Publisher : Biodiversity Journal
Place of publication :
Publication year : 2014
Thematic : Species
Language : English
Note
In the Mediterranean region, Medicago granadensis Willd. and M. muricoleptis Tineo (Fabales
Fabaceae) of the Intertextae subsection are rare and present, each one in well defined areas,
whereas the others taxa, in the same subsection, M. ciliaris (L.) All. and M. intertexta (L.)
Mill., are more frequent with large distribution. This kind of geographical distribution is not a
coincidence; certainly different factors are the origin of this distribution. In 125 sites of different
Mediterranean countries, the ecology of the four taxa was studied, 34 trapped strains in one
site of Intertextae rhizobiums were characterized by rep-PCR and some symbiotic tests were
carried out. The results confirm that M. muricoleptis and M. granadensis are endemic in the
north and east of the Mediterranean, respectively; whereas, M. ciliaris and M. intertexta are
widespread. Although their geographic specificity, the four taxa showed no important differences
in ecological conditions. M. muricoleptis, given its presence in the north of the Mediterranean
only, is distinguished by its precipitation requirement. By inference, the absence of M.
muricoleptis and M. granadensis in some regions is not due to the absence of the symbiont.
We confirm the symbiotic specificity of Sinorhizobium medicae (Rome, 1996) for the
Intertextae subsection and the existence of coevolution between taxa (widespread and endemic)
and rhizobia. We suppose that endemic taxa are in the process of allopatric speciation, which
explains their narrow distribution in the Mediterranean Basin.
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Keywords : coastal-resource-degradation
Encoded by : Pauline Carmel Joy Eje
