Article Images: 0702Cover

 

On the cover: Scanning electron photomicrograph of Arabidopsis thaliana (accession Niederzenz) cotyledeons two days after inoculation with different isolates of Peronospora parasitica: left, an incompatible isolate (Emoy2) causing formation of pits and reduced expansion of the cotyledon; and right, a compatible isolate (Cala2) causing no visible response. For the article by Holub et al., see page 223 (photo by Colin Clay, HRI-Wellsbourne, U.K.).