PAG-V: W1 - STRATEGIES FOR LOCATING GENES FOR SALT TOLERANCE IN BARLEY: MAPS, MARKERS AND WILD SPECIES

Plant & Animal Genome V Conference

Town & Country Hotel, San Diego, CA, January 12-16, 1997.

W1

STRATEGIES FOR LOCATING GENES FOR SALT TOLERANCE IN BARLEY: MAPS, MARKERS AND WILD SPECIES

FORSTER, BRIAN PETER(1), Hassan Pakniyat(1), Roger P. Ellis(1), Linda L. Handley(1), Eviator Nevo(2), Dennis C. Gordon(2), R. Keith(3), Wayne Powell(3)
1. Dept. of Cell and Molecular Genetics, Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, UK
2. Institute of Evolution, University of Haifa, Mount Carmel, Israel
3. Department of Cell and Molecular Genetics, Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, UK

At SCRI genetic and physiological components of abiotic stress tolerance are studied by a multidisciplinary team, using barley as a model. Our strategy involves: 1) measuring variation for responses to abiotic stress in wild barley genotypes; 2) genetically fingerprinting these lines; 3) finding associations between physiological responses and genetic markers; and 4) mapping the loci involved using genetically mapped barley doubled haploid populations. The genetic analysis aims to combine approaches which exploit natural wild species variation with genetic mapping using artificially produced doubled haploids. The advantages and limitations of these two component parts are compared both individually and in combination. We have chosen our work on salt tolerance to illustrate the strategy. 39 wild barley (Hordeum spontaneum) genotypes from various habitats were salt-stressed and tolerance measured in terms of shoot Na⁺ and del.¹³C which were highly correlated. The 39 wild barley lines were simultaneously fingerprinted using AFLPs. Of the 204 AFLPs, 12 were found to be significantly associated with salt tolerance. These markers were also found to be associated with site-of-origin eco-geographic data, particularly longitude, with the more salt tolerant lines coming from the south-eastern area of the Fertile Crescent. The 12 markers were partitioned into groups in which markers showed significant associations and between which there were no significant associations. These groupings may represent genetic linkage relationships which are currently being tested by mapping in a doubled haploid population derived from a cross between a salt tolerant wild barley and a sensitive cultivar. Genetically mapped doubled haploid populations have also been tested for other abiotic stressors to see if common markers/loci are involved.