Some effects of fluoride on the establishment and growth of propagules of Bruguiera gymnorrhiza and Avicennia marina

Some effects of dissolved fluoride on the establishment and growth of the two most common mangrove species of the Natal coast have been evaluated in view of the increasing offshore discharge of this potentially toxic pollutant. Young plants of Avicennia marina (Forssk.) Vierh. were found to be tolerant to substrate fluoride levels as high as 50 p.p.m., this species translocating and excreting the halogen. The growth of Bruguiera gymnorrhiza (L.) Lam., on the other hand, was severely retarded, this species accumulating far higher levels of tissue fluoride than did A. marina, and gross cellular and subcellular abnormality occurred. S. A ft. J. Bot. 1985, 51: 439 44 7 Sommige effekte van opgeloste fluoried op die vestiging en groei van die twee mees algemene wortelboomspesies van die Natalse kus is geëvalueer in die lig van toenemende uitskeiding van hierdle potensieel toksiese besoedelings-middel langs die kus. Jong plante van Avicennia marina (Forssk.) Vierh. het geblyk substraatfIuoriedvlakke so hoog as 50 d.p.m. te verdra, aangesien hierdie spesie die halogeen vervoer en uitskei. Die groei van Bruguiera gymnorrtiiza (L.) Lam., in teenstelling hiermee, is ernstig vertraag, aangesien hierdie spesie baie hoër vlakke van weefselfIuoried opgaar as A. marina, en grootskaalse sellulêre en subsellulêre abnormaliteite het voorgekom. S.-Afr. Tydskr. Plantk. 1985, 51: 439 — 447