Effects of long-term storage at different temperatures on conidia of Botrytis cinerea Pers.: Fr.

Survival of Botrytis cinerea conidia was studied after storage without pret reatments at different temperatures (-80 degreesC, -20 degreesC, 4 degreesC and 21 degreesC). Germination tests performed during 3 years showed that v iability at 21 degreesC was completely lost after I month. Conidia stored f or 30 months at -80 degreesC, -20 degreesC and 4 degreesC were able to germ inate, respectively, at 79%, 8% and 0.2%. Changes in adenylate level, energ y charge and respiration (O-2 consumption) made on each set of conidia were correlated to the germination rate. The 30-month-old stored conidia showed differences in pathogenicity tests on apples. While the pathogenic aggress iveness of conidia stored at -80 degreesC was almost the same as for fresh conidia, it decreased with increasing temperature of storage. An ultrastruc tural study made on conidia stored for 30 months at -80 degreesC has shown the emergence of a new wall layer in a retraction zone of the cytoplasm by comparison to fresh conidia. However, the integrity of the cytoplasmic cont ent was maintained. The effects of low temperature storage, maintenance of cell integrity and pathogenicity of conidia of B. cinerea are discussed. (C ) 2001 Federation of European Microbiological Societies. Published by Elsev ier Science B.V. All rights reserved.