Fungal contaminants of Primula, Coffea, Musa and Iris tissue cultures

Effect of medlium acidification on filamentous fungi, yeasts and bacterial contaminats inDelphinium tissue cultures

“…This confirmed previous investigations which had shown that the fungal and yeast species tested immediately grow and harm the plant and do not stay 'latent' when they are introduced into tissue cultures of plant species such as Delphinium or Coffea (Leifert et al 1990;Danby et al 1993). It also confirmed results of Cooke and coworkers (1992) who showed that bacteria which are pathogenic to Delphinium in vivo are also pathogenic in vitro.…”

“…The strains of filamentous fungi, yeasts and bacteria used were isolated as contaminants from plant tissue cultures and have been described previously (Leifert et al 1989a(Leifert et al , 1990Cooke et al 1992;Danby et al 1993). From each initial culture vessel 10 shoots were used for inoculation and 10 shoots as controls.…”

“…This clearly demonstrated the anti-bacterial preservative effect of medium acidification in shoot cultures of plant species such as Delphinium. However, it also became clear that the low pH had no effect on fungal and yeast contaminants, which are known to be more acid tolerant Danby et al 1993). For example, Candida and Rhodotorula spp.…”

“…Most fungal, yeast and some bacterial contaminants kill the plant material soon after they have been introduced (Leifert et al 1990;Leifert & Waites 1993;Danby et al 1993). Bacterial contaminants such as Staphylococcus, Micrococcus, Lactobacillus, Pseudomonas species, on the other hand, can remain 'latent' (not producing disease symptoms on the plant or visible growth on the medium) after they have been introduced into cultures of certain plant species .…”

Microbial hazards in plant tissue and cell cultures

“…( Table 2). Filamentous fungi and yeast contaminants may be introduced with the explant and/or during all subsequent in vitro stages (Danby et al, 1994). Specific fungi (e.g.…”