Maternally inherited mitochondrial DNA (mtDNA) has been used extensively to determine origin and diversity of taurine cattle (Bos taurus) but global surveys of paternally inherited Ychromosome diversity are lacking. Here, we provide mtDNA information on previously uncharacterised Eurasian breeds and present the most comprehensive Y-chromosomal microsatellite data on domestic cattle to date. The mitochondrial haplogroup T3 was the most frequent, whereas T4 was detected only in the Yakutian cattle from Siberia. The mtDNA data indicates that the Ukrainian and Central Asian regions are zones where hybrids between taurine and zebu (B. indicus) cattle have existed. This zebu influence appears to have subsequently spread into southern and southeastern European breeds. The most common Y-chromosomal microsatellite haplotype, termed here as H11, showed an elevated frequency in the Eurasian sample set compared with that detected in Near Eastern and Anatolian breeds. The taurine Ychromosomal microsatellite haplotypes were found to be structured in a network according to the Y-haplogroups Y1 and Y2. These data do not support the recent hypothesis on the origin of Y1 from the local European hybridization of cattle with male aurochsen. Compared with mtDNA, the intensive culling of breeding males and male-mediated crossbreeding of locally raised native breeds has accelerated loss of Ychromosomal variation in domestic cattle, and affected the contribution of genetic drift to diversity. In conclusion, to maintain diversity, breeds showing rare Y-haplotypes should be prioritised in the conservation of cattle genetic resources.
AimWe present a new method to economically map gradual changes in plant species composition in lowland rain forests using field data and satellite images. Such a method will be a useful tool in planning the sustainable use and conservation of Amazonian rain forests.
LocationThe study covered an area of c. 700 km 2 of primary rain forest in Amazonian Ecuador.
MethodsWe field inventoried the species composition of pteridophytes and Melastomataceae in 340 inventory plots (5 m × 50 m), described the prevailing topography and analysed soil cation concentration and texture. We used non-metric multidimensional scaling (NMDS) to summarize the floristic variation among the inventory plots in three ordination dimensions. The scores of the three ordination axes were predicted to non-visited places using a Landsat TM (thematic mapper) satellite image and the k nearest neighbours ( k nn) estimation method. To avoid extrapolation, we excluded from the analysis those pixel windows whose spectral values were not represented in the areas covered by field sampling. The accuracy of the predictions was evaluated by cross-validation and by comparing the predictions based on spectrally nearest neighbours to the predictions based on random neighbours.
ResultsThe floristic gradients presented by NMDS ordination were interpretable in terms of topography, drainage and soil cation content. Thirteen percent of the cloud-free pixels were excluded from the k nn analysis to avoid extrapolation. The estimates of the floristic ordination scores based on spectrally nearest neighbours were always more accurate than estimates based on random neighbours.
Main conclusionsThe presented method needs a relatively small input of work and resources, is mechanistic and produces maps that give relevant information on floristic variation over forest areas that are traditionally considered essentially homogeneous. Therefore, the method appears to have a great potential for use in mapping large areas of Amazonian rain forests.
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