Use of RFLP markers to study genetic diversity and to build a core-collection of the wild wheat relative Ae. geniculata Roth (= Ae. ovata L.)

Abstract

The wild wheat relative Ae. geniculata Roth (= Ae. ovata L.) is a preferentially selfing, allo-tetraploid species (MU genome) widely distributed around the Mediterranean Basin. Two hundred and two individuals belonging to one hundred and fifty one populations originating from different eco-geographical regions were used to study its genetic diversity. The diversity was revealed on Restriction Fragment Length Polymorphisms (RFLP). Nine clones mapped on the Triticeae group 2 chromosome consensus map were used as probes. The genetic variability was found to be highly structured. A fine scale study performed on populations from Bulgaria, France and Morocco suggested that 52% of the diversity was explained by differences among populations within regions. A Factorial Analysis of Correspondence (FAC) distinguished two main structures corresponding mainly to the North and South of the Mediterranean Sea. Differences among close regions separated by natural barriers were also found. Hypotheses concerning the dissemination of Ae. geniculata around the Mediterranean Sea are presented and examined. In order to improve the management of Ae. geniculata genetic resources, a methodology for core collection sampling is presented and the efficiency of RFLP markers in building this collection is discussed.