Unique sources of resistance to Fusarium head blight for durum wheat.

There was a major epidemic of FHB in the durum wheat crop in Canada in 2016. There is not as much variability for FHB resistance in the primary gene pool of T. durum as there is in bread wheat.

In a recent screening of synthetic hexaploids and their parents for FHB resistance by point inoculation, a number of T. dicoccon accessions appeared to have enhanced levels of FHB resistance. The floret infection frequencies ranged from 10-12% while the values for Langdon durum were 73%. These inoculations were repeated for a second time with similar results.

The T. dicoccon accessions were accessed from various gene banks. Records indicate that some of these accessions were collected in Russia and Georgia in the 1930s by N. I. Vavilov and deposited in the genebanks.

As would be expected from T. dicoccon accessions collected in the wild, some are deficient in useful agronomic traits. For example some are very tall and others have smaller spikes. However such traits could easily be removed by a few backcrosses so as to minimize any linked drag. On the other hand other accessions had very large seeds, a trait that could be an asset to a breeding program.

Another potential source of FHB resistance for durum wheat is that found in the amphiploid Triticum durum x Hordeum chilense with the genomes AABBHH. This source of resistance will be more difficult to integrate into durum wheat.