Agroscope | 2015 Annual Ph.D. students meeting 2015 - Novel Techniques in Science
RESISTANCE AGAINST FUSARIUM HEAD BLIGHT IN WHEAT VARIETIES WITH COLOURED GRAINS
Martin C. and Mascher F.
Agroscope, Institute for Plant Production Sciences, 1260 Nyon, Switzerland
Fusarium Head Blight (FHB) is one of the most threatening disease on wheat spikes, resulting in reduction of quantity and quality of the production. In particular, the Fusarium fungus produces mycotoxins that accumulate in the grains. Wheat breeders aim to develop varieties with enhanced resistant to symptoms on spikes, to yield reductions, and to the accumulation of mycotoxins. It is known that antioxidant compounds can play a role in plant resistance. As these compounds are also pigments, they are more concentrated in varieties with coloured grains. The aim of this work is to investigate the role of anthocyanins, giving blue to dark coloration to the grains, in Fusarium Head Blight resistance in wheat.
Conclusions
Varieties providing coloured grains seems to provide enhanced resistance.
Anthocyanins alone did not explain the enhanced resistance of the coloured lines. Other antioxidant compounds, as ferulic acid, may be involved.
Analyses of FHB resistance in barley varieties providing coloured are in progress.
Materials and methods
Impact of anthocyanins on FHB resistance was evaluated on 7 wheat varieties, including varieties with coloured grains (Fig. 1). All these varieties have been sown in 3 locations throughout Switzerland (Changins, Reckenholz, Vouvry) and artificially infected at flowering with Fusarium graminearum. Disease incidence and severity have been scored in spikes (Fig. 2a). To decipher the resistance of the grains, reduction of the thousand kernel weight (TKW), reflecting the yield losses, the percentage of kernels damaged by Fusarium (FDK) (Fig. 2b), and the DON toxin content of the grains were analysed. Anthocyanin contents of the grains were measured by spectrophotometry on extracts if whole meal flour (Fig. 3).
Fig. 1: Different antioxidant compounds give various colorations to the grains. Dark and blue colorations of samples a and c are partly due to anthocyanin compounds.
Results
Table 1: Spearman's rank correlation rho between the observed resistance parameters.Significant correlations have been observed, except for DON content.
Thus varieties with low symptoms on spikes have also provided grains more resistant. It was the case for most of the varieties providing coloured grains.
c c
bc a
c b
c
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
ACW 83 ACW 71 Arina Combin Hanswin Indigo Vanilnoir
AUDPCrel
Wheat varieties -orange plots correspond to varieties with coloured grains FHB incidence
Changins* Vouvry Reckenholz
b b
c
d d
b a
b
0 20 40 60 80 100 120
ACW 83 ACW 71 Arina Combin Hanswin Indigo Purendo Vanilnoir
Concentration anthocyanins (mg/kg)
Wheat varieties -orange plots correspond to varieties providing coloured grains
Anthocyanin contents of non infected samples
Changins* Vouvry** Reckenholz*
a b c
Fig. 2. a: Typical FHB symptoms on wheat spikes.
Fig. 2. b: Comparison between non infected grains (left) and Fusarium damaged grains (right). FDK, TKW losses and DON content have been analysed on infected grains.
a b
Fig. 3: Extraction of anthocyanin compounds of wheat varieties. Hanswin provides non coloured grains.
Spectrophotometry measurments have been made on these solutions to obtain anthocyanin contents of the grains.
Vanilnoir Hanswin Indigo Purendo
Fig. 4: FHB symptoms on spikes. Low AUDPCrel for incidence means low symptoms and thus higher FHB resistance. For all varieties symptoms
were higher in
Changins. Weak
symptoms on spikes were observed for most of the varieties with coloured grains.
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Fig. 5: Anthocyanin contents of wheat varieties. Significant differences between lines were observed, and among varieties providing coloured grains. Concentration for non-coloured grains is on average 5 mg/kg, 20 mg/kg for coloured grains, up to 100 mg/kg (cv Purendo). For all varieties, concentrations were lower in Vouvry.
• Anthocyanin contents in grains were not correlated with resistance parameters.
• FHB symptoms on spikes and grains, anthocyanin contents of the grains were dependent to the environment.
• A tendency to higher anthocyanin concentrations in infected grains compare to non-infected grains was observed.
