SUNFLOWER GERMPLASM DIVERSIFICATION AND CHARACTERIZATION UTILIZING WILD SUNFLOWER SPECIES, CYTOGENETICS, AND APPLIED GENOMICS
Location: Sunflower Research
Title: Chromosome engineering and transfer of alien sources for Fusarium head blight resistance in hard red winter wheat
| Friebe, B - |
| Cainong, J - |
| Chen, P - |
| Bockus, W - |
| Gill, B - |
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: October 4, 2010
Publication Date: December 7, 2010
Citation: Friebe, B., Cainong, J.C., Qi, L.L., Chen, P.D., Bockus, W.W., Gill, B.S. 2010. Chromosome engineering and transfer of alien sources for Fusarium head blight resistance in hard red winter wheat [abstract]. National Fusarium Head Blight Forum, December 7-9, 2010, Milwaukee, WI. p. 17.
We report on progress made in incorporating two new sources of resistance to Fusarium Head Blight (FHB) from Leymus racemosus and Elymus tsukushiense to hard red winter wheat. FHB resistance gene Fhb3 from Leymus racemosus was transferred to wheat in the form of a compensating Robertsonian translocation T7AL.7Lr#1S. The Fhb3 gene is located on the short arm of L. racemosus chromosome 7Lr#1S translocated to the long arm of wheat chromosome 7AL. The 7AL and 7Lr#1S arms are joined at the centromere. Fhb3 confers resistance to single-point inoculation in the greenhouse. Ten lines homozygous for Fhb3 in Jagger and Overley background were evaluated for their resistance to FHB and DON accumulation under field condition in the 2008-9 growing season. Although the lines were homozygous for Fhb3, variable reaction to FHB and DON accumulation was observed, which could be caused by genetic background effects. Lines 08-193 (in Jagger) and 08-184 (in Overley) with higher levels of resistance were evaluated in the field scab nursery in Manhattan in the 2009-10 growing season. 08-193 gave a disease index rating of 27.6% as compared to 36.8% for Jagger. 08-184 gave a disease index rating of 33.1% as compared to 50.2% for Overley. Both of these differences were significantly different (P<0.05, LSD=5.66). For further evaluating the genetic background effects we are backcrossing 08-193 to the cultivar Fuller. After a second backcross to Fuller, the selfed progenies will be screened for isolating homozygous Fhb3 lines and will be evaluated for FHB resistance and DON accumulation under greenhouse and field conditions.
Chromosome engineering was used to isolate three recombinant chromosomes, one proximal rec124 (T7AL.7Lr#1S-7AS), and two distal rec989 and rec679 (T7AL.7AS-7Lr#1S) and homozygous lines were developed in Overley background. In the 2009-10 growing season, all the recombinant lines along with Overley were evaluated for FHB and DON. Rec124 had FHB index rating of 27.6% as compared to rec679 (38.1%), rec989 (48.8%) and Overley (50.2%; LSD5.66)). DON ranged from 7.4 to 14.6 ppm as compared to 19.7 ppm for Overley (LSD=4.22). It appears that based on this data and previous data, Fhb3 is located in the interstitial region (FL 0.45-0.80) of the 7Lr#1S arm.
Another source of FHB resistance is derived from Elymus tsukushiense and was transferred to wheat in the form of a disomic chromosome addition stock (DA1Est#1), a ditelosomic addition stock (DtA1Est#1S), and a disomic addition/translocation stock DATW.1Est#1S. Testing of the DATW.1Est#1S stock from 2005 to 2007 indicated that this line conferred resistance to FHB under greenhouse conditions. In spring 2010 greenhouse test, the lines T7AL.7Lr#1S (Fhb3), DA1Est#1, DtA1Est#1S, and DATW.1Est#1S gave average spike index ratings of 19.2%, 26.2%, 23.5%, and 10%, respectively, whereas the resistant check Sumai#3 and the moderate susceptible check Chinese Spring had ratings of 5.3% and 32%, respectively (LSD=9.05). We are presently using directed chromosome engineering to produce recombinants with shortened E. tsukushiense chromatin, which will then be evaluated for their resistance to FHB and DON accumulation.