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SESSION 4: GENETICS OF HOSTS – PLANT RESISTANCE TO FUSARIUM,
VARIETY DEVELOPMENT
P82 - Interaction between Quantitative Trait Loci (QTL)
for Fusarium head blight (FHB) resistance and
Fusarium graminearum 15-ADON and 3-ADON
chemotypes in spring wheat
L. Tamburic-Ilincic, A. Muckle, A. Schaafsma
University of Guelph, Ridgetown Campus, 120 Main St. E. Ridgetown, Ontario, N0P2C0, Canada
E-mail: ltamburi@uoguelph.ca
Fusarium graminearum (Schwabe) (FG) is the principal cause of Fusarium head
blight (FHB) in North America, one of the most serious diseases of wheat
(Triticum aestivum L.). Deoxynivalenol (DON) is the most important mycotoxin
produced by FG. 15-acetyl DON (15-ADON) and 3-acetyl DON (3-ADON)
chemotypes of FG produce DON and 15-ADON and DON and 3-ADON analogs,
respectively. Quantitative trait loci (QTL) associated with FHB resistance from a
Wuhan x Nyubai spring wheat population were previously published. In the
present study we investigated: 1) which QTL or QTL combination (no QTL, 3B, 5A
and 3B+5A) result in the lowest FHB symptoms and DON accumulation and 2)
whether FG chemotype and QTL class interacted. We used eight lines (two from
each QTL class) and six FG isolates (three from each chemotype group) in field
experiments conducted over three years. Wheat lines were spray-inoculated at
50% anthesis with FG isolates and water (control). FHB symptoms were recorded
as severity and incidence and their product calculated as FHB index. The
harvested grain was analyzed for total DON using ELISA method, while 15-ADON
and 3-ADON analogs were confirmed using gas chromatography-mass
spectrometry (GC-MS). The lowest level of total DON and FHB index was
recorded in wheat lines from the 3B QTL class. In fact lines carrying both QTLs
had higher DON content than lines carrying each QTL individually. Lines
inoculated with either 15-ADON or 3-ADON FG reacted similarly, with no
interaction between chemotype and QTL class. Our results suggest that breeding
for FHB resistance in this population using only the 3B QTL is the best strategy
for development of wheat lines with lower DON level and FHB index regardless of
the FG chemotype used in the inoculations.
Keywords: Fusarium, wheat, resistance, mycotoxins
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