Soft Winter Wheat Responses to Two Major Resistance QTL for Fusarium Head Blight in F2 Derived Populations.

Soft winter wheat responses to two major resistance QTL for Fusarium head blight in F₂ derived populations

Daniela Sarti¹ , Anthony Clark¹, Gina Brown-Guedira² , Yanhong Dong³, David Van Sanford¹*

¹ University of Kentucky, Plant & Soil Science Dept. , Lexington, KY 40546; ² USDA-ARS, North Carolina State University, Raleigh, NC 27695; ³ University of Minnesota, Plant Pathology Dept., St Paul, MN 55108.

*Corresponding Author:  PH: 859-338-2409; E-mail: dvs@uky.edu

ABSTRACT

Fusarium Head Blight (FHB), caused by Fusarium graminearum Schwabe [teleomorph: Giberella zeae Schein. (Petch)] is a devastating disease of wheat (Triticum aestivum L). This study targeted the effects of FHB resistance QTL when present alone or combined. Donor parents with two FHB resistance quantitative trait loci (QTL) Fhb1 and QFhs.nau-2DL were crossed to four adapted SRW wheat lines to generate backcross and forward-cross progeny. F₂ individuals were genotyped and assigned to groups according to presence/ absence of resistance alleles at both QTL. The effectiveness of these QTL in reducing FHB in F₂ derived lines was assessed in a scab nursery for 2 years. Backcross-derived progeny were planted in replicated plots and in the scab nursery at Lexington, KY in 2011 and 2012. Traits included rating (1-9), severity, incidence, FHB index, FDK (Fusarium damaged kernels) and DON (deoxynivalenol). FDK and DON were predicted with Near Infrared Reflectance (NIR) and compared with actual values. One objective was to evaluate  F₂ populations as indicators of expression levels of QTL prior to extensive backcrossing. The Fhb1 + 2DL combination showed higher resistance and lower FDK than other QTL classes in all populations. Significant QTL effects on FDK and DON were also detected using NIR. Correlations between FDKNIR and actual FDK ranged from 0.35 to 0.73 across the populations. Correlations between DONNIR and actual DON ranged from 0.55 to 0.82 among populations. Heritabilities for FDK and DON ranged from 0.16 to 0.48 for FDK and 0.54 to 0.75 for DON levels. Some BC₁F₃ lines had yields not significantly different from commercial checks. Preliminary results indicated that BC₁ populations may be a useful source of breeding lines. F₂ populations should be used for genotyping, ensuring QTL are effective before extensive backcrossing.

ACKNOWLEDGEMENT AND DISCLAIMER

This material is based upon work supported by the U.S. Department of Agriculture, under Agreement No. 59-0206-9-054.  This is a cooperative project with the U.S. Wheat & Barley Scab Initiative. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.