meszaros.klara@atk.hun-ren.hu

Improving the resistance of cultivated wheat varieties to Fusarium head blight (FHB) due to the extremely harmful mycotoxins produced by the fungus is a constant great challenge for breeders. The genetic regulation of FHB resistance is very complex, involving many regions of the wheat genome, therefore the number of often unfavorable linked traits is also large. For this reason, the use of exotic, spring sources with the best FHB resistance in winter wheat breeding is limited.

FHB resistance of 188 wheat genotypes were investigated using three inoculation methods in three growing seasons (2020-2022) under field conditions. The wheat varieties originated from gene bank collection, and 80% of it are winter growing type, while three quarters of it was bred in Martonvásár (MV). Genotyping was carried out using the Illumina 25K wheat array.

Average seed infection rate for spray inoculation were: 2020 – 47%, 2021 – 7%, 2022 – 33% respectively. Every year, the spawn method (infected seeds scattered on soil surface) simulating the natural disease process proved to be the less efficient, with the average seed infection rate: 35%, 3% and 11%, respectively. The average ear infections on the 21st day after inoculation were 24%, 44% and 34% in consecutive years by single spikelet injection method.

FHB severity of the offspring lines from crosses between Far-Eastern and MV genotypes was the mildest. Some old Hungarian varieties, Bánkúti 5, Béta Bánkúti and BKT-9158-95, were among the best 25 genotypes representing the winter grow habit using spray and spawn inoculation methods. Considering the results of all three inoculation techniques, two Romanian genotypes, F12056G2-1FZ-2 and F12056G2-01, as well as the MVF44-17 and MVF24-20 lines from Martonvásár represented excellent resistance.

As a result of the CMLM analysis, MTA were identified on each wheat chromosome, however, the number of markers that proved to be effective in each year was much lower. The analysis of the database of the spray and spawn methods both confirmed the role of the markers located at the positions of chromosome 1A 48648359 and 6A 610349860.

The effect of the 1A locus was strongest by spray inoculation in 2020. The seed infection of the lines carrying the G allele was 12.55%, and the DON contamination was 22561 ppb less than of the T types lines. The effect of marker 6A was detectable in both ear and seed infection, which were decreased in average with 20.01% and 16.59% by T allele, respectively. Relevance of marker position 414957067 of 2D chromosome was revealed by the analysis of FHB severity after single spikelet injection (type II resistance).

The role of the chromosomal regions identified so far will be further investigated using bioinformatics methods and gene editing.

Acknowledgments

“Project no. TKP2021-NKTA-06 has been implemented with the support provided by the Ministry of Innovation and Technology of Hungary from the National Research, Development and Innovation Fund, financed under the TKP2021-NKTA funding scheme.” and RRF-2.3.1-21-2022-00007 grant.