EFFECT OF DIFFERENT SEED STORAGE-CONDITIONS ON GERMINATION AND ISOZYME ACTIVITY IN SOME BRASSICA SPECIES

Sixteen seed accessions of four Brassica species (B. cretica, B. incan a, B. montana and B. oleracea) were examined following 5-22 years' sto rage in the germplasm bank. Germinability and isozyme activity of seed s stored under long-term (-10 degrees C and 3% moisture content) and s hort-term (5 degrees C and 8% moisture content) storage conditions wer e compared. Long-term storage produced no deterioration and the abilit y to germinate was satisfactorily maintained over 8-22 years. Short-te rm storage conditions maintained germination ability up to 10-12 years in all accessions of B. cretica and B. montana. However, seed multipl ication might be essential every 10 years for some accessions of B. ol eracea stored in this way. In the 8 to 9-year-old accessions of B. cre tica, B. incana and B. montana, no significant differences were detect ed between conservation systems for germinability and frequency of see ds showing isozyme activity for seven enzyme systems (AGO, IDH, MDH, M E, PGI, PGM and 6-PGD). However, significant differences were found fo r the ADH enzyme system. Moreover, in the 5-22-year-old B. oleracea ac cessions, significant differences were found between storage condition s with respect to isozyme activity for all enzyme systems studied. (C) 1995 Annals of Botany Company