THE EFFECT OF CYANIDE, SHAM AND AZIDE ON THE GERMINATION AND RESPIRATION OF CITRULLUS-LANATUS SEEDS

The germination of Citrullus lanatus seeds is inhibited by cyanide, azide and SHAM. Azide at a concentration of 0.5 mmol dm-3 is sufficient to inhibit germinaton completely. Although azide is more effective than cyanide to inhibit germination, both substances inhibit respiration of these seeds to the same extent. The inhibitory effect of cyanide is antagonized by certain SHAM concentrations. No antagonism between azide and SHAM was found. These results imply that germination of C. lanatus seeds is controlled by a balance between cyanide sensitive and SHAM sensitive respiration and that azide and cyanide have different sites of action in inhibiting germination.