Nombre chromosomique des Ptéridophytes des Mascareignes : Première contribution (Plantae : Pteridophyta)

Abstract: Chromosome numbers of Mascarene’s Pteridophytes : First contribution. Reunion Islandand Mauritius with 275Pteridophytes species are the main islands of Mascarene archipelago and represent a hot spot of biodiversity. But, no regional compilations of Pteridophyte chromosome numbers have been hitherto published for Madagascan area. The meiosis of species of the Reunion Island Pteridophytes was studied cytologically.Specimens were collected in the Reunion Island forest, or ina private garden at Plaine des Palmistes. As they were collected the young sporangia were immediately fixed by using Carnoy’s (1 : 3) acetic alcohol. For each species one microphotography and one drawing of meiosiswerecompleted. This work with 34 counts for 10 families is the first contributionto chromosome numbers of Mascarene’s Pteridophytes. 26 countsamong them representthe first record. Wehave acquired chromosome numbers of8 strict endemic species of Reunion Island and of 4 endemic species of both Reunion Island and Mauritius. Further studies in other Mascarene families will be reported in the future, thus increasing the information on chromosome numbers inPteridophytes.Résumé : Le nombre de chromosomes de 34 espèces dePtéridophytes présentes à la Réunion dont8 sont endémiques strictes de l’île et4 autres, endémiques de la Réunion et de Maurice, a été compté. Sur les 34 espèces étudiées, le nombre chromosomique obtenu pour 26 d’entre elles constitue un premier enregistrement.mots clés : Nombres chromosomiques, Réunion, Mascareignes, Ptéridophyteskeywords : Chromosome numbers, Reunion island, Mascarene archipelago, Pteridophyte