ITEMS FROM AUSTRALIA
NEW SOUTH WALES
THE UNIVERSITY OF SYDNEY
PBI Cobbitty and Department of Crop Sciences, Private Bag 11,
Camden, NSW, 2570; and Sydney, 2006, Australia.
K. Adhikari, J. Bell, L.W. Burgess, G.N. Brown, C. Zhao, H-S. Hwang, S. Johnston, D.R. Marshall, J.D. Oates, R.F. Park, J.E. Roake, P.J. Sharp, S.X-Ren, D. Singh, F.L. Stoddard, A. Thomas, M. Turner, and C.R. Wellings.
Starch quality in wheat and related species. The amylose and amylopectin contents of starch are important for a number of end uses of wheat. In a survey of several hundred accessions of wild and cultivated wheat species, some accessions of T. monococcum had amylose contents as low as 15 % of the starch (i.e., 85 % amylopectin), and some accessions of T. tauschii were as high as 34 %. Intraspecific hybrids have shown significant and useful levels of transgressive segregation in the F2 generation.
Rust pathogenicity surveys. The continuation of the drought, although not as severe as in 1994, ensured that the levels of rust in the northern wheat areas remained low during 1995. The only reports of significant stripe rust infections came from Victoria and South Australia, where hot-spots in Tatiara and Meering were evident. Tests on rust samples from similar outbreaks in 1994 failed to show any changes in pathotype.
Host resistance studies. A
gene from durum K733, previously thought to be allelic with the
T. dicoccoides-derived Yr15, was shown to be
located at a separate locus in chromosome 1BS. A new gene for
stripe rust resistance has been identified in an Israeli T.
dicoccoides-derived hexaploid. The same line and a number
of others possess Yr15. Linkage studies indicated that
the stripe rust resistance gene from `Selkirk' and
a number of Mexican wheats such as `Ciano 79' and
`Bluejay `S'' are not located at the Yr7/Yr5
locus.
Sr10 was found to be linked
very closely with the Lr23/Lr13/Ne2 region
on chromosome 2BS. Preliminary studies of a range of UK winter
wheats showed that Lr13 occurs at high frequency; other
genes for seedling resistance include Lr26, Lr37,
Lr17, and Lr3. The synthesis of a range of NILs possessing
stripe rust-resistance genes based on the cultivar Avocet
and on the development of a monosomic series in a selection of
Avocet are continuing.
An inhibitor of Pm8 was located on chromosome
1AS. SuPm8 occurs at a much higher frequency in Mexican
wheat populations than in European wheats.
Gene SrV in the triticale cultivar Venus and
a number of other triticales is located in chromosome 2R. All
of the stem rust resistance genes so far identified in Mexican
triticales occur on either 2R or 3R. Yr9 is dispersed widely
in CIMMYT triticale lines; at least one additional gene confers
a high level of seedling resistance in triticale to pathotypes
virulent on wheat lines with Yr9.
Personnel.
Dr. Dante The retired in August 1995 (see separate
tribute, p. 3 of this volume). Dr. Harbans Bariana was selected
to replace Dr. The from March, 1996. Dr. C.R. Wellings spent 4
months at ICARDA, Tel Hadya, Syria, working on stripe rust. Dr.
R.F. Park was awarded a Humboldt Fellowship, enabling him to work
in Germany for 1 year.
IA Watson Wheat Research Centre, Narrabri, 2390,NSW Australia.
L. O'Brien, F.W. Ellison, D.J. Mares, and S.G. Moore.
Following the severe drought of 1994, good summer
rains promised a favorable season. However, dry conditions in
March and April meant that areas for early planting had to be
pre-irrigated. Good rains from mid-May to mid-June ensured good
winter growth. Above-average temperatures (> 30_C) in late
August forced crops along, and early-flowering crops suffered
frost damage, with some farmers experiencing total losses. Mild
temperatures in late spring and early summer enabled the crop
to mature relatively slowly, giving above-average yields in many
areas, and combined with the long fallowing effect on soil nitrate
accumulation, resulting in above-average protein levels. Ten days
of continuous rain in December came too late to damage farmers'
crops, but caused substantial sprouting among breeding lines.
The extent of the sprout damage means that much of the breeding
program in 1996 will have to be planted from reserve seed.
At a field day at the Centre in late September, the
Chancellor of the University named and released `Sunbrook'
a new, prime, hard-quality wheat. Released as a replacement for
`Suneca', Sunbrook (synonym, SUN 224A) is resistant
to the rusts and flag smut and has outyielded Suneca by 18 % in
tests across the region. Sunbrook is suited to early plantings
and is expected to be adopted rapidly by growers.
The Northern Wheat Improvement Program, a Grains
Research and Development Corporation initiative that combines
the wheat breeding efforts of the University and the Queensland
Department of Primary Industries with the testing resources of
NSW Agriculture, commenced operation. The program rationalizes
the yield and disease testing services of the three organizations
to avoid duplication in a collaborative, but competitive, model,
which will bring benefits in terms of new, improved cultivars
for the northern wheat belt.
QUEENSLAND
QUEENSLAND WHEAT RESEARCH INSTITUTE
P.O. Box 2282, Toowoomba, Qld 4350, Australia.
Wheat breeding program.
Paul Brennan, Phillip Banks, John Sheppard, Lloyd Mason, Peter Keys, Richard Uebergang, Wayne Crighton, Peter Agius, Martin Fiske, and Peter Horne.
Seasonal conditions. Adverse
seasonal conditions have hampered the QWRI wheat breeding program
since 1991. These are considered to be consequences of the change
in water surface temperatures in the south Pacific Ocean, with
a rise in the eastern and a lowering in the southwestern Pacific.
This is the `El Nino' effect and is measured by the
`Southern Oscillation Index' (SOI). Northeastern Australia
experienced a very wet summer in 1995-96, but the SOI cannot
predict whether this reversal in rainfall will continue into winter
when wheat is grown.
The El Ni-o effect also is considered to be
an indicator of severe late frosts. These were experienced when
the crop was at the flowering stage, and very severe damage affected
commercial crops and breeders' trials.
The northern Australian crop also was affected by
mice, which inflicted differential damage to trials prior to a
very effective strychnine baiting program that terminated the
plague.
Backcrossing. The yellow
(tan) spot-resistant variety, `Leichhardt',
was released in 1995. The features of, and role for, this variety
will be considered later in this report. Leichhardt is the third
variety emanating from backcrossing at QWRI. The other two are
`Pelsart' (root lesion nematode tolerant) and `Rowan'
(awnless). The latter is attractive to growers in risk situations
because the crop can be used for animal consumption without the
health disadvantages of awns.
Sprouting-resistant material also is well advanced
in the QWRI backcrossing program. A number of lines exhibiting
sprouting tolerance derived from `Transvaal' appear
to have good yield and quality. Several of these will be promoted
to final evaluation in 1996. This work is being assisted by Dr.
Daryl Mares from Sydney University.
Similar progress appears to have been achieved with
the crown rot (Fusarium graminearum) resistance breeding
program, for which Dr. Graham Wildermuth (QWRI) provides the screening
service. Thirty-two backcross derivatives of `Janz'
and `Cunningham', exhibiting high levels of crown
rot resistance derived from `2-49', will be evaluated
for yield and quality in 1996.
A number of Russian wheat aphid-resistant lines,
developed in association with Dr Jim Quick, Colorado State University,
also will be evaluated for yield and quality in 1996.
QT5664 (Pavon 76/Vasco)
has exhibited a 3-5 % yield advantage over `Hartog'
in the last 3 years.
QT4299 (Pitic/2*Hartog)
is a higher-yielding line than Hartog that has the short dough
development time required by Queensland domestic flour millers.
However, the quality is not commensurate with the requirements
of the export market.
QT7274 (Veery#5/4* Ford). `Ford' is a rust-susceptible hay wheat that is currently grown to small acreage in Queensland. The release of QT7274 will provide a rust-resistant alternative to these growers and alleviate concerns that the cultivation of Ford will place the rust resistance of other varieties in jeopardy.
Students. Mr. Ian Haak
was awarded a Master's Degree for his work on the transfer
of the barley FONT SIZE=2 FACE="Symbol"a-amylase
inhibitor to wheat. The resulting translocation stocks are being
evaluated for sprouting damage resistance.
D.J. Martin, B.G. Stewart, L.M. Stewart-Gwynne, and K. Rogers.
A major part of our work has been directed again
at screening early generation material and testing advanced lines
from the QWRI breeding program. Tests on advanced material were
expanded to include measurements of noodle colour development
and stability. Using data from these trials the crossbred QT5793
was registered and released as the variety Leichhardt. In 1996
we intend to expand testing on advanced material further by measuring
during test baking, work input, and mixing time and energy using
the Easymix software developed by the Bread Research Institute
of Australia.
Personnel.
Ms. Wendy Lawson was awarded a Master's Degree
for the location of a RAPD marker for one of the loci conferring
sprouting tolerance in the cultivar Transvaal. This work was confirmed
by Mr. Ma Wujun, who also located a less closely linked RAPD marker
for one of the two sprouting tolerance loci in Transvaal. We now
are attempting to use these markers in our breeding activities.
Ms. Nicole Copas commenced her studies on an examination
of the proported advantage of using BC1F2 populations as the starting
point for a pedigree program rather than F2 populations.
Publications.
Lorenz KJ, Martin DJ, and Stewart BG. 1995. Laboratory
bread test baking without bromate. Food Australia 47:66-70.
Martin DJ, Butler DG, Brennan PS, and Stewart-Gwynne
LM 1995. Sources of variation in wheat quality across sites. 45th
Australian Cereal Chemistry Conference, Adelaide.
Martin DJ, Stewart-Gwynne LM, and Stewart BG.
1995. Noodle colour stability of selected prime hard wheat varieties.
45th Australian Cereal Chemistry Conference, Adelaide.