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ARS Home » Plains Area » Manhattan, Kansas » Center for Grain and Animal Health Research » Hard Winter Wheat Genetics Research » Research » Publications at this Location » Publication #319798
Title: Genetic diversity among synthetic hexaploid wheat accessions with resistance to several fungal diseases

Author
item DAS, MODAN - Oklahoma State University
item Bai, Guihua
item MUJEEB-KAZI, ABDUL - International Maize & Wheat Improvement Center (CIMMYT)
item RAJARAM, SANJAYA - International Maize & Wheat Improvement Center (CIMMYT)

Submitted to: Genetic Resources and Crop Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2015
Publication Date: 9/10/2015
Publication URL: http://handle.nal.usda.gov/10113/5451332
Citation: Das, M.K., Bai, G., Mujeeb-Kazi, A., Rajaram, S. 2015. Genetic diversity among synthetic hexaploid wheat accessions with resistance to several fungal diseases. Genetic Resources and Crop Evolution. doi:10.1007/s10722-015-0312-9.

Interpretive Summary: Synthetic hexaploid wheat (SHW) is known to be an excellent vehicle for transferring many useful traits from the D genome donor, Aegilops tauschii, to cultivated wheat. This study evaluated genetic diversity of 32 SHW using Amplified Fragment Length Polymorphism (AFLP) and Simple Sequence Repeat (SSR) markers. These SHW were made from different sources of the D genome and selected for resistance to several fungal diseases from about 1,000 SHW developed at the International Maize and Wheat Improvement Center (CIMMYT), Mexico. Results indicated that average gene diversity and polymorphic information content were high for the D genome markers. Cluster analysis showed distinct groups among the wheat accessions studied. The SHW studied possess substantial genetic diversity and are useful pre-breeding materials for improving wheat with resistance to Fusarium head blight, leaf rust, Helminthosporium spot blotch, and Septoria diseases. In this effort the most diverse SHW can be used for pyramiding the resistance genes to these diseases.

Technical Abstract: Synthetic hexaploid wheat (SHW) is known to be an excellent vehicle for transferring large genetic variations especially the many useful traits present in the D genome of Aegilops tauschii Coss (2n=2x=14, DD) for improvement of cultivated wheat (Triticum aestivum L., 2n=6x=42, AABBDD). The objectives of the present study were to (i) evaluate genetic diversity among 32 selected SHW with resistance to several fungal diseases using Amplified Fragment Length Polymorphism (AFLP) and Simple Sequence Repeat (SSR) markers and (ii) identify diverse SHW for pyramiding genes conferring resistance to different diseases. These SHW containing different accessional sources of the D genome were identified from about 1,000 SHW developed by the Wheat Wide Crosses program at the International Maize and Wheat Improvement Center (CIMMYT), Mexico. Ten SHW had resistance to Fusarium head blight, nine were resistant to leaf rust, eight resistant to Helminthosporium spot botch and seven resistant to Septoria biotic stresses. Two SHW were resistant to Fusarium head blight and leaf rust. Seventeen EcoRI/MseI AFLP primer combinations and 27 highly polymorphic SSR markers with 20 genome specific markers were screened over all 32 synthetics. Amongst the 703 AFLP fragments scored, 225 were polymorphic across the 32 SHW. Polymorphic information content (PIC) among the SHW for AFLPs ranged from 0.06 to 0.50 with an average PIC of 0.24. Major allelic frequency from SSR analysis ranged from 0.23 to 0.81 with an average of 0.45. Number of alleles per locus for the SSR markers ranged from 3 to 15 with an average allele number of 7.4. Average gene diversity and PIC for the SSR markers was 0.69 and 0.66, respectively, with the highest values being for the D genome markers. Cluster analysis showed distinct groups among the wheat accessions studied. Mantel statistics between the distance matrices from AFLP and SSR analyses showed a moderate, but significant, correlation (r = 0.52**). Our results indicate that the SHW studied possess substantial genetic diversity and are useful pre-breeding materials for improving wheat with resistance to Fusarium head blight, leaf rust, Helminthosporium spot blotch, and Septoria diseases. In this effort the most diverse SHW can be used for pyramiding resistance genes to different diseases.