GENETIC ENHANCEMENT FOR RESISTANCE TO BIOTIC AND ABIOTIC STRESSES IN HARD WINTER WHEAT
Location: Hard Winter Wheat Genetics Research Unit
Title: A novel quantitative trait locus for Fusarium head blight resistance in chromosome 7A of wheat
Submitted to: Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 11, 2010
Publication Date: January 8, 2011
Citation: Jayatilake, D.V., Bai, G., Dong, Y. 2011. A novel quantitative trait locus for Fusarium head blight resistance in chromosome 7A of wheat. Theoretical and Applied Genetics. 122:1189-1198.
Interpretive Summary: Fusarium head blight (FHB) has caused significant yield losses in most of wheat growing regions in the US. The pathogen also produces a toxin called deoxynivalenol (DON) in infected grain, which dramatically reduces the end-use quality. Chinese line Sumai 3 has the best resistance to the disease. In this study, we crossed the FHB resistant Chinese Spring-Sumai 3-7A substitution line to Chinese Spring and developed Sumai 3-Chinese Spring chromosome 7A recombinant inbred line population. Using this population, we identified a new gene from Sumai 3. This gene was located near the centromere of chromosome 7A (7AC), and controls both low DON content and FHB resistance, thus has the potential to be used in improving wheat cultivars for both FHB resistance and low DON.
A Chinese Spring-Sumai 3 chromosome 7A disomic substitution line (CS-Sumai 3-7ADSL) was reported to have a high level of Fusarium head blight (FHB) resistance for symptom spread within a spike (Type II) and low deoxynivalenol accumulation in infected kernels (Type III), but quantitative trait locus (QTL) on chromosome 7A has never been identified from this source. To characterize QTL on chromosome 7A, we developed 191 7A chromosome recombinant inbred lines (7ACRIL) from a cross between Chinese Spring and CS-Sumai 3-7ADSL and evaluated both types of resistance in three greenhouse experiments. Two major QTL with Sumai 3 origin, conditioning both Type II and III resistance, were mapped in the short arm of chromosomes 3B (3BS) and near the centromere of chromosome 7A (7AC). The 3BS QTL corresponds to previously reported Fhb1 from Sumai 3, whereas 7AC QTL, designated as Fhb7AC, is a novel QTL identified from CS-Sumai 3-7ADSL in this study. Fhb7AC explains 22% phenotypic variation for Type II and 24% for Type III resistance. Marker Xwmc17 is the closest marker to Fhb7AC for both types of resistance. Fhb1 and Fhb7AC were additive, together explained 56% variation for Type II and 41% for Type III resistance and resulted in 66% reduction in FHB severity and 84% reduction in deoxynivalenol (DON) content. Both QTL showed significant pleiotropy on Type II and Type III resistance, suggesting both types of resistance may be controlled by the same gene(s). Haplotype analysis of Sumai 3 parents revealed that Fhb7AC originated from Funo, an Italian cultivar. Fhb7AC have the potential to be used in improving wheat cultivars for both types of resistance.