FLORAL MORPHOLOGY AND RECOGNITION OF VARIETIES IN CONANDRON RAMONDIOIDES (GESNERIACEAE) FROM JAPAN AND TAIWAN

2004 ◽  
Vol 61 (1) ◽  
pp. 21-30 ◽  
Author(s):  
G. KOKUBUGATA ◽  
C.-I. PENG
Keyword(s):  
Geographical Distribution ◽  
Floral Morphology ◽  
Tube Length ◽  
Mitotic Chromosomes ◽  
Iriomote Island ◽  
Corolla Morphology

Comparisons of corolla morphology were made between plants of Conandron ramondioides (Gesneriaceae) from 23 localities in Japan and Taiwan. Lobe-length to tube-length ratios were found to correlate with geographical distribution and support the recognition of two previously described varieties: var. ramondioides in mainland Japan (lobe length less than twice tube length) and var. taiwanensis from Iriomote Island (Japan) and Taiwan (lobe length more than three times tube length). Mitotic chromosomes were also observed but no differences were seen between accessions, all of which had 2n=32.

scholarly journals Intraspecific divergence and convergence of floral tube length in specialized pollination interactions

2014 ◽  
Vol 281 (1795) ◽  
pp. 20141420 ◽  
Author(s):  
B. Anderson ◽  
P. Ros ◽  
T. J. Wiese ◽  
A. G. Ellis
Keyword(s):  
Linear Relationship ◽  
Floral Morphology ◽  
Population Level ◽  
Tube Length ◽  
Length Variation ◽  
Positive Linear Relationship ◽  
Intraspecific Divergence ◽  
Floral Tube ◽  
Adaptive Specialization ◽  
Pollinator Fauna

Floral tubes are often thought to be a consequence of adaptive specialization towards pollinator morphology. We explore floral tube length evolution within Tritoniopsis revoluta (Iridaceae), a species with considerable geographical tube length variation. We ask whether tube lengths of T. revoluta populations are associated with pollinator proboscis lengths, whether floral divergence occurs in the presence of different pollinators and whether floral convergence occurs between distantly related populations pollinated by the same pollinator. Finally, we ask whether tube length evolution is directional. Shifts between morphologically different pollinators were always associated with shifts in floral morphology, even when populations were very closely related. Distantly related populations had similar tube lengths when they were pollinated by the same pollinator. Shifts in tube length tended to be from short to long, although reversals were not infrequent. After correcting for the population-level phylogeny, there was a strong positive, linear relationship between floral tube length and pollinator proboscis length, suggesting that plants are functionally specialized on different pollinators at different sites. However, because tube length evolution in this system can be a bidirectional process, specialization to the local pollinator fauna is unlikely to result in evolutionary or ecological dead-ends such as canalization or range limitation.

Sulfhydryl bond formation is a prerequisite for proper cycling of centrosomes and chromosomes in mammalian tissue culture cells

1993 ◽  
Vol 51 ◽  
pp. 342-343
Author(s):  
Heide Schatten ◽  
Neidhard Paweletz ◽  
Ron Balczon
Keyword(s):  
Tissue Culture ◽  
Cell Cycle Progression ◽  
Group Formation ◽  
Sulfhydryl Group ◽  
Mammalian Tissue ◽  
Mitotic Chromosomes ◽  
Microtubule Network ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Transmission Electron

To study the role of sulfhydryl group formation during cell cycle progression, mammalian tissue culture cells (PTK2) were exposed to 100¼M 2-mercaptoethanol for 2 to 6 h during their exponential phase of growth. The effects of 2-mercaptoethanol on centrosomes, chromosomes, microtubules, membranes and intermediate filaments were analyzed by transmission electron microscopy (TEM) and by immunofluorescence microscopy (IFM) methods using a human autoimmune antibody directed against centrosomes (SPJ), and a mouse monoclonal antibody directed against tubulin (E7). Chromosomes were affected most by this treatment: premature chromosome condensation was detected in interphase nuclei, and the structure in mitotic chromosomes was altered compared to control cells. This would support previous findings in dividing sea urchin cells in which chromosomes are arrested at metaphase while the centrosome splitting cycle continues. It might also support findings that certairt-sulfhydryl-blocking agents block cyclin destruction. The organization of the microtubule network was scattered probably due to a looser organization of centrosomal material at the interphase centers and at the mitotic poles.

Ecology and biogeography in the introduction to “De bestiis marinis” by Georg Wilhelm Steller

2019 ◽  
Vol 46 (1) ◽  
pp. 63-74
Author(s):  
Stefano Mattioli
Keyword(s):  
Body Size ◽  
Phenotypic Plasticity ◽  
Geographical Distribution ◽  
Functional Traits ◽  
Marine Mammals ◽  
Main Part ◽  
Wide Distribution ◽  
Restricted Range ◽  
Direct Influence ◽  
Modern Biology

The rediscovery of the original, unedited Latin manuscript of Georg Wilhelm Steller's “De bestiis marinis” (“On marine mammals”), first published in 1751, calls for a new translation into English. The main part of the treatise contains detailed descriptions of four marine mammals, but the introduction is devoted to more general issues, including innovative speculation on morphology, ecology and biogeography, anticipating arguments and concepts of modern biology. Steller noted early that climate and food have a direct influence on body size, pelage and functional traits of mammals, potentially affecting reversible changes (phenotypic plasticity). Feeding and other behavioural habits have an impact on the geographical distribution of mammals. Species with a broad diet tend to have a wide distribution, whereas animals with a narrow diet more likely have only a restricted range. According to Steller, both sea and land then still concealed countless animals unknown to science.

Una nueva localidad almeriense de Phyllariopsis purpurascens (C. Agardh) Henry et South

2005 ◽  
Vol 30 ◽  
pp. 176
Author(s):  
Diego Moreno ◽  
Julio De la Rosa ◽  
Pedro Sánchez Castillo ◽  
Antonio Flores-Moya
Keyword(s):  
Iberian Peninsula ◽  
Geographical Distribution ◽  
New Record

A new record of Phyllariopsis purpurascens (C. Agardh) Henry et South from AlmeríaPalabras clave. Phyllariopsis, corología, Península Ibérica.Key words. Phyllariopsis, geographical distribution, Iberian Peninsula.

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