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Natural hybridization occurs commonly in plants and blurs their interspecific delimitation. It is unclear whether spontaneous hybridization occurs in natural populations of Primula in China. In this study we examined natural hybridization between P. secundiflora and P. poissonii based on morphological and molecular analyses of individuals with intermediate morphology. Most morphological characters of these individuals were found to be intermediate between the putative parental species, but plant height and corolla tube length were significantly transgressive. Molecular analyses based on nuclear internal transcribed spacer (ITS) additivity and two types of cloned sequences (each corresponding respectively to one of two parental species) clearly suggested that these individuals result from hybridization between P. secundiflora and P. poissonii. We further used a maternally inherited chloroplast DNA fragment (rpl16 intron) to trace the maternal composition of the hybrids. Among 26 hybrids, ten (two thrums, eight pins) had the P. secundiflora haplotype, while 16 (ten thrums, six pins) possessed the P. poissonii haplotype. These results suggest that both parents served as the mother donors of the hybrids. Reciprocal hybridization between the two species seems to be symmetrical rather than unidirectional
Goat warble fly infestation is a subcutaneous myiasis present in many European and Asian countries. The causative agents of this myiasis have been assumed to be Przhevalskiana silenus (Brauer, 1858), P. aegagri (Brauer, 1863) and P. crossii (Patton, 1922) (Diptera, Oestridae). On the basis of morphological and biochemical data, some authors have considered P. silenus, P. aegagri and P. crossii as a single species. To clarify this taxonomie issue, the most variable regions of the mitochondrial gene encoding for the subunit I of cytochrome oxidase (COI) and of the 28S rRNA gene, were characterized molecularly for larvae morphologically identified as P. silenus, P. aegagri and P. crossii. The high genetic homology among the sequences of these putative species (≥ 99.71% for the COI gene and 100% for the 28S gene), indicates that P. aegagri and P. crossii are morphotypes of the single species P. silenus.
Hymenolepidid cestodes in Myodes glareolus from Lithuania and additional specimens originally attributed to Arostrilepis horrida from the Republic of Belarus are now referred to A. tenuicirrosa. Our study includes the first records of A. tenuicirrosa from the European (western) region of the Palearctic, and contributes to the recognition of A. horrida (sensu lato) as a complex of cryptic species distributed broadly across the Holarctic. Specimens of A. tenuicirrosa from Lithuania were compared to cestodes representing apparently disjunct populations in the eastern Palearctic based on structural characters of adult parasites and molecular sequence data from nuclear (ITS2) and mitochondrial (cytochrome b) genes. Morphological and molecular data revealed low levels of divergence between eastern and western populations. Phylogeographic relationships among populations and host biogeographic history suggests that limited intraspecific diversity within A. tenuicirrosa may reflect a Late Pleistocene transcontinental range expansion from an East Asian point of origin.
Potamogeton ×subrufus Hagstr. was described as a hybrid between P. lucens L. and P. nodosus Poir.; however, the taxon had not been widely accepted and regarded as conspecific with P. ×fluitans Roth, the hybrid between P. lucens and P. natans L. The origin of P. ×subrufus had been obscured till 2010, when, based on morpho-anatomical treatment, it was shown that P. ×subrufus displays several characters consistently different from those of P. ×fluitans. Here we report a successful amplification and sequencing of nuclear ribosomal ITS1 region from a 115 year-old herbarium specimen of P. ×subrufus, collected in locus classicus by J. Baagöe and preserved in the Herbarium of the Institute of Botany, Jagiellonian University (KRA). Based on the additive polymorphism pattern expressed in the ITS1 sequences of P. ×subrufus, we demonstrate that one of the parents of this hybrid was P. nodosus, as was claimed by Hagström.
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