1887

Abstract

Phytophthora cactorum grown on basal agarose medium or in liquid basal medium produced oospores after being transferred to water agarose. The numbers of oospores produced under such conditions depended on the age of the culture prior to exposure to nutrient deprivation. When the concentration of basal medium used for cultivation of was increased, the numbers of oospores produced after being transferred to water agarose was also increased. grown on basal agarose medium also produced oospores when its mycelial growth was restricted after reaching the edge of Petri plates. In 5 cm plates oospore formation occurred in the third week, whereas in 9 cm and 14 cm plates oospores appeared in the fourth week. Most oospores were formed near the edge of the plates. The non-saponifiables extracted from mycelia of grown in liquid basal medium were stimulatory to oospore formation by and , whereas the saponifiables were stimulatory to . Extracts from culture filtrate and basal medium were not stimulatory to oospore formation by either fungus. When the non-saponifiables were fractionated by Florisil columm chromatography, only fraction 1 was not active. Fractions 2, 3 and 4 were stimulatory to oospore formation by both and . These results support the hypothesis that , and possibly other pythiaceous fungi as well, can synthesize substances needed for sexual reproduction but requires a stress factor to trigger the process.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-144-4-1071
1998-04-01
2024-04-25
Loading full text...

Full text loading...

/deliver/fulltext/micro/144/4/mic-144-4-1071.html?itemId=/content/journal/micro/10.1099/00221287-144-4-1071&mimeType=html&fmt=ahah

References

  1. Society American Oil Chemists' Society (1971) Sampling and analysis of commercial fats and oils. A.O.C.S. Official Method Ca 6a-40. In Official and Tentative Methods of the American Oil Chemists’ Society, 3rd edn. edition, Chicago:: The American Oil Chemists’ Society;
    [Google Scholar]
  2. Bowman R. D., Mumma R. O. (1967); The lipids of Pythium ultimum.. Biochimica Et Biophysica Acta, 144:(3),501–510 [View Article]
    [Google Scholar]
  3. Carroll K. K. (1961); Separation of lipid classes by chromatography on Florisil.. Journal of Lipid Research, 2:(2),135–141 [View Article]
    [Google Scholar]
  4. Elliott C. G. (1983) Physiology of sexual reproduction in Phytophthora.. Edited by Erwin D. C., Bartnicki-Garcia S., Tsao P. H. In Phytophthora: its Biology, Taxonomy, Ecology, and Pathology St Paul, MN:: American Phyto- pathological Society;71–88
    [Google Scholar]
  5. Elliott C. G., Hendrie M. E., Knight G. A., Parker W. (1964); A steroid growth factor requirement in a fungus.. Nature, 203:(4943),427–428 [View Article]
    [Google Scholar]
  6. Harnish W. N. (1968); Effect of sterols in sexual reproduction of Phytophthora cactorum.. Proc W Va Acad Sci, 40:99–104
    [Google Scholar]
  7. Hendrix J. W. (1970); Sterols in growth and reproduction of fungi.. Annual Review of Phytopathology, 8:(1),111–130 [View Article]
    [Google Scholar]
  8. Hendrix J. W., Rouser G. (1976); Polar lipids of Phytophthora parasitica var. nicotianae in comparison with those of selected other fungi.. Mycologia, 68:(2),354–361 [View Article]
    [Google Scholar]
  9. Ho W. C., Ko W. H. (1980); Agarose medium for bioassay of antimicrobial substances.. Phytopathology, 70:(8),764–766 [View Article]
    [Google Scholar]
  10. Jee H. J., Ko W. H. (1997); Stimulation of sexual reproduction of Phytophthora cactorum and P. parasitica by fatty acids and related compounds.. Mycological Research, 101:(9),1140–1144 [View Article]
    [Google Scholar]
  11. Jee H.-J., Tang C.-S., Ko W.-H. (1997); Stimulation of sexual reproduction in Phytophthora cactorum by phospholipids is not due to sterol contamination.. Microbiology, 143:(5),1631–1638 [View Article]
    [Google Scholar]
  12. Ko W. H. (1985); Stimulation of sexual reproduction of Phytophthora cactorum by phospholipids.. Journal of General Microbiology, 131:2591–2594
    [Google Scholar]
  13. Ko W. H. (1986); Sexual reproduction of Pythium aphani- dermatum: stimulation by phospholipids.. Phytopathology, 76:(11),1159–1160 [View Article]
    [Google Scholar]
  14. Ko W. H., Ho W.C. (1983); Reassessment of apparent sterol requirement for sexual reproduction in Phytophthora.. Ann Phytopathol Soc Jpn, 49:(3),316–321 [View Article]
    [Google Scholar]
  15. Ko W. H., Lockwood J. L. (1967); Soil fungistasis: relation to fungal spore nutrition.. Phytopathology, 57:894–901
    [Google Scholar]
  16. Ko W. H., Chase L. L., Kunimoto R. K. (1973); A microsyringe method for determining concentration of fungal propagules.. Phytopathology, 63:(9),1206–1207 [View Article]
    [Google Scholar]
  17. Leal J. A., Friend J., Holliday P. (1964); A factor controlling sexual reproduction in Phytophthora.. Nature, 203:(4944),545–546 [View Article]
    [Google Scholar]
  18. Losel D. M. (1988) Fungal lipids.. Edited by Ratledge C., Wilkinson S. G. In Microbial Lipids vol. 1 London:: Academic Press;699–806
    [Google Scholar]
  19. Nes W. D. (1988); Phytophthorols — novel lipids produced by Phytophthora cactorum.. Lipids, 23:(4),9–16 [View Article]
    [Google Scholar]
  20. Wood S. G., Gottlieb D. (1978a); Evidence from mycelial studies for differences in the sterol biosynthetic pathway of Rhizoctonia solani and Phytophthora cinnamomi.. Biochemical Journal, 170:(2),343–354 [View Article]
    [Google Scholar]
  21. Wood S. G., Gottlieb D. (1978b); Evidence from cell free systems for differences in the sterol biosynthetic pathway of Rhizoctonia solani and Phytophthora cinnamomi.. Biochemical Journal, 170:(2),355–363 [View Article]
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-144-4-1071
Loading
/content/journal/micro/10.1099/00221287-144-4-1071
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error