Subprogramme 1 is charged with the exploration of the genetic diversity of global germplasm collections of GCP mandate crops. This exploration helps identify novel and diverse variants of genes involved in complex stress tolerance traits, thus providing the base for the research activities of the other 4 subprogrammes.

For each crop, Subprogramme 1 is building "composite sets" - each set representing the range of diversity of each crop species and its wild relatives-of germplasm from the genebanks and in situ collections around the world. Once complete, SP1 surveys the composite sets with anonymous molecular markers. These must be perfectly standardised so that simple, high throughput analyses will be possible for use in multiple laboratories, and valid anywhere in the future. This process results in the documentation of the structure of each composite set and helps identify diversity-rich components of the germplasm.

The information gathered on each composite set allows us to select a "reference sample" - the preferred material for advanced characterisation. This selection process, however, must reconcile several objectives. SP1 is responsible for meaningful phenotyping experiments, focusing on materials whose within-sample diversity enables accurate characterisation at the molecular and phenotypic levels. We promote populations of materials with continuous variation to best highlight functional relationships among polymorphisms, while exploring all the components of the global diversity.

To help identify useful traits and the genes that control them, SP1 has two options that work in concert. The identification of molecular polymorphisms can focus on candidate genes thought to be involved in the plant's reaction to stress (e.g., drought), so that the involvement of these genes can be tested and the most favourable alleles detected. Alternately, by investigating molecular variants at sufficient density across the whole genome, we may find unsuspected regions that explain part of the plant's resistance to drought.

Phenotyping is integrally important to the success of SP1 activities and the GCP as a whole. SP1 designs and executes phenotyping experiments that optimize the combination of germplasm surveyed and traits measured to more accurately determine how drought tolerance can be bred into plants.

SP1 is also developing protocols to ensure access to and benefit sharing for the products that are derived from germplasm accessions, in line with the Convention on Biological Diversity and the International Treaty on Plant Genetic Resources.