This chapter synthesizes our current knowledge on the ecological genetics of the model legume Medicago truncatula. After a short introduction to the life cycle of the species, we describe the mating system of M truncatula and how selfing rates in nature can be inferred both by progeny testing and population surveys. We then review what is currently known on the distribution of genetic diversity...

Phosphorus (P)-deficiency is a major abiotic stress that limits legume growth in many types of soils. The relationship between Medicago and Sinorhizobium, is known to be affected by different environmental conditions. Recent reports have shown that, in combination with S. meliloti 2011, Medicago truncatula had a lower symbiotic efficiency than Medicago sativa. However, little is known about how...

We have identified an active Medicago truncatula copia-like retroelement called Medicago RetroElement1-1 (MERE1-1) as an insertion in the symbiotic NSP2 gene. MERE1-1 belongs to a low-copy-number family in the sequenced Medicago genome. These copies are highly related, but only three of them have a complete coding region and polymorphism exists between the long terminal repeats of these differe...

Multilocus sequence typing (MLST) is a sequence-based method used to characterize bacterial genomes. This method was used to examine the genetic structure of Medicago-nodulating rhizobia at the Amra site, which is located in an arid region of Tunisia. Here the annual medics Medicago laciniata and M. truncatula are part of the natural flora. The goal of this study was to identify whether distinc...

The rhizobia present in a single arid region Tunisian soil that nodulate Medicago laciniata and Medicago truncatula were compared. All isolates, 40 from each host, were Sinorhizobium meliloti based on 16S rRNA polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) patterns and subsequent confirmation by sequence analysis of the 16S rRNA genes in four representatives from ...

Immanuel Kant noted this approach would not be suitable for understanding complex systems such as an organism. He said there would never be a " Newton of the blade of grass " : because the blade of grass is more than the sum of its parts, complete knowledge of the parts list will not necessarily be predictive of the behavior of the whole. Fortunately, we don't have to resort to a vitalistic exp...