Strategies to ensure the longevity of
blackleg resistance genes in canola
Project Report - GRDC project code UM020
Compiled by Dr Steve Marcroft
July 2007
Supported
by
Project Team
The University of Melbourne
Dr Phillip Salisbury (Project Supervisor)
Professor Barbara Howlett
The University of Western Australia
Dr Hua Li
Dr Martin Barbetti
Dr Sivasithamparam
Uni WA logo
CSIRO
Dr Susie Sprague
Marcroft Grains Pathology
Dr Steve Marcroft
Collaborators
SARDI
Mr Trent Potter
NuSeed
Dr Nelson Gororo
Birchip Cropping Group
Mr Peter Taylor
Growers
Mr Peter Taylor
Mr Simon Ballinger
Mr Ivan Schulz
Mr Ross Lutt
Mr Des Sergeant
The University of Melbourne
Ms Vicki Thomas
Dr Angela Van der Wouw
NVT
Mr Allan Bedggood
Contact: Dr Steve Marcroft, Marcroft Grains Pathology, Grains Innovation Park,
110 Natimuk Rd, Horsham Vic 3400
Email: [email protected]
Phone: 03 5381 2294
2
Contents
Project Summary
Page
4
Overview of project methodology
6
Sources of blackleg resistance used in this study
7
Experiments
1. Rotation of different sources of blackleg resistance
8
2. Isolation distance (space and time) required between
crops and stubble of the same resistance source
14
3. Pathogen monitoring - screening different sources
of blackleg resistance against single spore blackleg isolates
19
4. Field monitoring - survey of blackleg severity at
yield evaluation sites (NVT)
24
Future work
31
Publications and Presentations
32
Leptosphaeria maculans isolates collected during the project
(isolates available for research purposes)
34
3
Project Summary
Blackleg caused by Leptosphaeria maculans is the major disease of Brassica napus
(canola) worldwide. Monogenic resistance, derived from B. rapa ssp. sylvestris has
been overcome in Australia, causing severe yield losses in canola cultivars reliant on
this resistance source. In addition, polygenic resistance in some cultivars has been
eroded with time. This loss of resistance is due to the increased frequency of virulent
isolates in fungal populations under selection pressure from resistance genes in the
host. Experience in other crops suggests that rotation of different resistance genes in
space and time may reduce the frequency that resistance genes are rendered
ineffective by changes in fungal populations.
In this report, we describe results of experiments aimed at determining if rotation of
canola cultivars from different blackleg resistance sources can increase the durability
of the resistance sources in canola cultivars and thus reduce yield loss caused by
blackleg. The sources of blackleg resistance used were: Australian polygenic,
European winter, sylvestris and Brassica juncea.
Key findings
1. Populations of the blackleg fungus respond very quickly to changes in sources
of blackleg resistance in canola. For instance, on Eyre Peninsula in 2002
canola varieties containing sylvestris resistance were immune to blackleg,
whilst in 2003 and 2004 crops were totally susceptible. At trial sites in 2005
and 2006, these varieties had lower levels of blackleg severity, as local
farmers had not grown these sylvestris varieties since 2003.
2. Blackleg severity remained low over the three years of this project (2004-06)
when canola was sown into canola stubble from the previous year provided
that the new canola cultivar was based on a different resistance source to the
stubble into which it was sown.
3. Blackleg isolates display host specificity. Isolates collected from a particular
resistance source were more virulent against the source they were collected
from, than against different sources of resistance.
4. The isolation distance required between stubble and canola of the same
resistance source is approximately 500 m. This was consistent even where the
sylvestris resistance had been overcome.
5. Climate / environment and canola production intensity have a major influence
on blackleg severity enabling a risk based blackleg management plan to be
developed.
-High risk – continuous cropping, high rainfall;
-Medium risk – long rotations, medium rainfall;
-Low risk – opportunistic canola planting, low rainfall.
Canola cultivars reliant on the same resistance sources could be separated in
space and time. Therefore growers could be encouraged to:
 Grow polygenic cultivars, where possible.
 Grow cultivars with different sources of blackleg resistance but never in
successive years.
 Keep a minimum of 500 m between the current crop and previous stubble
of the same resistance source.
4
These results suggest that rotating canola cultivars that utilise different blackleg
resistance sources may reduce blackleg severity and in view of the experience in
other crops could also reduce the risk of blackleg resistance being overcome by the
blackleg fungus.
Given that the blackleg fungus responds so quickly to new sources of blackleg
resistance, the Australian canola industry must develop production systems that do
not expose the same resistance sources to the blackleg fungus for consecutive years
in the same vicinity. Rotation of resistance may reduce the frequency of blackleg
strains that are capable of overcoming particular sources of resistance. This
strategy thereby would prolong the life of cultivars.
5
Overview of project methodology
Four sources of blackleg resistance were used in this study. The sources were chosen
from results of previous work showing that they were effective against Australian
blackleg isolates. The chosen sources of resistance are already or are likely to be
available to the canola industry in the near future.
Sources of blackleg resistance used in this study
Source of blackleg
What the source is
resistance
referred to in this study
Cultivars derived from
the source of resistance
used in this study
ATR-Beacon
Australian polygenic
Polygenic
Brassica rapa subspecies
sylvestris
Sylvestris
Surpass501TT
Surpass400
European winter
Winter
Columbus
Brassica juncea
Juncea
JR-46
A number of experiments were undertaken from 2004 to 2007. The experiments were
designed to determine if rotation of different sources of blackleg resistance could
reduce blackleg severity and have the potential to increase the longevity of resistance
genes.
1. Rotation of different sources of blackleg resistance
The first experiment was to grow canola for three consecutive years in the same
paddock. However, each year a different source of blackleg resistance (polygenic,
sylvestris, European winter, juncea) was sown. Normally canola sown directly into
canola stubble results in severe infection, if canola could be sown directly into canola
stubble without severe infection this would provide evidence that rotation of
resistance sources could reduce blackleg severity.
Plants in pots containing the four different sources of blackleg resistance were raised
as seedlings and then placed onto the stubble of the field sites to allow natural
infection to occur. This allowed the collection of blackleg severity data on each
source of blackleg resistance during each year of the project. It also provided data on
all possible rotation sequences.
2. Isolation distance (space and time) required between crops and stubble of the same
resistance source
For industry to be able to exploit this rotation concept growers must be able to
manage resistance rotation on a relatively small scale (one to three farms). To trial
such an approach, pots containing sylvestris plants were placed at increasing distances
from sylvestris stubble. This experiment was used to determine how far the current
crop should be from stubble of the same resistance source to avoid the most damaging
levels of blackleg infection.
6
3. Pathogen monitoring - screening different sources of blackleg resistance against
single spore blackleg isolates
A major threat to resistance rotation is that blackleg isolates will inherit multiple
virulence alleles allowing one isolate to attack more than one resistance source. To
monitor this situation single spore isolates were collected and screened over the four
different sources of blackleg resistance to determine if some isolates have multiple
virulence alleles.
4. Field monitoring – blackleg survey of yield evaluation sites (NVT)
In some regions prior to 2004, growers had almost exclusively grown cultivars
containing sylvestris resistance each year for three years. Then in 2004, they
simultaneously switched to cultivars with polygenic resistance as the sylvestris
resistance was no longer effective. This gave us the opportunity to investigate two
scenarios:
i) how severe would blackleg be in polygenic cultivars with only sylvestris
stubble as the inoculum source;
ii) will the sylvestris resistance always be susceptible, or if sylvestris cultivars
are no longer grown, will sylvestris cultivars (in trial plots) have lower
blackleg severity?
7
1. Rotation of different sources of blackleg resistance
BACKGROUND
This experiment was undertaken in 2004, 2005 and 2006. It was designed to test if the
rotating of cultivars with different sources of blackleg resistance led to a reduction in
blackleg severity. Generally canola sown into canola stubble from the previous year
would result in more than 50% plant death. The rotation theory suggests that the
blackleg isolates from the stubble of one resistance source may be less virulent on
other sources of resistance.
METHODS
Site Locations
Two sites were chosen for this study. The first site was 20 km south of Horsham in
Victoria, and the second was at Bordertown in south-eastern South Australia. The
Horsham site was in a region with no history of severe blackleg infection in sylvestris
cultivars, while the Bordertown site had severe infection in 2003. In early 2004,
stubble from the two sites was surveyed for the presence of stem canker. At
Horsham, some canker was observed but the majority of stems were clean. In
contrast the majority of stems from Bordertown were severely cankered.
One Hectare Field Sites
At the Horsham and Bordertown sites in 2003, commercial crops of the sylvestris
cv. Surpass603CL were sown. In each successive year, one ha plots of a canola
cultivar based on a different source of blackleg resistance were sown into the same
paddocks. In 2004, the one hectare plots were sown to the polygenic cultivar ATRBeacon and in 2005 they were sown to the European winter cv. Columbus (with
major resistance genes Rlm1 and Rlm3) (see Table 1).
Figure 1. One hectare plot, Horsham site December 2004 – the canola has been
slashed at late flowering to provide stubble for subsequent year’s of the project.
Pots were placed on this site in 2004, 2005 and 2006.
8
In 2004 and 2005, the canola plants were scored for internal infection severity and the
percentage that had died (mortality percentage). Internal infection is determined by
severing the roots at the crown with a pair of secateurs and then visually inspecting
the crown to estimate the percent of the crown that is discoloured by blackleg
infection. The plants were scored as 0, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100%
internal infection. The mortality percentage is determined by dividing the number of
dead plants by the number of living plants.
When polygenic cultivars were sown into sylvestris stubble they had 30% internal
infection and 8-9% mortality (Table 1). In the same year, in the nearby Wonwondah
blackleg nursery, ATR-Beacon had 80% mortality.
Table 1. Horsham (Vic) and Bordertown (SA) one ha plots of canola were sown
directly on top of each other from 2003 to 2006. In 2004 and 2005 canola plants
grown in pots were placed onto the same one ha plots of stubble.
Year
Cultivar sown into the one ha
plots (plots were sown
directly on top of each other)
2003
Surpass 603CL (sylvestris)
commercial crops
Horsham
 Low blackleg severity
Bordertown
 High blackleg severity
2004
2005
2006
Canola stubble
in the one ha
plots
Canola plants (in pots)
containing:
sylvestris, polygenic, winter
and juncea plants were
placed onto the stubble of
same one ha plots
ATR-Beacon (polygenic)
one ha plots
Horsham
 Internal infection = 27%
 Mortality =8%
Bordertown
 Internal infection =30%
 Mortality =9%
2003- sylvestris
Pots placed onto:
sylvestris stubble
Columbus (winter)
one ha plots
Horsham
 Internal infection 0%
 Mortality 0%
Bordertown
 Internal infection 22%
 Mortality 2%

2004-polygenic
2003-sylvestris
Pots placed onto stubble:
2004-polygenic +
18 month old 2003-sylvestris
2005-winter
2004-polygenic
2003-sylvestris
Pots placed onto stubble:
2005-winter +
18 month old 2004-polygenic +
30 month old 2003-sylvestris
9
0%
10%
40%
70%
100%
Figure 2. Canola stems showing various levels if internal blackleg severity.
Yield loss generally occurs with more than 50% internal infection.
10
Rotation -pots
This experiment was used to provide knowledge on each possible rotation sequence.
For example polygenic, sylvestris, juncea and winter plants would be placed on
sylvestris stubble (year 1) then the same four sources of resistance would be placed on
polygenic stubble (year 2) and then winter stubble (year 3).
In 2004, 2005 and 2006 canola plants were propagated in 20 cm diameter pots in the
shade house. At the one leaf growth stage they were transported to the one ha field
sites at Horsham and Bordertown (Figure 3). The potted canola plants with different
blackleg resistance sources (cv. Surpass 400 – sylvestris resistance, cv. ATR-Beacon
– polygenic resistance, cv. Columbus – winter resistance and B. juncea JR46) were
left at the sites for four weeks during which time they were exposed to natural
blackleg infection (Table 1 & Figure 3). The pots were then returned to the
shadehouse and allowed to grow to maturity, when individual plants were assessed for
internal infection and mortality as previously described (Figure 2).
Figure 3. Pots containing the four sources of blackleg resistance placed on
polygenic stubble at the Bordertown one hectare site. The bird netting was used
to keep unwanted guests out.
11
RESULTS & DISCUSSION
Our results indicate that the rotation of different blackleg resistance sources can
reduce blackleg severity. In 2004, plants were severely infected when pots of
sylvestris cultivars were placed on sylvestris canola stubble, while the polygenic
plants on the same sylvestris stubble had significantly less internal infection (Table 2).
Interestingly, in 2005 and 2006 blackleg severity remained low in all cultivars. Even
where polygenic cultivars were placed onto polygenic stubble they still had relatively
low levels of infection. This may be due to the presence of only small numbers of
virulent isolates in populations of the blackleg fungus. As seen with the breakdown of
the sylvestris resistance in 2003, it took a number of years of sowing a particular
resistance source (sylvestris) for the majority of blackleg isolates to become virulent
against that source of resistance. If the sources of resistance are continually changed
the frequency of virulent isolates for any particular source of blackleg resistance may
remain low.
In 2006, blackleg severity in commercial crops was generally low due to the severe
drought seasonal conditions. However, in this experiment the plants in pots were
regularly hand watered so they were not water stressed. At Bordertown in 2006,
which was even more droughted than Horsham, sylvestris plants (in pots) were placed
onto sylvestris stubble (see next chapter) (Figure 6) resulting in 100% plant death.
These data suggest that the seasonal conditions and hand watering would have been
sufficient to cause severe blackleg infection had virulent blackleg isolates been
present.
In Table 2 the data shown is the percentage of plants with greater than 50% internal
infection. This level of disease was chosen as previous work has shown that lower
levels of disease do not always result in yield loss.
Table 2. Percentage of canola plants in pots with severe blackleg infection
(>50% internal infection). Pots were placed onto the one ha canola stubble plots
at Horsham (Vic) and Bordertown (SA).
Stubble at the
Sylvestris pots Polygenic pots
Winter pots
Juncea pots
one ha canola plots
Hor
Btwn
Hor
Btwn
Hor Btwn Hor
Btwn
2004 sylvestris
67%
100%
25%
46%
0%
17%
0%
0%
2005 polygenic
48%
100%
21%
21%
14%
21%
0%
8%
2006 winter
9%
66%
9%
16%
6%
13%
0%
6%
Hor = Horsham, Btwn = Bordertown.
12
Figure 4. Pots containing different sources of blackleg resistance, placed onto
sylvestris canola stubble. The third pot contains plants with sylvestris blackleg
resistance while the other pots contained plants with either polygenic, winter or
Juncea blackleg resistance.
13
2. Isolation in space and time required between crops and
stubble of the same resistance source
BACKGROUND
The method of rotating different sources of blackleg resistance to reduce blackleg
severity depends on the separation of the different sources of blackleg resistance in
both space and time. It is therefore essential to know what isolation and distance is
required between crop and stubble of the same resistance source.
Previous research on polygenic sources of blackleg resistance suggests that canola
should not be grown into canola stubble, but rotations with a break crop (canola –
wheat - canola) reduce severe blackleg infection. The same research showed that
leaving 500 m between this year’s crop and last year’s stubble was sufficient to
reduce blackleg severity. However, this previous research was undertaken on canola
crops where the polygenic blackleg resistance had not been overcome. It was assumed
in the situation where the sylvestris cultivars were completely susceptible, the
isolation time and distance would need to be greater than 18 months and 500 m.
METHODS
Site Location
To determine the minimum isolation distance and time required, the following
experiments carried out from 2003 to 2006. In 2003 commercial paddocks containing
sylvestris canola cultivars were surveyed for blackleg severity. An isolated paddock at
Bordertown S.A. (cv. Surpass 603CL) with high blackleg severity was identified. The
paddock was isolated from all other sylvestris canola crops by at least 5 km.
Transects
In 2004, pots were sown with sylvestris canola plants (cv. Surpass5001TT) and
propagated in the shade house. When the plants were at the one-leaf growth stage they
were transported to the paddock at Bordertown with the sylvestris stubble. Five pots
containing a total of 20 sylvestris canola plants were placed at various distances from
the commercial canola stubble paddock. The distances were: 0m (on the canola
stubble); 250m; 500m; 750m and between 850 to 1000 m away from the canola
stubble (Table 3).
In 2004, two transects were orientated in different directions from the 2003
commercial stubble paddock. In 2005, pots were placed along the same transects as in
2004 but the commercial canola stubble was now 18months old. In 2006 only one
transect was placed identical to the 2004 transect (commercial stubble now 30 months
old) and the second transect was placed from a new commercial canola stubble
paddock that was also sown to sylvestris canola cv. Surpass603CL in 2005. The
stubble of this new commercial sylvestris stubble paddock was inspected for blackleg
damage and had severely cankered stems (most roots were detached from their
stems).
The pots were left in the field for 4 weeks until blackleg leaf lesions were clearly
visible on the plants. The pots were then returned to the shade house and the plants
allowed to grow to maturity, when they were scored for internal infection and
mortality percentage as previously described.
.
14
Table 3. Distance in space and time of sylvestris canola plants (grown in pots)
from sylvestris canola stubble at Bordertown, South Australia.
Year
2003
2004
2005
2006
2005
2006
Number
of
transects
Paddock
Distance from sylvestris
stubble (metres)
2
2
1
Paddock A
Commercial paddock of sylvestris canola
Stubble 6 months old
Stubble 18 months old
Stubble 30 months old
0
0
0
250
250
250
500
500
500
750
750
750
>850
>850
>850
1
Paddock B
Commercial paddock of sylvestris canola
Stubble 6 months old
0
250
500
750
1000
RESULTS & DISCUSSION
Separating the same source of blackleg resistance in space
Figures 5 & 6 clearly indicate that 500 m is an adequate distance to separate the
current canola crop and stubble of the same resistance source. This means that
individual growers (or neighbouring growers in a region) can separate current crops
from stubble of the same source without the need to consider sources of blackleg
inoculum at distances greater than 500m (Figure 7). This finding is consistent with
previous research.
Separating the same source of blackleg resistance in time
Figures 5 & 6 show similar levels of infection in plants exposed to 6-month and 18month old stubble. In contrast in plants exposed to 30-month old stubble, low levels
of disease were present. This result indicates that leaving two seasons between
stubble and then sowing a cultivar of the same resistance source (2 year break) is an
adequate time to reduce blackleg severity (Figure 8). This conclusion is different to
the previous study that found 18-months (1 year break) was sufficient when
separating polygenic stubble from cultivars with effective polygenic resistance.
15
% Severe internal blackleg infection
100
90
6 Months
80
18 Months
70
30 Months
60
50
40
30
20
10
0
0
250
500
750
>850
Distance (m) from canola stubble
Figure 5. Severe blackleg (>50% internal infection) of sylvestris based canola
plants in pots placed at various distances from canola stubble aged 6 months, 18
months and 30 months.
100
90
6 Months
80
18 Months
% plant mortality
70
30 Months
60
50
40
30
20
10
0
-10
0
250
500
750
>850
Distance (m) from canola stubble
Figure 6. Canola plant mortality (%) in pots placed at various distances from
sylvestris canola stubble aged 6 months, 18 months and 30 months.
16
Pots on
canola
stubble from
previous
year’s crop
Pots 250m
from canola
stubble from
previous
year’s crop
Pots 500m
from canola
stubble from
previous
year’s crop
Pots 750m
from canola
stubble from
previous
year’s crop
Pots 1000m
from canola
stubble from
previous
year’s crop
Figure 7. Sylvestris based canola plants placed at increasing distances from
6-month old sylvestris canola stubble.
17
Figure 8. Sylvestris canola plants placed on 30 month old sylvestris canola
stubble.
18
3. Pathogen monitoring - screening different sources of
blackleg resistance against single spore blackleg isolates
(differential study)
BACKGROUND
This experiment was designed to determine if individual blackleg isolates are able to
attack multiple sources of blackleg resistance. The concept of rotating different
blackleg resistance sources assumes that individual blackleg isolates are only able to
attack one source of blackleg resistance. It is known that individual blackleg isolates
can have multiple virulence, for instance isolates virulent on sylvestris cultivars are
able to attack Rlm1 and LepR3 resistance genes, while isolates virulent on
cv. Columbus are able to attack both Rlm1 and Rlm3 resistance genes.
The rotation of resistance sources will fail if isolates evolve that are able to attack
multiple sources of resistance. Fortunately, in field situations blackleg isolates are
generally only able to attack one particular resistance source. If the blackleg fungus
developed multiple virulence then all blackleg resistance sources would have failed
during the past 30 years of canola production, this has not occurred. The reason why
isolates with the ability to attack multiple sources of resistance may not proliferate has
in part been explained by European research which found that such virulent isolates
may be less fit. If there is no positive selection pressure for isolates with multiple
virulence then these isolates will decrease in proportion to other isolates within the
pathogen population. For example, if isolate A is virulent against both sylvestris and
polygenic cultivars and isolate B is only virulent against sylvestris cultivars, then if
both isolates attack a sylvestris cultivar, isolate B will out-compete isolate A.
METHODS
To gain a snap shot of the population of the blackleg fungus across Australia,
approximately 100 individual isolates were collected each year in 2004, 2005 and
2006 (Table 5). A subsample of these isolates were then used to infect the four
different sources of blackleg resistance used in the field experiments to determine the
proportion of isolates that are virulent against more than one source of blackleg
resistance.
Isolates were collected from the stubble of two cultivars, ATR-Beacon (polygenic)
and Surpass501TT (sylvestris). These two cultivars were sown in all yield evaluation
trials (NVT) across Australia and individual plants with blackleg symptoms were
collected from these sites at plant maturity. Stubble from eastern Australia was
evaluated at Horsham and stubble from Western Australia evaluated at Perth.
The stubble was placed on bare soil underneath chicken wire (to stop scattering) and
allowed to weather over the summer and autumn. In late autumn the stubble was
taken to the laboratory to capture individual sexual ascospores. Small pieces of
stubble were stuck to the lid of a petri dish prior to being wet to initiate spore
discharge. The discharged spores adhered to agar in the bottom of the petri dish.
Individual ascospores on the agar were harvested using a compound microscope. The
captured spores were transferred to 10% V8 agar and cultured under UV light.
Isolates were preserved in distilled water.
19
Isolates have been preserved and will be maintained for future studies. They are
available for research purposes by contacting Steve Marcroft, Barbara Howlett
or Martin Barbetti. The information available for each isolate includes: when
and where it was collected, cultivar and source of resistance and the severity of
blackleg in the plot from which it was collected.
Figure 9. Stubble samples were weathered naturally prior to collecting blackleg
isolates.
Figure 10. Left; Ascospores caught in water agar prior to an individual spore
being separated and cultured.
Right; A single spore culture ready to be harvested and used as inoculum to
infect the different sources of blackleg resistance.
20
Plant infection of different sources of blackleg resistance
Individual blackleg isolates from the collection were chosen to screen against
different sources of blackleg resistance to determine if they were virulent against
more than one source of blackleg resistance. The isolates were screened over
polygenic cv. ATR-Beacon, sylvestris cv. Surpass501TT, the winter resistant cv.
Columbus and B. juncea line JR46.
Harvested asexual pycnidiospores were adjusted to a concentration of 1 x 106 spores
per ml of water. Tween surfactant was added to the spore solution which was directly
sprayed onto the cotyledons of the seedlings to be screened. Inoculated plants were
placed in a dew chamber with 100% humidity for 48h. Plants were grown to maturity
in the shade house at Horsham and mature plants were assessed for internal infection
and mortality as previously described.
Figure 11. Plants in dew chamber after inoculation.
In each year of the study, 20 polygenic and 20 sylvestris based isolates were screened
over the differential host set, in total 120 isolates were screened over three years. In
order to compare isolates, each was classified as either virulent or non-virulent. A
virulent isolate caused more than 50% internal infection on at least 3 of the 5 plants.
21
RESULTS & DISCUSSION
If blackleg isolates are specific to a particular source of resistance, isolates collected
from stubble of a particular source of resistance would be virulent on the crop of the
same source of resistance, but be non-virulent on other sources of resistance. That is,
isolates from sylvestris stubble would be virulent on the plants with sylvestris
resistance, but non-virulent on the polygenic, juncea or winter canola. Isolates from
polygenic stubble would be virulent on polygenic cultivars but not on plants with
sylvestris resistance, or other sources of blackleg resistance. As no isolates were
collected from B. juncea or the winter canola, few isolates would be expected to be
virulent on these sources of resistance.
The majority of polygenic isolates were only virulent on the polygenic cultivar, they
were not virulent on juncea or on winter canola (Figure 12). However, 10% of
polygenic isolates were also able to attack the sylvestris cultivar. The sylvestris
isolates were less specific in their virulence. In addition to being virulent on the
sylvestris cultivar, over 40% of them were also virulent on the polygenic cv.
ATR-Beacon, they also had a small effect on the juncea and winter cultivars.
70
Polygenic isolates
% virulent blackleg isolates
60
Sylvestris isolates
50
40
30
20
10
0
Sylvestris
Polygenic
Winter
Juncea
Sources of blackleg resistance
Figure 12. The percentage of polygenic and sylvestris blackleg isolates that were
virulent on each source of blackleg resistance. In total 120 isolates were screened
over the four sources of blackleg resistance.
As expected, few isolates could attack the juncea or winter cultivars. This probably
reflects the situation in Australia prior to release of plants with sylvestris resistance. A
small proportion of isolates were already virulent on sylvestris resistance but they
increased in frequency when sylvestris cultivars were grown, eventually causing the
failure of these cultivars. We can therefore hypothesise that juncea and winter
cultivars may have the same fate if they are not managed carefully, as there are
already isolates that are virulent on these sources of blackleg resistance.
22
Of concern to the canola industry is the finding that almost 20% of isolates were able
to attack both plants with either sylvestris or polygenic resistance (Figure 13).
However, the theory of genetic fitness suggests that these isolates should be outcompeted over time. Although the number of isolates tested in this study was small,
the number of isolates with multiple virulence appeared to decline over time. For
example in 2005, 4/6 isolates from the Eyre Peninsula had multiple virulence, while
only 1/8 isolates collected from the same location had multiple virulence in 2006.
% of virulent blackleg isolates
60
50
40
30
20
10
Sylv+poly+win+jun
Poly+win+jun
Sylv+win+jun
Poly+jun
Poly+win
Sylv+jun
Syly+win
Sylv+poly
Jun only
Winter only
Poly only
Sylv only
Jun total
Win total
Poly total
Sylv total
0
Sources of blackleg resistance
Figure 13. Percentage of all screened blackleg isolates that were virulent on each
source of blackleg resistance and on multiple sources of resistance.
23
4. Field Monitoring - Survey of Blackleg Severity at Yield
Evaluation Sites (NVT)
INTRODUCTION
Monitoring blackleg severity in the field was used to obtain “real-life” data and to
observe if blackleg was responding (in the field) in a similar way as seen in the small
scale experiments. Specifically the field monitoring was used to investigate:
i) how much blackleg would be in polygenic cultivars sown after sylvestris-cultivars
(polygenic resistance and sylvestris stubble)?
ii) will the sylvestris resistance always be susceptible, or if sylvestris cultivars are no
longer grown will there be less blackleg damage over time?
METHODS
Between 2004 to 2006, cvs. ATR-Beacon (polygenic) and Surpass501TT (sylvestris)
were sown in all advanced yield evaluation (NVT) trial sites across southern
Australia. Over this 3 year period both ATR-Beacon and Surpass501TT were assessed
for blackleg severity (internal infection and mortality percentage) at 180 sites.
Sites were assessed by pulling 20 plants from each of 3 reps (60 plants per site) out of
the ground and then cutting the crown to score internal infection.
RESULTS & DISCUSSION
Figure 14 shows the results from South Australian sites excluding the low rainfall
sites of Minnipa and Lameroo, SA sites were chosen because sylvestris attacking
isolates were generally more widespread in this state. Prior to 2004 sylvestris
cultivars were widely grown, from 2004 onwards few if any sylvestris cultivars were
sown in most regions of SA.
% Severe internal blackleg infection
70
60
Polygenic cultivar
50
Sylvestris-derived cultivar
40
30
20
10
0
2004
2005
2006
Year
Figure 14. Percentage of plants with severe blackleg infection from both the
polygenic cultivar ATR-Beacon and the sylvestris cultivar Surpass 501TT in all
NVT sites in South Australia over 3 years (2004-2006).
24
This data indicates that isolates virulent against both sylvestris and polygenic cultivars
collected from these sites for the differential study have not become prevalent over
time.
The data shows that each year (after growers stopped sowing sylvestris cultivars) that
the damage from blackleg on sylvestris cultivars fell markedly. Conversely blackleg
severity increased on the polygenic cv. ATR-Beacon even in the drought of 2006.
This result is clear evidence that the blackleg population changes very rapidly in
response to the source of blackleg resistance deployed by growers.
In other regions of Australia, namely Western Australia, this marked trend towards
less disease in sylvestris cultivars was not seen (Table 4). The likely explanation for
this is due to the commercial cultivars grown during the study. In Western Australia,
no large scale breakdown in resistance occurred in 2003, and although growers were
warned and most stopped growing sylvestris cultivars, a number of growers still
continued to grow sylvestris cultivars. Therefore, the sylvestris stubble was
maintained in the production systems.
Figure 15. Cutting a canola plant at the crown to assess blackleg internal
infection.
25
Figure 16. Scoring NVT trials for blackleg severity.
2002
2003
2005
2006
2004
Figure 17. Sylvestris based cultivars in NVT trial sites from 2002 to 2006 on the
Eyre Peninsula SA.
26
Table 4. The percentage of plants from each NVT site with severe infection
(>50% internal blackleg infection).
Year
2004
State
NSW
2004
SA
2004
Vic
Site
Barmedman
Binalong
Boree Creek
Coleambally
Combaning
Coolamon
Finley
Galong
Grenfell
Gundibindyal
Illabo
Oaklands
Thuddungra
Wagga Wagga
Wakool
Wallendbeen
Arthurton
Bordertown
Frances
Keith
Lamaroo
Lock
Minlaton
Minnipa
Mt Hope
Naracoorte
Riverton
Spalding
Ungarra
Yeelanna
Charlton
Diggora
Gerang
Hamilton
Hopetoun
Horsham
Inverleigh
Katamatite
Kerang
Lake Bolac-SFS
Lake Bolac
Minyip
Moyston
Rutherglen
Sea Lake
Walpeup
Warracknabeal
Wilby
Polygenic
resistance
0
30
0
0
0
2
5
33
18
12
5
7
12
7
0
13
15
13
13
22
0
43
40
0
17
37
23
5
7
42
2
2
3
18
0
3
17
8
0
15
10
8
0
7
0
0
0
5
Sylvestris
resistance
0
10
0
0
0
0
0
2
0
2
7
0
0
5
0
2
73
15
15
80
2
62
93
0
58
28
68
13
72
100
2
0
3
5
0
0
8
0
0
3
0
2
2
2
0
2
0
0
27
Year
2004
State
WA
2005
NSW
2005
SA
Site
Badgingara
Eradu
Esperance
Kalanie
Katanning
Mt Barker
Newdegate
Wongan Hills
Yuna
Ariah Park
Ariah Park
Berrigan
Cowra
Forbes
Gerogery
Grenfell
Harden
Harefield-Pioneer
B'leg
Lockhart
Lockhart
Marrar
Parkes
Wagga Wagga
Wellington
Arthurton
Bordertown
Frances
Keith
Lameroo
Lock
Minlaton
Minnipa
Moyhall
Mt Hope
Riverton
Spalding
Turretfield
Wanilla
Yeelanna
Polygenic
resistance
65
13
25
0
18
17
12
3
5
38
43
42
37
45
3
25
17
62
Sylvestris
resistance
68
0
13
0
23
27
7
0
0
50
22
13
3
3
2
8
5
25
8
2
15
13
32
13
23
63
15
42
3
13
20
67
40
0
3
17
23
17
5
3
7
0
3
33
0
35
77
43
93
7
18
12
70
58
5
10
43
20
62
32
28
Year
2005
State
Vic
2005
WA
2006
NSW
2006
SA
Site
Birchip
Charlton
Diggora
Gerang
Hamilton
Horsham
Katamatite
Laharum
Lake Bolac
Minyip
Streatham
Ultima
Walpeup
Wilby
Calingiri
Cunderdin
Eneabba
Merredin
Mingenew
Mt Barker
Nabawa
Nyabing
Wickepin
Williams
Ariah Park
Cowra
Gerogery
Grenfell
Lockhart
Parkes
Wellington
West Wyalong
Arthurton
Frances
Keith
Lameroo
Minlaton
Minnipa
Moyhall
Mt Hope
Riverton
Spalding
Turretfield
Yeelanna
Polygenic
resistance
37
43
33
45
38
28
43
73
37
30
37
5
7
43
23
12
0
5
0
52
10
82
72
77
2
0
0
0
0
3
0
0
38
27
15
0
23
0
50
33
30
13
17
17
Sylvestris
resistance
8
13
10
50
7
23
7
70
2
18
17
2
0
25
38
12
0
2
0
87
0
60
43
48
0
0
3
0
0
0
2
0
15
10
5
0
15
0
30
35
17
2
18
45
29
Year
2006
State
Vic
2006
WA
Site
Charlton
Diggora
Hamilton
Horsham
Inverleigh
Katamatite
Minyip
Streatham
Teesdale
Calingiri
Cunderdin
Eneabba
Holt Rock
Jerramungup
Katanning
Kojonup
Lake Grace
Merredin
Munglinup
Nyabing
Scaddan
South Stirling
Wickepin
Williams
Wubin
Polygenic
resistance
2
0
35
0
0
15
0
42
72
2
2
33
12
40
17
23
10
0
82
43
58
47
0
17
0
Sylvestris
resistance
0
0
15
0
2
0
0
5
0
13
2
3
23
33
17
30
5
0
95
28
88
30
2
15
0
30
Future Work
Monitoring blackleg severity on different sources of host resistance.
Data collected from the field are crucial to support any management plan for durable
blackleg resistance. Monitoring advanced yield trials will be an early warning system
to growers to advise if a source of blackleg resistance has been overcome by the
fungus. It will also show if the durable blackleg management plan is working in the
field. The following activities will be pursued:
1. NVT field surveys - to determine areas where (if) resistance is being
overcome.
2. Replicated sites – for destructive sampling in yield and blackleg nurseries.
Regions of high blackleg severity will be targeted.
3. Screen new isolates for multiple virulence –virulent isolates will be collected
from field surveys and replicated sites, they will be screened for virulence
across different sources of resistance.
4. Resistance erosion alerts - blackleg rating data and the data collected in the
above points will be used to place alerts on cultivars with possible erosion of
blackleg resistance.
Pilot scale implementation
A pilot scale program will be undertaken for three years before a durability plan is
released to farmers in 2010.
1. Sources of blackleg resistance available
 Polygenic (most commercial cultivars).
 Winter/polygenic group (commercially available).
 Sylvestris/polygenic (commercially available).
 Brassica juncea – (commercial release in 2007 – Dune).
2. Classify cultivars into four groups – using pedigree information, molecular markers
where available, and screening commercial cultivars against known blackleg isolates.
3. Working Group (pathologists, breeders, growers, advisors) - to determine best
practical management guide, that utilises the results from UM020.
4. Potential grower package
1. Australian Blackleg Ratings with resistance erosion alerts.
2. Cultivar resistance groups guide.
3. Durable blackleg resistance management guide; could be produced as a
management practice within the existing guide.
31
Summary of Publications and Presentations
Papers in internationally refereed journals
Gladders P, Evans N, Marcroft S, Pinochet X (2006) Dissemination of information
about management strategies and changes in farming practices for the exploitation of
resistance to Leptosphaeria maculans (Phoma stem canker) in oilseed rape cultivars.
European Journal of Plant Pathology 114, 117-126.
Sprague SJ, Balesdent M, Brun H, Hayden H, Marcroft SJ, Pinochet X, Rouxel T,
Howlett BJ (2006). Major gene resistance in Brassica napus (oilseed rape) is
overcome by changes in virulence of populations of Leptosphaeria maculans in
France and Australia. European Journal of Plant Pathology 114, 33-40.
Delourme R, Chevre A, Brun H, Balesdent M, Dias P, Salisbury P, Renard M,
Rimmer S.(2006) Major gene and polygenic resistance to Leptosphaeria maculans in
oilseed rape (Brassica napus). European Journal of Plant Pathology 114, 41-52.
Sprague SJ, Marcroft SJ, Hayden H, Howlett B (2006) Major gene resistance to
blackleg in Brassica napus overcome within three years of commercial production in
South eastern Australia. Plant Disease 90, 190-198.
Manuscript papers to be published during 2007
1. Blackleg severity across Australia
2. Rotation of different sources of blackleg resistance to decrease blackleg
severity
3. Blackleg isolate specificity
Conference proceedings
Marcroft SJ, Howlett BJ, Salisbury PA (2005) Is durable blackleg resistance
possible? Australian Research Assembly on Brassicas, Pt Linclon.
Salam MU, Marcroft SJ, Potter TD, Wratten N, Macleod WJ, Diggle AJ (2005)
Blackleg severity in canola during 2004 across Australia: why was it high in South
Australia and low elsewhere? Australian Research Assembly on Brassicas, Pt Lincon.
Sprague SJ, Marcroft SJ, Hayden HL, Howlett BJ (2005) Breakdown of major
gene resistance to blackleg (Leptosphaeria maculans) in canola (Brassica napus).
Australasian Plant Pathology Symposium, Geelong.
Van de Wouw AA, Cozijnsen AJ, Marcroft SM, Salisbury PA, Rouxel T,
Balesdent MH, Howlett BJ (2007) Use of molecular markers to assess changes in
frequency of virulent isolates in populations of Leptosphaeria maculans. Australian
Research Assembly on Brassicas, Geraldton.
Marcroft SJ, Potter TD, Howlett BJ, Salisbury PA (2007) Management strategies
for durable blackleg resistance in canola in Australia. Australian Research Assembly
on Brassicas, Geraldton.
32
Marcroft SJ, Potter TD, Howlett BJ, Salisbury PA (2007) Management strategies
for durable blackleg resistance in canola in Australia. 26th Australasian Plant
Pathology Symposium, Adelaide.
Marcroft SJ, Li H, Sprague SJ, Howlett BJ, Barbetti MJ, Sivasithamparam K,
Potter TD, Burton WA, Barnes S, Robson D, Kay J, Ludwig I, Hoskings M, Flett P,
Taylor P, Lutt R, Schulz I, Sargeant D, Ballinger S, Salisbury PA (2007) Is durable
blackleg resistance feasible in Australia? International Rapeseed Congress, China.
Thomas V, Salisbury PA, Norton R, Marcroft SJ (2007) The current situation in the
Brassica juncea- Leptosphaeria maculans pathosystem and how future changes will
be monitored. International Rapeseed Congress, Wuhan, China.
GRDC updates
Marcroft SJ, Sprague SJ (2004) Blackleg resistance breakdown in canola – results,
reasons and recommendations. Wagga Wagga, Bendigo, Adelaide and Perth.
Marcroft SJ, Sprague S.J., Hind-Lanoiselet T (2005) Blackleg and Sclerotinia in Canola.
Wagga Wagga, Bendigo and Adelaide.
Marcroft SJ, Potter TD, Egan J, Crouch J (2006) Blackleg – ratings, bushfires, future
management options. Wagga Wagga, Bendigo and Adelaide.
Marcroft SJ (2007) Blackleg – ratings, bushfires, future management options. Perth.
Marcroft SJ, Barbetti MJ, Li H, Sivasithamparam K, Salisbury PA, Howlett BJ,
Sprague SJ (2007) Blackleg severity in WA. Presented at Perth.
Marcroft SJ, Potter TD, Egan J, Crouch J, (2007) Did the 2005 Eyre Peninsula bush
fire reduce blackleg severity? Presented at Perth.
Other communication activities
 Fact Sheet - Burning canola stubble may not control blackleg.
 Newspaper articles in Weekly Times, Stock Journal, Stock and Land,
GroundCover, Wimmera Farming and Landcare Newsletter, CAA-Canola
news.
 Presentations at Birchip Cropping Group, Southern Farming Systems,
Wimmera Farming Systems, MacKillop Group and TopCrop.
 Local radio interviews, Local rural report, County Hour (Vic and SA).
 Articles for media groups such as Jon Lamb Communications etc.
 Presentations at advisor training workshops (approx 250 attendees over 3
years).
 Three presentations at the annual National Canola Pathology Workshops held
in Melbourne and Perth.
 Chair and coordinator of two National Canola Pathology Workshops.
 Public seminar at Grains Innovation Park
33
Table 5. Leptoshaeria maculans isolates collected during the project (isolates
available for research purposes).
Collection
Year
Code
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
04MGP-P001
04MGP-P002
04MGP-P003
04MGP-P004
04MGP-P005
04MGP-P006
04MGP-P012
04MGP-P013
04MGP-P014
04MGP-P015
04MGP-P016
04MGP-P017
04MGP-P018
04MGP-P019
04MGP-P020
04MGP-P021
04MGP-P022
04MGP-P023
04MGP-P024
04MGP-P025
04MGP-P026
04MGP-P027
04MGP-P028
04MGP-P029
04MGP-P030
04MGP-P031
04MGP-P032
04MGP-P033
04MGP-P034
04MGP-P035
04MGP-P036
04MGP-P037
04MGP-P038
04MGP-P039
04MGP-P040
04MGP-P041
04MGP-P042
04MGP-P043
04MGP-P044
04MGP-P045
04MGP-P046
04MGP-P047
04MGP-P048
04MGP-P049
04MGP-P050
04MGP-P007
04MGP-P008
04MGP-P009
Resistance
Source
Cultivar
State
Collection
location
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Rainbow
Rainbow
Rainbow
Rainbow
Rainbow
Rainbow
Emblem
Emblem
Emblem
Emblem
Emblem
Emblem
Emblem
Emblem
Emblem
Emblem
Grace
Grace
Grace
Grace
Grace
Grace
Grace
Pinnacle
Pinnacle
Pinnacle
Pinnacle
Pinnacle
Pinnacle
Pinnacle
Pinnacle
Pinnacle
Pinnacle
Pinnacle
Grace
Grace
Grace
Grace
Grace
Grace
Pinnacle
Pinnacle
Pinnacle
Pinnacle
Pinnacle
Polygenic
Polygenic
Polygenic
NSW
NSW
NSW
NSW
NSW
NSW
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
NSW
NSW
NSW
NSW
NSW
NSW
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Moyhall
Moyhall
Moyhall
Moyhall
Moyhall
Moyhall
Moyhall
Geelong
Geelong
Geelong
Geelong
Geelong
Geelong
Geelong
Geelong
Geelong
Geelong
Geelong
Wonwondah
Wonwondah
Wonwondah
Wonwondah
Wonwondah
Wonwondah
Laharum
Laharum
Laharum
Laharum
Laharum
Wonwondah
Wonwondah
Wonwondah
34
Collection
Year
Code
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2004
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
04MGP-P010
04MGP-P011
M1
04MGP-S001
04MGP-S002
04MGP-S003
04MGP-S004
04MGP-S005
04MGP-S006
04MGP-S007
04MGP-S008
04MGP-S009
04MGP-S010
04MGP-S011
04MGP-S012
04MGP-S013
04MGP-S014
04MGP-S015
04MGP-S016
04MGP-S017
04MGP-S018
04MGP-S019
04MGP-S020
04MGP-S021
04MGP-S022
04MGP-S023
04MGP-S024
04MGP-S025
04MGP-S026
04MGP-S027
04MGP-S028
04MGP-S029
05MGPP015
05MGPP016
05MGPP017
05MGPP018
05MGPP019
05MGPP020
05MGPP021
05MGPP022
05MGPP023
05MGPP024
05MGPP025
05MGPP001
05MGPP002
05MGPP003
05MGPP004
05MGPP005
05MGPP006
05MGPP007
05MGPP008
Resistance
Source
Polygenic
Polygenic
Polygenic
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Cultivar
State
Collection
location
Polygenic
Polygenic
Vic
Vic
Wonwondah
Wonwondah
Surpass 400
Surpass 400
Surpass 400
Surpass 400
Surpass 400
Surpass 400
Surpass 400
Surpass 400
Surpass 400
Surpass 400
Surpass 603CL
Surpass 603CL
Surpass 603CL
Surpass 603CL
Surpass 603CL
Surpass 603CL
Surpass 603CL
Surpass 400?
Surpass 400?
Surpass 400?
Surpass 400?
Surpass 400?
Surpass 400?
Surpass 603CL
Surpass 603CL
Surpass 603CL
Surpass 603CL
Surpass 603CL
Surpass 603CL
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
SA
SA
SA
SA
SA
SA
SA
SA
Eyre Peninsula
Eyre Peninsula
Eyre Peninsula
Eyre Peninsula
Eyre Peninsula
Eyre Peninsula
Eyre Peninsula
Eyre Peninsula
Eyre Peninsula
Eyre Peninsula
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Eyre Peninsula
Eyre Peninsula
Eyre Peninsula
Eyre Peninsula
Eyre Peninsula
Eyre Peninsula
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Illabo
Illabo
Illabo
Illabo
Illabo
Wagga
Wagga
Wagga
Wagga
Wagga
Wagga
Woseley
Woseley
Woseley
Woseley
Woseley
Woseley
Woseley
Woseley
35
Collection
Year
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
Code
05MGPP009
05MGPP010
05MGPP011
05MGPP012
05MGPP013
05MGPP014
05MGPP026
05MGPP027
05MGPP028
05MGPP029
05MGPP030
05MGPP031
05MGPP032
05MGPP033
05MGPP034
05MGPP035
05MGPP036
MU-4
MU-5
MU-6
MU-11
MU-12
MU-13
MU-14
MU-18
MU-19
MU-20
MU-21
MU-25
MU-26
MU-27
MU-28
MU-29
MU-30
MU-33
MU-34
MU-35
MU-38
MU-39
MU-40
05MGPS004
05MGPS005
05MGPS006
05MGPS007
05MGPS008
05MGPS009
05MGPS010
05MGPS042
05MGPS043
05MGPS044
05MGPS045
Resistance
Source
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Poly
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Cultivar
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Skipton
Skipton
Skipton
Skipton
Skipton
Skipton
Skipton
Skipton
Skipton
Skipton
Skipton
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
State
Collection
location
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
Minlaton
Minlaton
Minlaton
Minlaton
Minlaton
Minlaton
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Katanning
Katanning
Katanning
Mt Barker
Mt Barker
Mt Barker
Mt Barker
Esperence
Esperence
Esperence
Esperence
Badgingarra
Badgingarra
Badgingarra
Yuna
Yuna
Yuna
Eradu
Eradu
Eradu
Newdegate
Newdegate
Newdegate
Illabo
Illabo
Illabo
Illabo
Illabo
Illabo
Illabo
Wagga
Wagga
Wagga
Wagga
36
Collection
Year
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
2005
Code
05MGPS046
05MGPS047
05MGPS001
05MGPS002
05MGPS003
05MGPS011
05MGPS012
05MGPS013
05MGPS014
05MGPS015
05MGPS016
05MGPS017
05MGPS018
05MGPS019
05MGPS020
05MGPS021
05MGPS022
05MGPS023
05MGPS024
05MGPS025
05MGPS026
05MGPS027
05MGPS028
05MGPS029
05MGPS030
05MGPS031
05MGPS032
05MGPS033
05MGPS034
05MGPS035
05MGPS036
05MGPS037
05MGPS038
05MGPS039
05MGPS040
05MGPS041
MU-1
MU-2
MU-3
MU-7
MU-8
MU-9
MU-10
MU-15
MU-16
MU-17
MU-22
MU-23
MU-24
MU-31
MU-32
Resistance
Source
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Cultivar
Surpass501TT
Surpass501TT
Surpass603CL
Surpass603CL
Surpass603CL
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass603CL
Surpass603CL
Surpass603CL
Surpass603CL
Surpass603CL
Surpass603CL
Surpass603CL
Surpass603CL
Surpass603CL
Surpass603CL
Surpass603CL
Surpass603CL
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
Surpass501TT
State
Collection
location
NSW
NSW
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
Wagga
Wagga
Bordertown
Bordertown
Bordertown
Minlaton
Minlaton
Minlaton
Minlaton
Minlaton
Minlaton
Minlaton
Minlaton
Minlaton
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Yeelana
Horsham
Horsham
Horsham
Horsham
Horsham
Horsham
Horsham
Horsham
Horsham
Horsham
Katanning
Katanning
Katanning
MtBarker
MtBarker
MtBarker
MtBarker
Esperence
Badgingarra
Badgingarra
Badgingarra
Badgingarra
Badgingarra
Yuna
Yuna
37
Collection
Year
Code
Resistance
Source
2005
2005
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
MU-36
MU-37
06MGPP019
06MGPP020
06MGPP021
06MGPP022
06MGPP023
06MGPP024
06MGPP025
06MGPP026
06MGPP027
06MGPP028
06MGPP001
06MGPP002
06MGPP003
06MGPP004
06MGPP005
06MGPP006
06MGPP007
06MGPP008
06MGPP009
06MGPP010
06MGPP011
06MGPP012
06MGPP013
06MGPP014
06MGPP015
06MGPP016
06MGPP017
06MGPP018
06MGPP029
06MGPP030
06MGPP031
06MGPP032
06MGPP033
06MGPP034
06MGPP035
06MGPP036
06MGPP037
06MGPP038
06MGPP039
06MGPP040
06MGPP041
06MGPP042
06MGPP043
06MGPP044
06MGPP045
06MGPP046
06MGPP047
06MGPP048
MU41
MU42
Sylvestris
Sylvestris
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Cultivar
Surpass501TT
Surpass501TT
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Skipton
Skipton
Skipton
Skipton
Skipton
Skipton
Skipton
Skipton
Skipton
Skipton
Beacon
Beacon
State
Collection
location
WA
WA
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
WA
WA
Newdegate
Newdegate
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Yeelanna
Yeelanna
Yeelanna
Yeelanna
Yeelanna
Yeelanna
Yeelanna
Yeelanna
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Keith
Keith
Keith
Keith
Keith
Keith
Keith
Keith
Keith
Keith
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Williams
Williams
38
Collection
Year
Code
Resistance
Source
Cultivar
State
Collection
location
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
MU43
MU44
MU49
MU-50
MU-55
MU-56
MU-63
MU-64
MU-72
MU-73
MU-74
MU-75
MU-76
MU-77
06MGPS017
06MGPS018
06MGPS019
06MGPS020
06MGPS021
06MGPS022
06MGPS023
06MGPS024
06MGPS025
06MGPS026
06MGPS027
06MGPS028
06MGPS001
06MGPS002
06MGPS003
06MGPS004
06MGPS005
06MGPS006
06MGPS007
06MGPS008
06MGPS009
06MGPS010
06MGPS011
06MGPS012
06MGPS013
06MGPS014
06MGPS015
06MGPS016
06MGPS029
06MGPS030
06MGPS031
06MGPS032
06MGPS033
06MGPS034
06MGPS035
06MGPS036
06MGPS037
06MGPS038
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Polygenic
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Beacon
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
NSW
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
Williams
Williams
Wickepin
Wickepin
Wickepin
Wickepin
Cunderdin
Cunderdin
Calingiri
Calingiri
Nyabing
Nyabing
Nyabing
Nyabing
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Wagga Wagga
Yeelanna
Yeelanna
Yeelanna
Yeelanna
Yeelanna
Yeelanna
Yeelanna
Yeelanna
Yeelanna
Yeelanna
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Bordertown
Keith
Keith
Keith
Keith
Keith
Keith
Keith
Keith
Keith
Keith
39
Collection
Year
Code
Resistance
Source
Cultivar
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
2006
06MGPS039
06MGPS040
06MGPS041
06MGPS042
06MGPS043
06MGPS044
06MGPS045
06MGPS046
06MGPS047
06MGPS048
MU45
MU46
MU47
MU48
MU-51
MU-52
MU-53
MU-54
MU-57
MU-58
MU-59
MU-60
MU-61
MU-62
MU-65
MU-66
MU-67
MU-68
Mu-69
MU-71
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Sylvestris
Hyola 60
Hyola 60
Hyola 60
Hyola 60
Hyola 60
Hyola 60
Hyola 60
Hyola 60
Hyola 60
Hyola 60
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
Surpass 501TT
State
Collection
location
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
Vic
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
WA
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Lake Bolac
Nyabing
Nyabing
Nyabing
Nyabing
Merridin
Merridin
Merridin
Merridin
Williams
Williams
Williams
Williams
Cunderdin
Cunderdin
Wickepin
Wickepin
Wickepin
Wickepin
Calingiri
Calingiri
40