1,721,002 research outputs found
Evolutionary Processes and Hybridization within the Peat Mosses, Sphagnum
No full textThe aim of this thesis was to reveal details of the interspecific hybridization among bryophytes as exemplified by Sphagnum capillifolium and S. quinquefarium. I used a combination of morphometric and molecular methods, and cultivation experiments to (1) identify hybrid gametophytes, (2) reveal the contribution of each of the parents to the genomes of hybrids, (3) study the fertility of primary hybrid sporophytes, (4) explore the fitness of hybrids as compared to their parents. The results showed that S. capillifolium and S. quinquefarium are morphologically and genetically well differentiated. Hybrid sporophytes had low fertility. However, when the two species grow sympatrically, hybrid individuals are often present. They are morphologically and genetically more similar to S. capillifolium but possess a restricted number of traits and molecular markers of S. quinquefarium. A comparison with the genetic composition of hybrid gametophytes raised from primary hybrid sporophytes indicated that the natural hybrid gametophytes may be first generation recombinants. The inheritance of chloroplasts was found to be uniparental from the maternal plant. The growth experiment showed that Sphagnum hybrids are likely to survive in habitats with high and constant humidity, similar to the typical environment of S. quinquefarium. In such habitats they would be good competitors due to relatively high growth rate and high regeneration ability, enabling them to expand clonally and persist for long periods. The conclusion is, that interspecific gene flow in bryophytes, as exemplified by S. capillifolium and S. quinquefarium, may be more frequent and with farther reaching consequences then previously anticipated
Check-list of the bryophytes of Bulgaria with data on their distribution. I. Hepaticae and Anthocerotae
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Hybridization between the peat mosses, Sphagnum capillifolium and S. quinquefarium (Sphagnaceae, Bryophyta) as inferred by morphological characters and isozyme markers
No full textIsozyme markers and morphological characters were studied in four populations of Sphagnum capillifolium and S. quinquefarium. Recombinant plants were found in three populations, where the two species occur sympatrically. All recombinants possessed different haplotypes and combinations of morphological characters, which show that they are results of independent hybridization events. Strongly male-biased sex ratios were found for Sphagnum capillifolium in all populations where it grew sympatrically with S. quinquefarium. Most of the recombinants were also male fertile. These observations suggest that S. quinquefarium is the female parent in the primary crosses and in subsequent backcrosses
Genetic diversity in populations of Sphagnum capillifolium from the mountains of Bulgaria, and their possible refugial role
No full textGenetic diversity in eight populations of Sphagnum capillfolium from different Bulgarian mountains was investigated by means of isozyme electrophoresis. High levels of allelic diversity were found (H-s = 0.119), comparable to earlier estimates for northern European populations (H-s = 0.116). Strong differentiation among populations and a low number of widespread genotypes suggest a high degree of isolation and restricted gene flow between populations, which is consistent with generally small and scattered populations. The large proportion of distinguishable genotypes (mean 0.498) suggests high levels of out-crossing either currently or in the past. Introgression between S. capillfolium and S. rubellum, a species not found in Bulgaria, was suggested by the occurrence of rubellum-alleles in five populations from different mountains. This could be explained by an ancient hybridization event in a sympatric population. Based on (1) the high genetic diversity, (2) the fairly wide distribution of alien alleles, and (3) the isolated distribution of populations even within one mountain. a possible survival of S. capillifolium in the Balkan area during the Quaternary ice periods is hypothesized
Three new species for the bryophyte flora of Bulgaria.
No full textAbstract. Sphagnum fimbriatum, Dicranoweisia cirrata and Drepanocladus longifolius, are reported for the first time for the bryophyte flora of Bulgaria
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