Bioassaying for Ozone with Pollen Systems

Abstract

Sensitivity to ozone of pollen germinating in vitro is closely correlated with ozone sensitivity of the pollen parent. Ozone In a previous paper (1) this author alluded to the fact that pollen populations differed in ozone sensitivity and that these differences were closely related to the ozone sensitivity of the pollen parent (source) (2, 3). S02 (4,5) and fluorides (6-9) also cause a reduction in germination and tube elongation indicating that pollen behavior in vitro can be modified or influenced by several gases generally considered to be environmental pollutants.Species and cultivar differences in ozone sensitivity have been well documented and are now often considered when evaluating the horticultural worth of plant materials (10). Differences in cultivar tolerance to ozone injury have been noted in alfalfa (11), eastern white pine (12), other coniferous species (13), beans (14, 15) is only a partial list of those plant species showing differences in cultivar sensitivity to ozone, but it is broad enough to demonstrate that the condition is widespread. It also suggests the possibility of using this diversity as expressed through the pollen populations, to devise a system for measuring air quality by observing pollen performance in vitro. This paper attempts to illustrate how that might to done for the gaseous photochemical pollutant ozone(O3).

Ozone affects pollen viability and NAD(P)H oxidase release from Ambrosia artemisiifolia pollen

“…Our results show a significant decrease in ragweed pollen viability after O 3 fumigation. A reduction in pollen viability by O 3 has also been reported in other studies and in other species ( Feder, 1968, 1981; Mumford et al., 1972 ). The fluorochromatic reaction used to test pollen viability provides an indirect measurement of esterase activity and the intactness of the plasma membrane ( Heslop-Harrison and Heslop-Harrison, 1970 ).…”

“…The O 3 effect on pollen grains has been considered in particular in studies of plant germination in vitro . However, opposing effects have been reported: Feder (1968, 1981) observed a reduction in Nicotiana tabacum pollen tube elongation, and similar results were reported for corn pollen by Mumford et al. (1972) .…”

Tansley Review No. 115

“…For example, Hormaza et al (1996) reported that reductions in pollen germination and tube growth, induced when the pollen of various fruit and nut tree species -apricot (Prunus armeniaca), apple (Malus domestica), nectarine and peach (Prunus persica), pear (Pyrus communis) and almond (Prunus dulcis) -was exposed in vitro to 20, 40 or 60 nl l −" ozone for 4 h were directly related to exposure concentration in most species. Feder (1981) noted a similar response in tobacco and petunia, and suggested that pollen from these species might be used as a bioassay for air quality. Moreover, Stewart (1998) found that exposure of B. campestris pollen to 100 nl l −" ozone for 6 h had no detectable effect on germination or pollen tube growth in vitro, whereas significant effects were observed when the concentration was raised to 120 nl l −" (Table 2), suggesting the existence of a threshold concentration for damage.…”

“…For instance, an early study of petunia (Petuniaihybrida) showed that ozone might alter the topography of the stigmatal surface (B. H. Harrison & W. A. Feder, unpublished results cited by Feder & Shrier, 1990), suggesting a direct effect on the maternal structures. More recent studies of oilseed rape (Brassica napus ; Bosac, 1992 ; Hormaza et al, 1996† Hormaza et al, 1996† Hormaza et al, 1996† Hormaza et al, 1996† Hormaza et al, 1996† Hormaza et al, 1996† Benoit et al, 1983Feder & Sullivan, 1969b† Harrison & Feder, 1974† Krause et al, 1975‡ Feder, 1981Feder et al, 1982‡ Feder, 1968Nicotiana tabacum Tobacco Feder & Sullivan, 1969a,b † Krause et al, 1975 Feder, 1968Feder et al, 1982Stewart, 1998†, § Stewart, 1998 § *Upward and downward arrows indicate ozone-induced increases or decreases in pollen germination or tube growth. †Differential sensitivity observed between cultivars or populations.…”