Embed Size (px)
Citation preview
Notes:2.3: EST-SSR Marker resources for groundnut SameerKhanal*,ShunxueTang,ErvinNagy,YufangGuo,YanLi,
VadimBeilinson,PhillipSanMiguel,BaozhuGuo,NielsNielsen,ThomasStalker,Marie-MicheleCordonnier-Pratt,LeeHPratt,VirgilEdJohnson,ChristopherATaylor,GrahamBWiley,SimoneL. Macmil, Bruce Roe, Koppolu Ravi, Gautami Naidu, David Hoisington,RajeevVarshney,andStevenJKnapp*DepartmentofCropandSoilScienceandInstituteofPlantBreeding,
Genetics, and Genomics, The University of Georgia, Athens, Georgia, 30602,USA;e-mail:[email protected]
Narrow genetic diversity and a deficiency of polymorphic DNA markers have hindered genetic mapping and the application of translational genomics approaches and marker-assisted selection in groundnut (Arachis hypogaea). We developed and mined a groundnut EST database for simple sequence repeats (SSRs), assessed the frequency of polymorphic SSRs in ESTs, and developed 2,054 EST-SSR markers. We assembled 71,448 long-read (Sanger) ESTs and 304,215 short-read (454) ESTs into 37,914 unigenes, identified 7,413 perfect repeats, designed and tested primers for 80 EST-SSRs sampled from broad spectrum of motifs and repeat lengths, and screened 58 EST-SSR markers for polymorphisms among elite and exotic germplasm accessions. Of the 58 EST-SSR markers, 55 were polymorphic, 32 were polymorphic among elite lines (mean heterozygosity = 0.18), 27 were polymorphic among four elite x elite mapping populations, and 48 were polymorphic in two diploid mapping populations. The frequency of polymorphic EST-SSRs seems to be sufficient for developing the critical mass of DNA markers needed for routine genetic mapping and marker-assisted selection applications in groundnut. The EST-SSR markers described here are currently being screened for polymorphisms and mapped in multiple diploid and tetraploid mapping populations and could play an important role in breaking the DNA marker bottleneck in groundnut.
Related GCP project—SP2 Commissioned G4008.06: SNP discovery, validation, and mapping in groundnut
22
Poster abstracts, GCP Annual Research Meeting 2008
