title: [Effects of fungus on the growth of Dendrobium candidum and D. nobile in vitro culture].
abstract: OBJECTIVE
  To examine effects of fungus AR-18 (Epulorhiza sp.) on the growth of Dendrobium candidum and D. nobile in vitro culture.
  
  
  METHODS
  Effects of fungus AR-18 on fresh weight and dry weight of D. candidum and D. nobile were studied in vitro culture, when agar was used as rest, and effects of fungus AR-18 and nutrients on fresh weight and dry weight of D. candidum and D. nobile were studied in vitro culture, when vermiculite was used as rest.
  
  
  RESULTS
  In agar medium, effects of fungus AR-18 on fresh weight and dry weight of D. candidum and D. nobile were not significant (P > 0.05). However, in vermiculite medium, the effect of fungus AR-18 on fresh weight of D. nobile was significant (P < 0.05). Fresh weight of D. nobile inoculated with fungus AR-18 was increased by 16% compared with the non-inoculated ones (control). The effect of fungus AR-18 on dry weight of D. nobile was very significant (P < 0.01). Dry weight of D. nobile inoculated with fungus AR-18 was increased by 21% compared with the control. In vermiculite medium, the effect of combination treatment (Fungus AR-18 + Distilled H2O) on fresh weight of D. nobile was very significant (P < 0.01). Fresh weight of D. nobile inoculated with fungus AR-18 was increased by 47% compared with the control, while the effect of combination treatment (Fungus AR-18 + Nutrients) on fresh weight of D. nobile was not significant (P > 0.05). In addition, the effect of combinations treatment (Fungus AR-18 + Nutrients) and (Fungus AR-18 + Distilled H2O) on dry weight of D. nobile was not significant (P > 0.05). So the combination treatment (Fungus AR-18 + Distilled H2O) was the best for the growth of D. nobile. In vermiculite medium, effects of fungus AR-18 and nutrients on fresh weight and dry weight of D. candidum were not significant (P > 0.05).
  
  
  CONCLUSIONS
  It is important in vitro culture to select a proper rest for the control of the growth of fungus to establish a beneficial symbiotic relationship between plants and fungi. If the fungus AR-18 is utilized as biological manure in got-up planting of D. nobile, a good result may be obtained.
authors.affiliation: Department of Mycology, Institute of Medicinal Plant Development, CAMS, PUMC, Beijing 100094, China.
authors.forename: J Y
authors.initials: JY
authors.lastname: Song
authors.forename: S X
authors.initials: SX
authors.lastname: Guo
mesh_terms: D000362:Agar; D003470:Culture Media; D046508:Culture Techniques; D031667:Dendrobium / Q000254:growth & development* / Q000382:microbiology; D005658:Fungi / Q000502:physiology*; D013559:Symbiosis / Q000502:physiology*
chemical_list: D003470:Culture Media; D000362:Agar