CASPARIAN BAND-LIKE STRUCTURES IN THE ROOT HYPODERMIS OF SOME AQUATICANGIOSPERMS

Casparian band-like structures were detected in the root hypodermis of Potamogeton pectinatus L., Ruppia maritima L., Zostera capensis Setch ell, Z. marina L., Z. japonica Aschers and Graebn, Halophila ovalis (R .Br.) Hook f. and Nymphaea capensis Thumb, but not in Egeria densa Pla nch, Eichhornia crassipes (Mart.) Solms and Lema minor L. The bands st ained with the fluorochrome berberine hemi-sulphate which is specific for Casparian bands. They also contained suberin, resisted acid digest ion and had an ultrastructure resembling Casparian bands of the endode rmis. They were always associated with suberin lamellae, and blocked a poplastic transport into the interior tissues of the roots. Symplastic transport through the root tissues, however, was not affected by the bands' presence.