Morphology, development and plant architecture of M. truncatula

A M. truncatula plant is made up of (1) a main axis that can organize either in a rosette (i.e. the leaves are at the level of the neck with very short internodes) or as an elongated axis; and (2) branches of different orders (e.g. primary, secondary, tertiary, branches). Plant morphology and architecture strongly vary between genotypes and are very dependent upon environmental and cultural conditions (Aitken 1955). For instance, when A17 plants are cultivated with a high plant density or with low radiations, the main axis is elongated and only very few branches are formed (erect plant). By contrast, when they are grown with a low plant density, the main axis organizes in a rosette and numerous branches develop (prostrate plant).