Sexual reproduction in desmids with special reference to Micrasterias thomasiana var. notata (Nordst.) Grönblad

摘要: Strains of several forms Micrasterias thomasiana, isolated in Tasmania and Victoria, conjugated when mixed all combinations. Homothallism was not detected rarely were both mating strains present one locality. Conjugation, preceded by an initial pairing subsequent cell division, takes place between offspring this either within or parental groups. Conjugants, invested a mucilage envelope, secrete pinkish medially, which conjugation cylinder differentiates. Its relationship to structures other species is discussed. Conjugation anisogamous. The spiny zygospore has at least three walls undifferentiated operculum the exospore facilitates germination. Only gone produced. Meiosis occurs immediately preceding Most chromosomes are too small reveal details centromeric organization but two longer apparently sub-telocentric. partially asynchronous. A presumably haploi...