, 1968; Puhalla, 1968). By auxotrophic complementation experiments, Holliday (1974) has isolated solopathogenic strains of U. maydis that Lapatinib price are diploid cells able to grow in axenic culture. Such strains are useful genetic tools, leading to the discovery that cell signalling transduction pathways involved in mating, virulence, dimorphism and cell cycle are intertwined processes (Banuett & Herskowitz, 1988, 1989; Kahmann &

Kamper, 2004). In spite of the genetic interest of the solopathogenic strains, their incidence in the biology of Ustilaginaceae is poorly documented. In the present study, we compare the ability of teliospores from three species of smut fungi to form solopathogenic yeasts: Sporisorium reilianum f.sp. zeae (Khün) Langdon & Fullerton, U. maydis and

Moesziomyces penicillariae (Bref.) Vánky. Sporisorium reilianum f.sp. zeae is the causal agent of maize head smut, infecting maize plantlets via the roots under field conditions (Matyac & Kommedahl, 1985; Martinez et al., 2000, 2002). Ustilago maydis, causing common smut of maize, is known to be infective on different aerial parts of corn (Agrios, 1993). Moesziomyces penicillariae is a pathogen of pearl millet, largely present in the subsahelian zone. It is an airborne pathogen spread by the wind but also by insects infecting young inflorescences (Baht, 1946; Wilson, 1995). We designed a protocol on S. reilianum Selumetinib solubility dmso to isolate solopathogenic strains based on the isolation of stable fuzzy strains from germinated teliospores. crotamiton This approach was applied on the three Ustilaginaceae species to compare their frequency of formation of solopathogenic strains. Sori of S. reilianum f.sp. zeae (Kühn) Landon & Fullerton were collected from seven cornfields in France (Arçais, Deux Sèvres; Bischoffsheim, Bas Rhin; Buros, Pyrénées Atlantiques; Corbreuse, Essonne; Gourville, Charente; Montclar-Lauragais, Haute Garonne; Saint Ciers, Gironde, France). Two compatible

haploid yeast strains, SRZN and SRZM, were isolated from a sample collected in Saint Ciers (Gironde). Moesziomyces penicillariae (Bref.) Vánky sori were collected in pearl millet fields in 10 areas of Senegal (Doubalampor; Kaffrine; Keur Baka; Koumpentoum; Louga; Mountôgou; Mpack; Rao; Tambacounda; Ziguinchor) (Diagne-Lèye, 2005). Ustilago maydis (DC) Corda galls were collected in corn fields at Le Vernet, Muret (Haute Garonne, France), Pau (Hautes Pyrénées, France) and Gerona (Catalunya, Spain). The haploid, compatible strains SRZN and SRZM were inoculated in maize and the resulting teliospores were collected 6 weeks later. These teliospores were then sterilized by Chloramine T 3% for 15 min, rinsed twice with sterilized water and resuspended in water at a concentration of 500 cells mL−1. A volume of 100 μL of this suspension was spread on water–agar (3%) medium.