Validierung vom Kandidatengenen und Identifizierung günstiger Allele der Trockenstresstoleranz bei Perlhirse

Effective conservation and use of genetic resources in agriculture are key factors in achieving long term and sustainable food security. An increased availability of plant genetic resources for crop breeders relies on the identification of the genes involved in important agronomical traits. New approaches integrating population genetics and genomic information allow validation of candidate genes and identification of interesting alleles by searching for association between DNA polymorphism and phenotypic variation in populations. Drought tolerance in plants is an important trait to consider for food security because global climate changes and human activity favour the extension of dry areas, and because local human population pressure is high in these particular regions that are the most subject to dry conditions. Alleles providing added value in terms of drought tolerance are likely to be found in species that present a global high adaptation to drought, like pearl millet, which is a minor crop grown in semi-arid and arid regions of Africa and of India. The purpose of my project is to validate candidate genes involved in drought tolerance in pearl millet and to identify interesting alleles for that trait by applying an association strategy. The methodology involves the sampling of African pearl millet lines that will be genotyped for microsatellite markers and sequences at selected candidate genes for drought tolerance. The choice of candidate genes will be based on genomic information developed in major cereals like maize, wheat or rice, which share with pearl millet a substantial amount of genomic homologies. Phenotypes for drought tolerance will be evaluated from greenhouse and field experiments through measurement of primary traits involved in drought tolerance (osmotic adjustment, root system) and overall trait expression (yield components).