NEW MOLECULAR EVIDENCES FOR FHB RESISTANCE IN TOW AND ELITE WHEAT CULTIVARS

Abstract.

Fusarium head blight (FHB) is one of the major fungus diseases that dramatically decrease yield and quality of many crops including wheat. In the 1990’s, an epidemic FHB threat caused at least $160 million of loss for wheat growers in the Great Plain’s major States for wheat production in the US. Therefore, wheat breeding programs, including NDSU, started intensive investigation for germplasms with high resistance for FHB. Between 1999 and 2005, many elite wheat cultivars were released, including the high dominating cultivars “Glenn” and “Parshall”. Glenn was supposed to acquire its resistance based on an exotic Chinese genetic source. However, our molecular analysis showed that this hypothesis could be not true. Parshall has indigenous resistance with no exotic genetic sources and no previous molecular studies. Further, we used DArT and SNP, tow high throughput molecular marker technologies, to investigate the true genetic sources of resistance in Glenn and Parshall. These markers were applied on the recombinant inbred lines of the two populations (GM and PR), generated from the crosses (Glenn/MN00261-4) and (Parshall/Reeder), respectively. Both populations were tested in multiple location’s experiments in three states (ND, MN, and SD) for three years period (2010-2012). Field experiments were confirmed with two years (2011-2012) greenhouse’s experiments in ND. Based on the new genetic maps generated for Glenn and Parshall, our QTL analysis showed unique results. Glenn and Parshall acquired new genomic regions responsible for FHB resistance, which were expressed stably in multiple states and across multiple years. The major genomic region of the famous exotic Chinese QTL (3BS-Fhb1) was undetectable in Glenn especially after multiple states/years tests. Since Parshall is a domestic ND cultivar all its identified QTL were considered solely unique as FHB resistance sources. The conclusion, Glenn and Parshall are ND germplasm with molecular evidence for high FHB resistance. The pyramided resistance in both cultivars has no major exotic genetic sources. Our new genetic maps for such tow important and elite wheat cultivars enriched the global genetic map of wheat. Our implementation with these new genomic regions (QTL) can emphasize the complicated genetics of FHB resistance in wheat. Our ND germplasm (Glenn and Parshall) can be used, nationally and internationally, as donor germplasm for FHB resistance and to be implemented in other wheat breeding programs. Our results for these two cultivars can open a wide global cooperation between ND and other research groups, worldwide, interested in FHB resistance and/or wheat genetics.