Exploration of genetic resources collections at ICARDA for adaptation to climate change: Identification and utilization of sources of stress tolerance
IPK-Gatersleben, Germany: Rajeev K. Varshney, Andreas Graner
ICARDA, Aleppo, Syria: Jan Valkoun, Stefania Grando, Michael Baum
in collaboration with
WUR, Wageningen, The Netherlands: Joao Paolo, Rients Niks, Fred van Eeuwijk
In order to meet the challenges that drought represents for sustainable crop production, we plan to estimate the genetic diversity, at functional level, for drought tolerance in a collection of barley germplasm and then devise strategies for the deployment of useful genes in crop improvement programs. In this context, functional diversity for drought tolerance in a barley collection has been estimated at both DNA and RNA level by using gene- or EST (expressed sequence tag)- derived SSR (simple sequence repeat) and SNP (single nucleotide polymorphism) markers and cDNA macroarrays, respectively. For assaying the genetic variation at DNA level, 68 EST-SNP (71 datapoints) and 45 EST-SSR markers were used with a set of 223 barley entries (comprising of landraces, modern varieties and Hordeum spontaneum, see Table 1) that is well characterized for drought tolerance. Fingerprinting work with more EST-SNP as well as AFLP (amplified fragment length polymorphism) markers will be continued in order to conduct LD (linkage disequilibrium)- based association mapping for drought tolerance by using genome wide scanning methodology. An intermediate dataset of 499 alleles (356 SSR alleles + 143 SNP alleles) was used to analyze the relationship among the genotypes examined. Basically all genotypes could be distinguished. The GS (genetic similarity) coefficient for all genotypes ranged from 0.263 to 0.832 and averaged 0.385. Detailed relationships among genotypes can be seen in the Fig. 1.
In the direction of functional association study, work is in progress and details can be obtained from Andreas Garner (graner@ipk-gatersleben.de) or Rajeev Varshney (rajeev@ipk-gatersleben.de).
This table is available for download in Excel-Format:
Submitted by Rajeev Varhsney
September 22, 2005