CLONAL DIVERSITY IN THE AGAMOSPERMOUS POLYPLOIDS OF TARAXACUM-HONDOENSE IN NORTHERN HONSHU, JAPAN

Chromosome numbers and allozyme variations were surveyed in 74 polyplo id populations of Taraxacum hondoense, in northern Honshu, Japan. Most of the populations (94.4%) consisted of triploid (2n=24), indicating the predominance of this ploidy level. Approximately 42.6% were found to contain tetraploid (2n=32), and a few plants were pentaploid (2n=40 ). Electrophoretic analysis at 6 Pgdh-1 revealed twelve phenotypes wit h four alleles (including one putative null allele). The triploids sho wed excessive heterozygosity (82.4%) and all of the tetraploids and pe ntaploids were heterozygote. Phenotype IV was the most frequent and wi dely distributed in northern Honshu. Forty five percent of the populat ions were found to contain multiple phenotypes at 6 Pgdh-1. A total of 21 clones were distinguished using three polymorphic loci (6 Pgdh-1, Got and Mdh), and a considerable amount of clonal diversity was detect ed both within and among polyploid populations of T. hondoense. Factor s causing multiclonality in agamospermous polyploids are discussed.