Reaction of wheat varieties to infection with barley yellow dwarf virus and prospects for resistance breeding

Abstract

Abstract:The reaction of winter and spring wheat to infection with barley yellow dwarf virus (BYDV-PAV) was evaluated in three-year small-plot field trials on 71 wheat varieties registered in the Czech Republic and at two locations for two years on 63 selected potential sources of resistance. Disease symptoms (VSS) were visually recorded using a 0-9 scale and the percent reduction of grain weight per spike (GWS-R) was measured on twenty plants per plot. The evaluation showed that among the registered varieties of winter and spring wheat no variety had a high resistance to BYDV (with VSS lower than 3.5). GWS-R ranged between 24% and 60%. Higher variability in VSS was detected for the registered varieties of spring wheat compared to winter wheat. Among the registered varieties of winter wheat, Saskia, Rialto, Meritto, Rexia, and Svitava, as well as the spring wheat Leguan, received the best long-term evaluations. The highest level of resistance was detected for the PSR 3628 line (a hybrid of wheat and couch-grass), but in connection with a low agronomic value. The WKL91-138 line of spring wheat and some varieties (lines) with the detected moderate level of resistance, in particular, could offer good prospects for use in breeding. The presence of the Bdv2 gene was expressed only in the reduction of virus content on the 11 th day after inoculation. Nevertheless, genotypes carrying this gene were evaluated in field trials as susceptible or very susceptible to infection with the Czech PAV isolate. Similarly, the presence of the Bdv1 gene detected with the help of WMS130 marker was no assurance of an increased level of resistance to BYDV. Hybridological analyses of crosses with the WKL91-138 line showed a polygenic nature of inheritance. Thus, the marker-assisted selection does not obviously promise success without a focus on detecting a larger number of QTLs.

The Evaluation of Wheat Cultivar Resistance and Yield Loss Thresholds in Response to Barley Yellow Dwarf Virus-PAV Infection

“…Sparta, moderately susceptible cv. Vlada, and the susceptible breeding line SG-S 27-03 were chosen as the control checks based on earlier studies [16,18]. The plants were grown in double-row, 1-m-long plots, with two replications (22 cm row spacing, 6 cm within the row).…”

“…Thus far, four resistance genes, Bdv1 [10], Bdv2 [11], Bdv3 [12], and Bdv4 [13], have been reported in wheat, but the introduction of these genes in commercial cultivars has not been effective [14,15]. Furthermore, evaluation of resistant sources carrying the Bdv1 and Bdv2 genes suggests a polygenic nature for BYDV resistance [16]. The only exception from other genes is Bdv1, which originated from the Brazilian spring cultivar Frontana that confers tolerance to BYDV-MAV [17].…”

Results of the Czech National Ring Tests of disease resistance in wheat

“…It is evident that the introduction of a single gene is not sufficient for achieving the required level of resistance while marker-assisted selection is not very well justified for the time being without a focus on detecting a larger number of QTLs (Veškrna et al 2009). …”

Sixty years of the Crop Research Institute and its impact on plant breeding

“…Special attention is paid to the study of resistance. This includes the detection of resistance sources, validation of the effectiveness of resistance genes, as well as participation in the development of wheat and barley breeding material with a higher level of resistance (Veškrna et al 2009). Special attention was also devoted to the application of the effective gene Yd2 that can be safely detected by the marker Ylp (Šíp et al 2004) in the breeding programme.…”