KARYOLOGY AND AGAR ANALYSIS OF THE AGAROPHYTE GELIDIELLA-ACEROSA (FORSSKAL) FELDMANN-ET-HAMEL FROM THE PHILIPPINES

Microspectrophotometry with the DNA-localizing fluorochrome DAPI demon strated ploidy level differences in tetrasporophytic and presumptive g ametophytic phases of Gelidiella acerosa from the Philippines. Compari son of mean nuclear DNA (I-f) values to chicken erythrocytes (RBC) res ulted in an estimate of 0.32 pg/2 C genome. Karyological studies with aceto-orcein revealed a chromosome complement of six bivalents during diakinesis of tetrasporocytes. The agar yield ranges from 13-24% dry w eight, depending on the method of extraction. Agar extraction in 1 N N aOH resulted in an increased gel strength of 189 g cm(-2) at 1.5% conc entration. Infrared spectroscopy indicated a relatively high sulfate c ontent in native agar. The low (61 degrees) melting temperature is ind icative of high sulfation and small molecular size.