METHODS FOR INCREASING THE EFFICIENCY OF SEED-GERMINATION IN THE FODDER LEGUMES TAGASASTE AND ESCOBON (CHAMAECYTISUS-PROLIFERUS (L FIL) LINK SENSU-LATO)

The breaking of seed dormancy in the seven,morphological forms of Cham aecytisus proliferus (L. fil.) Link is reported. These seven forms had similar responses to the treatments studied and high percentage germi nation (> 90%) was obtained after (1) boiling in water for 6-9 min, (2 ) boiling in water for 3 or 6 min followed by immersion in concentrate d sulphuric acid for 6 or 3 min respectively, (3) immersion in concent rated sulphuric acid for 3 or 6 min followed by boiling in water for 3 or 6 min respectively and (4) culture of excised embryos. Manual scar ification of the and region also gave high germination percentages but cotyledons were shed from many of the seedlings which died shortly af ter radicle emergence. Seeds treated with concentrated sulphuric acid for 10-20 min had low germination percentages ( < 20%) although this t reatment gave rise to some differences between the forms endemic to th e island of La Palma (i.e. white tagasaste and typical tagasaste) and the other morphological types. Treatments (1)-(3) are recommended for large scale propagation of tagasaste whereas treatment (4) is recommen ded for experimental studies in which a limited number of samples is n eeded. Ultra-structural changes in the seedcoat epidermis after breaki ng of seed dormancy are reported and the relationship between seed dor mancy and the ecology of tagasaste and escobon suggests C. proliferus is a pyrophyte species.