N. Cronberg, CLONAL STRUCTURE AND FERTILITY IN A SYMPATRIC POPULATION OF THE PEAT MOSSES SPHAGNUM-RUBELLUM AND SPHAGNUM-CAPILLIFOLIUM, Canadian journal of botany, 74(9), 1996, pp. 1375-1385
Data from isozyme and leaf shape variation are combined to explore the
clonal structure at a site where hybridization between Sphagnum rubel
lum and Sphagnum capillifolium was previously indicated. Shoots of bot
h species were sampled at 10-cm intervals along seven transects across
different hummocks. Allelic data from 13 enzyme systems revealed 22 m
ultilocus genotypes representing different clones, 18 being S. capilli
folium and 4 being S. rubellum. The mean +/- SE and maximum clonal len
gth were 35 +/- 8 cm and 160 cm, respectively. The sets of alleles fou
nd in the progeny of S. capillifolium were identical to the maternal c
omplement of alleles in 78% of the material, indicating either self-fe
rtilization or fertilization by a male with the same set of alleles at
the screened loci. Outcrossing was detected in six cases. Patterns of
differentiation and the hierarchical structuring of diversity among s
pecies, transects, and clones were analysed with canonical variates an
alysis using stem-leaf characters. A stronger relative differentiation
was found between transects than between species. Clones identified b
y electrophoresis were usually morphologically well defined. Hybridiza
tion was indicated by morphological characters, occasional misplaced a
lleles, and signs of developmental instability.