Nuclear ribosomal DNA variation in Leucobryum glaucum and L. albidum (Leucobryaceae): A preliminary investigation

Leucobryum glaucum and L. albidum are generally distinguished by quantitative differences in plant height, leaf length, and transverse sectional leaf anatomy. Although extremely small plants can be readily identified as L. albidum, and large plants can be confidently assigned to L. glaucum, intermediate forms are common and many identifications are arbitrary. We amplified approximately 815 bp of the nuclear ribosomal DNA ITS from plants varying in size, and cut the products with three restriction endonucleases (Hhal, Hinfl, and Taql). Two DNA haplotypes were detected in a sample of 23 plants growing at a forested site in Durham, North Carolina. All plants with leaves 5.0 mm in length or shorter had one haplotype, and all plants with leaves longer than 5.0 mm had the other haplotype. Our results support the interpretation that L. albidum (small plants) is genetically discontinuous with L. glaucum (large plants), at least in the limited area from which we sampled.

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Author A. Jonathan Shaw Biology