Reduced height (Rht) alleles, commonly known as the ‘Green Revolution’ genes, have facilitated wheat breeding programs and achieved globally a more than 10% wheat yield increase. However, studies in barley indicate that shorter plant habits are associated with reduced seed vigour and longevity. Therefore, wheat seeds of six near-isogenic lines (NIL) carrying the dwarfing alleles Rht-B1b, Rht-D1b, Rht-B1c, Rht-B1b -D1b, Rht-B1c -D1b and the wild-type allele Rht-B1a -D1a, each in four background cultivars, were stressed by controlled deterioration. Seed vigour expressed as root and shoot lengths, time to 50% (T50) and time between 16 and 84% (T16-84) germination showed significant changes after treatment. However, after controlled deterioration only a combination of Rht alleles highly affected T16-84 and T50, which followed the general pattern Rht-B1c -D1b followed by > Rht-B1c > Rht-B1b -D1b > Rht-B1b > Rht D1b = Rht-B1a -D1a (wild type). Interestingly, only under control conditions seed vigour correlated positively with thousand-kernel weight, which decreased with severity of Rht type. Further, the seed length was not affected by the different NIL. In conclusion, NIL carrying combinations of Rht alleles tend to influence seed vigour, which could influence seed longevity. Therefore, plant breeders but especially genebank managers should consider that the genetic background of genotypes may affect seed deterioration processes, which could be an economically important aspect in future.

The 1BL.1RS chromosomal translocation in wheat is the result of replacement of the short arm of chromosome 1B of wheat by the short arm of chromosome 1R of rye, which had been widely used as a parental line in worldwide wheat breeding, resulting in a high percentage of wheat cultivars containing this translocation. A fast and reliable approach to identify this translocation is highly desirable in modern wheat breeding. This study compared reversed-phase ultra-performance liquid chromatography (RP-UPLC), acidic polyacrylamide gel electrophoresis (A-PAGE), liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), allelic-specific PCR, and reversed-phase high-performance liquid chromatography (RP-HPLC) approaches to identify the 1BL.1RS translocation in 76 bread wheat cultivars. Two gliadin bands in the Gli-B1 region of A-PAGE separation were confirmed by LC-MS/MS to be omega secalins from the 1BL.1RS translocation, and they can be used as reliable protein markers for identifying the translocation. A few specific minor peaks eluted at 12–13 min on the RP-UPLC patterns can readily differentiate the 1BL.1RS translocation. Of the 76 wheat cultivars tested, 40 were identified as carrying the 1BL.1RS translocation by RP-UPLC, which was consistent with the results of A-PAGE, HPLC, and PCR. Compared with other established methods, RP-UPLC showed a clear advantage in fast identification of the 1BL.1RS translocation with higher reliability and lower costs, and it is therefore ideal for large-scale screening of the 1BL.1RS translocation in wheat breeding.

Triticale (Triticosecale × Wittmack) is a high yielding cereal crop with the potential to increase grain production for human food in the coming decades. The quality of triticale flour is usually intermediate between its progenitor species; however, there are considerable differences in quality and response to agronomic conditions among cultivars. The aim of this research was to quantify existing genetic variation to provide preliminary data for classification of triticale cultivars for a milling market. Eleven triticale cultivars from three growing environments were compared with five wheat cultivars bred for various end users. Average protein content, milling yield, thousand-kernel weight, test weight, hardness, colour and ash content supported previous reports. One cultivar was identified with grain hardness and milling yield equivalent to durum wheat, suggesting a null allele at the rye softness protein locus. Ash content was higher than wheat, particularly in the flour despite lower extraction rates, suggesting triticale naturally stores more minerals in its endosperm and the benchmark for milling-grade triticale should be higher than the standard for wheat. Cookie dough weight of triticale was significantly lower per unit volume, indicating current baking processes must be altered to deal with the generally poor water retention of triticale. Significant differences were observed among cultivars for cookie quality and some produced cookies equivalent to soft wheat. There is a clear need to classify cultivars into suitability for various end users to facilitate production and marketing of quality triticale.

Arbuscular mycorrhizal (AM) fungi are known to facilitate effective acquisition of phosphorus (P) by host plants in low P soils. However, the contribution of mycorrhizal traits to high P-use efficiency in modern-bred maize genotypes is still not clear. In the present study one backcross maize inbred line 224 (bred for high P-use efficiency) was used as the host plant associated with AM fungal species (Rhizophagus irregularis or Glomus mosseae) grown at a range of soil P treatments (10, 20, 30, 40, 50, 100 mg P kg^–1, Experiment 1) or foliar P applications (0, 0.025%, 0.5% m/v, Experiment 2). The experiments were to test the hypothesis whether the change point of the mycorrhizal growth and P responsiveness of 224, as well as the expression of ZEAma;Pht1;6 was at or near the optimal P supply level. In addition, different AM inoculants might differ in regulating P uptake of the host. Our results indicated that inbred line 224 was highly responsive to mycorrhizal inoculation. In Experiment 1, root colonisation rate, hyphal length density and alkaline phosphatase increased with the increase of soil P supply level. However, the mycorrhizal growth response (MGR) and P accumulation in shoot (MPR) were greatly affected by soil P supply level and varied between the two fungal species. Maize plants exhibited higher MGR and MPR at lower P supply when inoculated with R. irregularis, and at intermediate P supply when inoculated with G. mosseae. In Experiment 2, shoot P uptake was significantly increased by foliar P supply and inoculation, whereas shoot growth was significantly affected by P supply and the interaction. The expression of the AM-inducible Pi transporter gene ZEAma;Pht1;6 was neither significantly affected by soil (except at 100 mg P kg^–1, Experiment 1) or foliar P supply level, nor by fungal species. Root P uptake efficiency (RPUE) was generally greatly increased by mycorrhizal colonisation at all P supply levels in both experiments, and significant correlations were observed between mycorrhizal variables and RPUE in Experiment 1. Our results indicate that the formation of mycorrhizal association could increase RPUE and thus may be partly attributed to high P-use efficiency of inbred line 224. The different responsiveness of mycorrhizal fungi to soil-available P implies the importance for the development of precision strategies to optimise the potential function of AM fungi under different P fertilisation management regime in agricultural soils.

Resistance of sugarcane plants to smut is believed to be manifested by two mechanisms, (i) external resistance, governed by structural barrier of bud scale and/or chemical secretion from the bud, and (ii) internal resistance, regulated by interaction of plants and fungus within the plant tissue. Hot water treatments are routinely used to treat seed cane to eliminate a range of diseases including smut. It is believed that hot water treatment predisposes sugarcane plant to smut. This study was conducted to determine the resistance mechanisms of some important Australian parent clones, and their response to hot water treatment in relation to smut infection. Twenty-one clones, used regularly in the Australian sugarcane breeding program, were evaluated. Results showed that ∼47% of clones had external and 33% had internal resistance mechanisms, indicating that parent clones selected for this study possessed diverse mechanism of resistance. There is a possibility some or all clones with internal resistance mechanisms could also possess external resistance mechanism. Except one highly susceptible clone (Q205) in one trial, none of the clones subject to hot water treatment became more susceptible to smut. Although some clones showed increased resistance after hot water treatment. These findings will benefit breeders in selecting parent materials in their crossing programs to develop smut-resistant cultivars.

Average yield of canola in the high-rainfall zone (HRZ) of southern Australia are about half the predicted potential yield based on seasonal water supply. Current cultivars of canola that are available to growers were not bred specifically for the HRZ and tend to be short-season types aimed at escaping water stress during grain filling in the drier regions of the cropping belt. In the HRZ, these cultivars fail to utilise all available growing-season water due to early maturity. Field experimentation and crop simulation studies across the HRZ landscape of south-eastern Australia were used to determine the increased yield potential of longer-season canola cultivars compared with short-season cultivars. In this study the Catchment Analysis Tool spatial modelling framework was used to determine the expected canola yields of three cultivars across the entire HRZ of south-eastern Australia. Hyola50 (‘spring-short’) was used to represent the current recommended spring-type canola cultivar within the HRZ and was evaluated against an unreleased long-season spring-type cultivar CBI8802 (‘spring-long’) and a newly released winter-type cultivar Taurus (‘winter’). Spring-long outperformed spring-short across much of the study area. Yield advantages of winter over spring-short were mainly confined to the coastal fringe of Victoria and Tasmania and small pockets in New South Wales where at one location the average yield over 50 growing seasons exceeded spring-short by up to 60% or 1.4 t/ha. The superior performance of spring-long, (up to 17% or 0.9 t/ha at one location) was over a wider area than winter (26.4 compared with 8.8 million ha for winter) and although the magnitude of the yield increase over spring-short was not as great as winter at some locations, the overall result determined that spring-long had the greater production potential. The superior performance of spring-long beyond the HRZ challenges the trend of selecting earlier maturing cultivars by current breeders following the abnormal sequence of dry years in an attempt to minimise yield loss due to water stress during grain filling. This study has provided breeders, growers and advisors with information on where in the HRZ a longer-season canola cultivar can be grown to improve overall crop productivity. It has also provided evidence that new canola types may be required to maximise grain yields not only for the HRZ but potentially also in lower rainfall regions.

White lupin (Lupinus albus L.) is an important grain legume crop in Australia. The anthracnose incursion in the mid-1990s wiped out the white lupin industry in Western Australia (WA). Since then, incorporation of anthracnose resistance has been a major focus in white lupin breeding. After a series of experiments and targeted breeding in WA, high-yielding anthracnose-resistant genotypes were developed. One of these lines, Amira, was released in 2012 as a replacement for the then-benchmark variety Andromeda. Amira is high-yielding and early-maturing and it has substantially improved resistance to anthracnose compared with Andromeda. Its yield and grain quality are similar to Kiev Mutant and it will be suitable for growing in parts of the Northern Agricultural Region of WA where anthracnose risk is moderate to low. With the adoption of this new variety, reliable production of white lupin can recommence in WA. The growing season in WA is characterised by terminal drought, and early flowering is as important as anthracnose resistance. However, combining these traits was difficult and their combination was not achieved at a desired level in earlier work. The incorporation of the early-flowering trait from a different genetic source from France demonstrated that it is possible to combine these traits at an appropriate level. There was no genetic linkage between the two traits, and consequently, new genotypes with earlier phenology and higher levels of resistance than Amira were developed. The combination of early flowering and anthracnose resistance represents a breakthrough that will significantly improve the adaptation and profitability of white lupin production in WA.

The majority of rain used by winter grain crops in the Mallee region of Victoria, Australia, falls during the cooler months of the year (April–October). However, rain falling during the summer fallow period (November–March) and stored as soil moisture contributes to grain yield. Strategies to better capture and store summer fallow rain include (i) retention of crop residues on the soil surface to improve water infiltration and evaporation; and (ii) chemical or mechanical control of summer fallow weeds to reduce transpiration. Despite the widespread adoption of no-till farming systems in the region, few published studies have considered the benefits of residue management during the summer fallow relative to weed control, and none quantify the impacts or identify the mechanisms by which summer fallow weeds influence subsequent crop yield.

Over 3 years (2009–11), identical experiments on adjacent sand and clay soil types at Hopetoun in the southern Mallee were conducted to quantify the effect of residue management (standing, removed, or slashed) and summer fallow weed control (± chemical control) compared with cultivation on soil water and nitrogen (N) accumulation and subsequent crop yield. The presence of residue (2.4–5.8 t/ha) had no effect on soil water accumulation and a small negative effect on grain yield on the clay soil in 2011. Controlling summer weeds (Heliotropium europaeum and volunteer crop species) increased soil water accumulation (mean 45 mm) and mineral N (mean 45 kg/ha) before sowing on both soil types in 2 years of the experiment with significant amounts of summer fallow rain (2010 and 2011). Control of summer weeds increased grain yield of canola by 0.6 t/ha in 2010 and wheat by 1.4 t/ha in 2011. Using the data from these experiments to parameterise the APSIM model, simulation of selected treatments using historical climate data (1958–2011) showed that an extra 40 mm of stored soil water resulted in an average additional 0.4 t/ha yield, most of which was achieved in dry growing seasons. An additional 40 kg/ha N increased yield only in wetter growing seasons (mean 0.4 t/ha on both soil types). The combination of extra water and N that was found experimentally to result from control of summer fallow weeds increased subsequent crop yield in all season types (mean 0.7 t/ha on sand, 0.9 t/ha on clay). The co-limitation of yield by water and N in the Mallee environment means that yield increases due to summer weed control (and thus returns on investment) are very reliable.

Thirteen current and potential pasture species in southern Australia were examined for differences in their nutritive values and in vitro rumen fermentation profiles, including methane production by rumen microbes, to assist in selection of pasture species for mitigation of methane emission from ruminant livestock. Plants were grown in a glasshouse and harvested at 7 and 11 weeks after sowing for in vitro batch fermentation, with nutritive values assessed at 11 weeks of growth. The pasture species tested differed significantly (P < 0.001) in methane production during in vitro rumen fermentation, with the lowest methane-producing species, Biserrula pelecinus L., producing 90% less methane (4 mL CH₄ g^–1 dry matter incubated) than the highest methane-producing species, Trifolium spumosum L. (51 mL CH₄ g^–1 dry matter incubated). Proxy nutritive values of species were found not to be useful predictors of plant fermentation characteristics or methane production. In conclusion, there were significant differences in fermentative traits, including methane production, among selected pasture species in Australia, indicating that the choice of fodder species may offer a way to reduce the impact on the environment from enteric fermentation.