Relations between glasshouse climate and dry weight of petals, epicuticular wax, cuticle, pre-harvest flowering period and susceptibility toBotrytis cinerea of gerbera and rose flowers

Abstract

Studies were conducted on the effects of seasonal levels of relative humidity, temperature, and total radiation, on dry weight of petals, on fresh weight of epicuticular wax and of cuticle of petals, on numbers of Botrytis cinerea lesions in petals, and on preharvest flowering periods in gerbera mad rose. No temporal relationships or significant correlations were found among dry weight of petals, weight of wax and cuticle of petals, and numbers of lesions on the petals. Temperature, relative humidity and total radiation did not correlate significantly with dry weight of petals, or with fresh weights of wax and cuticle of petals, except for a positive correlation between relative humidity and cuticle weight in the gerbera cultivar Delphi. No relation was found between weight of epicuticular wax and cuticle of petals and susceptibility of gerbera and rose petals to B. cinerea. The thickness of wax and cuticle on flowers did not seem to be an important factor influencing the susceptibility of flowers to B. cinerea. The seasonal pattern in number of lesions produced on the flowers by B. cinema was related to the effects of relative humidity and radiation on infectivity of conidia of the pathogen on the flower surface but not to the effects on the susceptibility of flowers.

Control of Botrytis cinerea in glasshouse fuchsia by specific climate management

“…This was not due to the used method, which displayed differences in the susceptibility of fuchsia plants from differently dense stands or with a different nutrient supply (S. Friedrich, D. Gebelein, and C. Boyle, unpublished). In other studies similarly, no significant correlations were found between environmental factors and the susceptibility of gerbera (Kerssies, 1996) and rose flowers (Hammer and Evensen, 1996;Kerssies, 1996) to postharvest infection by B. cinerea. In another study, the susceptibility of rose flowers to this pathogen, however, was inversely correlated to the overall mean VPD from 08:00 to 19:00 h for the 5-week growth period before harvest during different seasons of the year (Marois et al, 1988).…”

Virulence factors of Botrytis cinerea.

“…ることで上昇したが (Sutton et al, 1984) ，ガーベラとバラ の花弁におけるワックス層の厚さと B. cinerea に対する感受 性との間に関連性は見出されなかった (Kerssies and Frinking, 1996) (Clark and Lorbeer, 1976;Cole et al, 1998;Collmer and Keen, 1986) ．エ ンドポリガラクツロナーゼ活性は分生子の発芽以前に観察 され (Verhoeff and Warren, 1972)…”

Unraveling the genetics of Botrytis cinerea resistance in Gerbera hybrida

“…B. cinerea lesion numbers on gerbera flowers counted under the microscope after cutting were observed with a seasonal pattern: few lesions in spring and early summer, many lesions at other times of the year (Kerssies 1993b). This was mainly related to the effects of relative humidity (Kerssies and Frinking 1996). Once the humidity reaches to 90% or higher, Botrytis spores will germinate and invasion will start at any temperature either in pre-harvest or post-harvest stage (Eden et al 1996).…”