Authors:Steve Haber, Jeannie Gilbert, and Saber Golkari
McCartney, C., Somers, D., Fedak, G., DePauw, R., Thomas, J., Fox, S., Humphreys, D., Lukow, O., Savard, M., McCallum, B., Gilbert, J., and Cao, W. 2007. The evaluation of FHBresistance in elite Canadian spring wheat germplasm. Mol. Breeding 20
Authors:Ágnes Szabó-Hevér, Beáta Tóth, Szabolcs Lehoczki-Krsjak, and Ákos Mesterházy
head blight (FHB) is a devastating disease of wheat (
L.) world-wide. The objective of this study was to identify FHB resistance QTLs of the Brazilian spring wheat cultivar Frontana through molecular mapping. Frontana has small and medium effective QTLs. These types of QTLs are sensitive for the environmental factors and for the problems of heterogeneity. 206 DH lines from Frontana/Remus (IFA-Tulln) /2005–2006/ and 105 DH lines of Mini Mano/Frontana (CRC Szeged) /2006–2007/ were inoculated with isolates of
. The Frontana/Remus DH population had wide differences in flowering time and plant height. MM/Frontana was created by CRC, Szeged so that too early and late DH lines were discarded and the remaining lines flowered within five days. Lines with extra plant height were also discarded, so differences were kept within 20–30 cm. In the Frontana/Remus population QTLs were identified on the chromosomes 3B, 5A, 6B. In the MM/Frontana population chromosomes 3B and 5B gave positive signal. Although in both populations Frontana was the resistant parent no QTL markers were identical for them. It seems that the more homogeneous population increases the accuracy of the QTL analysis. An increased morphological homogeneity seems to be necessary to decrease „background noise“ in QTL analyses and increase precision. Until now no QTL were found that gave positive signs for all epidemic situations. As QTLs are not validated, it is early to apply MAS in breeding.
Authors:J. Groth, L. Tamburic-Ilincic, A. Schaafsma, A. Brûlé-Babel, and L. Hartl
Fusarium head blight (FHB) is a serious problem in many wheat-growing areas worldwide. The breeding and cultivation of resistant wheat cultivars is the most promising strategy to reduce the risk of FHB. We report on the comparison of 20 Canadian and 20 European genotypes for FHB response and associated traits (deoxynivalenol content, Fusarium damaged kernels, plant height, heading date) in multi-environmental field trials in Canada and Germany after artificial inoculation with Fusarium culmorum (Germany) / F. graminearum (Canada). Our study revealed Canadian and European wheat lines that were stable in performance across countries and which therefore appear as valuable FHB resistance donors in Canadian as well as in German wheat breeding programs to further improve the resistance level of wheat cultivars against FHB.
Authors:S.M. Pirseyedi, A. Kumar, F. Ghavami, J.B. Hegstad, M. Mergoum, M. Mazaheri, S.F. Kianian, and E.M. Elias
Fusarium head blight (FHB) damage in durum wheat (Triticum turgidum L. var. durum Desf., turgidum) inflicted massive economic losses worldwide. Meanwhile, FHB resistant durum wheat germplasm is extremely limited. ‘Tunisian108’ is a newly identified tetraploid wheat with FHB resistance. However, genomic regions in ‘Tunisian108’ that significantly associated with FHB resistance are yet unclear. Therefore, a population of 171 backcross inbred lines (BC1F7) derived from a cross between ‘Tunisian108’ and a susceptible durum cultivar ‘Ben’ was characterized. Fusarium graminearum (R010, R1267, and R1322) was point inoculated (greenhouse) or spawn inoculated (field) in 2010 and 2011. Disease severity, Fusarium-damaged kernel (FDK) and mycotoxins were measured. Analysis of variance showed significant genotype and genotype by environment effect on all traits. Approximately 8% of the lines in field and 25% of the lines in greenhouse were more resistance than Tunisian108. A framework linkage map of 267 DArt plus 62 SSR markers was developed representing 239 unique loci and covering a total distance of 1887.6 cM. Composite interval mapping revealed nine QTL for FHB severity, four QTL for DON, and four QTL for FDK on seven chromosomes. Two novel QTL, Qfhb.ndsu-3BL and Qfhb.ndsu-2B, were identified for disease severity, explaining 11 and 6% of the phenotypic variation, respectively. Also, a QTL with large effect on severity and a QTL with negative effect on FDK on chromosome 5A were identified. Importantly, a novel region on chromosome 2B was identified with multiple FHB resistance. Validation on these QTL would facilitate the durum wheat resistance breeding.
Authors:A. Mesterházy, B. Tóth, T. Bartók, and M. Varga
Type I resistance is a significant and powerful resistance component. Spraying inoculation covers reactions to both Type I and Type II. A significant synergetic effect was detected between Type I and Type II QTLs. It seems that Type I resistance at present cannot be directly measured, only as a difference between point and spraying inoculation. However, this does not influence the success of the selection. For breeding the spraying methodology is more suitable as it considers much wider genetic background than the point inoculation does. The highest resistance in the Szeged program was achieved by the use of exotic spring wheat sources in winter wheat, but excellent agronomy types were identified at a relative low ratio. Good or excellent resistance can be identified at a low rate in breeding material without exotic FHB resistance sources, but their agronomy value is much better. Ratio of high resistance is frequent in winter wheat lines created form winter and spring wheat resistance sources. An efficient phenotypic selection is inevitable. Repeatability of the test is generally good or excellent; LSD values are normally less than 10 % of the variation width. FDK and toxin measurements are integrant part of the program since 35 and 20 years, respectively. Several methodical considerations are discussed.
Wangshuibai is an indigenous scab resistance germplasm originated from Jiangsu, China. To characterize the genetic basis of scab resistance in this germplasm, QTLs for type I and type II resistances were detected using a recombinant inbred line (RIL) population created by single seed descent from Nanda2419 × Wangshuibai and a molecular marker map of more than 4000 cM constructed using RAPD, SSR and STS markers. The major QTLs for type I resistance in Wangshuibai were mapped to chromosomes 4BL and 5AS, and those for type II resistance were mapped to chromosomes 3BS. In addition, a QTL on chromosome 2B showed association with both types of resistance. These QTLs were verified with QTL nearisogenic lines. We found, by mapping QTLs for agronomical traits in the same population, that on chromosomes 4BL and 5AS the scab resistance QTLs co-located with QTLs for plant height, thousand grain weight or flag leaf width. However, these associations could be break down by recombinant selection. We concluded that Wangshuibai is a valuable scab resistance gene resources and marker assisted selection would be of great help for its better utilization.