Authors:Katalin Puskás, Gyula Vida, Judit Komáromi, Hermann Bürstmayr, Marc Lemmens, Zoltán Bedo, and Ottó Veisz
Buerstmayr, H., Lemmens, M., Hartl, L., Doldi, L., Steiner, B., Stierschneider, M., Ruckenbauer, P., 2002. Molecular mapping of QTLs for Fusariumheadblight resistance in spring wheat. I. Resistance to fungal
Authors:C.C. Dweba, H. Shimelis, T. Tapera, and T.J. Tsilo
Fusarium head blight (FHB) is an important disease of wheat causing significant yield and quality losses globally. Breeding for host plant resistance is an economic approach to FHB control and management. The aim of this study was to identify potential sources of resistance from newly developed recombinant inbred lines (RILs) of wheat. A total of 778 RILs were developed through a bi-parental mating design followed by continuous selfing and selection. The RILs along with their eight parental lines (Baviaans, Buffels, Duzi, #910, #936, #937, #942 and #1036) and FHB resistant check cultivar ‘Sumai 3’ and susceptible check ‘SST 806’ were field evaluated across four environments in South Africa. Fusarium graminearum isolates were artificially inoculated to initiate infection and disease development. The percentage of wheat spikes showing FHB symptoms were scored. The research identified six percent of the RILs with disease resistance. Heritability for FHB resistance was the highest (64%) indicating the possibility of achieving higher selection gains for FHB resistance across the selected environments. The following five RILs were identified as potential sources of resistance: 681 (Buffels/1036-71), 134 (Duzi/910-8), 22 (Baviaans/910-22), 717 (Baviaans/937-8) and 133 (Duzi/910-7) with mean FHB scores of 6.8%, 7.8%, 9.5%, 9.8% and 10%, respectively. The selected lines expressed comparatively similar levels of resistance compared with that of Sumai 3. The identified RILs are useful genetic resources for resistance breeding against FHB disease of wheat. Since the presence of the F. graminearum is associated with deoxynivalenol (DON) accumulation, the DON levels amongst the selected lines should be determined to ensure the release of improved wheat cultivars with reduced levels of DON accumulation.
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:K. Gromadzka, L. Lenc, C. Sadowski, A. Baturo-Ciesniewska, J. Chełkowski, P. Goliński, and J. Bocianowski
Fusarium head blight (FHB) of cereals is one of the most important pre-harvest diseases worldwide. One possible method to reduce the intensity of FHB and mycotoxin levels is to apply fungicides to wheat at the flowering stage. This paper reports the efficacy of fungicides to control FHB and reduce the associated mycotoxin biosynthesis. In a two-year experiment eight combinations of fungicides were tested. Ear inoculation with a suspension of conidia of Fusarium culmorum representing the DON chemotype, confirmed by PCR assay, was conducted during anthesis. All fungicides significantly reduced FHB severity. The best control and the highest wheat yield were obtained after the application of spiroxamine + prothioconazole at GS 29-32, combined with prothioconazole + fluoxastrobin at GS 49-55 (yield 166.5% of the control) or tebuconazole and prothioconazole (165.8%). All the other protection programs resulted in higher yields (117.1–138.5% of the control). A clear relation was observed between the disease intensity and mycotoxin concentrations.