NUCLEOLAR PATTERNS IN ANTHERIDIAL FILAMENTS OF MONOECIOUS AND DIOECIOUS CHARA SPP (CHARACEAE) WITH DIFFERENT DNA C-VALUES

Using NOR-silver-staining technique, nucleolar arrangements have been studied in antheridial filaments among 5 taxa of Char a with different genome sizes: monoecious Chara vulgaris L., C. fragilis Desv., C. con traria Kutz, and dioecious: Chara aspera Willd., and Chara tomentosa L . It is argued that due to a chain-series of regulatory processes esta blishing correlations between nucleolar cycles and consecutive cell gr owth cycles, the diminution of nucleoli observed throughout the develo pment of antheridial filaments is a common and widespread feature of s permatogenesis shared by all the studied species. It is probably a con trolling mechanism acting over the morphogenetic reduction of cell dim ensions and cessation of mitotic divisions.