Effects of population size and forest management on genetic diversity and structure of the tuberous orchid Orchis mascula (original) (raw)
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Scientific Reports
Understanding how environmental factors shape patterns of genetic and phenotypic variations in a species is necessary for conservation and plant breeding. However, these factors have not yet been completely understood in tuberous orchid species used to make ‘Salep’, an important ingredient in traditional medicine and beverages in middle eastern countries and India. In many areas, increasing demand has pushed species to the brink of extinction. In this study, 198 genotypes from 18 populations of the endangered species Orchis mascula L. spanning a large-scale climatic gradient in northern Iran were used to investigate patterns of genetic diversity and plant functional traits. Populations were sampled from three land cover types (woodland, shrubland, and pastureland/grassland). Plant height, stem length, number of flowers, bulb fresh and dry weight, glucomannan, and starch concentrations showed high variation among populations and were significantly related to land cover type. In gener...
Gene variation and gene flow in Orchis morio ( Orchidaceae ) from Italy
Plant Systematics and Evolution, 1992
Data are presented on genetic variation at 27 enzyme loci of the Green-Winged orchid,Orchis morio, in 18 population samples from Italy. The existence in Italy of two subspecies, i.e. subspp.morio andpicta, is not supported by allozyme data. No genetic heterogeneity was found betweenmorio-like andpicta-like samples and specimens. Moreover, morphological transition between the two forms was observed in different Italian populations. The parameters of genetic variability estimated forO. morio populations are consistent with those found among monocotyledon plants, and among those outcrossing, animal-pollinated and with wind-dispersed seeds. Genetic diversity of ItalianO. morio is mostly within populations. Correspondingly, low values of interpopulational genetic distance were found. This appears to be due to high levels of gene flow, which were estimated with different methods. The lack ofO. longicornu from Italian samples, as well as of any hybrid withO. morio (F1, backcrossed or recombinant individuals) is demonstrated on the basis of genetic data. It is concluded that recurrent reports ofO. longicornu from Italy are due to confusion withO. morio or with otherOrchis species.
Plant Systematics and Evolution, 2000
Genetic differentiation in space can be detected at various scales. First, habitat fragmentation can produce a mosaic genetic structure. Second, life history aspects of a species such as dispersion, mating system, and pollination can generate a genetic structure at a finer level. The interplay of these levels has rarely been studied together. In order to assess the effects of forest fragmentation we analyzed the genetic structure at two spatial scales of the terrestrial orchid Cyclopogon luteoalbus, which lives in patches inside forest fragments in a cloud forest of eastern Mexico. We hypothesized high differentiation between forest fragments and strong spatial genetic structure within fragments under this scenario of strong fragmentation and restricted dispersal patterns. Using 11 allozymic loci we found high genetic diversity at fragment level with moderate differentiation among fragments, and at patch level, strong and variable spatial genetic structure among life cycle stages with high inbreeding coefficients. We also found bottlenecks indicating recent population size reductions. While both inbreeding and restricted seed dispersal may explain the strong spatial genetic structure at patch level, reduction in population size may explain the genetic structure at fragment level. However, the levels of genetic diversity indicate that some between-fragment gene flow has occurred. Bottlenecks and high inbreeding at patch level may result in local extinctions, but as long as an important number of fragments remain, patch recolonization through immigration is possible in C. luteoalbus.