Humber, R. A., 1973. Phototropism in Conidiobolus coronatus. Mycologia 65: 335–354.
Papierok, B. & Wilding, N., 1979. Mise en évidence d'une différence de sensibilité entre 2 clones du puceron du pois, Acyrthosiphon pisum Harr. (Homoptères Aphididae) exposés à 2 souches du champignon Phycomycète: Entomophthora obscura Hall & Dunn. C.R. Acad. Sc. Paris, série D 288: 93–95.
Pekrul, S. & Grula, E. A., 1979. Mode of infection of the corn ear worm (Heliothis zea) by Beauveria bassiana as revealed by scanning electron microscopy. J. Invertebr. Pathol. 34: 238–247.
Preece, T. F., 1976. Some observations on leaf surface during the early stages of infection by fungi. In: Biochemical aspects of Plant-Parasite Relationships (Friend, J. & Threlfall, D. K., eds.), pp. 1–10. Academic Press, London & New York.
Remaudière, G., Latgé, J. P. & Papierok, B., 1979. Reconsidération taxonomique de Entomophthora obscura Hall & Dunn. Ann. Microbiol. (Inst. Pasteur) 130A: 151–162.
Schabel, H. G., 1978. Percutaneous infection of Hylobius pales by Metarrhizium anisopliae. J. Invertebr. Pathol. 31: 180–187.
Smith, R. J. & Grula, E. A., 1981. Nutritional requirements for conidial germination and hyphal growth of Beauveria bassiana. J. Invertebr. Pathol. 37: 222–230.
Uziel, A., Schwartz, A. & Kenneth, R. G., 1981. Positive phototropism and hydromorphogenesis in germination structures of Conidiobolus species. Isr. J. Botany 30: 75–80.
Uziel, A., 1981. The effect of light regimes and substrates on the mode of germination of conidia of certain fungi of the Entomophthorales (Phycomycetes: Zygomycetes). M. Sc. Thesis, Faculty of Agriculture, Rehovot, Israel.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sampedro, L., Uziel, A. & Latgé, J.P. Agressivité de Conidiobolus obscurus vis à-vis du puceron du pois. Mycopathologia 86, 3–19 (1984). https://doi.org/10.1007/BF00437224
Issue Date:
DOI: https://doi.org/10.1007/BF00437224