Authors:J. Chrpová, V. Šíp, L. Štočková, and V. Dumalasová
Resistance of 28 winter wheat cultivars registered in the Czech Republic and ten potential sources of resistance to Fusarium head blight (FHB) was evaluated after artificial inoculation with Fusarium culmorum in field trials lasting for three years (2008, 2009, 2010). The data on deoxynivalenol (DON) content were supplemented by symptom scores and determination of% of Fusarium damaged grains and% reductions of grain weight per spike due to infection. The examined traits were significantly interrelated and showed high variation in all years. Significantly lower DON content, combined with relatively lower manifestation of the disease was observed in the modern, commercially grown cultivars Bakfis, Graindor, Sakura and Bodycek (catalogued in the Official Journal of EU), besides Novokrymka 102, PI 166910 (line resistant to dwarf and common bunt) and Arina, which could be effectively used in resistance breeding. However, the experiments performed under high infection pressure were also able to reveal high susceptibility to FHB in some commercially grown wheat cultivars, which may pose a serious threat to wheat production.
Authors:V. Šíp, J. Chrpová, L. Štěrbová, and J. Palicová
The aims of the present study were to estimate the general combining ability (GCA) and the specific combining ability (SCA) effects controlling type II FHB resistance across environments in a set of European winter wheat varieties and, for purposes of future selection, to identify potential combinations of parents with suitable levels of FHB resistance. Parental varieties as well as F1 generations were evaluated under both field and greenhouse conditions in two years. The results of the present study indicate that in the F1 generation mean DON content was relatively lowest after crossing of moderately resistant parents (Sakura/Bakfis, Sakura/Federer, Petrus/Bakfis, and Sakura/Petrus), and mean DON content is low also after crossing the moderately resistant Bakfis variety with the susceptible Biscay and Cubus varieties. Evaluation of crosses in the F1 generation was followed by evaluation of selected crosses (derived from the Bakfis and Sakura varieties) in the F2 generation. Correlations between F1 and F2 were highly significant in relation both to their DON content and visual symptom score (VSS), as well as between the individual experiments (and in the different years). The only exception was in the case of the 2014 field experiment, when inoculation was successful but conditions were not optimal for the disease to progress and DON to accumulate. The selection of a suitable parental variety (with a high GCA) can markedly influence the success rate of breeding for resistance to FHB. Detection of high SCA in the F1 generation is important for directing breeders to promising combinations for achieving FHB resistance. It was demonstrated here that low DON content may be achieved even after crossing a moderately resistant variety with susceptible varieties. Another possibility is to make use of heterosis directly for acquiring resistance in hybrid wheat (for decreasing DON content and manifestation of symptoms).
Authors:T. Sumíková, J. Remešová, L. Leišová, L. Kucera, J. Chrpová, and V. Šíp
Amplified fragment length polymorphism (AFLP) analysis was applied to genotype 186 Czech isolates of the Fusarium species responsible for head blight disease in wheat. Using 15 primer combinations, 694 polymorphic fragments were detected. The effective number of patterns was dependent on both the identity of the selective primer combination and on which Fusarium species was involved. The most informative primer combinations were CAT + AT, CAT + AC and CTA + AG, and a triplex assay based on CAT was able to distinguish all 186 isolates from each other. A principal component analysis identified six phylogenetic clusters, and this genetic architecture was supported by an analysis of population structure. AFLP profiling is an appropriate method for uncovering differences between these groups of Fusarium species.