Velocity of temperature and flowering time in wheat – Assisting breeders
to keep pace with climate change
Bangyou Zheng1, Karine Chenu2, Scott Chapman1*
CSIRO Agriculture Flagship, Queensland Bioscience Precinct, 306 Carmody Road, St. Lucia,
QLD 4067, Australia
1
The University of Queensland, Queensland Alliance for Agriculture and Food Innovation
(QAAFI), 203 Tor Street, Toowoomba, QLD 4350, Australia
2
Corresponding Author: Scott Chapman, Tel: +61 (0)7 3214 2254, Fax: +61 (0)7 3214
2920, email: Scott.Chapman@csiro.au
*
Fig. S1 Map of the four geographic areas (a) and 22 regions (b) of the Australian wheatbelt
used in this study. State abbreviations: QLD, Queensland; NSW, New South Wales; SA, South
Australia; WA, Western Australia; NT: Northern Territory. Regions defined by Chenu,
Deihimfard, and Chapman (2013).
Fig. S2 Locations for datasets of historical heading times in Western Australia. The size of
symbol represents the number of observations.
Fig. S3 Historical trends of heading times in Western Australia (WA). For the five major
regions of WA (Fig. S1), heading time data were assembled from multiple sources,
including the CVT (Crop Variety Testing) dataset of DAFWA (Department of Agriculture
and Food in Western Australia), time of sowing trials (Zheng et al 2013), association
mapping yield experiments (unpublished data) and NVT trials (Zheng et al 2013). The
observed heading times were filtered to retain only locations where data were collected for
at least 15 years on a given variety for sowing occurring in May. This resulted in collation of
378 observations for 4 varieties (Cadoux, Reeves, Spear and Machete) in 49 sites collected
over the period 1986 to 2009. At least two varieties were overlapping in any year. All these
observed data were used in a mixed model to get estimates of heading time (plotted on the
graph), as detailed in the material and method.
Fig. S4 The spatial distribution of mean (a), temporal trends (b), spatial gradients (c) and
velocities (d) for annual average (A), maximum (B) and minimum (C) temperature across
the Australian wheatbelt from 1957 to 2010. Negative temporal trends correspond to a
decrease in temperature, and negative velocities correspond to change towards colder
temperatures.
Fig. S5 Average of mean (°C), temporal trends (°C y-1), spatial gradients (°C km-1) and
velocity (km y-1) for annual mean (green), maximum (red) and minimum (blue)
temperature of the different regions (Supplementary Fig. S1) from 1957 to 2010. The
temperature trends are summarized for annual (a) and season (b from May to October) and
Australian wheatbelt (region Australia in the right).
Fig. S6 Average of mean (°C), temporal trends (°C y-1), spatial gradients (°C km-1) and
velocity (km y-1) for season mean (green), maximum (red) and minimum (blue)
temperature of the different regions (Supplementary Fig. S1) from 1957 to 2010 (May to
October). The temperature trends are summarized for annual (a) and season (b from May
to October) and Australian wheatbelt (region Australia in the right).
Fig. S7 The spatial distribution of flowering time median (DAS, days after sowing),
temporal trends (d y-1), spatial gradients (d km-1) and velocity (km y-1) across Australian
wheatbelt from 1957 to 2010. This figure shows results for Westonia (a short-season
cultivar) sown at a mid-season sowing date for this cultivar (22nd June).
Fig. S8 The spatial distribution of flowering time median (DAS, days after sowing),
temporal trends (d y-1), spatial gradients (d km-1) and velocity (km y-1) of flowering time
from 1957 to 2010. This figure shows results for Bolac (a long-season cultivar) sown at a
mid-season sowing date for this cultivar (11th May).
Fig. S9 The summary of median (DAS, days after sowing), temporal trends (d y-1), spatial
gradients (d km-1) and velocity (km y-1) of flowering time for Westonia (short-season
cultivar, sown at 22nd June), Janz (median-season cultivar, sown at 1st June) and Bolac
(long-season cultivar, sown at 11th May) from 1957 to 2010. The temperature trends are
summarized for annual (a) and season (b from May to October) and Australian wheatbelt
(region Australia in the right).
Fig. S10 Distribution of flowering-time temporal trends (d y-1) and velocities (km y-1) in
response to sowing date for the 22 regions of the Australian wheatbelt (Supplementary Fig.
S1). The data concern 208 virtual lines which encompassed all combinations of Vrn-A1,
Vrn-B1, Vrn-D1 and Ppd-D1, and a wide range of target thermal time from floral initiation to
flowering (Zheng et al. 2013).
Fig. S11 Influence of climate data resolution on velocity vectors estimated for flowering
time in the Australian wheatbelt. The resolutions of climate data are presented for 0.05° to
0.50°, for the cultivar Janz sown at 1st June.
Fig. S12 Direction (arrow) and intensity (colour, km y-1) of flowering-time velocity for
Westonia (short-season, sown at 22nd June), Janz (medium-season, sown at 1st June) and
Bolac (long-season, sown at 11th May). The directions were calculated for a coarse
resolution (0.25° x 0.25°), with the distribution of velocity directions shown as ‘ wind
roses’ for the different production areas. Arrows are only displayed in grids with
significant climate trends (P < 0.10). The significant trend was calculated with a linear
model fit and corrected for serial autocorrelation (Santer et al. 2000).
Fig. S13 Genetic range of flowering dates for current and future climates for all simulated
sowing dates at 22 sites. The range of median flowering time for all possible genotypes is
shown for (i) the baseline (1957-2010; grey area), and (ii) best 2030 scenario (blue area)
for 208 virtual genotypes which encompassed the full range of possible maturities present
in the commercial germplasm pool (see text).The lower and upper bounds of the shaded
areas correspond to earliest and latest possible median-flowering times, respectively. The
thick black line indicates the flowering time (y-axis) of the best-yielding genotype for each
sowing date (x-axis) in the baseline scenario (1957-2010). The thickness of this line
corresponds to the median yield of this best-yielding genotype for each sowing date for the
years 1957-2010.
Fig. S14 Genetic range of flowering dates for current and future climates for all simulated
sowing dates at 22 sites. The range of median flowering time for all possible genotypes is
shown for (i) the baseline (1957-2010; grey area), and (ii) worst 2030 scenario (blue
area) for 208 virtual genotypes which encompassed the full range of possible maturities
present in the commercial germplasm pool (see text).The lower and upper bounds of the
shaded areas correspond to earliest and latest possible median-flowering times,
respectively. The thick black line indicates the flowering time (y-axis) of the best-yielding
genotype for each sowing date (x-axis) in the baseline scenario (1957-2010). The thickness
of this line corresponds to the median yield of this best-yielding genotype for each sowing
date for the years 1957-2010.
Fig. S15 Genetic range of flowering dates for current and future climates for all simulated
sowing dates at 22 sites. The range of median flowering time for all possible genotypes is
shown for (i) the baseline (1957-2010; grey area), and (ii) best 2050 scenario (blue area)
for 208 virtual genotypes which encompassed the full range of possible maturities present
in the commercial germplasm pool (see text).The lower and upper bounds of the shaded
areas correspond to earliest and latest possible median-flowering times, respectively. The
thick black line indicates the flowering time (y-axis) of the best-yielding genotype for each
sowing date (x-axis) in the baseline scenario (1957-2010). The thickness of this line
corresponds to the median yield of this best-yielding genotype for each sowing date for the
years 1957-2010.
Fig. S16 Genetic range of flowering dates for current and future climates for all simulated
sowing dates at 22 sites. The range of median flowering time for all possible genotypes is
shown for (i) the baseline (1957-2010; grey area), and (ii) worst 2050 scenario (blue
area) for 208 virtual genotypes which encompassed the full range of possible maturities
present in the commercial germplasm pool (see text).The lower and upper bounds of the
shaded areas correspond to earliest and latest possible median-flowering times,
respectively. The thick black line indicates the flowering time (y-axis) of the best-yielding
genotype for each sowing date (x-axis) in the baseline scenario (1957-2010). The thickness
of this line corresponds to the median yield of this best-yielding genotype for each sowing
date for the years 1957-2010.
Fig. S17 Sites where current flowering time for early sowing dates cannot be maintained in
the best 2030 scenarios (a), best 2050 scenarios (b) and worst 2050 scenarios (c) unless
new genetic variation is introduced (sites indicated in colour on the graph). For 22
representative sites across the wheatbelt, the colours indicate the sowing date prior to
which current germplasm do not have sufficient genetic variation to be flower as late as
currently (1957-2010) in the worst 2030 scenario (cf. Fig. 7). Sites in dark grey correspond
to location where sufficient genetic variation exist. The black squares indicate where
Dubbo and Roseworthy (Fig. 7) are located. Note that in the West and South, the current
genetic range is either not limiting (grey points) or limiting only for sowing dates in March.
For the East and South-East regions, the current genetic range in flowering time is limiting
for sowing dates prior to early/mid-April. Dashed and dotted lines indicate annual rainfall
isolines (in mm).
References
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Drought Pattern: A Continent-Wide Modelling Approach Applied to the Australian
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Zheng, B. Y., B. Biddulph, D. Li, H. Kuchel, and S. C. Chapman. 2013. “Quantification of the
Effects of VRN1 and Ppd-D1 to Predict Spring Wheat (Triticum aestivum) Heading Time
Across Diverse Environments.” Journal of Experimental Botany 64 (12): 3747–61.