The proposal aims to exploit new molecular genomic resources for the small wild grass Brachypodium distachyon to understand the molecular basis of natural variation in grain morphology related traits that are believed to be locally or generally adaptive. I will complete a cellular and developmental characterisation of grain development in Brachypodium, characterise new accessions collected by collaborating groups from its native range (Israel, Spain and Turkey) for both morphological and genetic variation with the aim of relating morphological variation with its underlying genetic cause and its possible adaptive significance.The main objective over the next 3 years is to assess natural variation in key morphological characteristics of the grain in different accessions and define how this variation relates to geographic origin and population structure. These studies will provide new knowledge of the population structure and how plant architecture responds to the environment. I will also begin to establish the genetic lines required for QTL mapping and in the longer term identify the genes underlying the observed variation.