Use of Selenate-Resistant Strains as Markers for the Spread and Survival ofBotrytis cinereaUnder Greenhouse Conditions

Abstract

Botrytis cinerea marked strains combining traits of fungicide resistance or sensitivity (carbendazim, iprodione) with resistance to selenate were created and assessed for use in studying the dispersal of B. cinerea and its survival inside plant tissue under greenhouse conditions. Marked strains differed in their ability to cause lesions and to disperse in the greenhouse. A strain that was the most aggressive in infecting plants was also the most successful in spreading across the greenhouse. Following 7 to 14 days of exposure to marked inoculum, about 90% of plants showed quiescent B. cinerea infection with no significant difference between hosts or seasons. However, in a warm season, most of the plants were infected with wild-type B. cinerea, whereas most of the winter-recovered B. cinerea strains were of the marked phenotype, showing the importance of local inoculum from within the glasshouse in winter. The air of the greenhouse contained the same population of marked B. cinerea in warm and in cold periods, whereas the total population was significantly higher in summer. In the warm season, mycelium of B. cinerea inside plant debris lost viability within 3 to 4 months, whereas it stayed viable for 4 months in the winter (December to March) and started to lose viability in April.

Vegetative compatibility grouping in Botrytis cinerea using sulphate non-utilizing mutants

“…The MM used in this study was a modified Vogel's medium N (Korolev et al 2006;Vogel 1964). MM or MM amended with sodium selenate at 1 g l −1 and taurine at 100 mg l −1 were used to recover and subculture selenate-resistant mutants.…”

“…Malt extract agar (MEA; Difco Laboratory, Detroit) amended with NaCl at 40 g l −1 Parkes 1993, 2003) and an additional 15 g l −1 of agar (Difco) was used for testing mycelial incompatibility (barrage). A defined MM modified from the Difco Czapek-Dox agar (CDA) recipe according to Yourman and Jeffers (1999), and CDA amended with carbendazim and iprodione at 0.5, 1.0, 5.0, 50.0 and 500.0 μg of active ingredient ml −1 were used to test parental strains for resistance to fungicides (Korolev et al 2006). …”

“…The sul mutants were generated as described previously (Weeds et al 1998;Korolev et al 2006). Plugs were taken from the growing edge of 3 to 5 day-old colonies on PDA and placed on MM amended with sodium selenate (1 g l −1 ) and taurine (100 mg l −1 ) at six to ten points in 9 cm diam plates, and incubated at 20°C to 22°C in the dark.…”

“…Sectors that grew as thin expansive colonies with little or no aerial mycelium on MM, but similarly to the wild-type on L-methionineamended MM were considered to be sul mutants. Two B. cinerea strains were subjected to UV irradiation (UV-C 254 nm, Vilber Lourmat, France; Korolev et al 2006). Slow compact colonies of Botrytis that developed on MM supplemented with Triton 100 were counted and the UV dosage was adjusted to kill 95% of the conidia.…”

Comparison of Botrytis cinerea Populations Collected from Tomato Greenhouses in Northern Algeria

“…Using selenate‐resistant mutants, Korolev et al. () clearly demonstrated the exchange of airborne inoculum in both directions (in‐ and outbound) between a glasshouse and its close environment. Modelling approaches have also been developed for the quantification of such exchanges (Leyronas et al.…”