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Full-Text Articles in Life Sciences

Speciation In Duckweeds (Lemnaceae): Phylogenetic And Ecological Inferences, Daniel J. Crawford, Elias Landolt, Donald H. Les, Rebecca T. Kimball Jan 2006

Speciation In Duckweeds (Lemnaceae): Phylogenetic And Ecological Inferences, Daniel J. Crawford, Elias Landolt, Donald H. Les, Rebecca T. Kimball

Aliso: A Journal of Systematic and Floristic Botany

Species of duckweeds (Letnnaceae) that were resolved as sister taxa in a phylogeny based on combined molecular and non-molecular data were compared for morphological, physiological, and ecological attributes to infer factors important in the initial divergence leading to speciation. The ability to survive extreme conditions such as desiccation and cold temperatures is the most common difference identified between species. Two morphological characters facilitating survival in extreme environments are production of special resting buds called turions and increased seed production. The prevalent geographic pattern for species pairs consists of one restricted species occurring on the periphery of a more widespread taxon; …


Morphological, Anatomical And Palynological Investigation On Sonchus Erzincanicus Matthews (Asteraceae), Ali̇ Kandemi̇r, Serdal Makbul, Zafer Türkmen, Murat Yilmaz Jan 2006

Morphological, Anatomical And Palynological Investigation On Sonchus Erzincanicus Matthews (Asteraceae), Ali̇ Kandemi̇r, Serdal Makbul, Zafer Türkmen, Murat Yilmaz

Turkish Journal of Botany

In this study, Sonchus erzincanicus Matthews (Asteraceae) collected from Erzincan (Turkey) has been investigated by its leaf and stem anatomical features, pollen grain characteristics and ecological features. It is an endemic perennial herbs growing in slightly basic with low organic content soil. Stem cortex seen transparently is composed of parenchyma cells. The leaves are bifacial and have stomata cells that are anomocytic. The pollen type of the species is trizonocolporate. All anatomical studies including transverse sections of the stems and leaves and surface section of leaves are illustrated for the firs time.


Distribution And Ecology Of Freshwater Ichthyofauna Of The Biga Peninsula, North-Western Anatolia, Turkey, Hasan Musa Sari, Süleyman Balik, Mustafa Ruşen Ustaoğlu, Ali̇ İlhan Jan 2006

Distribution And Ecology Of Freshwater Ichthyofauna Of The Biga Peninsula, North-Western Anatolia, Turkey, Hasan Musa Sari, Süleyman Balik, Mustafa Ruşen Ustaoğlu, Ali̇ İlhan

Turkish Journal of Zoology

This research was carried out at 35 stations in 16 different streams on the Biga Peninsula during the spring and summer of 2000 and 2001 to determine the freshwater ichthyofauna and community features. In addition, some physical and chemical parameters of the streams were determined in their natural environment. Fourteen taxa belonging to 5 families were determined. Leuciscus cephalus, Petroleuciscus borysthenicus, Rhodeus amarus, Phoxinus phoxinus, Chalcalburnus chalcoides, Barbus tauricus escherichi, Gobio gobio, Capoeta capoeta bergamae, Vimba vimba, Cobitis fahirae and Neogobius fluviatilis are recorded for the first time from the Biga Peninsula. The most abundant species in the study area …