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DAWA contribution to Final Report for UWA340
SUMMARY
The two responsibilities for GRDC project UWA340 involving research from DAWA were to:
(1) Rank current WA cereal varieties for waterlogging tolerance
(2) Judge the success of improvement of waterlogging tolerance of wheat using DH lines produced from international
germplasm reputed to be waterlogging tolerant.
Ranking of varieties for waterlogging tolerance in large field experiments using waterlogging gradients and row trials is
difficult, and development of protocols still requires further research support. Waterlogging tolerance data from one
site may be completely different to another site, i.e. the level of waterlogging tolerance may differ or the varietal
ranking may be completely different, or both. This is a major concern, since this means that reproducible
characterisation of large sets of germplasm (>100) in the field at one site is particularly difficult, and multiple sites are
prohibitively expensive; even small sets of germplasm (12) can give completely different results in different sites or
different years as shown here for 11 waterlogging conditions/ trials evaluated over 2002 to 2004. There are two
approaches to this problem: (1) use a pragmatic approach and characterise germplasm as either generally waterlogging
tolerant, generally waterlogging intolerant, or variable; or (2) use a mechanistic approach and determine the
environmental factors responsible for variations in waterlogging tolerance in different field environments, and then
group waterlogging tolerance results from similar trials/environments. Both approaches have now been used with
results contributing to (i) the identification of several different types of waterlogging in WA, (ii) the better
understanding of key mechanisms involved in different soils (Setter et al., 2004; Setter et al., 2005).
Project UWA340 is responsible for contributing to a major new approach of screening for waterlogging tolerance in
“semi-field” experiments (using pots in the target environment). The major achievements include (i) development of
an accurate, reproducible screening protocol for waterlogging tolerance in specific soils, and (ii) development of the
structure and layout of a major screening facility for waterlogging tolerance at Katanning, WA. In contrast to other
field trails, these protocols and facility are relatively inexpensive since they enable controlled treeatments, and they
enable reproducible screening of large numbers (hundreds or thousands) of genotypes per year. Varietal screening
results clearly demonstrate that newly released varieties like EGA Tammarin Rock have some of the highest
waterlogging tolerance in Katanning soil for any wheat, while other varieties like EGA Bonnie Rock, Cascades and
Brookton are intolerant to waterlogging in Katanning soil.
The above work relates to waterlogging tolerance at the vegetative stage, when waterlogging occurs in the target
environment. However in many years (like 2005 in WA) waterlogging also occurs at the seed germination and seedling
emergence stage. Until this project and support from GRDC Project DAW292, there was little or no information on
waterlogging tolerance of wheat at the seed germination stage. Seeds from 54 varieties of wheat, barley, oats, triticale,
lupin and canola were screened for waterlogging tolerance. Seeds of wheat (also barley and lupin) varieties are
generally intolerant to waterlogging, but there is genetic diversity for waterlogging tolerance (Setter and Waters, 2003).
After 4 days of waterlogging in completely saturated soil at 15C, about 50% seed death occurs for most wheat; after 8
days waterlogging at 15C, 95% or more death usually occurs. Temperature is particularly important in the ability of
seeds to tolerate waterlogging in the field. High temperatures (above 15C ) exacerbate adverse effects; low
temperatures minimise effects. Data provided are useful for consideration of crop and varietal selections in
waterlogging prone regions, since there is a 3-fold difference in waterlogging tolerance at the seed germination stage of
different wheat varieties.
A second output of this project by DAWA was to evaluate the progress of doubled haploid (DH) development in
producing genotypes more tolerant than current varieties. This data is provided in Section 2 confirming that one DH
population (Ducula-4/2*Brookton) gives good transgressive segregation with over 10% of lines having a greater
waterlogging tolerance than either parent, even though this population has two backcrosses to the intolerant parent.
Varietal data for waterlogging tolerance has already been used in 2005 by wheat breeders at DAWA to identify new
crosses for tomorrow’s varieties, potentially incorporating an even greater level of waterlogging tolerance.
In summary, this project has been productive, and ultimately successful, with key impacts to develop important
screening protocols for producing tomorrow’s varieties. However, new concerns are already appearing in relation to
this work. Original measurements on waterlogging tolerance of wheat during germination were done at the beginning
of this project, and they highlight that unless protocols are adopted by the breeding programs, this information will lose
much of its value due to rapid introduction of new varieties. Screening for waterlogging tolerance at the vegetative and
seed germination stage must be taken up by breeding programs if this information is to be completely exploited by
growers and by breeders. We now know how to screen but this must be integrated into breeding programs. It is
proposed that a Centre for Abiotic Stresses be established to provide services and research support to rapidly
characterise germplasm for waterlogging and other abiotic stresses that occur across Australian wheat production
regions.
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RESULTS AND DISCUSSION
The two responsibilities for GRDC project UWA340 involving research from DAWA were to:
(1) Rank current WA cereal varieties for waterlogging tolerance based on (i) screening experiments at germination
and seedling stage under controlled conditions and (ii) growth and yields of plants grown to maturity in field plots
across waterlogging gradients across selected sites on the South Coast.
(2) Judge the success of improvement of waterlogging tolerance of wheat using DH lines produced from
international germplasm reputed to be waterlogging tolerant.
These two contracted outputs are described in the two sections below.
Work on field screening using Waterlogging gradients and Row trials (Section 1.1 and 1.2) was completely managed by
support from UWA340; DAWA staff on UWA340 (G. McDonald and others) were also crucial in set up and
monitoring of the “Semi-field” pot trials that were also supported by the Australian Centre for International Agricultural
Research (ACIAR) and in 2004 by the Molecular Plant Breeding Cooperative Research Centre (MPBCRC) to evaluate
waterlogging tolerance under controlled conditions (Section 1.1.3).
1 Rank current WA wheat varieties for waterlogging tolerance
The definition of waterlogging tolerance
Waterlogging tolerance is a relative measure, and it is defined here as the growth (grain yield or biomass of plants) or
survival, e.g. seeds, of waterlogged plants relative to non (or less-) waterlogged plants. A high value is therefore not
necessarily for those varieties have the highest absolute grain yield or biomass at the end of waterlogging, but which
have the highest relative grain yield or biomass in waterlogged relative to drained conditions. This is important to
distinguish, since the highest absolute biomass or grain yield after waterlogging may simply relate to greater yield
potential in a specific site, and it may have nothing to do with “waterlogging tolerance” per se. Data based on both
absolute biomass/grain yield after waterlogging and relative waterlogging tolerance are available for all trials presented
here.
1.1 Waterlogging tolerance of vegetative plants
1.1.1 Screening methods for vegetative plants
Three types of field experiment trials were run during 2001-2004 at DAWA aimed at ranking WA wheat varieties and
breeding lines for waterlogging tolerance:
Waterlogging Gradients (utilising transects across waterlogging gradients),
Row Trials, and
“Semi-Field” [Pot] Trials (described in Section 1.4).
7 waterlogged sites were run as waterlogging gradients, resulting in 9 waterlogging situations varying in severity.
6 waterlogged sites were run as Row Trials with only 3 resulting in waterlogging situations.
~6000 pots were used in a semi-field trial using controlled waterlogging at Katanning in 2004.
Waterlogging gradients are natural gradients in the landscape where there is a marginal slope (~0.5-1%; but
sometimes up to 5%) resulting in drained areas on the upper slope and waterlogged areas at the lower end of the slope.
Waterlogging gradients are ideal for screening reasonable numbers (usually <30 genotypes) in replicated trials in long
(50-100 m) plots running from the top to the bottom of the slope. These trials are ideal, since if waterlogging is severe
in one year, sampling can be done further up the slope where varietal discrimination is good; and where waterlogging is
low in one year sampling can be done further down the slope where varietal discrimination is good. In these years if
trials were set up without a gradient, either all plots would be lost, or no plots would be waterlogged, respectively – the
end result is an expensive and time consuming loss of one year.
Row trials are where genotypes are screened in single rows usually 20-40 m long; this screening method is used for
large numbers of genotypes. In early trials the genotypes were sown in much shorter often intermittently in rows, and
they were randomised and unreplicated; therefore waterlogging treatments often did not affect all varieties equally and
mean data were highly variable. Subsequently, sowing long rows (>20m) enabled reasonable discrimination to be
resolved. No data on row trials are presented here because these early methods was judged as being largely
unsuccessful for the sites and seasons in the present work.
Semi-field [pot] trials are where varieties are grown in pots in the target environment and then exposed to
waterlogging (or drainage) under identical environmental conditions of natural waterlogging. The advantages of this
system are that (1) plants have the same temperature, light and soil as in the target environment; (2) plants are grown
and treated at optimum (high) nutrition; (3) waterlogging can be highly controlled to optimise genotypic discrimination;
(4) complete root systems can be sampled; and natural soil heterogeneity can be removed; (5) the system is inexpensive
requiring some earthmoving and plastic sheets with no power supply, in contrast to a $300,000 phytotron, plus
electricity costs; and (6) an almost unlimited number of genotypes or treatments (different soils, different nutrition, etc)
can be used due to almost unlimited space. The key disadvantage of this screening method is that you only get one shot
at this per year. Such methods ultimately also need to be validated in multi-locational field trials.
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1.1.2 Ranking varieties for waterlogging tolerance at vegetative stage using waterlogging gradients in the field
Waterlogging tolerance field trails at different sites were either successful (5 sites), partially successful (2 sites), or
unsuccessful (5 sites) in the ranking of varieties (Fig. 1). Sites where waterlogging tolerance evaluations were
successfully made included Culbin, South Stirling and Cranbrook (2002), South Stirling, Congelin and Mt. Barker
(2003) and Kalgan (2004). Unsuccessful trials occurred where rainfall was insufficient in the year to cause natural
waterlogging. The overall conclusion for ranking of varieties using Waterlogging Gradients is that results for
waterlogging tolerance are highly variable and often inconsistent between sites. Sometimes the ranking of
genotypes for waterlogging tolerance is just the opposite in one site in comparison to another (see below). These
results may be due to differences in the [1] soil physical and chemical properties, [2] waterlogging severity, [3]
waterlogging timing, or other factors. Even with these challenges we have made good progress in characterisation of
germplasm for waterlogging tolerance.
Table 1A summarises data across all sites where successful evaluations for waterlogging tolerance were made. Note
that data for waterlogging tolerance are based on grain yield of waterlogged plots relative to non (or less-) waterlogged
plots. This table shows that the effect of waterlogging on grain yield was severe at two sites (Congelin and Kalgan),
moderate in four sites (Mt. Barker, South Sterlings, Congelin and Culbin) and low at two sites (South Stirling and
Cranbrook). The site averages for waterlogging tolerance show that these natural waterlogging conditions in the field
reduced the overall grain yield to only 28-42% in the most severely affected site, 62-89% in moderately affected sites,
and 90-94% in least affected sites relative to non (or less) waterlogged plants (Table 1A).
Varietal data for waterlogging tolerance in Table 1A should not be averaged across sites due to the large variation in
intensity of waterlogging and the random selection of sites naturally ranging in waterlogging intensity. Data in Table
1B are calculated from Table 1A and the waterlogging tolerance of each variety is expressed relative to the site mean
(shown in Table 1A). This enables estimate of an Adjusted Mean Waterlogging Tolerance for each variety, and a
standard error of the mean (SEM) used to indicate variation across all sites. In Table 1B the two most waterlogging
tolerant and least waterlogging tolerant varieties in each site are indicated by bold and italic numbers, respectively.
Data from waterlogging gradients were also grouped according to the waterlogging intensity (SEW30 values) as
measured by the extent and duration of water in the soil profile at each site (Table 2). Using this approach, the top five
waterlogging tolerant varieties (Westonia, Calingiri, Camm, EGA Bonnie Rock and Chara) were the same as the top
five varieties identified when data were calculated based on waterlogging tolerance and site average grain yields (cf.
Table 2 and Table 1B). Both analyses also supported that varieties with low overall waterlogging tolerance were GBA
Ruby, GBA Sapphire, Wyalkatchem, Carnamah and Spear, however this only occurred under conditions of severe
waterlogging in Table 2. These data are also being analysed for GxE interactions and by cluster analysis.
Data on varietal ranking for waterlogging tolerance between sites (Table 1B) highlight a major concern. The top two
waterlogging tolerant varieties at one site are often among the two most waterlogging intolerant varieties at another site
(bold and italic numbers respectively in Table 1B). Out of only 12 varieties screened, this applies for: Westonia,
Carnamah, EGA Bonnie Rock, Brookton, Cascades, GBA Sapphire and GBA Ruby (Table 1B). Overall, the most
consistent waterlogging tolerant varieties are Camm and Calingiri, which were among the top two varieties in three or
four out of 11 sites/trials shown in Table 1B. Westonia, Chara, and EGA Bonnie Rock also have high overall
waterlogging tolerance (Table 1B). The most inconsistent, variable variety for waterlogging tolerance is Cascades,
since it is one of the two lowest varieties for waterlogging tolerance in four sites, however it was in the top two varieties
at three other sites (Table 1B). This variation in waterlogging tolerance across sites helps to explain why little or no
progress has been made in past projects aimed at germplasm improvement for waterlogging tolerance.
Detailed statistical analyses of these data are still in progress and under preparation for publication. Data collected here
are generally unsuitable for combining data sets and looking for quantitative GxE effects because of different varieties
used, different levels of stress, and inadequate degrees of freedom. Nevertheless, each trial was analysed using spatial
linear mixed models and adjusted means were predicted. Some spatial trends were identified and the means were
adjusted for Cal02, Kalgan04, SS02 (Table 1). Other trials were analysed by randomised block design. Ten varieties
were selected at four sites where these varieties were present. These were used to erect the “Environment” factor of
treatment (severity) and location, producing 11 environments shown in Table 1A and 1B. Clustering analyses showed
that the GxE effect is significant for these data at P<0.001. Data were also analysed using a bi-plot analysis; this
confirmed the above results and further indicated that there are at least three different environments for waterlogging
tolerance.
In summary, field screening for waterlogging tolerance using waterlogging gradients or row trials in diverse sites often
gives variable and highly inconsistent results. A pragmatic approach to interpreting such data is to classify genotypes
into groups of “stable” or “unstable” genotypes and try to mathematically minimise the variations, as we have done
here. A mechanistic approach is to identify what the mechanism(s) of tolerance or intolerance is to waterlogging in
these different sites (soils), and then try to establish whether there are consistent different types of waterlogging in
different soils or groups of soils. We are focusing on the latter approach particularly in the semi-field [pot] trials at
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Katanning. The concern raised here for inconsistent results at different sites highlights that it is incorrect to
average data across different sites without further information. This is supported by bi-plot analyses indicating
at least three different clusters for waterlogging tolerance based on data collected from only 5 locations here.
Subsequent research supported by ACIAR and MPBCRC have supported the conclusion that more controlled
waterlogging tolerance screening is required such as that provided by the Katanning Waterlogging Tolerance Facility.
This follows since there are different types of waterlogging due to different microelement toxicities that occur in several
of these sites, and this explains why the ranking for tolerance may be completely different, i.e. since the mechanisms of
tolerance will be different during waterlogging in these different soils (Setter et al., 2004, 2005). Another factor
affecting waterlogging tolerance evaluated from field trials using waterlogging gradients may involve waterlogging at
different stages of development. Such results make the semi-field pot trials at the Katanning Waterlogging Tolerance
Facility attractive (see next section), since there are stable screening conditions (time of waterlogging), and the timing
or soil or other environmental factors can be easily controlled. 1 We now know more about what the problem is under
conditions used here. Such findings are the beginning of developing a logical approach for pyramiding genes for
waterlogging tolerance in diverse environments.
1.1.3 Ranking varieties for waterlogging tolerance at vegetative stage using “semi-field” pot trials at Katanning
“Semi-field” waterlogging tolerance trials are where plants are grown in pots in one or more specific soils under
optimal nutrition, and they are exposed to controlled waterlogging conditions in artificial ponds constructed in the target
environment (Plate 1). The latter is important since when plants are sown at the same time as the field season
commences, this gives identical temperature, light and other climatic conditions that varieties receive during natural
waterlogging, i.e. confounding factors are minimised or eliminated.
Ranking of current WA varieties in controlled “semi-field” experiments was unsuccessful during the first years of the
project (2002 and 2003) due to extreme variations in sample replication. This was finally resolved in 2004 when the
first reproducible, and significantly different, characterisation for waterlogging tolerance was determined in a set of 39
varieties and advanced breeding lines waterlogged in Katanning soil (see range in sample variations over different years
in Fig. 2). It took two years (field seasons) to resolve why the variation was so high, e.g. in 2002 and 2003 in Fig. 2,
and subsequently enable us to amend protocols and equipment. In summary, extreme variation in shoot growth and
“waterlogging tolerance” occurred (1) if roots were able to escape from pots during the long time (6-7 weeks) of
waterlogging treatment used to simulate field conditions and/or (2) inadequately mixed soil was used in pots.
Following the discovery of root escape from typical pots used in experimental work at the end of 2003, approximately
10,000 specially designed pots (Plate 2) were mass-produced. Subsequent work after the termination of this project has
seen this facility moved adjacent to the Department of Agriculture District Office, Katanning, WA, where experiments
were conducted in 2004 (Plate 3) and the final detailed varietal characterisation was completed within a year after the
project completion (2004 data in Fig. 2). Currently the same site is being set up for 2005 waterlogging tolerance
screening using 4 soils and nearly 300 genotypes with approximately 8000 pots. Protocols are also in preparation for
screening segregating populations (Section 4(2)).
Ranking of varieties for waterlogging tolerance in Katanning soil using the screening facility at Katanning clearly
shows that the most tolerant and intolerant WA varieties are EGA Tammarin Rock and EGA Bonnie Rock, respectively
(2004 data, Fig. 2). The Indian varieties HD2009 and HD2329, as well as Cascades and Brookton are also highly
intolerant to waterlogging; while the varieties Westonia, Carnamah, Janz, Wyalkatchem, Chara, KRL1-4, Savannah and
Machete are most tolerant to waterlogging in Katanning soil.
Note that several of these rankings for waterlogging tolerance at Katanning (2004 data in Fig 2) conflict with overall
averaged data from the field trials shown in Table 1B and Table 2. This is due to averaging data across field sites that
in fact should not be averaged. In 2005, screening at Katanning in the controlled waterlogging facility will include
evaluation of a larger number of about 80 varieties; and 20 of these will be evaluated in 4 different soils from
waterlogging-prone target environments.
1.2 Waterlogging tolerance of seeds.
Seeds of wheat, barley and lupin cultivars are generally intolerant to waterlogging, but there is genetic diversity for
waterlogging tolerance. After 4 days of waterlogging in completely saturated soil at 15C, about 50% seed death occurs
for most wheat, barley and lupin cultivars. After 6 days waterlogging at 15C, 95% or more death usually occurs.
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Note: The use of highly controlled screening protocols for abiotic stresses is not unknown in germplasm improvement
programs. For example, cereal breeders have a high level of confidence about B and Al toxicity measurements made
from seedlings grown in solution culture. This is certainly the preferred selection criterion rather than reliance on large
field trials where there is considerable spatial and temporal variation for such stresses. Similar arguments can be
developed for waterlogging tolerance based on semi-field trials in pots in ponds. The bottom line is that these
ultimately need to be validated in large scale screening trials.
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Triticale cultivars have intermediate tolerance to waterlogging. Oat and particularly canola varieties have the greatest
tolerance to waterlogging at the seed stage. One canola variety, Monty, even had 90% seed survival after 8 d
continuous waterlogging.
Temperature is particularly important in the ability of seeds to tolerate waterlogging in the field. High temperatures
(above 15C ) exacerbate adverse effects; low temperatures minimise effects. Data provided are useful for
consideration of crop and varietal selections in waterlogging prone regions.
1.2.1 Introduction
Research at the Crop Improvement Institute DAWA, has evaluated waterlogging tolerance of seeds of 47 cereal
varieties (33 WA varieties), 12 lupin varieties, and 8 canola varieties. The primary aims are to identify national and
international cereal germplasm that may be suitable for crop improvement in WA and compare this to tolerance of other
crops. These results have been released to assist growers in decision making where it is necessary to sow or re-sow
under waterlogged conditions or where there is a possibility of waterlogging exposure. To our knowledge this is the
only information available on waterlogging tolerance of seeds of cereals, lupins and canola grown commercially in
Australia. Varietal differences in tolerance of cereal, lupin and canola seed, are presented in sections below. WA
germplasm gives a high level of tolerance to waterlogging over durations of 4-8 days.
1.2.2 Methods
Measurements involved replicated evaluations of varieties of wheat, barley, oats, triticale, lupins and canola. Seeds (50
per replicate) were exposed to waterlogged gravelly sand in 500 mL vials, for 4 days at constant 15C. Soil used was
topsoil from a grey sandy duplex soil (Fleming Series) from a waterlogging prone site at Esperance, WA. After
waterlogging, seeds were recovered from soil, washed, and tested for survival according to the International Seed
Testing Association (ISTA, 1985) guidelines using No.1 seed testing filter papers.
1.2.3 Results and Discussion
Cereal seeds
There are large varietal differences in waterlogging tolerance of seeds between cereals, and also within varieties of any
one cereal (Table 3). The most intolerant cereals are barleys with as little as 20% survival, while the most tolerant
cereals are oats with up to 100% survival following 4 d waterlogging. Survival is the germination ability which is
defined according to ISTA as the ability to produce a healthy seedling, in this case after a waterlogging event.
Cereal seeds are generally most tolerant in the order of :
Oats >> wheat and triticale > barley
Oats have the highest waterlogging tolerance of cereal seeds with most varieties giving 80 to 100% survival
after 4 d waterlogging. Mortlock was the worst performing oat variety with only 72% survival after 4 d
waterlogging (Table 3).
Wheat varieties have a high genetic diversity for survival of 32 to 92% following waterlogging for 4 days. Brookton,
Cadoux, Cascades, Cunderdin, Eradu were the only varieties evaluated that have above 80% survival under these
conditions. Several varieties were particularly intolerant to waterlogging at the seed stage, with about 50% or less
survival, including Camm and Stiletto (Table 3).
Triticale varieties had moderate to high tolerance, ranging from 75 to 96% survival after 4 d waterlogging.
Barleys are least tolerant of cereals to waterlogging at the seed stage, with varieties having only 19 to 73% survival
following 4 d waterlogging. Skiff was the most tolerant barley evaluated, and Gairdner the most intolerant variety to
waterlogging at the seed stage.
There is some evidence that some antibiotic-acting seed dressings may have a positive effect in increasing survival of
barley varieties by about 50%, but this still may make overall survival low. Seed dressings with calcium peroxide are
often used to enhance waterlogging tolerance of seeds in many countries. Other varieties and crops may be evaluated as
part of future research. In decision making for varietal selections, the results presented here must be taken in
consideration with other factors that relate to time of sowing, details of specific locations, and varieties suitable for local
crop establishment.
Lupin and canola seeds
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Replicated germination trials confirm that the most waterlogging tolerant commercial canola grown in WA is the
variety Monty (Table 4). Monty is a quick maturing variety, suitable for 250-450 mm rainfall, and it is a replacement
for Narendra.
In contrast, most lupin varieties have low survival to waterlogging (10-50%), except for the narrow leafed lupin, Kalya,
which has 70% survival after 4 days waterlogging. Varieties in Table 4 were treated identically to waterlogging
treatments for cereal varieties (Table 3). These data demonstrate that canola is the most tolerant crop to waterlogging at
the seed stage, relative to wheat, barley, oats, triticale or lupin varieties currently grown in Western Australia.
Long term waterlogging tolerance
For an extreme waterlogging test, the top surviving cereal and canola varieties were treated to continuous waterlogging
for 8 days. The survival percentages were Monty (canola) 90%, Coomallo (oats) 30%, Cadoux (wheat) 7%, and Skiff
(barley) 3%.
In general, the ranking of field crop seeds for waterlogging tolerance is therefore:
Canola >> Oats > triticale > wheat > barley and lupins
These results for canola are surprising since canola is generally considered a waterlogging intolerant crop later in its
vegetative development (Niknam, 1998). This suggests that waterlogging tolerance at the seed stage does not reflect
tolerance at the vegetative stage of development. Other results with cereals showed that varieties which have good
survival of seeds to waterlogging, often have a poor survival of vegetative plants to waterlogging. Data presented here
can be used to show that there is no correlation between waterlogging tolerance at the seed and vegetative stages. For
example, Cascades, which is highly intolerant to waterlogging at the vegetative stage in Katanning soil (calculated from
Fig. 2, 2004 data), has a high waterlogging tolerance at the germination stage (Table 3). This highlights an excellent
opportunity to improve germplasm for waterlogging tolerance at multiple stages of development.
Environmental factors affecting waterlogging tolerance at the seed stage
Data for survival of seeds during waterlogging are highly dependant on environmental factors, particularly temperature.
The higher the temperature, the faster the oxygen depletion in the soil due to respiration (oxygen consumption) by
microorganisms and the seed itself.
Oxygen consumption occurs normally by seeds to produce energy required for germination. However in drained soil,
the oxygen concentration is maintained similar to air because gases can diffuse from the atmosphere through the soil
pores. In waterlogged soils, the soil pores are filled with water and gas diffusion is reduced about 10,000 times relative
to in air. Therefore, when oxygen is consumed by the seed, it is not replaced, seeds asphyxiate, and they die.
At high temperatures, oxygen consumption by the seed and soil microorganisms occurs much faster than at low
temperatures. The impact is that after 4 days of waterlogging in a completely saturated soil at 25C, about 100% seed
death will occur for most wheat and barley cultivars, compared with only 50% death during waterlogging at 15C
(Table 3). Similar effects occur with lupins (Sarlistyaningsih, 1990). Where waterlogging occurs at very low
temperatures, e.g. 5C, little or no adverse effects may occur on crops or pastures. This is often why waterlogging
effects may be much less severe in countries like New Zealand, than in Australia.
The need to re-sow after waterlogging
Determination of whether a paddock will need to be re-sown following waterlogging will depend on seed survival,
which will depend on the duration and the severity of waterlogging.
Duration is simply the days of waterlogging. This will vary based on the sowing depth, since deeply sown seeds will be
exposed to waterlogging for longer than shallow sown seeds. The severity of waterlogging will depend on
(1) environmental factors,
(2) stage of development of the plant (established plants are more tolerant than seeds), and
(3) crop and cultivar.
Environmental factors include soil temperature (high is worse than low), but will also include soil type (heavy soil is
worse than light), water movement in soil (rapid percolation and seepage is better than stagnant conditions), soil organic
carbon (high is worse than low), and soil microbial activity (high is worse than low).
The above factors affecting seed survival seem complex, but the dominant factor affecting waterlogging tolerance in
the field in WA is usually temperature. For example, over the 10 day period from 17 to 27 May, 1999, when flooding
occurred in the Northern wheatbelt of WA, the average daily temperature for Geraldton was 19C. This is high relative
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to waterlogging events that normally occur during mid-winter at 15C or less in WA. The impact is that seed survival
would be expected to decline to zero for most crops within 5 days (Chuvativat 1990).
2.
Judge the success of improvement of waterlogging tolerance of wheat using DH lines produced from
international germplasm reputed to be waterlogging tolerant.
Research on waterlogging tolerance has little value unless we can demonstrate a capacity for breeding to directly
contribute to germplasm improvement. In this project, one output is to judge the improvement of waterlogging
tolerance in wheat using doubled haploid lines produced from international germplasm reputed to be waterlogging
tolerant. The international germplasm selected for making doubled haploids was Ducula-4, a variety identified by
CIMMYT to be able to withstand waterlogging for 3-4 months and still yield more than 2 t/ha (van Ginkel et al., 1992;
see also Sayer et al., 1994) under conditions at Obregon, Mexico. Mr. Robin Wilson used this variety in 1996 in a cross
with the WA variety Brookton to create the DH population Ducula-4/2*Brookton. Approximately 200 DH lines were
multiplied and made available for screening in this and other projects on waterlogging tolerance.
In 2004, the entire DH population of Ducula-4/2*Brookton (~200 lines) was screened through this project with major
support also from the MPBCRC. A replicated pot trial for waterlogging tolerance in Katanning soil was used with over
1500 pots at the semi-field waterlogging facility at Katanning, WA. The frequency distribution of these DH lines for
waterlogging tolerance (%) is shown in Fig. 3, and the waterlogging tolerance of the parental lines, Ducula-4 and
Brookton are shown for comparison in solid boxes. The data in Fig. 3 clearly demonstrate that (i) there is transgressive
segregation for waterlogging tolerance, and (ii) about 10% of the population consists of lines that have higher
waterlogging tolerance than either parent. Note that the frequency distribution of this population is skewed towards the
intolerant parent, Brookton, which is consistent with the double backcross of Brookton (…/2*Brookton) in this
population. These results demonstrating transgressive segregation have been confirmed in other trials in India where
the ranking of genotypes differs from the ranking in waterlogged Katanning soil, however the conclusion remains the
same (Setter et al., 2005). In India, the tolerance of DH lines in this population is so much greater than either of the
parents, that 4 DH lines were given varietal (KRL) names and released for All-of-India Coordinated Trials in 2005.
While the improvement for waterlogging tolerance is clearly evident from this DH population, the development of new
and even better DH populations is the subject of future work. Fig. 3 also shows the relative waterlogging tolerance of
two other varieties (EGA Bonnie Rock and EGA Tammarin Rock) which have a high diversity for waterlogging
tolerance in Katanning soil (Fig. 2, 2004 data). These recently identified varieties offer even greater potential to
improve waterlogging tolerance, and so these varieties are currently being crossed and used to develop two reciprocal
DH populations in 2005 for molecular marker development and for potential varietal release. These varieties are
particularly suited to potential variety release, since they have extremes in waterlogging tolerance, are both AH grain
quality, and EGA Tammarin Rock has some resistance to stripe rust. In summary, DH populations have been, and will
continue to be, important for research on waterlogging tolerance. They result in rapid genetic fixation of diverse
material, and they offer opportunities for molecular marker development as well as potential lines for varietal release.
3. Impacts of Project UWA340 and proposal to implement work into breeding programs by development of a
“Centre for Abiotic Stresses:”
Project UWA340 has formed the basis for major achievements in waterlogging tolerance due to its contributions to
development of screening methodologies and facilities which are important at a State, national and international level.
This statement is not a grandiose claim: State waterlogging tolerance screening facilities have been established at
Katanning, WA, capable of screening 500-1000 genotypes from the DAWA breeding program per year; and the
Molecular Plant Breeding Cooperative Research Centre (MPBCRC) has funded the development of molecular markers
for waterlogging tolerance with support here worth over $1.5 million. Furthermore, the Australian Centre for
International Agricultural Research has just finished supporting a $0.8 million project here on waterlogging tolerance
screening using these methods and facilities in WA and India, and a project extension for waterlogging tolerance work
in India is currently under consideration. Without support from project UWA340, the capacity to accurately
characterise germplasm for waterlogging tolerance would have either been greatly delayed or non existent today.
What remains necessary is to transfer this technology, as well as approaches for other abiotic stresses, to the breeding
programs for implementation as continued criteria for germplasm characterisation and improvement in WA and across
Australia. Our State and national breeding programs would benefit from continued routine screening for tolerance of
abiotic stresses. Already, for example, the data originally collected in this project on waterlogging tolerance at the seed
germination stage (Section 1.2) has moved towards being outdated relative to the recently released varieties. The
bottom line is simply: Don’t use it, lose it. Our recommendation is therefore to create an “IP neutral” Centre for
Abiotic Stresses where this, and other information, can be used routinely to characterise and supply germplasm for
Australian breeding institutions and Australian crop production (Section 4(1)).
4. Opportunities: what needs to be done in future work on waterlogging tolerance?
1) Proposal for a Centre for Abiotic Stresses. Where a project like UWA340 has been successful in research,
development of screening protocols, and identification of tolerant and intolerant genotypes, the highest priority for
8
GRDC is to guarantee that results are integrated into breeding programs for future benefits. It is our highest
recommendation to develop a Centre for Abiotic Stresses where commercial varieties can be characterised and new
material evaluated and introduced into suitable backgrounds for Australia in an “IP neutral” environment. This means
that such a Centre can strongly contribute benefits across Australia, while not competing with existing institutions. An
E-Concept note has been submitted for this purpose and copies are available on request from Dr. T. Setter at
[email protected].
2) Need to expand to screening entire DH populations and segregating populations.
All of the work described here involves genetically fixed varieties or breeding lines. What about the segregating
populations breeders most often work with and are most interested in? And what about the large numbers of doubled
haploid populations already available for waterlogging tolerance?
The current situation, with a terminating ACIAR project on waterlogging tolerance, is that 10 DH populations
(approximately 1700 lines) are available now, and at least another 10 DH populations with a grand total of
approximately 4000 lines will be available by the end of 2005. These populations are an excellent resource of crosses
between Australian and Indian germplasm specifically aimed at waterlogging tolerance in different soils, different
environments, or for when waterlogging occurs at different stages of development. Yet only the single Ducula4/2*Brookton population has been thoroughly screened to date. Normally, even in the rapid semi-field screening
facility at Katanning, this number of 4000 lines would take approximately 20 years to screen using replicated pots
(~200/year). Therefore, we need to develop effective methods to screen at least 10 times faster – this is possible.
One solution to screening faster is to screen entire DH populations as replicated bulks. Using this approach we could
screen all 20 DH populations in one year! The tolerant populations identified could then be carried through as bulks, or
re-screened as individuals, or individual (genetically fixed) tolerant plants could be selected for further evaluations.
Similar methods could be used to screen segregating populations using the controlled waterlogging facility at
Katanning, WA. To our knowledge, screening bulked DH populations or segregating populations for waterlogging
tolerance under controlled conditions has never been done before.
At present, there are clearly exciting capabilities of providing both important information on new varieties to growers,
as well as evolving a good screening method into something even better and of primary interest to breeding programs.
3) Research on waterlogging tolerance of seeds. Production of waterlogging tolerant crop varieties with tolerance at all
stages of development is one of the priorities of the Crop Improvement Institute at DAWA. There remain several
opportunities and unresolved questions for future research on waterlogging tolerance at the seed stage:
 Can we pyramid genes for waterlogging tolerance at the seed germination and vegetative plant stages?
 Does waterlogging tolerance of seeds vary in different soils, as has been found here for waterlogging tolerance of
vegetative plants?
 What is the waterlogging tolerance of new released varieties and why has this information not been taken up by the
breeding programs to characterise newly released germplasm?
 High waterlogging tolerance of canola at the seed germination stage (Section 1.2.4) only relates to seed survival.
If seeds are waterlogged in soil and then drained, are they able to produce healthy seedlings (validation of existing
work in the field is required)?
 How do results for waterlogging tolerance at the seed germination stage compare to waterlogging tolerance at the
seedling emergence stage? This is the critical period between seed germination and vegetative growth, yet no
information is available on how important this stage is to waterlogging tolerance.
5.
References cited
Chuvativat, A. (1990). Waterlogging effects on germination and survival of wheat, barley and rice seeds. MSc thesis, Plant Sciences
Group, The University of Western Australia, Nedlands, WA 6009. 180pp.
Niknam, R. (1998). Waterlogging tolerance in populations of Brassica napus. PhD thesis, The University of Western Australia.
Nedlands, WA 6009.
ISTA, (1985). International Rules for Seed Testing. Seed Science and Technology 13: Number 2.
Sarlistnaningsih, L. (1990). The adverse effect of microorganisms during waterlogging on germination and survival of lupin seeds
(Lupinus angustifolium cv. Gungurru). MSc thesis, Plant Sciences Group, The University of Western Australia 76pp.
Sayre K D, Van Ginkel M, Rajaram S and Ortiz-Monasterio I (1994). Tolerance to waterlogging losses in spring bread wheat: effect
of time of onset on expression. In Annual Wheat Newsletter 40. Pp 165–171. Colorado State University.
Setter, T.L., Burgess, P., Waters, I., and Kuo, J. (1999). Genetic Diversity of Barley and Wheat for Waterlogging Tolerance in
Western Australia. 9th Australian Barley Technical Symposium, 12-16 Sept, 1999 Melbourne. pp2.17.1-2.17.7
Setter, T.L. and Waters, I. (2003). Review of prospects for germplasm improvement for waterlogging tolerance in wheat, barley and
oats. Plant and Soil 253: 1-34.
Setter T, Waters I, Khabaz-Saberi H, McDonald G, Biddulph B. (2004). Screening for waterlogging tolerance of crop plants. In: 8th
Conference of the International Society for Plant Anaerobiosis 20th –24th September 2004, Perth, Western Australia.
Setter, T.L. Waters, I., Khabaz-Saberi, H., McDonald, G. Wilson, R., Barclay, I., Colmer, T. Goggin, D.; Ram, P.C., Singh, B.N.,
Rane, J., Singh, K.N., Sharma, S.K., Yaduvanshi, N.P.S. (2005). ACIAR Annual Report – 2004 for ACIAR Project
9
CS1/1996/025. 110. pp. Department of Agriculture, WA; and Australian Centre for International Agricultural Research
(ACIAR), Canberra, ACT.
Van Ginkel M, Rajaram S and Thijssen M 1992 Waterlogging in wheat: Germplasm evaluation and methodology development. In
The Seventh Wheat Workshop for Eastern, Central and Southern Africa. Eds. D G Tanner and W Mwangi. pp 115–124.
Nakuru, Kenya, Sept. 16–19, 1991.
T. Setter, G. McDonald, I. Waters, B. Biddulph, K. Stefanova and R. Wilson*
Department of Agriculture, South Perth, WA
24/05/05
*Note: I. Waters, B. Biddulph, K. Stefanova provided technical and sometimes experimental support even though they
were not formally stated as participating in the project.
10
Table 1A - RESULTS FROM WATERLOGGING GRADIENT TRIALS - % WATERLOGGING TOLERANCE OF VARIETIES
Tolerance to Severe Waterlogging
- based on site average yields <50%
Tolerance to Moderate Waterlogging
- based on site average yields 50-89%
Tolerance to Low Waterlogging
- based on site average yields 90100%
Congelin03 Kalgan04
SStirl02 Culbin02
SStirl03
MtBarker03 MtBarker03 Congelin03 Cranbr02 Cranbr02
SStirl03
Soil Group
Lateritic
Coastal
Coastal
Lateritic
Coastal
Lateritic
Lateritic
Lateritic
Valley
Valley
Coastal
Waterlogging Intensity
Severe
Severe
Low
Moderate
Severe
Severe
Moderate
Moderate Moderate
Low
Moderate
WL Intensity (SEW30)* 1000-1600
>1500
~0-550 500-1000
700-1100
1000-1450
400-1000
700-1000
100-550
0-200
350-800
Brookton
52
86
64
56
84
89
93
94
17
73
99
Calingiri
26
59
85
89
56
76
109
Camm
50
54
68
94
89
93
85
38
67
107
111
Carnamah
35
64
66
54
80
101
94
24
83
48
101
Cascades
73
78
78
88
27
59
53
82
43
93
100
Chara
38
35
87
61
66
80
97
95
114
108
EGA Bonnie Rock
23
83
81
53
59
73
105
GBA Ruby
31
95
86
10
80
GBA Sapphire
32
26
68
50
106
GBA Shenton
48
73
Krichauff
93
Norin46
82
83
Spear
48
32
88
56
84
92
87
60
53
73
88
WAWHT2668
88
89
100
Westonia
50
91
63
65
68
90
98
95
76
70
Worrakatta
75
77
Wyalkatchem
30
20
59
62
84
89
92
101
Site Average**
42
28
89
64
62
64
87
83
90
94
93
Average (all data)
35
76
92.2
*SEW30 quantifies waterlogging over the season as the Sum of Excess Water in the top 30 cm soil/d (SEW30 of 300 = waterlogging to the surface for 10 days).
** Site average is the mean grain yield for all varieties expressed in % for waterlogged relative to non (or less-) waterlogged plots (see SEW30 values).
(cont’d)
11
Table 1B - Waterlogging Tolerance - Fractional proportion of site average
Tolerance to Severe Waterlogging
(based on site average yields <50%)
VARIETY
Soil Group:
WL Intensity:
Camm
Calingiri
Chara
EGA Bonnie Rock
Westonia
WAWHT2668
Krichauff
Brookton
Cascades
Spear
Carnamah
Wyalkatchem
GBA Sapphire
Norin46
GBA Ruby
Worrakatta
GBA Shenton
Congelin03
Lateritic
Severe
1.11
1.24
0.85
1.32
1.10
Kalgan04
Coastal
Severe
1.35
0.93
1.24
0.83
1.16
0.60
1.08
0.53
0.67
0.72
0.61
1.54
1.13
1.24
0.73
0.92
0.68
0.37
Tolerance to Low Waterlogging
(based on site average yields
90-100%)
Tolerance to Moderate Waterlogging
(based on site average yields 50-89%)
SStirl02
Coastal
Low
0.93
Culbin02
Lateritic
Moderate
1.12
0.95
1.00
0.96
1.02
0.95
1.02
0.96
0.91
1.11
1.17
1.07
0.99
1.00
1.06
SStirl03
Coastal
Severe
0.99
1.08
1.10
1.33
1.14
MtBarker03
Lateritic
Severe
1.11
1.25
1.09
0.87
1.07
MtBarker03
Lateritic
Moderate
1.14
1.33
0.98
1.02
0.93
Congelin03
Lateritic
Moderate
1.06
1.01
1.36
0.96
0.81
1.33
0.97
0.97
1.20
1.07
0.92
1.19
0.91
0.89
1.02
1.11
1.02
0.95
1.03
0.97
1.02
1.29
1.06
1.19
1.10
0.57
1.05
0.59
1.31
1.16
1.02
0.79
0.90
Cranbr02 Cranbr02
Valley
Valley
Moderate
Low
1.22
1.20
1.22
1.05
1.02
1.02
1.07
1.09
1.06
0.88
0.83
1.15
1.02
0.96
0.95
1.09
0.93
0.91
0.85
0.84
SStirl03
Coastal
Moderate
0.98
0.94
1.00
1.11
1.00
1.04
0.86
0.93
0.99
0.97
Overall Adjusted Means
Adjusted
Mean WL
Tolerance
1.11
1.11
1.09
1.06
1.03
1.02
1.02
1.02
1.01
0.99
0.96
0.96
0.93
0.92
0.91
0.85
0.84
Adj Mean
WL Tol
SEM
Experimental
Variation
across sites
0.12
0.16
0.15
0.20
0.11
0.06
MEDIUM
MEDIUM
MEDIUM
HIGH
MEDIUM
LOW
0.18
0.24
0.09
0.23
0.16
0.28
0.02
0.38
0.01
0.49
MEDIUM
HIGH
LOW
HIGH
MEDIUM
HIGH
LOW
VERY HIGH
LOW
VERY HIGH
Table 1. Waterlogging tolerance of wheat varieties using sites grouped according to overall site averages for grain yields: (A) Waterlogging (WL) tolerance based on
% grain yield of varieties in waterlogged relative to less- or non-waterlogged locations at each site, and (B) Waterlogging (WL) tolerance based on the fractional
proportion of grain yield for each variety relative to the site average as shown in Table 1A. Means used to calculate data in Table 1A are adjusted for spatial variation
at each site. Data in Table 1B are calculated directly from Table 1A, and varieties are ranked according to the Adjusted Mean WL tolerance. Calculating WL tolerance
for all varieties based on the site means (Table 1B) enables comparison across sites, calculations of an Adjusted Mean Waterlogging Tolerance SEM across all sites,
and an overall assessment of experimental variation for each variety across sites (but see text). Bold numbers in Table 1B are the top two varieties with the highest WL
tolerance at each site; italic numbers are the two varieties with the lowest WL tolerance at each site. Data from 2002-2004.
12
PERCENT TOLERANCE OF CULTIVARS AT THREE WATERLOGGING LEVELS WITH STABILITY RATINGS
Low Waterlogging
Moderate Waterlogging
Severe Waterlogging
Tolerance
Stability
Tolerance
Stability
Tolerance
94.8
Westonia
2
79.8
Westonia
1
59.2
*Westonia
_
2
94.5
*Calingiri
5
54.4
Calingiri
97.8
Camm
3
90.3
Camm
2
52.5
Camm
_
2
89.8
*EGA Bonnie Rock
5
52.2
EGA Bonnie Rock
91.8
Chara
3
99.2
*Chara
3
50.1
Chara
90.1
Brookton
3
85.8
Brookton
5
49.7
Brookton
90.6
Cascades
4
79.3
Cascades
4
49.0
Cascades
_
_
73.4
*GBA Shenton
*
48.4
*GBA Shenton
87.6
Spear
3
79.4
Spear
2
47.3
Spear
91.8
Carnamah
5
77.2
Carnamah
4
44.7
Carnamah
100.9
*Wyalkatchem
1
88.1
*Wyalkatchem
4
43.0
Wyalkatchem
_
5
77.7
*GBA Sapphire
4
41.9
*GBA Sapphire
_
1
90.4
*GBA Ruby
5
40.4
*GBA Ruby
_
_
77.3
*Worrakatta
75.1
*Worrakatta
_
_
83.5
*Norin46
82.0
*Norin46
_
_
94.0
WAWHT2668
89.5
*WAWHT2668
_
_
93.1
*Krichauff
_
4
84.7
*Fitzgerald (B)
1
59.3
*Fitzgerald (B)
_
3
74.7
*Onslow (B)
1
50.2
*Onslow (B)
124.3
*Skiff (B)
3
92.5
*Skiff (B)
5
40.6
Skiff (B)
_
2
89.8
*Franklin (B)
4
40.1
*Franklin (B)
89.1
Dalyup (O)
3
82.0
Dalyup (O)
1
52.9
Dalyup (O)
84.1
Toodyay (O)
4
74.4
Toodyay (O)
1
51.5
*Toodyay (O)
91.5
Credit (T)
4
80.9
Credit (T)
3
49.3
Credit (T)
80.1
Muir (T)
5
80.5
Muir (T)
4
43.0
Muir (T)
Stability
2
4
2
2
1
1
3
_
_
_
3
_
_
2
3
3
1
B = Barley, O = Oat, T = Triticale, all other cultivars wheat
Stability Ratings: 1 = most stable, 5 = most unstable
% Tolerance = Waterlogged yield / drained yield * 100
* Not at all sites
Table 2. Waterlogging tolerance of wheat varieties using sites grouped according to the intensity of waterlogging (cf groupings according to site mean grain yield in
Table 1). The intensity of waterlogging is characterised by SEW30 measurements (see footnote to Table 1A). Data were collected using natural waterlogging
gradients in the field in 2002-2004. The top two waterlogging tolerant and intolerant varieties are highlighted in bold and italic numbers respectively. Means are
adjusted for spatial variation. Comparative data for barley (B), oats (O) and triticale (T) are also presented.
13
Table 3. Survival (sem) of wheat, barley, oat and triticale varieties following waterlogging in soil at
the seed stage for 4 days at 15C. Data are % germination relative to non waterlogged seeds; non
waterlogged seeds had at least 95% germination. (Setter et al., 1999; Setter and Waters, 2003).
CROP
Wheat
CUTIVAR
Amery
Aroona
Arrino
Brookton
Cadoux
Camm
Carnamah
Cascades
Champtal
Cunderdin
Eradu
Gamenya
Kalannie
Perenjori
Spear
Stiletto
Tammin
Westonia
SURVIVAL
786
764
5718
845
912
325
643
8619
473
8816
8510
6214
6710
7810
733
369
595
575
Barley
Fitzgerald
Franklin
Gairdner
Harrington
Molloy
Onslow
Skiff
478
426
197
363
348
453
7312
Triticale
Abacus
Muir
Tahara
962
756
876
Oats
Carrollup
Coomallo
Dalyup
Mortlock
Pallinup
Toodyay
961
1004
963
728
8311
878
14
Table 4. Survival of lupins and canola during waterlogging–seed stage. Survival is expressed as % of
non waterlogged treatments. (Setter and Waters, unpublished).
CROP
Lupins
CUTIVAR
Belara
Danja
Gungurru
Kalya
Kiev Mutant
Merrit
Moonah
Myallic
Tallarack
Tanjil
Walan 2005
Wodjil
SURVIVAL
5010
369
3814
705
6112
109
3826
3819
4515
3521
334
4210
Canola
Charlton
Karoo
Monty
Mystic
Narendra
Pinnacle
Pioneer
Pioneer 46-COI
931
856
1003
939
1001
897
988
846
15
Wandering
X
X
X
Katanning
X
X
Esperance
X
Mt Barker
Albany
Fig. 1. Map of field sites used for waterlogging tolerance measurements (2001-2004). Symbols: successful
sites (closed circles), partially successful sites (open circles), unsuccessful sites (x’s).
16
2002
Machete
EGA Tammarin Rock
Savannah
Chara
KRL 1-4
Janz
Wyalkatchem
Carnamah
Sapphire
WESTONIA
KRL 19
EGA Eagle Rock
Ruby
Cotipora
SARC 1
NW1014
Cranbrook
WAWHT 2714
Stiletto
Norquay
CAMM
Ducula-4
Lang
Columbus
BR35
Tasman
Sunco
Calingiri
EGA Blanco
Arrino
Halberd
H45
Hordium marinum
Spear
Brookton
Cascades
HD 2329
2004
EGA Bonnie Rock
3.00
2.50
2.00
1.50
1.00
0.50
0.00
HD 2009
Shoot DW (g/plant)
2003
Variety
Fig. 2. Varietal tolerance to waterlogging in Katanning “semi-field” [pot] trials in 2002, 2003 and 2004.
All trails used Katanning soil from the same field site and were waterlogged at the same time and
location. Only data in the 2004 figure are presented to show statistical differences in varieties; data in
other figures for 2002 and 2003 are only presented to highlight large standard errors in data prior to
development of reproducible methods for waterlogging tolerance screening. In each figure, data for
varieties are ranked on waterlogging tolerance from low (left) to high (right) based on relative biomass in
waterlogged/drained treatments. In 2004, low SEMs were obtained since special pots were developed to
prevent root escape, and soil (18t) was thoroughly mixed several times before seeds were sown. Open
bars are drained plants, closed bars are waterlogged plants; vertical lines are sems (revised from Setter et
al., 2005).
17
Brookton
EGA Bonnie Rock
50
45
Num be r DHLs
40
35
30
Ducula-4
25
20
EGA Tammarin Rock
15
10
5
95.1-100
90.1-95
85.1-90
80.1-85
75.1-80
70.11-75
65.1-70
60.1-65
55.1-60
50.1-55
45.1-50
40.1-45
35.1-40
30.1-35
25.1-30
20.1-25
15.1-20
10.1-15
5.1-10
0-5
0
W a te r l o g g i n g to l e r a n c e (% )
Fig. 3 Frequency distribution for waterlogging tolerance of the Ducula-4/2*Brookton doubled haploid lines
showing transgressive segregation relative to parental lines. Parental lines, Brookton and Ducula-4, are
shown in solid boxes with arrows indicating their waterlogging tolerance. Other recent varieties evaluated
with extremes in waterlogging tolerance (EGA Bonnie Rock and EGA Tammarin Rock; calculated from Fig.
2, 2004 data) are shown in dashed line boxes. Waterlogging tolerance evaluated in semi-field trials at
Katanning, WA, in 2004, in collaboration with MPBCRC.
18
Plate 1 (Top)
Semi-field pot trials for screening germplasm for waterlogging tolerance at Katanning, WA (2003). This
photograph featured on the cover of Plant and Soil in 2003.
Plate 2(Middle) Traditional pot (left) and modified pot for waterlogging tolerance screening (right). Holes in the pot on
right are in a raised bottom (like the central bottom portion of a wine bottle). Pots are layered with a root mat
barrier before filling with soil.
Plate 3 (Bottom) Semi-field pot trials for screening germplasm for waterlogging tolerance at Katanning, WA (2004).
Note access to DAWA facilities (background) and size of the facility relative to the 2003 trial (Plate 1). This has
potential to be established as a long term / semi-permanent facility.