bluuebunny/crossref_metadata_2025 huggingface dataset:
Responses of sugarcane, maize, and soybean to phosphorus and vesicular-arbuscular mycorrhizal fungi
Authors: Kelly R. M. , Edwards D. G. , Thompson J. P. , Magarey R. C.
Published: September 2002

The presence of vesicular-arbuscular mycorrhizal (VAM) fungi in long-term
cane-growing fields associated with yield decline led to the supposition that
VAM fungi may be responsible for the poor yields. A glasshouse trial was
established to test the effectiveness of a species of VAM fungi,
Glomus clarum, extracted from one of these North
Queensland fields on the growth of sugarcane (Saccharum
interspecific hybrid), maize (Zea mays), and soybean
(Glycine max) for 6 phosphorus (P) rates (0, 2.7, 8.2,
25, 74, 222 mg/kg). For maize and soybean plants that received VAM
(+VAM), root colonisation was associated with enhanced P uptake, improved
dry weight (DW) production, and higher index tissue-P concentrations than
those without VAM (–VAM). By comparing DW responses of maize and soybean
for different P rates, savings in fertiliser P of up to 160 and 213 kg/ha,
respectively, were realised. Sugarcane plants were generally less responsive.
Apart from a 30% DW increase with VAM when 2.7 mg P/kg was added,
DW of +VAM plants was equivalent to, or worse than in the case of 222 mg
P/kg, DW of –VAM plants. For all 3 host species, colonisation was
least at the highest P application, presumably from excessive P within the
plant tissue. Critical P concentrations for the 3 host species were below
those reported elsewhere, and for soybean and sugarcane, the critical
concentration for +VAM plants was lower than that of –VAM plants.
There are 3 implications that arise from this study. First, VAM fungi present
in cane-growing soils can promote the growth of maize and soybean, which are
potential rotation crops, over a range of P levels. Second, the mycorrhizal
strain taken from this site did not generally contribute to a yield decline in
sugarcane plants. Third, application of P fertiliser is not necessary for
sugarcane when acid-extractable P is <30 mg/kg if sufficient VAM
propagules are present, or mp;lt;47 mg/kg if a mycorrhizal response is
not anticipated.
Effects of daily herbage allowance on the organic reserves at the end of grazing and the accumulation of herbage during regrowth
Authors: Kim T. H. , An K. W. , Jung W. J.
Published: September 2002

The effects of daily herbage allowance during prior grazing on the consequent
regrowth of Lolium perenne were measured throughout 3
experimental periods. Morphological structure and organic compounds in the
residual sward were analysed at the end of grazing, and herbage mass measured
during regrowth period. About 29%, 35%, and 52% of the
biomass offered was removed by grazing in high [44 kg organic matter
(OM)/cow.day], medium (30 kg OM/cow.day), and low (19 kg
OM/cow.day) herbage allowance plots. The proportion and density of live
lamina in the post-grazing swards linearly decreased with decreasing herbage
allowance. The density of sheath plus dead materials increased slightly or
remained at the high and medium herbage allowances, whereas 17% of
these materials was removed at the low allowance. Herbage allowance had a
significant effect on the contents of organic compounds (total N, soluble
proteins, reducing sugars, fructans) in the residual live lamina and sheath,
without significantly (P < 0.05) affecting those
in the roots. Reducing sugars were the largest pool of organic reserves in
residual tissues. The pool size of organic reserves in live lamina decreased
in parallel with the residual biomass of this tissue in response to herbage
allowance. A large portion of organic reserves, especially for fructans, was
found in the sheath. The quantity of organic reserves in the residual sheaths
was not significantly (P > 0.05) different with
high or medium allowances, but tended to be lower with the low allowance. The
organic reserves in live lamina had a higher significance for the first 6 days
of regrowth, while those in remaining sheath were more important in the later
stages of regrowth.
Processing tomato fruit quality: influence of soil water deficits at flowering and ripening
Authors: Renquist A. Richard , Reid Jeff B.
Published: September 2002

One way to reduce the production cost of tomato solids is to increase fruit
solids at harvest time. In a field trial using 200-L containers the effects of
early and late soil water deficits (treatments DE and DL) on fruit yield and
quality were tested during either flowering or late fruit growth. The effect
of standard irrigation, with water cut off during the 3–5 weeks before
harvest (SC), was also compared with full-season irrigation (FS). Manual
irrigation of containers twice per week replaced soil water loss, measured by
time domain reflectometry. A rain shelter was used as needed. The duration of
the DL treatment was 43 days, which was intended to equate to 60–70 days
of slower root-zone drying by finer textured field soils. Soil matric
potentials were as low as –1500 kPa during both DE and DL. Fruit colour
change was accelerated by DL; fruit were 97% red at harvest as against
89–93% for the other 3 regimes. Fruit yields of treatments other
than DL were all near 93 t/ha. Yield of DL was reduced 38%, mainly
due to 35% smaller fruit. Fruit quality parameters [soluble
solids concentration (SSC), total solids, and titratable aciditymp;rsqb;
were similar in the 3 higher yielding regimes, but were much greater in the DL
treatment. Fruit pH was also more favourable (i.e. lower) in DL. The SSC was
2.8;deg;Brix higher in DL, sufficiently so that soluble solids
yield/ha was not significantly lower than other treatments. This occurred
without a decrease in juice viscosity or consistency (Bostwick). Simple models
were developed for predicting soil water deficit effects on fruit quality.
There is clearly an opportunity for irrigation management to improve tomato
processing quality and profitability.
The influence of pre-weaning nutrition on biochemical and myofibre characteristics of bovine semitendinosus muscle
Authors: Allingham Peter G. , Harper Gregory S. , Hennessy David W. , Oddy V. Hutton
Published: September 2002

This study investigates pre-weaning growth of cattle and its effect on
biochemical and histochemical markers of muscle development and subsequent
biophysical attributes of eating quality. Combinations of cow (late pregnancy
to mid-lactation) and pre-weaning (varying duration of access to a high-energy
ration) supplementation were used to vary calf growth to weaning in 6
treatment groups. After weaning, calves were grazed together on pasture
(backgrounding) and then grown rapidly on a feedlot ration (finishing) until
slaughter. Biochemical and myofibre characteristics were determined in
semitendinosus muscle samples collected just prior to
weaning (7 months), at the end of backgrounding (13 months), and at slaughter
(17 months). The concentration of sarcoplasmic protein and the activity of
lactate dehydrogenase in the muscle at weaning were associated with
differences in pre-weaning growth and both variables correlated positively
with liveweight at weaning. Isocitrate dehydrogenase activity varied with sex,
not treatment, at weaning and at the end of backgrounding. The size of
myofibres at weaning related to differences in growth path and correlated
positively with liveweight. Pre-weaning growth effects on these
characteristics were not evident at slaughter. Biophysical properties of the
meat were not affected by earlier growth path treatment, and were not
correlated with biochemical characteristics or myofibre type profile.
Variation in both shear peak force and adhesion was related to sex. We
conclude that the effects of divergent early life growth do not persist 10
months after weaning, at least in meat quality characteristics.
Alfalfa mosaic and pea seed-borne mosaic viruses in cool season crop, annual pasture, and forage legumes: susceptibility, sensitivity, and seed transmission
Authors: Latham L. J. , Jones R. A. C.
Published: September 2002

Field experiments determined the susceptibilities and sensitivities of a wide
range of crop, annual pasture, and forage legumes to infection with alfalfa
mosaic (AMV) and pea seed-borne mosaic (PSbMV) viruses. Seed harvested from
most of the species was tested for virus seed transmission. With AMV, all 23
Cicer arietinum genotypes tested were ranked as highly
susceptible, and 9 out of 19 Lens culinaris genotypes as
highly susceptible, 8 susceptible, 1 moderately resistant, and 1 resistant.
Genotypes of Vicia narbonensis (5),
Lathyrus cicera (5), L. sativus
(5), L. ochrus(2), V. sativa (1),
and V. benghalensis (1) were highly susceptible,
susceptible, or moderately resistant. Genotypes of
Pisum sativum (5) and V. faba(3)
were susceptible, moderately resistant, or resistant but 1 genotype of
V. faba was not found infected. Sensitivities ranged
from low in L. ochrus to high in some genotypes of most
species tested exceptV. benghalensis. The 20 genotypes
(19 species) of pasture and forage legumes ranged from ‘not found
infected’ in Hedysarum coronarium to ‘highly
susceptible’ in Ornithopus sativus and
Trifolium resupinatum. Sensitivity varied from low in
T. michelianum to very high in
Biserrula pelecinusand
Ornithopus sativus. With PSbMV, the genotypes
ofP. s a t i v u m (17),
V. narbonensis (5), and
L. cicera(3) were ranked as highly susceptible,
susceptible, or moderately resistant, while those of
L. ochrus(3), V. faba(6),
V. sativa (3), V. benghalensis (2)
and V. ervilia(1) were either moderately resistant or
resistant. The genotypes of C. arietinum (6) and
Lens culinaris (6) were all resistant. With
L. sativus, 2 genotypes were resistant and 1 was not
found infected. Sensitivities ranged from low in some
P. sativum genotypes to high in some
ofL. ciceraand V. narbonensis. The
seed coats of 9 crop legume species developed necrotic ring markings, a
serious quality defect due to PSbMV infection. Of the 19 genotypes
(1/species) of pasture and forage legumes, 4 were resistant with only
symptomless infection developing and the remainder not found infected. In
glasshouse inoculations to genotypes not found infected in the field, AMV
infected V. faba cv. Ascot systemically
butH. coronarium cv. Grimaldi (with AMV) and
L. sativus BIO L254 (with PSbMV) only became infected in
inoculated leaves, H. coronarium developing a localised
hypersensitive reaction.
Seed transmission of AMV was detected in
L. cicera(2%), L. sativus
(0.9–4%), V. benghalensis(0.9%),
V. narbonensis (0.1%), and
V. sativa (0.7%). It was also found in 15 pasture
and forage legume species, ranging from 0.05% in
T. michelianum to 7% in
Trigonella balansae. Seed transmission of PSbMV was
detected in L. cicera(0.4%),
L. clymenum (5%), L. ochrus
(0.7%), L. sativus (1%),
P sativum(1–18%),
V. benghalensis (0.1%),
V. faba (2%), and V. sativa
(0.3%). The implications of these findings and their importance to the
management of these and other virus diseases are discussed.
Physiological causes for decreased productivity under high salinity in Boma, a tetraploid Chloris gayana cultivar
Authors: de Luca M. , Seffino L. García , Grunberg K. , Salgado M. , Córrdoba A. , Luna C. , Ortega L. , Rodríguez A. , Castagnaro A. , Taleisnik E.
Published: September 2002

Rhodes grass (Chloris gayana Kunth) is widely cultivated
in the semi-arid tropics and favoured for salt tolerance; nevertheless,
productivity decreases significantly under saline conditions, especially in
tetraploid cultivars. The purpose of this work was to explore, in the
tetraploid cultivar Boma, the physiological causes for such decrease.
Experiments were carried out in vegetative plants in the greenhouse. At high
salinity (200 mM NaCl), an early reduction in leaf area expansion was
observed, and, later, decreased dry matter accumulation, suggesting that the
central effect of salinity was a limitation of leaf growth. This was evaluated
in 2 closely related Boma clones, exhibiting different degrees of salt
tolerance. Growth, ion accumulation and excretion, sugars, and proline
concentrations were measured under a range of salt concentrations (0–200
mM NaCl). Differences between the clones in leaf expansion were expressed only
at high salinity, but were not associated with differences in water potential
or hydraulic conductance in the expanding region. At all salinity levels, the
proportion of dry leaves was higher in the clone which also had lower salt
gland density and Na excretion rates. Less efficient Na extrusion, associated
with high oxidative stress, may be the main cause for leaf senescence and
differences in productivity between these clones.
Evaluation of solvent-extracted canola meal for growing pigs and lactating sows
Authors: King R. H. , Eason P. E. , Kerton D. K. , Dunshea F. R.
Published: September 2002

The response of weaner pigs, grower/finisher pigs, and lactating sows to
inclusion levels of solventextracted canola meal up to 250, 300, and 202
g/kg, respectively, was examined in 3 experiments. The average composition
of the canola meal used in the experiments was 884 g DM/kg, 376 g
CP/kg, 41 g fat/kg, 21.6 g lysine/kg, 12.4 MJ digestible energy
(DE)/kg, and 4.5 mol glucosinolates/g. In all experiments, canola meal
replaced other common protein sources in equal DE and equal lysine diets that
were offered ad libitum to pigs. In Expt 1, 49 male pigs
were weaned at 19.6 days of age and 6.27 kg liveweight and allocated to 7
diets containing 0–250 g/kg of canola meal for 42 days. Growth rate
and voluntary feed intake were not significantly affected by level of canola
meal up to 250 g/kg. However, there was a significant linear response in
feed conversion ratio (FCR), indicating that as the level of canola meal
increased, feed efficiency was improved. In Expt 2, pigs were randomly
allocated at about 63 days of age and 24 kg liveweight to 16 group pens, each
containing 12 pigs. Four pens were each allocated to one of 4 diets containing
0–300 g/kg canola meal up to slaughter at 140 days of age when pigs
were approximately 97 kg liveweight. Canola meal level had no significant
effect on growth performance, carcass quality, or weight of the thyroid gland.
In Expt 3, 386 mixed parity sows were randomly allocated over a 70-day period
to diets containing 0, 101, and 202 g/kg of canola meal that were offered
during the lactation period of about 25 days. Average piglet growth between
Day 3 and weaning was 244 g/day and was unaffected by inclusion level of
canola meal in the sow diet. However, there was a significant positive linear
response between sow feed intake and canola meal, which was particularly
evident in the sows allocated during the initial period of the experiment when
environmental temperatures were hotter. Average feed intake during lactation
was 5.08, 5.50, and 5.67 for sows offered 0, 101, and 202 g/kg of canola
meal, respectively. In conclusion, solvent-extracted canola meal can be
included at levels up to 250, 300, and 202 g/kg in weaner pig,
grower/finisher pig, and lactating sow diets, respectively, without
adversely affecting the performance of these classes of pigs.
Targetting microsatellites (SSRs) in genetic linkage maps of bread wheat
Authors: Hayden M. J. , Khatkar S. , Sharp P. J.
Published: September 2002

The construction of genetic linkage maps from intraspecific crosses of bread
wheat is slow and difficult due to very limited levels of polymorphism, which
hinder the assignment of linkage groups to chromosomes and leave large genomic
regions without markers. Simple sequence repeats (SSRs) reveal a higher
incidence of polymorphism and are more informative than any other DNA marker,
and are therefore considered a marker of choice for self-pollinating crops
with little intraspecific polymorphism. However, the availability of SSRs in
bread wheat is still limited. In this study, selectively amplified
microsatellite (SAM) analysis was used to develop informative SSR markers to
assist in the construction of an intraspecific wheat map. Three markers were
developed for under-represented regions in the genetic map, and 7 for
unassigned linkage groups. The latter SSRs permitted the chromosomal origin of
4 unassigned linkage groups to be determined. These results demonstrate the
utility of SAM analysis for the targetted development of informative SSR
markers to genomic regions of interest, and assignment of linkage groups to
chromosomes. Furthermore, SAM analysis facilitates the development of markers
for relatively short (<11) dinucleotide repeat sequences, a class of SSRs
generally inaccessible to traditional hybridisation-based methods used to
develop these markers.
Diagnostic DNA markers for cereal cyst nematode resistance in bread wheat
Authors: Ogbonnaya F. C. , Subrahmanyam N. C. , Moullet O. , Majnik J. de , Eagles H. A. , Brown J. S. , Eastwood R. F. , Kollmorgen J. , Appels R. , Lagudah E. S.
Published: September 2002

The development of cultivars resistant to cereal cyst nematode (CCN) is a
primary objective in wheat breeding in the southern wheatbelt of Australia.
Nine CCN resistance genes have been identified in wheat and its relatives,
some of which confer resistance to the Australian pathotype of CCN (Ha13).
Cultivars released in Australia with CCN resistance carry either the
Cre1 or CreF gene, with the
Cre3 gene present in advanced breeding lines. The
biological assay for CCN resistance screening in wheat is time-consuming, not
reliable on a single-plant basis, and prone to inconsistencies, thus reducing
the efficiency of selection amongst breeding lines. Using gene sequences
initially isolated from the Cre3 locus, a DNA-based
marker selection system was developed and applied to unambiguously identify
wheat lines carrying resistance alleles at theCre1
and/or Cre3 loci in breeding populations derived
from diverse genetic backgrounds. Homologues of sequences from the
Cre3 locus, located elsewhere in the wheat genome, can
also be used to select wheat lines with a newly identified CCN resistance gene
(Cre6) introgressed from
Aegilops ventricosa. Application of these markers has
become an integral part of the southern Australian breeding programs.
Development of robust PCR-based DNA markers for each homoeo-allele of granule-bound starch synthase and their application in wheat breeding programs
Authors: McLauchlan A. , Ogbonnaya F. C. , Hollingsworth B. , Carter M. , Gale K. R. , Henry R. J. , Holton T. A. , Morell M. K. , Rampling L. R. , Sharp P. J. , Shariflou M. R. , Jones M. G. K. , Appels R.
Published: September 2002

The absence of expression of the granule-bound starch synthase I (GBSSI)
allele from chromosome 4A of wheat is associated with improved starch quality
for making Udon noodles. Several PCR-based methods for the analysis of GBSS
alleles have been developed for application in wheat. A widely applied
approach has involved a simple PCR followed by electrophoretic separation of
DNA products on agarose gels. The PCR amplifies one band from each of the loci
on chromosomes 4A (Wx-B1), 7A
(Wx-A1), and 7D (Wx-D1), and the
band from the Wx-B1 locus is diagnostic for the
occurrence of the null Wx-B1 allele that is associated
with improved starch quality. The reliable detection of the null
Wx-B1 allele has been important in identifying wheat
breeding lines. Allele-specific PCR has also been used to successfully detect
the occurrence of the null Wx-B1 allele. In the present
paper the various protocols were evaluated by testing a segregating double
haploid population from a cross between Cranbrook and Halberd and the tests
gave good agreement in different laboratories. The application of the DNAbased
tests applied in wheat breeding programs provides one of the first examples of
a molecular marker selection for a grain quality trait being successfully
applied in an Australian wheat breeding program.
Application of a high-throughput antibody-based assay for identification of the granule-bound starch synthase Wx-B1b allele in Australian wheat lines
Authors: Gale K. R. , Panozzo J. F. , Eagles H. A. , Blundell M. , Olsen H. , Appels R.
Published: September 2002

An enzyme-linked immunosorbent assay (ELISA) for the discrimination of
Wx-B1a and Wx-B1b genotypes at the
granule-bound starch synthase I (GBSSI) or waxy locus of hexaploid wheat
(Triticum aestivum L.) was adapted to a high-throughput,
96-well microtitre plate format. This test is applicable to the direct
analysis of starch, flour, or crushed grain and requires less than 1 grain to
perform. Several hundred samples may be routinely analysed in one day. The
assay was validated using quantitative trait locus (QTL) analysis of a doubled
haploid mapping population of the cross Cranbrook
(Wx-B1a)/Halberd (Wx-B1b).
This demonstrated that the assay unambiguously identified 153 of 161 lines
analysed, with a highly significant QTL (LRS value 270) accounting for
83% of ELISA variation, at the Wx-B1 locus on
chromosome 4AL. In addition, measurement of total GBSSI variation using a
non-isoform-specific GBSSI detection monoclonal antibody also gave a
significant QTL (LRS of 84, accounting for 42% of ELISA variation) at
the Wx-B1 locus. Application of the assay to crude flour
extracts of 8 grains for each of 1093 progeny from 4 crosses segregating at
the Wx-B1 locus permitted the unambiguous scoring of
lines as pure Wx-B1a or pure
Wx-B1b. The scoring by ELISA was strongly related to the
flour swelling volume of the lines, thus demonstrating the utility of this
high-throughput screening method for the faster, more efficient development of
Australian noodle wheats.
The analysis of quantitative traits in wheat mapping populations
Authors: Eckermann P. J. , Verbyla A. P. , Cullis B. R. , Thompson R.
Published: September 2002

This paper discusses the analysis of quantitative trait loci (QTLs) using
molecular markers from a doubled haploid wheat mapping population arising from
the Cranbrook Halberd cross. Two field trials are used to provide phenotypic
information on the trait of interest, which is grain percentage protein.
Methods for QTL analysis are reviewed together with methods for the analysis
of field trials. The aim of the paper is to examine different approaches for
QTL analysis, namely the conventional approach available in standard software,
which ignores field variation, a 2-stage approach that provides adjusted
phenotypic effects for a subsequent QTL analysis, and a joint marker and
spatial analysis. The major effect, however, is the maturity class of the
doubled haploid lines. Maturity and percent protein appear highly correlated
genetically so QTL analysis shows marked changes if maturity is included as a
covariate. More subtle changes occur due to field variation but this may not
be the standard situation.
Mapping of durable adult plant and seedling resistances to stripe rust and stem rust diseases in wheat
Authors: Bariana H. S. , Hayden M. J. , Ahmed N. U. , Bell J. A. , Sharp P. J. , McIntosh R. A.
Published: September 2002

Doubled haploid populations of CD87/Katepwa, Cranbrook/Halberd, and
Sunco/Tasman were assessed for seedling response to stem rust and stripe
rust. The CD87/Katepwa population was also screened as adult plants in the
field against stripe rust. The respective parents differed in presence or
absence of various stem rust and stripe rust resistance genes. At least 4
resistance loci controlled adult plant resistance to stripe rust in the
CD87/Katepwa population, and based on quantitative trait loci mapping
results, two of these were contributed by CD87. Pedigree information indicated
that these regions correspond to durable adult plant stripe rust resistance
genes Yr18 and Yr29.
Yr29 was mapped to the distal region of chromosome 1BL.
The third gene, contributed by Katepwa, YrKat, was
located in chromosome arm 2DS. Sr30 mapped distal to
markers abg3 and P36/M61-170 in chromosome arm 5DL. Genes
Yr7 and Pbc (completely linked
with durable stem rust resistance gene Sr2) showed close
associations with markers in chromosome arms 2BL and 3BS, respectively. A
distally located genomic region in chromosome 6AS also affected the expression
of Pbc. The temperature-sensitive stripe rust resistance
gene, YrCK, carried by Sunco showed monogenic
inheritance and was located in chromosome arm 2DS. Several markers showed
complete association with Triticum timopheevi derived
stem rust resistance gene Sr36. Microsatellite markers
stm773 and gwm271A were validated on a set of wheat genotypes and were found
to be diagnostic for the detection of Sr36.
TheSr36-linked Xstm773 allele
showed better amplification than the Sr36-linked
Xgwm271A allele. These markers could be used for marker
assisted identification of Sr36 in breeding populations.
Quantitative trait locus analysis of late maturity a-amylase in wheat using the doubled haploid population Cranbrook Halberd
Authors: Mrva K. , Mares D. J.
Published: September 2002

Mapping of the late maturity α-amylase (LMA) gene using quantitative
trait locus (QTL) analysis represents an important step in identification of
potential molecular markers that would greatly improve efficiency and accuracy
of screening for LMA. QTL controlling the expression of LMA in wheat were
detected in a doubled haploid (DH) cross/population derived from wheat
(Triticum aestivum L. em. Thell) cultivars Cranbrook
(LMA source) and Halberd (non-LMA). The DH population and parents were sown in
replicated trials at Narrabri with sowing times differing by 2 weeks. Cool
temperature treatment of detached tillers was used to induce expression of LMA
in lines carrying the defect. The number of grains in ripe, treated tillers
that contained high pI (malt, germination type) α-amylase isozymes was
measured using an ELISA antibody kit highly specific for high pI isozymes. QTL
analyses were conducted separately for each sowing, but results from both
sowings were consistent and indicated that there was a highly significant
(P < 0.001) QTL on the long arm of chromosome 7B
(accounting for 31% of the variation in the first experiment), with
Cranbrook contributing the higher value allele. A second QTL that accounted
for 13% of the variation was found close to the centromere on
chromosome 3B. Although it was less important than the QTL on 7B it was
nevertheless still significant (P < 0.05).
The frequent classes of expressed genes in wheat endosperm tissue as possible sources of genetic markers
Authors: Clarke B. C. , Larroque O. R. , Békés F. , Somers D. , Appels R.
Published: September 2002

Frequently expressed genes in wheat endosperm tissue provide a potentially
useful source of genetic markers because genes that are relatively highly
expressed in seed development may provide new candidate genes contributing to
quality traits in wheat. Wheat endosperm tissue at 8–12 days post
anthesis (DPA) was characterised with respect to the accumulation of the major
classes of seed storage proteins. The accumulation of these proteins
characterises the wheat endosperm and provides a framework within which the
frequencies of different expressed sequence tags (ESTs) could be categorised.
Major seed storage protein classes such as glutenins and gliadins comprised
approximately 40% of the proteins in 8–12 DPA endosperm tissue,
and the levels of transcripts from the respective genes provided a benchmark
for assessing the frequency of transcripts from other genes. Based on the
analysis of 4374 sequences, 2 categories were defined: frequent class,
comprising ESTs occurring at a frequency of >4 copies, and a second
category containing ESTs occurring at a frequency of <3. Comparison of
frequent class sequences of wheat with sequences from a corn library of an
equivalent category identified genes apparently characteristic of wheat and
others that were conserved during endosperm development. A significant new
class of seed storage protein genes present in wheat but absent from corn, and
related to avenin-3 of oats, was identified. Other prominent wheat ESTs,
including a glycine-rich cell wall protein, End-1 (originally identified in
early barley endosperm), Brittle-1 (corn, possible adenylate translocator),
and an endosperm specific protein (EST expressed specifically in endosperm),
were mapped in wheat using single nucleotide polymorphisms. The analysis
demonstrated the feasibility of identifying new genes by large-scale
sequencing and targetting these as possible markers for quality attributes.
Genetic mapping of commercially significant starch characteristics in wheat crosses
Authors: Batey I. L. , Hayden M. J. , Cai S. , Sharp P. J. , Cornish G. B. , Morell M. K. , Appels R.
Published: September 2002

Starch properties were measured on the doubled haploid progeny of 2 crosses,
one between Cranbrook and Halberd and the other between CD87 and Katepwa.
Properties studied included starch peak and final viscosity measured by Rapid
Visco Analyser, starch granule size distribution measured by laser light
scattering, starch gelatinisation temperature by differential scanning
calorimetry, and flour swelling volume. In the Cranbrook Halberd cross
(samples from 2 environments), a highly significant quantitative trait locus
(QTL) was located on chromosome 4A for both starch peak viscosity and
starch/flour swelling volume, centred around the
Wx-B1 locus. In previous studies, this locus has been
found to be linked to Japanese noodle quality. The increases in starch peak
viscosity and flour swelling volume are derived from the Halberd parent,
consistent with the fact that Halberd is null for the
Wx-B1 locus on chromosome 4A and is missing the
respective granule-bound starch synthase protein, whereas Cranbrook is a wheat
line carrying the normal 3 Wx loci. The final starch
viscosity also showed an association with the Wx-B1
locus. In the CD87 Katepwa cross, the progeny showed an association between
peak viscosity and a marker on chromosome 7A. This appeared to be near the
Wx-A1 locus. In some experiments, flour viscosity showed
a highly significant QTL on chromosome 7B, apparently at the same locus as the
late maturity - amylase derived from the Cranbrook parent. Starch
gelatinisation onset temperature indicated a significant QTL on chromosomes 2B
and 7A (LOD = 2.58 and 3.66, respectively, in interval analyses).
Starch gelatinisation peak temperatures indicated a QTL on chromosome 7A,
which, although not in the significant (P = 0.05)
class based on regression analyses, indicated a LOD score of 3.06 in interval
analyses. Heat of gelatinisation (H) indicated a suggestive QTL (LRS =
14.5 with a threshold of 14.7 for P < 0.05, LOD
= 2.65 for interval analysis), on chromosome 4A, at the
Wx-B1 locus with an increased effect coming from the
Halberd parent. The A:B granule ratio analysis indicated a significant QTL on
chromosome 4B, but this was not observed in all environments and may be due to
the fact that the QTL corresponded to the position of a major QTL controlling
plant growth.
Identification of quantitative trait loci for traits conferring weed competitiveness in wheat (Triticum aestivum L.)
Authors: Coleman R. K. , Gill G. S. , Rebetzke G. J.
Published: September 2002

As weeds develop resistance to a broad range of herbicides, wheat
(Triticum aestivum L.) cultivars with superior weed
competitive capacity are needed to complement integrated weed management
strategies. In this study, agronomic and morphological traits that enable
wheat to compete effectively with weeds were identified. Halberd, Cranbrook,
and 161 Cranbrook x Halberd doubled haploid (DH) lines were examined in field
experiments conducted over two growing seasons. The weed species
Lolium rigidum L. (annual ryegrass) was sown in strips
perpendicular to the direction of wheat seeding. Various traits were measured
during each season with competitive ability determined by both percent loss in
wheat grain yield and suppression of ryegrass growth. Width of leaf 2, canopy
height, and light interception at early stem elongation (Z31), and tiller
number, height at maturity, and days to anthesis were important for
competitive ability in 1999. In the previous year, length of leaf 2 and size
of the flag leaf contributed to competitiveness. Seasonal effects appeared to
have some impact on the relative contribution of crop traits to competitive
ability. The morphological traits involved in maintaining grain yield differed
from those that contributed to the suppression of ryegrass growth.
Development of the Cranbrook x Halberd chromosomal linkage map enabled the
putative identification of quantitative trait loci (QTL) associated with
competitive ability in the DH population. Many of the QTL were mapped to
similar positions in both years. Further, several traits, including time to
anthesis, flag leaf size, height at stem elongation, and the size of the first
2 leaves, were mapped to similar positions on chromosomes 2B and 2D.
Narrow-sense heritabilities on an entry-mean basis were typically high within
each year for traits associated with weed competitive ability. However, large
genotype x year interactions reduced these heritabilities, making genetic gain
through phenotypic selection difficult. The identification of QTL repeatable
over seasons indicates the potential for marker-assisted selection in a wheat
breeding program selecting for improved grain yield and weed competitiveness.
Trends in genetic and genome analyses in wheat: a review
Authors: Langridge P. , Lagudah E. S. , Holton T. A. , Appels R. , Sharp P. J. , Chalmers K. J.
Published: September 2002

The size and structure of the wheat genome makes it one of the most complex
crop species for genetic analysis. The development of molecular techniques for
genetic analysis, in particular the use of molecular markers to monitor DNA
sequence variation between varieties, landraces, and wild relatives of wheat
and related grass species, has led to a dramatic expansion in our
understanding of wheat genetics and the structure and behaviour of the wheat
genome. This review provides an overview of these developments, examines some
of the special issues that have arisen in applying molecular techniques to
genetic studies in wheat, and looks at the applications of these technologies
to wheat breeding and to improving our understanding of the genetic basis of
traits such as disease resistance and processing quality. The review also
attempts to foreshadow some of the key molecular issues and developments that
may occur in wheat genetics and breeding over the next few years.
Identification of stem rust and leaf rust resistance genes in Amagalon oats
Authors: Adhikari K. N. , McIntosh R. A.
Published: September 2002

Studies were undertaken to identify the genes conferring stem rust and leaf
rust resistances in Amagalon and to determine the usefulness of this line as a
source of rust resistance in oat breeding programs. Amagalon was crossed with
certain rust-resistant and rust-susceptible lines and segregating populations
were tested with pathotypes of Puccinia graminis avenae
and P. coronata avenae. Tests with the widely virulent
P. graminis avenae pt
94+Pg-13 indicated that resistance in Amagalon was
governed by the complementary recessive gene complex known as
Pg-a. This hypothesis was further substantiated by
temperature sensitivity tests and by a test of induced susceptibility to stem
rust, known to be unique to lines possessing Pg-a.
However, Amagalon yielded a unique source of resistance to leaf rust that was
effective against current pathotypes of
P. coronata avenae in Australia. This gene, assumed to
be Pc91, was inherited independently of a second leaf
rust resistance gene present in cv. Culgoa. It was concluded that Amagalon is
a useful source of resistance to leaf rust that should be used in combination
with other genes for resistance to prolong its effectiveness.
Growth and carcass composition of second-cross lambs. 1. Effect of sex and growth path on pre- and post-slaughter estimates of carcass composition
Authors: Hall D. G. , Gilmour A. R. , Fogarty N. M. , Holst P. J . , Hopkins D. L.
Published: September 2002

Carcass composition was estimated for 2316 second-cross lambs sired by 20 Poll
Dorset rams over 2 years. The lambs were separated into ewes or cryptorchids
at weaning with half of each sex group grown at a fast rate from weaning to
slaughter at 40 kg liveweight for ewes or 48 kg for cryptorchids. The other
half of each sex group was grown at a slower rate to the same slaughter weight
10–13 weeks later. Cryptorchids had fat scores about 0.4–1 unit
lower and ultrasound C fat depths (45 mm from the mid-line over the 12th rib)
about 0.8–1.3 mm less than ewes at the same liveweight. The carcass
measures unequivocally showed that at the same carcass weight, fast-growing
lambs were fatter than slow-growing lambs in both years and for both sexes.
The average differences were 1.5 mm GR (total tissue depth 110 mm from the
mid-line of the carcass over the 12th rib) and 1.4 mm C fat depth. Fat
measurements on live lambs showed fast-growth cryptorchids were fatter than
slow-growth cryptorchids; however, results for ewes were inconclusive. Slow
growth to increase leanness needs to be evaluated against prevailing costs of
lamb production and seasonal variation in prices. The correlations among and
between live measures and carcass measurements of fatness were relatively low.
The highest live to carcass R 2
values were ultrasound C fat depth with carcass C fat depth (0.36) and with
the AUS-MEAT probe GR (0.34). There is a need to identify the best live lamb
predictors of carcass composition.
A greater relative growth rate of Brassica rapa L. at low temperatures increases biomass at anthesis
Authors: Si P. , Thurling N.
Published: September 2002

0t, n.s.).
These relationships suggested that it might be possible to develop early
flowering cultivars with increased seed yield by selecting for higher RGR
before anthesis.
RGR of BC 2 F 3:4 lines in the
field during winter was correlated with RGR at low temperatures
(13/4°C) in a controlled environment, suggesting that genotypes
producing more dry weight at anthesis grew more at the low temperatures
normally experienced in the field. This was supported by a significant
(P < 0.05 0.05) negative correlation
(r = –0.69**) between growth in
the field and potassium leakage from leaf tissue at 4
LIGULE: An evaluation of indigenous perennial grasses for dryland salinity management in south-eastern Australia. 1. A base germplasm collection
Authors: Johnston W. H. , Mitchell Meredith L. , Koen T. B. , Mulham W. E. , Waterhouse D. B.
Published: September 2002

This paper reports on the collection phase of a research program which aimed
to identify Australian native grasses that may be useful for pastoral purposes
and for controlling land degradation on hill-lands in the high (>500 mm)
rainfall zone of south-eastern Australia. Live plants of 37 target species
were collected along a number of transects, and at specific locations, in New
South Wales and Victoria. The collection sites were generally along public
roads, and were chosen for their vegetation diversity. Each collection site
was marked on a 1: 250000 topographic map, and detailed notes were taken of
the native vegetation, geology, soil types, land use, and other features.
Surface (00—10 cm) soil samples were collected at most sites and
analysed for phosphorus, pH CaCl 2 , electrical
conductivity, and particle size distribution.
A total of 807 accessions were collected from 210 locations. At most
collection sites, soils were acidic (median pH 5.6); soil phosphorus (Olsen)
was in the low range (<8.5 mg/kg); and the target genera occurred with
a low frequency (half of the sites yielded 3 accessions or less). Although
genera collected in the study could be ranked on the basis of the mean pH of
their collection sites, they all tolerated a considerable soil pH range (of
about 2mp;mdash;5 pH units). Allowing root and shoot growth to recommence by
growing collected plants for a short period in coarse sand considerably
improved establishment success. Accessions collected in this study will be
further evaluated.
Water deficit effects on sweet corn. I. Water use, radiation use efficiency, growth, and yield
Authors: Stone P. J. , Wilson D. R. , Reid J. B. , Gillespie R. N.
Published: September 2002

The responses of sweet corn biomass and yield to timing and severity of water
deficit were determined in an experiment using a mobile rainshelter. Six
irrigation treatments were applied such that plots experienced: (1) no water
deficit; (2) full water deficit; (3) moderate pre-silking deficit; (4) severe
pre-silking deficit; (5) moderate post-silking deficit; or (6) severe
post-silking deficit. Drought was quantified using the concept of potential
soil moisture deficit, which was calculated from climatic data. Potential soil
moisture deficit can be related simply to a wide range of plant performance
variables, making it possible to compare the relative importance of variables
in determining the overall response of the crop to drought. For all
treatments, yield was related strongly to biomass, especially that accumulated
after silking. Biomass, in turn, was reduced by water deficit, mainly because
of reduced radiation use efficiency, but also because of reduced total
radiation interception, particularly in early deficit treatments. Both water
use efficiency and transpiration efficiency increased with water deficit, even
though soil evaporation as a proportion of total water use also increased with
deficit. There was no stage of crop development at which yield was
particularly sensitive to water deficit, although yield components changed
with timing of deficit. Importantly, measures of potential soil moisture
deficit integrated the effects of timing and severity of drought, making it
possible to simply and mechanistically account for the effects of water
deficit on biomass and particularly yield.
An analysis of the frequency and timing of false break events in the Mediterranean region of Western Australia
Authors: Chapman R. , Asseng S.
Published: September 2002

Historical meteorological data were used to estimate the frequency and timing
of false break events at 10 locations in the annual pasture and wheat
producing area in the Mediterranean climatic region of Western Australia. The
seasonal pattern of false breaks identified by this analysis was compared with
the dynamics of dormancy release in a field population of subterranean clover
(Trifolium subterraneum L.) to determine the influence
that these events may have on the legume content of annual pasture communities
in this region. False break events were estimated to occur on approximately 2
of every 3 years (611–72% of years) with no significant
differences across the area investigated. Changes in the risk of false break
events were examined over discrete time periods. The period of greatest risk
was predicted to occur during early autumn (early March to mid April). Seed
softening is virtually complete in subterranean clover at this point. The seed
bank strategy of this species is, therefore, not well adapted to withstand the
effects of false breaks. This might largely explain the poor persistence of
subterranean clover in the annual pasture communities in the Mediterranean
region of Western Australia. The legume content of these pastures might be
improved by selecting species with late dormancy release strategies that will
give better protection from false breaks.
Water use and drainage under phalaris, annual pasture, and crops on a duplex soil in Western Australia
Authors: Dolling P. J.
Published: September 2002

Rising water tables in southern Western Australia are causing waterlogging and
salinity problems. These issues are related to a lower level of water use by
annual plants than by the native vegetation. Phalaris can use more water than
annual pastures and crops because of deeper rooting characteristics and longer
growing season. However, there is limited information on the water use of
phalaris in the Western Australian environment. There is also very little
information on water balances under annual crops and pastures outside the
growing season. A field experiment was carried out on a duplex soil between
March 1994 and March 1999. Annual rainfall varied between 321 and 572 mm. The
study examined soil water content, deep drainage, and productivity of
phalaris-based pasture, continuous annual pasture, annual pasture–wheat
rotation, and a wheat–lupin rotation. The results showed that the
phalaris-based pasture after the establishment year was 25% (1.9 t dry
matter/ha) more productive than continuous annual pasture, with the main
difference occurring in late spring–early summer. The phalaris-based
pasture used, on average, 45 mm/year more water and reduced drainage below
1 m by 44 mm/year compared with the annual pastures and crops. Total
drainage below 1 m was 30 mm under the phalaris-based pasture and 74 mm under
annual pasture. The greater water use in the phalaris-based pasture occurred
in late spring and early summer.
Although differences in total biomass per year occurred between wheat in
different rotations there was no difference in the soil water storage prior to
the break of the season. There was also no difference in the soil water
balance between any of the annual crops and pastures. Differences in soil
water storage did occur in some years in October but disappeared by May the
following year.
Comparative soil water, pasture production, and crop yields in phase farming systems with lucerne and annual pasture in Western Australia
Authors: Latta R. A. , Blacklow L. J. , Cocks P. S.
Published: September 2002

Two field experiments in the Great Southern region of Western Australia
compared the soil water content under lucerne
(Medicago sativa) with subterranean clover
(Trifolium subterranean) and annual medic
(Medicago polymorpha) over a 2-year period. Lucerne
depleted soil water (10–150 cm) between 40 and 100 mm at Borden and 20
and 60 mm at Pingrup compared with annual pasture. There was also less stored
soil water after wheat (Triticum aestivum) and canola
(Brassica napus) phases which followed the lucerne and
annual pasture treatments, 30 and 48 mm after wheat, 49 and 29 mm after canola
at Borden and Pingrup, respectively.
Lucerne plant densities declined over 2 seasons from 35 to 25
plants/m2 (Borden) and from 56 to 42
plants/m2 (Pingrup), although it produced herbage
quantities similar to or greater than clover/medic pastures. The lucerne
pasture also had a reduced weed component.
Wheat yield at Borden was higher after lucerne (4.7 t/ha) than after
annual pasture (4.0 t/ha), whereas at Pingrup yields were similar (2
t/ha) but grain protein was higher (13.7% compared with
12.6%) . There was no yield response to applied nitrogen after lucerne
or annual pasture at either site, but it increased grain protein at both
sites.
There was no pasture treatment effect on canola yield or oil content at Borden
(2 t/ha, 46% oil). However, at Pingrup yield was higher (1.5
t/ha compared to 1.3 t/ha) and oil content was similar (41%)
following lucerne–wheat.
The results show that lucerne provides an opportunity to develop farming
systems with greater water-use in the wheatbelt of Western Australia, and that
at least 2 crops can be grown after 3 years of lucerne before soil water
returns to the level found after annual pasture.