INRA 2012

Why a collection ? The genus Medicago A complex of species Advices

On the basis of a consensus tree (Giles Bena, 1998, 1999) built on the Ribosomal External and Internal Transcribed Spacers, the proximity between a cluster of annual species including Medicago truncatula and the perennial species of the genus including Medicago sativa can easily been observed. For Medicago truncatula, the cluster is very robust. The node was totally stable whatever the method of phylogenetic reconstitution used. Moreover, in the 1990 Small & Brookes taxonomy, Medicago littoralis is considered as a sub-species of Medicago truncatula.
This relationship is confirmed by the possibility to obtain viable and fertile hybrid between these species (less easily between Medicago truncatula and italica). As an example, a source of aphid tolerance was transferred by Andrew Lake from Medicago italica to Medicago truncatula, with Medicago littoralis as bridge species.
That the reason why we prefer to speak about a complex of species including truncatula, littoralis and italica (tornata) and why we have decided to introduce these three species in the Medicago Truncatula Genetic Ressource Center.

 

References:

  • G. Bena, MF Jubier, I. Olivieri and B. Lejeune, 1998. Ribosomal external and internal transcribed spacers: combined use in the phylogenetic analysis of Medicago (Leguminosae). J. Molec. Evol. 46, 299-306.
  • G. Bena, JM prosperi, B. Lejeune and I. Olivieri, 1998. Evolution of annual species of the genus Medicago: a molecular phylogenetic approach. Molec.Phyl. Evol., vol 9,n3, june, pp 552-559.
  • G. Bena, B. Lejeune, JM Prosperi and I. Olivieri, , 1998. Molecular phylogenetic approach for studying life-history evolution: the ambiguous example of the genus Medicago L. R.Soc.Lond. B (1998) 265, 1141-1151.

 

botanical varieties of Medicago truncatula Gaertn.

manual crossing
identification of a pod after hybridisation
pods
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