Effects of Enhanced Solar UV-B Radiation on Growth and Function of Selected Crop Plant Seedlings

The damaging effects of enhanced UV-B radiation which is to be expected after a possible destruction of the ozone layer by chlorofluorohydrocarbons (Stolarski, 1988) have been demonstrated by several research groups. Mainly reductions of leaf area, fresh weight, lipid content and of photosynthetic activity were found in UV-B sensitive plants (Sisson and Caldwell, 1976; Bogenrieder and Klein, 1977; Brandle et al., 1977;Teramura, 1983;Teramura and Murali, 1986; Tevini and Iwanzik, 1983; Caldwell, 1981; Tevini et al., 1981,1983a,b,1986;Norudeen and Kulandaivelu, 1982;Iwanzik et al., 1983). In addition structural alterations of the leaf surface (Tevini et al., 1981), the epicuticular waxes (Steinmuller and Tevini, 1985) and the diffusion of water vapour through the stomates (Teramura et al., 1983) have been observed.