Sporulation des fougères aquatiques ("Azolla") en fonction des conditions climatiques

Résumé

Azolla is an aquatic fern symbiotic with Anabaena azollae, a nitrogen-fixing cyanobacterium. The sporulation period of various strains of Azolla was determined. One hundred fronds were observed for sporocarps once a week during the productive period of January to April for two consecutive years (1991-1992). Minimum and maximum temperatures were recorded during the observations period. Seven out of nine Azolla strains observed actually sporulated, with maximum rates occurring at the time of year when temperatures were low (22-27 °C), i.e. from January to February.