bluuebunny/crossref_metadata_2025 huggingface dataset:
Survival of dispersed urediniospores of Tranzschelia discolor Fckl. (Tranz. Litv.) on leaves of Prunus domestica L. cv. 'd'Agen' in spring and summer in the Murrumbidgee irrigation areas
Authors: Ellison PJ , McFadyen LM , Cullis BR , Kable PF
Published: November 2004

The survival of dispersed urediniospores of Tranzschelia discolor on the undersurfaces of dry prune foliage was monitored during spring and early summer under outdoor conditions in the Murrumbidgee Irrigation Areas of New South Wales. The spores were produced under standard glasshouse conditions to ensure high initial viability (generally >90%) and samples were exposed to outdoor conditions at fortnightly intervals. Early in the season, viability declined relatively slowly, and in the first four samples >60% of urediniospores were viable 20 days after initial exposure dates. From late November the decline in viability increased markedly and suddenly, and in a sample exposed on 30 November only 20% of urediniospores were viable 21 days later. Other samples exposed from late November onwards showed similar or faster rates of decline. It was shown that temperature was the main climatic factor affecting urediniospore viability and that relative humidity and solar radiation did not contribute to decline in viability. A model based on temperature was constructed to forecast decline in urediniospore viability. This showed that urediniospores of T. discolor were critically affected by temperatures in the range 25-30�C. At temperatures below this range decline in viability was shown to be negligible, whereas exposure to temperatures > 25-30�C resulted in a 34-fold increase in the rate of decline.
Autofluorescence of necrotic phloem cells and laticifers, and a reduced latex flow: new symptoms for papaw dieback disease in Australia
Authors: Harding RM , Teakle DS
Published: November 2004

When petiole and root sections taken from papaw plants affected by dieback disease were examined under a fluorescence microscope, specific autofluorescence was observed in some phloem cells and/or laticifers. Such autofluorescence was never observed in similarly treated sections taken from healthy plants. Light and electron microscopic examination of areas showing specific autofluorescence revealed the presence of necrotic phloem cells, but close examination of these cells failed to show a parasitic agent. Papaw plants affected by dieback disease and showing necrosis of laticifers also displayed a marked reduction in latex flow. The results indicate that autofluorescence of necrotic phloem cells and laticifiers, and a reduced latex flow, are new symptoms of papaw dieback disease in Australia.
Corrigendum - Autofluorescence of necrotic phloem cells and laticifers, and a reduced latex flow: new symptoms for papaw dieback disease in Australia
Authors: Harding RM , Teakle DS
Published: November 2004

When petiole and root sections taken from papaw plants affected by dieback disease were examined under a fluorescence microscope, specific autofluorescence was observed in some phloem cells and/or laticifers. Such autofluorescence was never observed in similarly treated sections taken from healthy plants. Light and electron microscopic examination of areas showing specific autofluorescence revealed the presence of necrotic phloem cells, but close examination of these cells failed to show a parasitic agent. Papaw plants affected by dieback disease and showing necrosis of laticifers also displayed a marked reduction in latex flow. The results indicate that autofluorescence of necrotic phloem cells and laticifiers, and a reduced latex flow, are new symptoms of papaw dieback disease in Australia.
Response of Sonia roses to continuous daytime CO2 supplementation under controlled environment conditions
Authors: Zeroni M , Gale J
Published: November 2004

Rose plants (Rosa hybrida cv. Sonia, Syn. Sweet Promise) were placed in growth chambers under conditions resembling winter in a controlled environment greenhouse in the desert: mild temperatures, high incident photosynthetic photon flux density (PPFD), high air humidity and 10.5 h daylenght. Concentrations of CO2 in the air were maintained throughout the day at 320, 600 or 1200 8l l-1 with approximately 350 8l l-1 at night. Plant growth (length, fresh and gry weight), development (breaks, blindness), flower yield and flower quality (flower bud diameter, fresh weight and cane length) indices were monitored throughout three consecutive flowering cycles. CO2 supplementation caused an increase in leaf resistance to water vapour diffusion, accompanied by a reduction in the rate of transpiration per unit leaf area, Total leaf area increased at higher CO2 concentrations. Water use per plant did not change. Plant water potentials increased with rising CO2 concentrations. Growth, development, flower yield and flower quality were greatly enahnced in the CO2-enriched atmosphere. The response of growth and development to CO2 supplementation tended to decrease slightly with time when calculated per branch, but increased when calculated per plant. Flower yield and qualtiy did not change with time. The highest CO2 treatment resulted in a sustained, approximately 50% increase in yield, and doubling of the above quality indices throughout the three growth cycles.
Heterosis and combining ability effects on cotton. I. Combining ability
Authors: Thomson NJ , Luckett DJ
Published: November 2004

Combining ability for a number of yield and quality attributes of cultivated cotton (Gossypium) was studied in two diallel experiments under high-yielding conditions in northern Australia. The first diallel comprised nine G. hirsutum parents of North American and African origin, the second diallel of thirteen parents besides American and African cultivars also included an Indian line, some Australian lines and an American G. barbadense cultivar. Each set of hybrids was grown as a half-diallel (plus the parents), first as a plant crop and then as a ratoon crop in the following season. Generally variation due to general combining ability (GCA) was significant and substantial for all traits, although specific combining ability (SCA) was also significant. GCA was shown to be closely associated with parental performance per se which may, therefore, be used with good reliability in choosing parents for use in a breeding program. The plant and ratoon performances were very similar in most instances. The African cultivars together with some medium-quality American ones showed high combining ability for yield, but the best GCA for quality characters was found in the high- quality parents. The G. barbadense cultivar was exceptional in this regard, hut it had a low GCA for yield, and there are other technical problems associated in establishing good inbred lines from hybrids between the two cultivated tetraploid species. Genotypic correlations between a pair of traits were usually similar for the plant and its respective ratoon crop, but often quite different for the two diallel combinations. In both populations selection for increased lint yield would tend to be accompanied by adverse changes in some other important characteristics.
The effect of selection for fleece weight upon urea metabolism and digestive function in Romney sheep
Authors: Thompson BC , Dellow DW , Barry TN
Published: November 2004

The effect of 30 years genetic selection for greasy fleece weight upon rumen metabolism, apparent digestibility and nitrogen metabolism was investigated in Romney sheep.Fleece weight (Fwt) animals had a 1 mM lower plasma urea concentration than control (C) animals when fed on both diets given, but there was no difference in plasma urea IRL, urinary urea excretion or urea recycling to the digestive tract between the Fwt and C sheep when fed either diet. Relative to the C shccp, the Fwt animals had a higher creatinine clearance rate when fed the meadow hay diet, and a higher urea clearance rate when fed both diets.When fed the meadow hay diet there were no differences between the Fwt and C animals in voluntary feed intake (VFI) or apparent DM digestibility. However, when fed on the lucerne chaff diet the Fwt animals had a higher VFI than the C animals and a lower apparent DM digestibility. These changes were associated with an increase in the rumen fractional outflow rate (FOR) of lignin in the Fwt sheep, and a higher molar proportion of acetate and a lower proportion of propionate in rumen fluid.The differences in urea and creatinine clearance rates suggest that selection for fleece production may have altered kidney function, with expression of this and rumen FOR being related to nutritional level. A factor contributing to the superior wool production of the Fwt sheep is suggested.
Yield losses of soybeans due to Phytophthora megasperma f.sp. Glycinea
Authors: Ryley MJ , Mosetter HF , Rose JL
Published: November 2004

Field trials were conducted in two seasons to determine the influence of Phytophthora megasperma f.sp. glycinea on seed yields of soybean genotypes with different levels of resistance. The fungicide metalaxyl, applied as a seed dressing and soil drenches, was used to control the disease. The cultivar Davis, which has high field resistance, did not suffer significant losses in either year. whereas the yield depression of less resistant genotypes ranged up to 72%, depending on the genotype and year. In 198 1 - 82 high death rate of plants occurred early in the season, but yield losses were less than in 1982-83 when mortality occurred late in the season. The declining ability of surviving plants to compensate for disease losses during the latter growth stages may account for the differences in yield losses between seasons.Genotypes with immunity to P. megasperma f.sp. glycinea have been widely grown in the United States because they offer complete protection against some races. However, new pathogenic races have developed quickly, and previously immune genotypes have then suffered severe yield losses. The results of these trials demonstrate that yield losses can be prevented without resorting to fungicide treatments. It is likely that a stable long-term solution to phytophthora root and stem rot will be conferred by field resistance.
Effect of stocking rate, season and pasture characteristics on liveweight gain of beef steers grazing perennial pastures
Authors: Bird PR , Watson MJ , Cayley JWD
Published: November 2004

In each of 4 years (1975-78) yearling steers at stocking rates (SR) of 1.1-3.6 steers/ha continuously grazed pastures sown in 1971 with Trifolium subterraneum cv. Mt. Barker, Phalaris aquatica cv. Australian and Lolium perenne cv. Victorian at Hamilton from Mar. to Jan. Data on liveweight gain (LWG), fat depth and pasture attributes were collected over the 4 years. Body composition was estimated periodically over the first 2 years, using tritiated water. Relationships between LWG and SR were established and the overall annual effect was LWG (kg)=237-39.7 SR. However, most or all of the gains made at intermediate or higher SR were achieved in the spring and summer. Compensatory gains in these 5 months were greatest at 3 steers/ha but varied from 6.5 kg (in 1976) to 34 kg (in 1978) more than achieved at the lowest SR. The heaviest steers had more subcutaneous fat and steers at higher SR were leanest, but in 1 year of prolonged spring growth (1978) there was no difference in fat depth at any SR despite a 68 kg difference in liveweight (W) between lowest and highest SR. Seasonal LWG was modelled from W and/or pasture mass (green and dead fractions). Use of green pasture mass rather than total mass substantially improved precision in all seasons. A smaller but significant further improvement was obtained using green mass, dead mass and the interaction in the regressions. Severe penalties to LWG occurred in grazed pastures with a large component of dead material.
Variation in herbicide cross-resistance among populations of annual ryegrass (Lolium rigidum) resistant to diclofop-methyl
Authors: Heap IM , Knight R
Published: November 2004

A population of annual ryegrass (Lolium rigidurn), known to be susceptible to diclofop-methyl, and eleven populations known to be resistant to the herbicide, were evaluated for their cross-resistance to fluazifop-butyl, haloxyfop-methyl, sethoxydim, chlorsulfuron, glyphosate and propham, applied postemergence as a spray treatment. None of the populations were cross-resistant to glyphosate or propham. All the populations showed some level of cross-resistance to the other herbicides, but there was considerable variation between populations in this resistance. The variation could not be related in any simple manner to the origin of the populations in Australia, nor to their past histories of herbicide applications. The results indicate the complexity that will be faced in resolving the biochemistry and genetics of the phenomenon and the formulation of advice to farmers.
A genetic analysis of lysosomal enzyme activities in Brahman cattle
Authors: McPhee CP , Reichmann KG
Published: November 2004

Analyses of variance and covariance were carried out on the activities of three lysosomal enzymes in mononuclear blood cells from Brahman cattle. These were hexosaminidase (HEX), beta-D-galactosidase (GAL) and acid alpha-glucosidase (GLU) which had been measured in blood mononuclear cells from 1752 cattle from 6 herds in a Pompe's disease control programme. Herd of origin and date of bleeding significantly affected the level of activity of all enzymes. In addition, HEX and GAL were affected by age and HEX by the sex of the animal bled. Estimates of heritability from sire variances were 0.29 � 0.09 for HEX, 0.31 � 0.09 for GAL and 0.44 � 0.09 for GLU. Genetic correlations between all enzymes were positive. The data indicate the existence of a major gene causing Pompe's disease and responsible for 16% of the genetic variation in GLU. One standard deviation of selection differential for high GLU should almost eliminate Pompe's disease from the population. The efficiency of selection would be aided by estimating the breeding value for GLU using measurements of HEX and GLU and taking account of an animal's sex, age, date of bleeding and herd of origin.
Flowering times of wheats in south-western Australia: a modelling approach
Authors: Loss SP , Perry MW , Anderson WK
Published: November 2004

The time of flowering is important for the yield of wheat crops in south-western Australia, where the risk of frost damage and the onset of drought can occur in the same month. Relationships to predict the time from sowing to flowering were derived by linear regression of duration on mean temperature and photoperiod for 11 cultivars. The models were tested against independent observations of flowering measured in time-of-sowing experiments conducted at five locations over three years. The model accounted for 71-95% of the variation in the independent observations of duration from sowing to flowering. The slopes of the regressions of observed versus predicted values were always less than 1.0, significantly so for four cultivars (P<0.01). The mean deviation of the predicted from the observed varied from 2 to 10 days, depending on the cultivar, site and year. The model was used to examine the effects of seasonal variation, sowing time and location on the flowering times of early, mid-season and semi-winter cultivars in south-western Australia. Predictions over sites, sowing dates and years demonstrated that widely differing developmental patterns may be required to exploit the range of environments and sowing dates in the Western Australian wheatbelt. The durations from sowing to flowering for mid-season and semi-winter cultivars were less affected by the variation in temperature than cultivars with rapid development patterns, and the variation in flowering times between cultivars was smaller at cool locations than at warm sites. The use of the model for farmers and breeders is indicated.
Effect of high temperature on the rate and duration of grain growth in field-grown Sorghum bicolor (L.) Moench
Authors: Muchow RC
Published: November 2004

Sorghum was sown at six dates in a tropical environment and grown under high water and nutrient supply. For each sowing, mean temperature during grain-filling was relatively stable, but across sowings it ranged from 24.6 to 30.2�C. The effect of this variation on the following was examined: the linear rate of grain growth, the duration of the effective grain-filling period, the rate of increase in harvest index during grain-filling, the rate of development of black layer (as an indicator of maturity) and final grain yield. Contrary to previous findings from controlled environment experiments, the rate of grain growth increased linearly with temperature to 30�C. However, the duration of grain-filling and the rate of development of black layer were not closely related to mean temperature. Final grain yield was not necessarily adversely affected by high temperature during grain-filling. Also, high grain yield was not necessarily associated with long duration of grain-filling. Similar to the rate of grain growth, harvest index increased linearly during grain-filling. The rate of increase in harvest index was not significantly related to temperature, with a mean value across sowings of 0.0185 day-1. An important implication of the linear increase in harvest index is that grain yield accumulation can be estimated from the crop biomass at any stage of grain growth without knowledge of grain number or the rate of grain growth.
Forage tree legumes. II. Investigation of nitrogen transfer to an associated grass using a split-root technique
Authors: Catchpoole DW , Catchpoole DW , Blair GJ , Blair GJ
Published: November 2004

In an earlier field experiment in this series, we found no significant transfer of N between Leucaena or Gliricidia and Panicum maximum. The glasshouse study reported here employed a split-root technique, whereby trees of leucaena and gliricidia were grown in boxes with 15N fed to one half of the root system and the transfer of N to the other half of the box was measured by sampling tree and planted grass. Detection of l5N in the grass tops and roots from the unlabelled half of the box was used to indicate N transfer from the tree roots to the grass. Transfer of labelled N to the grass amounted to 4.1% in the first 6 week period when 15N was being injected into the tree root zone. A harvest of the tree and grass was made at 6 weeks and both allowed to regrow for a further 6 weeks with no further addition of l5N. Over the entire 12 week experimental period 7.6% of the labelled N from the tree was transferred to the grass. The low proportion of N transferred from tree legume to the grass in this experiment, where herbage was cut and removed, is similar to the findings in the earlier field experiment and indicates that, in such a system, little direct beneficial effect of N fixation would be expected in an understorey grass or food crop.
Population dynamics of Heterodera avenae Woll. in South Australia
Authors: Fisher JM , Hancock TW
Published: November 2004

Population changes of the cereal cyst nematode (Heterodera avenae Woll.) under various rotational regimes in the field were examined. A density of 5 eggs/g soils caused a loss of about 10% in yield of wheat cv. Bayonet under the experimental conditions. Maximum multiplication rate at low initial densities was about l0x, but this rapidly decreased as initial density increased. Equilibrium levels ranged from 15 eggs/g soil up to 40 eggs/g under different conditions. The resistant wheat, Aus 10894, maintained an equilibrium level of about 1 egg/g soil-a level low enough to avoid damage in a following crop. Annual percentage hatch varied from 70-90% with an average of 85%. Presence or absence of plant species had little effect on per cent hatch. About 7.5% of the nematodes successfully penetrated and became established in the root systems of seedlings, invading both seminal and nodal roots, but only about 0.5% became established in the principal axes of the seminal roots. The implications of these data for various rotational practices are discussed.
Morphological influences on the seed yield of field peas
Authors: Walton GH
Published: November 2004

In a preliminary trial at Perth with spaced plants which were supported to prevent lodging and allow for irrigation, the seed weight on plants was correlated with the ability of pea plants to produce reproductive nodes on the main stem and branches. Tall cultivars such as Dundale, Dun and Wirrega produced more aerial branches than dwarf cultivars like Huka which gave more basal branches. By contrast, in the dry, short-season Mediterranean climate of the Western Australian wheatbelt at Merredin, the seed yield of peas was derived principally from yield components on the main stem. The plant characters; the number of reproductive nodes, plant height and seed number per pod, had a significant (P< 0.01) and positive correlation with seed yield. The early- and mid-flowering cultivars, Collegian and Dundale (67 and 72 days to flower respectively), had more reproductive nodes on the main stem, with more seeds produced on the first six reproductive nodes than later flowering (88-96 days) cultivars such as Dun and Wirrega. At Merredin, basal branch number was negatively correlated with seed yield and tall cultivars like Collegian, Dundale and Dun had significantly (P< 0.05) less basal branches. Plant breeders should select for increased seed number per pod in early flowering, medium to tall pea plants, to improve the total seed weight from the first three reproductive nodes produced on the main stem.
Competition between Clare and Seaton Park, and Clare and Daliak subterranean clovers in replacement series mixtures in the field.
Authors: Hill MJ , Gleeson AC
Published: November 2004

Binary mixtures of Clare and Seaton Park, and Clare and Daliak subterranean clovers were grown for three years in de Wit replacement series in the field and defoliated at approximately 4-week intervals between mid-winter and the end of October. For the most part both mixtures exhibited competition for the same resources with Clare dominant, and progressively excluding the other cultivars; this exclusion was more rapid with Daliak than with Seaton Park. Seed production of both Seaton Park and Daliak was depressed in mixtures, and seed reserves were reduced to virtually zero by the third year, although significant growth and seed reserves remained in the monocultures. Seed production from Clare was much less dependent on plant population than was seed production from Seaton Park and Daliak. Variation between replicates and spatial heterogeneity of sward composition was greater in the Daliak experiment on a heavy clay than in the Seaton Park experiment on a lighter soil. In both experiments, large quantities of seed could not be accounted for in germinations and residual seed reserves-80% in 1986 and 33% in 1987. Significant seed losses may be characteristic of the ecology of subterranean clover in summer rainfall zones. The success of Clare in northern New South Wales may be due mainly to the vigour and high seed production capacity of individual plants.
The effect of temperature on germination and seedling growth of temperate perennial pasture legumes.
Authors: Hill MJ , Luck R
Published: November 2004

Germination of 10 perennial pasture legumes, white clover, red clover, strawberry clover, lucerne, Caucasian clover, cicer milkvetch, crownvetch, birdsfoot trefoil, big trefoil and sericea lespedeza, was compared under five day/night temperature regimens: 24/20, 20/15, 15/10, 12/6 and 8/2�C. Growth of seedlings of Caucasian clover, birdsfoot trefoil, cicer milkvetch, crownvetch and sericea lespedeza was compared with that of white clover at four serial harvests over a 5-week period at the three highest temperatures. Three main patterns of germination were observed. Firstly, temperature had little effect on maximum percentage, time to first germination and rate of germination in lucerne. Secondly, all Trifolium species and birdsfoot trefoil exhibited reductions in rate of germination and increases in time to germination at the two lowest temperatures. Thirdly, the remaining species showed either very slow or no germination at the two lowest temperatures, where there were large reductions in the maximum germination where germination occurred. Seedling growth was characterized by better dry matter and leaf production from white and Caucasian clovers at 15/10�C than for the other species, but very marked increases in growth at the higher temperatures by the other four species. Lespedeza was always the least vigorous seedling, and birdsfoot trefoil and crownvetch grew as well or better than the Trifolium species at 24/20�C. Slow first leaf appearance in crownvetch and cicer milkvetch seemed to be associated with a much greater capacity for cotyledon expansion in these species. While Caucasian clover appears to be well suited for establishment under Australian conditions, promising species such as cicer milkvetch and crownvetch will require selection for better germination and seedling growth at low temperatures or the introduction of more winter active germplasm if they are to become useful plants in Australian pastures.
Wool sulfur concentration and output in fleeceweight-selected and control Romney rams
Authors: Antram RJ , McCutcheon SN , Blair HT , Lee J , McClelland LA
Published: November 2004

Wool sulfur concentration and output of Romney sheep from fleeceweight-selected and control lines were measured with a view to determining their potential use as genetic markers for fleeceweight. Midside wool samples were collected at 28 day intervals from 4 to 14 months of age from 35 fleeceweight-selected and 30 control rams. Clean wool growth during each sampling period was calculated. Wool samples were digested using an open wet digestion method and the wool sulfur concentration was determined by plasma emission spectrometry. Fleeceweight-selected rams had significantly greater midside wool growth than the control animals throughout the trial except on day 56. Average wool sulfur concentration in both lines increased over the sampling period to a peak at day 308. The wool sulfur concentration of control rams was significantly higher than that of fleeceweight-selected rams only on days 28 and 280. Total sulfur output (the product of midside wool growth rate and sulfur concentration) was significantly higher in the fleeceweight-selected than in the control rams on days 84-140 (March-May) and 196-308 (June-October). It is concluded that midside wool sulfur concentration and output of 4 to 14 month-old-Romney hoggets are unlikely to be useful genetic markers for fleece production.
Potential for increasing early vigour and total biomass in spring wheat. I. Identification of genetic improvements
Authors: Whan BR , Carlton GP , Anderson WK
Published: November 2004

Increased early vigour and vegetative biomass at anthesis should lead to yield improvements in wheat. Fifteen introductions were compared with five standard cultivars in Western Australia at Wongan Hills in 1988, and Wongan Hills, Merredin and Esperance in 1989 to identify useful parents for their early vigour and biomass production. Two times of sowing were included at Wongan Hills in 1989. Dry matter production was measured at all sites except Esperance at the early vegetative stage (49 to 55 days after sowing), late vegetative stage (56 to 75 days after sowing), and at anthesis. Some introductions were more vigorous in the vegetative stages, and produced more biomass at anthesis than the standard cultivars. Experiments under irrigated, non-stress conditions showed these lines produced leaves and tillers more quickly than the standard cultivars. The full growth potential of these lines may not have been expressed fully due to environmental limitations. While variation for dry matter production existed within the standard cultivars, it was not adequate or consistent enough to be of value in breeding. Dry matter production at the vegetative and anthesis stages was correlated significantly with grain yield in 1989, but not in 1988. Broad sense heritabilities for dry matter production at the three stages were generally high, averaging 72, 73 and 69% for early vegetative, late vegetative and anthesis dry matter production respectively. The importance of assessing the value of early vigour and biomass in breeding populations is discussed.
Glasshouse and field evaluation of quantitative resistance to Colletotrichum gloeosporioides in tetraploid accessions of Stylosanthes hamata
Authors: Iamsupasit N , Cameron DF , Chakraborty S , Gordon G , Irwin JAG , Davis RD
Published: November 2004

A total of 20 field isolates of Collectotrichum gloeosporioides from Stylosanthes hamata was tested for pathogenicity and differential virulence in glasshouse inoculation experiments. No pathogenic specialization towards S. hamata was noted, but all three major races of the pathogen causing Type A disease were detected using the host differential set of one S. viscose and four S. scabra accessions. There was also little evidence of pathogenic specialization to S. hamata when 37 accessions were inoculated with three isolates representing the three main Type A races on S. scabra and a field isolate from S. hamata cv. Verano. The resistance of 38 accessions of S. hamata, including cvv. Verano and Amiga, was evaluated by inoculating field plots with a mixture of four isolates of C. gloeosporioides. Anthracnose progress was monitored by regular disease assessments and accessions were compared using the terminal disease severity, the rate parameter of logistic and linear models of disease progress and the area under the disease progress curve (ADPC). Accessions showed a continuous range from moderate to high resistance, with Verano and Amiga taking intermediate values. Spearman rank correlations among ADPC, terminal severity in the field, apparent infection rate and the severity in glasshouse tests were generally significant. Several resistant accessions were identified with potential for use in a breeding program to improve the anthracnose resistance of cvv. Verano and Amiga.
Effects of pH and aluminium on the growth of temperate pasture species. I. Temperate grasses and legumes supplied with inorganic nitrogen
Authors: Edmeades DC , Blamey FPC , Asher CJ , Edwards DG
Published: November 2004

A flowing solution culture experiment was conducted in which four temperature pasture grasses and 11 temperate pasture legumes were grown in solutions of low ionic strength for 29 days at six aluminium (Al) levels with average Al3+ activities {Al3+} of 1.0, 5.1, 5.9, 9.9, 20.8, 41.6 8M at pH 4.5. Growth of these species was also measured at pH 5.5 in the absence of Al. In the absence of added Al, lucerne (Medicago sativa) cv. Hunter River and phalaris (Phalaris aquatica) cv. Grasslands Maru grew better at pH 5.5 than at 4.5. The reverse was so for ryegrass (Lolium perenne) cv. Grasslands Nui and subterranean clover (Trifolium subterraneum) cv. Tallarook. Increasing the pH from 4.5 to 5.5 had no effect on the growth of the other 11 species and cultivars tested. Micromolar activities of Al (<10 8M) markedly reduced the growth of all species. Four groups were tentatively identified in terms of their tolerance to Al. The two cultivars of ryegrass and the two red clover (Trifolium pratense) cultivars, together with Lotus corniculatus cv. Maitland, were relatively sensitive to Al. A 50% reduction in total dry matter (TDM) was associated with {Al3+} of 2-3 8M. The four white clover (Trifolium repens) cultivars, tall fescue (Festuca arundinacea) cv. Grasslands Roa, phalaris cv. Grasslands Maru, and Lucerne cv. Hunter River were intermediate in their tolerance, with {Al3+} of 3-5 8M reducing TDM by 50%. The two subterranean clover cultivars were more tolerant to Al than white clover (50% TDM reduction at 5-6 8M {Al3+}. Lotus pedunculatus CV. Grasslands Maku was exceptional in its tolerance to Al. Its growth was unaffected by {Al3+} up to 5 8M and 50% growth reduction was associated with {Al3+} of 7 8M The results of this study emphasize the need to conduct solution culture experiments at realistic solution concentrations and ionic strengths when examining the effects of Al on plant growth.
Selection of wheat breeders' lines for improved baking quality based on their free lipid content
Authors: Panozzo JF , Bekes F , O'Brien L , Khan A
Published: November 2004

To determine if a relationship exists between the amount of extracted lipid and loaf volume, the free lipid content in wholemeal wheat and flour samples was extracted using n-hexane. Three different extraction methods, classical Soxhlet, a commercial Soxhlet instrument known as the Soxtec and batch extraction at room temperature, were used. The aim was to ascertain which method could best be applied to screen large numbers of wheat lines in a breeding program. The results showed that the Soxhlet and Soxtec methods extracted similar amounts of lipid while the batch method extracted a lower amount. The relationships between loaf volume and free lipid extracted from either flour or wholemeal were highly significant. A protocol for screening wheat lines in a breeding program was developed. When evaluated over 2 years, measurement of free lipid content was sufficiently accurate to be used as a small scale test to select wheat lines for baking quality.
Experimental copper and Heliotropium europaeum intoxication in sheep: clinical syndromes and trace element concentrations
Authors: Howell JM , Deol HS , Dorling PR
Published: November 2004

Merino wethers were used to determine the effects of copper (Cu) and heliotrope (Heliotropium europeaum), given together or separately, on the development of toxicity and trace element concentration in liver and kidney. The 14 sheep fed both Cu and heliotrope were given Cu and heliotrope concurrently (9 sheep) or heliotrope alone for 12 weeks, and then Cu starting 8 weeks after heliotrope consumption ceased (5 sheep). Clinically and biochemically, there was no significant difference between these two regimes. Thirteen developed clinical signs. Of those, three developed haemolysis, eight became jaundiced and two became weak without jaundice. Of the eleven given Cu alone, three developed haemolysis but no jaundice, while there was neither haemolysis nor jaundice in the ten fed heliotrope only, although one died. Throughout the experiments a similar concentration of Cu was found in liver of control and heliotrope groups. The concentration of Cu in the liver of animals fed Cu alone increased to twice, and in groups fed Cu and heliotrope it increased to three times that found in the control groups. In animals which developed haemolysis, the concentration of Cu in the blood rose prior to the onset of haemolysis. It also rose in some animals which became jaundiced, but did not develop clinical haemolysis. Feeding heliotrope alone induced the histologic changes reported in pyrrolizidine alkaloid intoxication, but was not associated with an excessive accumulation of Cu nor the development of clinical illness. However, such sheep were made more susceptible to effects of a second toxin, for in animals given Cu and heliotrope, toxicity of the two substances was markedly enhanced and excessive accumulation of Cu occurred in liver.
Fruit set in lychee (Litchi chinensis Sonn.). Variation between flowers, panicles and trees
Authors: McConchie CA , Batten DJ
Published: November 2004

The ability of lychee cv. Bengal (Litchi chinensis Sonn.) female flowers to produce fruit has been investigated within individual panicles. Female flowers were pollinated with pollen from the same cultivar or removed manually. These experiments showed that 13.3% of the flowers opening on the first three days of the female phase of anthesis produced fruit. This was significantly fewer than the 22.8% of female flowers opening 4 to 6 days after commencement of female anthesis. Only 9.2% of flowers produced fruit on panicles in which every female flower was pollinated and none removed. No panicle yielded more than 28 fruit. The variation in female flower fecundity within a panicle, and the decrease in the proportion of flowers that yielded fruit as the number of flowers pollinated per panicle increased imply that comparisons between different treatments to lychee flowers should be made on entire panicles and not individual flowers. There was no difference between replicates of treatments on the same tree nor in the performance of individual trees. The time of day that pollination was performed appeared to have little effect on the percentage of fruit retained. There was no obvious relationship between prevailing weather conditions on the day of pollination and fruit production.
Inhibition of growth of fungi isolated from plants by Acremonium strictum
Authors: McGee PA , Hincksman MA , White CS
Published: November 2004

The fungus Acremonium strictum was isolated from rye grass, kikuyu and another species of Pennisetum. Two isolates of A. strictum significantly inhibited, in vitro, the rate of growth of five fungi commonly associated with grasses. Extracts from cultures of the isolates also inhibited the rate of hyphal elongation. From the evidence, these isolates of Acremonium are classified as endophytes and their relationship with the 'Balansioid' endophytes must be reconsidered.
Effect of clover-free rotations upon the severity of root rot and yield in regenerating subterranean clover pastures
Authors: Barbetti MJ
Published: November 2004

In two field trials, complete removal of subterranean clover for one season, or in particular two seasons, significantly reduced tap and lateral root disease in the immediate following year in which subterranean clover was allowed to regenerate. By the second season of regeneration these effects were either small or absent. Subterranean clover removal had greater effect on reducing lateral root disease than tap root disease in regenerating pastures. There were often large increases in plant size in regenerating pastures following complete removal of subterranean clover for one season or, in particular, two consecutive seasons. This effect also persisted poorly beyond the first season of regeneration. The losses in terms of subterranean clover herbage and seed yield during the period of subterranean clover removal were not offset by subsequent benefits from root disease reductions, as there was no corresponding increase in total herbage production. Subterranean clover removal had a variable effect upon the per cent subterranean clover v. grass ratio in regenerating pastures. Removal of subterranean clover for short periods (1 or 2 years) as an agronomic practice does not appear to be useful in overcoming root rot problems associated with this species in the high (> 750 mm) rainfall zone, the zone where severe root rot most frequently occurs in Western Australia.
Distribution of wild annual legume species in Morocco and relationship with soil and climatic factors
Authors: Beale PE , Lahlou A , Bounejmate M
Published: November 2004

Pods and seed of all annual legume species and a soil sample were collected within a 1 m2 sample area at each of 161 sites in Morocco, and the surrounding area of approximately 0.5 ha intensively searched for all species. This paper reports findings for all genera except Medicago and Trifolium which are the subject of separate papers. Annual legumes were found at 138 sites and 15 genera and 31 species were identified. Scorpiurus sulcata, the most prolific species, was found at 117 sites, followed by Astragalus hamosus (52 sites) and Hippocrepis unisiliquosa (30 sites). The distribution of the genera was related to pH, sand and clay content, altitude and rainfall, but very little to soil nutrient status. The highest pod yield was 890 kg/ha for Scorpiurus sulcata whilst Hedysarum coronarium had the highest average pod yield of 392 kg/ha but occurred at only 3 sites. Scorpiurus had the highest average pod yield of any genus that occurred at more than just a few sites. Overall pod yields were strongly related to sand and clay content of the soil, rainfall and minimum temperature and to a lesser extent, to altitude and soil potash. The most significant finding was the widespread distribution of Scorpiurus sulcata which did not appear to have any specific requirements for soil type, soil nutrient status, altitude or climate. The need to assess Scorpiurus sulcata as a potential pasture plant for Morocco and other areas of similar climate is clearly indicated.
Effect of rotation and inoculation with Bradyrhizobium on nitrogen fixation and yield of peanut (Arachis hypogaea L., cv. Virginia Bunch)
Authors: Peoples MB , Bell MJ , Bushby HVA
Published: November 2004

The effect of different rotational systems on symbiotic N2 fixation by, and yield of, peanut (Arachis hypogaea L. cv. Virginia Bunch) was determined over two growing seasons in southern Queensland. Estimates of N2fixation were obtained with the 15N natural abundance procedure by using a non-nodulating peanut genotype as a non-N2-fixing reference plant. Three rotational treatments were compared in both years. Crops were rainfed and dependent solely upon indigenous rhizobia for nodulation in the first season, but in the second, supplementary irrigation was supplied and portions of the trial were inoculated with three different rhizobial strains. Dry matter, crop N and pod yield were greatest in both years following a period of grass ley and lowest in a continuous peanut system. However, the proportion of the crop N derived from N2 fixation (PN2) was the same across all rotational and inoculation treatments, despite pre-sowing differences in the levels of soil nitrate and numbers of native rhizobia, and despite seasonal differences in the amounts of N mineralized. Proportions and amounts of N2 fixed were lower (22-31% and 32-57 kg N/ha, respectively) during the first year than under the better moisture conditions and lower concentrations of soil nitrate that prevailed in following season (44-48s and 82-120 kg N/ha). A greater proportion of fixed N was located in the pods and kernels (PN2 62-70%) than in the supporting shoot (PN2 13-21%) in the second year. When estimates of N2 fixation were compared with N removal in the pods at harvest, the net N balance suggested that soil N reserves had been depleted by 27-37 kg N/ha as a result of that season's peanut cropping.
A Periodic Table for Benzenoid Hydrocarbon Isomer Classes and Beyond
Authors: Dias Jerry Ray
Published: November 2004

The Periodic Table of Atomic Elements is a two-dimensional array (spreadsheet) generated according to an aufbau principle. As will be illustrated by a Formula Periodic Table for Benzenoid Hydrocarbons, this construction turns out to be more general than heretofore realized. These ‘super spreadsheets’ have a unique structure of their own, which contains chemical information in compact form. The concept of a periodic table set is like the concept of a group in mathematics. Once their respective criteria are fulfilled, one can anticipate their characteristic set properties. As such, a periodic table set is a useful mnemonic device for organizing, studying, and understanding property trends in large classes of related molecules. The Periodic Table for Benzenoid Hydrocarbons has organized this class of hydrocarbons into a systematic framework and has led to the identification of a new topological paradigm.
The Structure of Two 1-(Nitrophenyl)-Δ2-pyrazolines: a Crystallographic and Theoretical Study
Authors: Yap Glenn P. A. , Alkorta Ibon , Jagerovic Nadine , Elguero José
Published: November 2004

The crystal and molecular structures of two nitrophenylpyrazolines have been determined. The geometries have been used as starting geometries for density functional theory (DFT) calculations. The differences in conformation between both molecules and between the solid state and gas phase are explained in terms of steric effects. An attractive intramolecular N···N interaction between the nitro group and the pyrazoline N2 nitrogens has been found. Absolute shieldings have been calculated (GIAO) and compared with experimental 1H and 13C chemical shifts.
The Role of Virtual Screening in Computer Aided Structure-Based Drug Design
Authors: Branson Kim M. , Smith Brian J.
Published: November 2004

The pharmaceutical industry has embraced computational methods to improve the successful negotiation of hits and leads into drugs in the clinic. This review examines the current status of in silico screening methods and aspects of compound library design.
Bv8 and endocrine gland-derived vascular endothelial growth factor stimulate hematopoiesis and hematopoietic cell mobilization
Authors: LeCouter Jennifer , Zlot Constance , Tejada Max , Peale Franklin , Ferrara Napoleone
Published: November 2004

Bv8 and endocrine-gland-derived VEGF (EG-VEGF), or prokineticins, are two highly related, secreted proteins that we previously described as selective angiogenic mitogens. Here we describe the expression and functional characterization of Bv8 in peripheral blood cells, notably monocytes, neutrophils, and dendritic cells, and in the bone marrow. In human and mouse, the two Bv8 G protein-coupled receptors are expressed in hematopoietic stem cells and specific mature blood cells, including lymphocytes. Bv8 is highly expressed by neutrophils at sites of inflammation and can stimulate migration of monocytes, in a pertussis toxin-sensitive manner. Bv8, or EG-VEGF that shares the same receptors, increased numbers of colony-forming units granulocytic and monocytic in cultures of human or mouse hematopoietic stem cells. Systemic
in vivo
exposure to Bv8 or EG-VEGF resulted in significant increases in total leukocyte, neutrophil, and monocyte counts. Additionally, adenovirus (Av)Bv8 or AvEG-VEGF delivered just before 5-fluorouracil injury promoted the survival of hematopoietic cells and enhanced progenitor mobilization. In conclusion, Bv8 can promote survival and differentiation of the granulocytic and monocytic lineages. Bv8 potentially modulates growth, survival, and function of cells of the innate and adaptive immune systems, possibly through autocrine or paracrine signaling mechanisms.
TheArabidopsisPeroxisomal Targeting Signal Type 2 Receptor PEX7 Is Necessary for Peroxisome Function and Dependent on PEX5
Authors: Woodward Andrew W. , Bartel Bonnie
Published: November 2004

Plant peroxisomal proteins catalyze key metabolic reactions. Several peroxisome biogenesis PEROXIN (PEX) genes encode proteins acting in the import of targeted proteins necessary for these processes into the peroxisomal matrix. Most peroxisomal matrix proteins bear characterized Peroxisomal Targeting Signals (PTS1 or PTS2), which are bound by the receptors PEX5 or PEX7, respectively, for import into peroxisomes. Here we describe the isolation and characterization of an Arabidopsis peroxin mutant, pex7-1, which displays peroxisome-defective phenotypes including reduced PTS2 protein import. We also demonstrate that the pex5-1 PTS1 receptor mutant, which contains a lesion in a domain conserved among PEX7-binding proteins from various organisms, is defective not in PTS1 protein import, but rather in PTS2 protein import. Combining these mutations in a pex7-1 pex5-1 double mutant abolishes detectable PTS2 protein import and yields seedlings that are entirely sucrose-dependent for establishment, suggesting a severe block in peroxisomal fatty acid β-oxidation. Adult pex7-1 pex5-1 plants have reduced stature and bear abnormally shaped seeds, few of which are viable. The pex7-1 pex5-1 seedlings that germinate have dramatically fewer lateral roots and often display fused cotyledons, phenotypes associated with reduced auxin response. Thus PTS2-directed peroxisomal import is necessary for normal embryonic development, seedling establishment, and vegetative growth.