Differential response of buddleia (Buddleia davidii Franch.) to ozone

Tansley Review No. 115

“…Floral initiation and development can also be affected by ozone ; for instance, Fernandez-Bayon et al (1993) found that flower production was significantly reduced in two cultivars of watermelon (Citrullus lanatus cvs Sugar Baby and De La Reina) and muskmelon (Cucumis melo cvs Verde Tendral Tardio and Amarillo Temprano) following 21 d exposure to 70 nl l −" ozone for 6 h d −" . Similar effects have been observed for other species, including carnation (Feder & Campbell, 1968 ;Feder, 1970), duckweed (Feder & Sullivan, 1969b ;Feder, 1970), B campestris (Stewart, 1998) and buddleia (Findley et al, 1997). However, such effects are strongly influenced by the timing and duration of exposure.…”

“…Tapidor and the number of raceme branches in both cvs Tapidor and Libravo. Increases in plant height have also been reported for tomato (Neil et al, 1973) and carrot (Daucus carota ; Bennett & Oshima, 1976 ; Table 3) following wholeplant exposures to ozone, while exposure of buddleia (B. davidii) to ambient ozone levels in Alabama, USA was found to induce increases in inflorescence length comparable to those observed in oilseed rape, although these were accompanied by reductions in inflorescence dry weight associated with reduced partitioning of dry weight to the reproductive components (Findley et al, 1997). By contrast, ozone-induced reductions in plant height have been reported for carnation (Feder, 1970) and wheat (Mulholland et al, 1997a(Mulholland et al, , 1998a.…”

“…However, although ozone-treated plants of both cultivars exhibited greater losses of fertile sites up to 25 d after exposure, the number present at final harvest was not significantly different from control plants, demonstrating that oilseed rape is capable of compensating for ozone-induced losses of fertile sites during flowering (Bosac et al, 1994). This recovery contrasts sharply with buddleia (Findley et al, 1997) and dogbane (Bergweiler & Manning, 1999), in which the numbers of inflorescences produced and reproductive sites retained to maturity were reduced in plants grown under the prevailing ambient ozone concentrations relative to charcoalfiltered control plants.…”

“…Co-ordinated experimental programmes such as the US National Crop Loss Assessment Network and the European Open-Top Chamber Programme, along with numerous other studies, have shown that current ground-level concentrations of ozone are sufficiently high to reduce crop yields (Mulchi et al, 1986(Mulchi et al, , 1988Heck et al, 1988 ;Ja$ ger et al, 1993 ;Wahid et al, 1995). The impact of ozone is known to vary between species and cultivars (Findley et al, 1997 ;Davison & Barnes, 1998 ;Barnes et al, 1999a) and to be influenced by both climatic factors (Wolfenden & Mansfield, 1991 ;Krupa et al, 1995) and cultural practices (Taylor & Rich, 1973). In view of the increasing frequency and severity of exposure, it is important to understand more fully the causes and consequences of the impact of ozone on reproductive biology for the productivity and yield of domesticated species, and the stability of native ecosystems.…”

“…Exposure to ozone has been reported to delay flowering in various species, including soybean (Glycine max ; Amundson et al, 1986), cotton (Gossypium hirsutum ; Oshima et al, 1979), duckweed (Lemna perpusilla ;Feder & Sullivan, 1969b ;Feder, 1970), geranium (Pelargoniumihortorum ;Feder, 1970), carnation (Dianthus caryophyllus ;Feder & Campbell, 1968 ;Feder, 1970) and buddleia (Buddleia davidii ; Findley et al, 1997 ; Table 3). Amundson et al (1986) reported that flowering began 37, 40, 42 and 44 d after seedling emergence when soybean plants were exposed to 10, 50, 90 or 130 nl l −" ozone for 6.8 h d −" over an 8 wk period ; similarly, Bergweiler & Manning (1999) found that flowering was delayed by 10 d relative to plants receiving charcoal-filtered air when dogbane (Apocynum androsaemifolium) was grown under ambient air conditions in the Eastern USA.…”