This Article Full Text Full Text (PDF) Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Peabody, R. B. Articles by Semelrath, K. M. Search for Related Content PubMed Articles by Peabody, R. B. Articles by Semelrath, K. M. Agricola Articles by Peabody, R. B. Articles by Semelrath, K. M.

Haploid vegetative mycelia of Armillaria gallica show among-cell-line variation for growth and phenotypic plasticity

     Biology Department, Stonehill College, Easton, Massachusetts 02357

Vegetative mycelial cells of Armillaria are expected to have diploid nuclei. Cells from a single mycelium therefore would not be expected to differ from one another for ecologically relevant quantitative traits. We isolated two sets of basidiome cell lines (from spores and stipe cells) and one set of vegetative cell lines (from an attached rhizomorph) from a single contiguous Armillaria gallica mycelium. We isolated a second set of vegetative cell lines from the soil 20 cm from the above basidiomerhizomorph complex. In all four sets of cell lines in situ DAPI-DNA measurements showed cells are haploid and quantitative-trait analyses of cell lines grown at different water potentials revealed high levels of among-cell-line genetic variation for both growth and phenotypic plasticity. Haploidy and the existence of ecologically relevant genetic variation within vegetative individuals are unexpected and mean that a process similar to evolutionary adaptation could take place within the soma of a genetic individual. We believe this is a key to understanding how large A. gallica mycelia survive exposure to variation in ecological conditions during lives that potentially span several tree (host) generations.

Key words: basidiomycete, genetic mosaicism, indeterminate fungal growth, long-lived species, natural selection, phenotypic plasticity