ABSTRACT
Axenic cultivation has been shown as an important tool for studies related to the biology, the pathogenicity and the maintenance of pure cultures of biotrophic species. Therefore, the present study aimed to analyze the in vitro growth of Puccinia psidii uredospores, using enriched culture media that had success in the axenic cultivation of other rusts. Compounds such as salts, amino acids, carbohydrates and vitamins were selected for the preparation of three enriched culture media: ASZV Kuck (1010 Kuck, K.H. Über die infektionsbedingte Veränderungen der Aminosäuren und Fettsäuren in Puccinia graminis f. sp. tritici, Rasse 32, infizierten Weizenblättern und die “in vitro” Sporulation des Pilzes. 1979. Ph.D Thesis. Rheinisch- Westfälischen Technischen Hochschule, Aachen.), SH Schenk & Hildebrandt (2121 Schenk, R.U.; Hildebrandt, A.C. Medium and technique for induction and growth of monocotyledonous and dicotyledonous plant cell cultures. Canadian Journal of Botany, Ottawa, v.50, p.199-204, 1972.) and HG Harvey & Grasham (77 Harvey, A.E.; Grasham, J.L. Axenic culture of the mononucleate stage of Cronartium ribicola. Phytopathology, Saint Paul, v.64, n.7, p.1028-1035, 1974.), modified. Comparatively, enriched media were prepared from leaves of “jambeiro” (FJ) at four concentrations: 0.5; 1.0; 3.0 and 5.0 g L-1 (grams of leaves per one liter of distilled water). In this study, verification covered only the first stage of fungal growth, germ tube growth, not continuing in the pathogen development. The enriched media that provided greater P. psidii germ tube growth were the media ASZV, HG and FJ at 0.5 g L-1 concentration.
Keywords
Puccinia psidii; Myrtaceae; biotrophic cultivation