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On the Life Cycle, Cytology and Taxonomy of Cladophora Callicoma from India

R. Shyam
American Journal of Botany
Vol. 67, No. 5 (May - Jun., 1980), pp. 619-624
Stable URL: http://www.jstor.org/stable/2442655
Page Count: 6
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On the Life Cycle, Cytology and Taxonomy of Cladophora Callicoma from India
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Abstract

The present investigation deals with the cultural observations on the morphology, reproduction, life cycle, cytology and taxonomy of a freshwater Cladophora, C callicoma (L) Kutz, from India There is a regular isomorphic alternation of generations between quadriflagellate zoospore-producing diploid plants and biflagellate isogamete-producing haploid plants, coupled with heterothallism in the latter Chromosome numbers of n = 12 and 2n = 24 were determined respectively for gametophytes and sporophytes. Twelve bivalents were counted in meiosis where chiasmata varied from one to three. In light of above observations, the affinity of C callicoma with C. glomerata, to which the former has often been assigned, has been discussed. It is proposed that the C glomerata complex, which consists of intraspecific polyploid races, might have two distinct lines of evolution with regard to life cycle; one with forms having higher ploidy levels and lacking an alternation of generations, and the other with forms having low ploidy levels and alternation of generations

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