Post-registration Assessment of Spring Wheat Varieties Response to Fusarium Head Blight

Post-registration Assessment of Spring Wheat Varieties
Response to Fusarium Head Blight
Pam de Rocquigny, MSc., P.Ag
Provincial Cereal Crops Specialist
Crops Knowledge Centre, Manitoba Agriculture, Food & Rural Development, Carman, Manitoba R0G 0J0, [email protected]
Discussion
Background & Introduction
A study was initiated in 2009 to evaluate the effect of FHB on CWRS wheat
varieties with varying levels of FHB resistance under natural conditions over
a wide geographic area. Results from that three year study were presented
at the 2011 Manitoba Agronomists Conference. The study has continued and
builds upon the previous three years as varieties evaluated by Manitoba Crop
Variety Evaluation Trials (MCVET) are continually changing. Varieties are
normally tested for three to four years, with the final year of testing normally
corresponding with the year of commercial release.
The turnover of varieties requires on-going analysis to evaluate the
responses of newly registered varieties. However, this produces an
unbalanced situation from year to year in terms of the variety composition. It
is possible to use such data in a multi-year analysis, and the mixed model
statistical methods described by Smith et al. (2001) and Piepho et al. (2008)
are well-suited to this type of data structure. Analysis of the previous data
(2009 to 2012) was limited to trial by trial statistical analysis. With the
application of the Best Linear Unbiased Prediction (BLUP) method, as
described by Smith et al. 2001, the five years of fusarium damaged kernel
(FDK ) and deoxynivalenol (DON) data over many MCVET sites will give
increased accuracy in predicting variety performance.
Results
There were variable levels of FHB in each year of the study (see Figure 1). The
highest levels of FDK and DON were measured in 2010, while the lowest levels
occurred in 2009. There was variability in the level of FHB infection between
MCVET sites in each of the five years, where location had a significant effect on
FDK and DON levels (data not shown). The Boissevain site had the highest
average FDK and DON (2.97% and 3.5 ppm, respectively), while Dauphin
consistently had the lowest levels (0.27% and 0.4 ppm). From 2009 to 2013, the
average FDK for all sites was 1.06% and DON was 1.1 ppm.
Figure 1: Levels of Fusarium Damaged Kernels (FDK) and Deoxynivalenol (DON)
from 2009 to 2013
FDK (%) and DON (ppm)
Fusarium head blight (FHB) is a major disease of wheat in Manitoba and can
impact producer’s profitability through reduced grain yield and quality.
Canada Western Red Spring (CWRS) varieties with improved resistance are
available to Manitoba producers to mitigate the risk of FHB. Testing to
determine a variety’s resistance level to FHB, as presented in SEED
MANITOBA, is done during the three years the variety is entered in the
Cooperative Registration Trials. However, disease data generated for variety
registration provides limited comparisons with other registered varieties, over
limited locations. In some cases, those three years of testing may not provide
sufficient information about the disease reaction to FHB in a field situation.
In SEED MANITOBA 2014, there are twelve CWRS varieties with a MR rating
to FHB. With advances in breeding, it is important to evaluate the
performance of varieties post- registration so expectations can be managed
in how varieties rated as MR will perform relative to other varieties. If disease
pressure is high (i.e. high inoculum levels, conducive environmental
conditions for a long period of time), yield and quality loss due to FHB can
still happen in varieties that have improved resistance.
Figure 2: Levels of Fusarium Damaged Kernels (FDK) and Deoxynivalenol (DON) of CWRS Varieties
from 2009 to 2013
Moderately Resistant (MR)
Intermediate (I)
Moderately Susceptible
(MS) & Susceptible (S)
FDK (%) & DON (ppm)
Objective 1: To evaluate how CWRS varieties being tested by MCVET
respond to fusarium head blight under non-misted conditions (natural
infection) over a wide geographic area.
Objective 2: To use mixed model analysis in calculating long term average
variety means of fusarium damaged kernels and deoxynivalenol.
The mixed model analysis was used to calculate a model-based estimate of
FDK and DON level means, adjusting for factors such as year, location and
interactions. This analysis was first implemented in SEED MANITOBA 2013
to calculate long term yield and protein data. Analyzing the FDK and DON
data using this type of statistical analysis allows head to head comparisons of
varieties which may not have been tested together. As well, the relative
variety performance is better represented, even when data is limiting. Both
of these situations often occurs in the MCVET program as new varieties are
only tested at five locations the first year of entry, and varieties are only
tested for thirty-two site years before being removed to make room for new
varieties.
The main advantage of using mixed model analysis is results for each variety
will be more accurate since more data is used to assess each variety, and
perhaps more importantly the summary for each variety will be based on a
larger range of environments (from all locations and across years).
Summary
Objectives
Results from the study will provide post-registration information on reaction of
current and new CWRS varieties to FHB, with the aim to improve the
decision-making capability of producers and agronomists.
This is why it remains important to use more than one management practice.
Extensive research over the past 20 years have shown that using multiple
management options, including crop rotation, fungicide application, tillage,
and variety selection, is the best way to mitigate the risk of FHB. But
unfortunately, FHB infection will always be highly influenced by environment.
Materials & Methods
To reduce the risk of fusarium head blight, select varieties with improved
resistance in combination with other management strategies. Results
indicate Moderately Resistant (MR) and Intermediate (I) rated varieties
generally had lower FDK and DON levels.
The use of mixed model analysis allows for head to head comparisons of
varieties to determine if significant differences are evident. The FDK and
DON means will be incorporated into Seed Interactive – A Manitoba Crop
Variety Evaluation Tool (www.seedinteractive.ca) and www.seedmb.ca so
producers and industry agronomists have further information on postregistration performance when selecting varieties.
Acknowledgements
From 2009 to 2013, composite samples of the CWRS varieties were collected
from fourteen MCVET locations, including Arborg, Beausejour, Boissevain,
Brandon, Dauphin, Hamiota, Melita, Neepawa, Portage la Prairie, Rosebank,
Souris, St. Adolphe, Stonewall and Thornhill. Sites did vary by year; not all
sites were sampled each year.
There were thirty-three CWRS varieties evaluated by MCVET and tested for FDK
and DON during the five-year period of the study. All varieties were not tested in
each of those years. The effect of variety on FDK and DON levels was significant,
as was the interaction between variety and location.
In 2009, 2010 and 2011, the samples were analyzed at the Canadian Wheat
Board Laboratory in Saskatoon, SK. In 2012 and 2013, BioVision Seed Labs
in Winnipeg, MB conducted the analysis. For all years, the level of FDK (%)
was measured as per the Official Grain Grading Guide of the Canadian Grain
Commission. The accumulation of DON (ppm) was measured using the
ELISA test method. No fungicides were applied to any of the trials and FHB
levels present were a result of natural infection. Results were analyzed using
mixed model analysis to determine FDK and DON long term means.
In Figure 2, there is a slight trend where the varieties rated as Moderately
Susceptible (MS) or Susceptible (S) have higher levels of FDK and DON
compared to the varieties rated as MR or Intermediate (I). However, results also
show there is variability of performance within each resistance category. Over the
five years of the study, there are varieties either performing better than their FHB
resistance rating, or not as expected based on their FHB rating. It was also
observed that the midge tolerant wheat varieties tended to have lower FDK and
DON levels within each resistance rating category.
 Western Grains Research Foundation (WGRF) for funding support from 2012 to
2013, and Pest Management Centre, AAFC from 2009 to 2011.
 In-kind support of the Manitoba Crop Variety Evaluation Team (MCVET).
 Patti Rothenburger, MCVET Chair, MAFRD & Anastasia Kubinec, MAFRD.
 Craig Linde, Interim MCVET Chair, MAFRD who provided statistical support.
 BioVision Seed Labs for conducting the analysis.
References
 Piepho, H.P., J. Mohring, A.E. Melchinger and A. Buchse. 2008. BLUP for phenotypic selection in plant
breeding and variety testing. Euphytica. 161: 209-228.
 Smith, A., B. Cullis and A. Gilmour. 2001. The analysis of crop variety evaluation data in Australia. Aust.
N.Z. J. Stat. 43: 129-145.
 Seed Manitoba 2014
 Brule-Babel, A., Friesen, L., and Crow, G. 2012. New approaches to variety performance analysis.
Manitoba Agronomists Conference.