Computer-based crop simulation models (CSMs) are well entrenched as tools for a wide variety of research, development and extension applications. Despite this, critics remain and there are perceptions that CSMs have not contributed to impacts on-farm or in the research community, particularly with plant breeding. This study reviewed the literature, interviewed 45 stakeholders (modellers, institutional representatives and clients of modelling), and analysed the industry-funded project portfolio to ascertain the current state of use of CSMs in the grains industry in Australia, including scientific progress, impacts and development needs. We found that CSMs in Australia are widely used, with ∼100 active and independent users, ∼15 model developers, and at any one time ∼10 postgraduate students, chiefly across six public research institutions. The dominant platform used is APSIM (Agricultural Production Systems Simulator). It is widely used in the agronomic domain. Several cases were documented where CSM use had a demonstrable impact on farm and research practice. The updating of both plant and soil process routines in the models has slowed and even stalled in recent years, and scientific limitations to future use were identified: the soil–plant nitrogen cycle, root growth and function, soil surface water and residue dynamics, impact of temperature extremes on plant function, and up-to-date cultivar parameter sets. There was a widespread appreciation of and optimism for the potential of CSMs to assist with plant-breeding activities, such as environmental characterisation, trait assessment, and design of plant-breeding programs. However, we found little evidence of models or model output being used by plant breeders in Australia, despite significant impacts that have emerged recently in larger international breeding programs. Closer cooperation between geneticists, physiologists and breeders will allow gene-based approaches to characterise and parameterise cultivars in CSMs, demonstrated by recent progress with phenology in wheat. This will give models the ability to deal with a wider range of potential genotype × environment × management scenarios.

The common wheat variety Chinese Spring (CS) chromosome substitution line CS-1S^l(1B) was used in this study, in which the 1B chromosome in CS (Triticum aestivum L., 2n = 6x = 42, AABBDD) was substituted by the 1S^l from Aegilops longissima (2n = 2x = 14, S^lS^l). The results showed that the substitution of 1B in CS by 1S^l chromosome could significantly increase amylopectin and total starch contents. The dynamic changes in starch granules during grain development in CS and CS-1S^l(1B) demonstrated that the substitution line possessed higher amount of A-type starch granules and greater diameter of both A- and B-granules. qRT-PCR revealed that some key genes involved in starch biosynthesis, such as starch synthases (SSI, SSII and SSIII), starch branching enzymes (SBE IIa and SBE IIb) and granule-bound starch synthase (GBSS I), displayed higher transcript levels of mRNA expressions during grain development in CS-1S^l(1B). Our results indicate that the substituted 1S^l chromosome carries important genes that influence starch granule development and starch biosynthesis, which may be used as potential gene resources for improvement of wheat starch quality.

Approximately 70% of crop yield losses are caused by abiotic stresses, with drought being the most serious threat to crop production in many areas of the world. Plants have developed physiological and biochemical responses at multiple levels to allow them to grow and survive under drought stress. Among these, hydrophilins (BSPs, proteins soluble after boiling), representing 0.2% of the total genome, play an important role in the stress adaptation in plants. In this study, we examined the effect of drought on BSPs at different developmental stages of leaves and seeds in drought-tolerant (cv. PBW 175) and drought-susceptible (cv. PBW 621) cultivars of Triticum aestivum. The BSP profiles of seeds were outlined via SDS-PAGE followed by immunoblot analysis using anti-HSP (heat shock protein-90), anti-GST (glutathione S-transferases) and anti-p40 (protein 40). In SDS-PAGE profile, BSPs were detected in a genotype- and treatment-dependent manner. Notably, no BSPs were detected in shoots at any stage, whereas in seeds, many BSPs were detected, indicating organ-specific regulation of BSPs. In western blotting, the induced accumulation of protein bands Bsp40-51 and 59 and presence of differential band of BsHSP44 under drought conditions was observed only in tolerant cv. PBW 175, not in sensitive cv. PBW 621, indicating the roles of such proteins in drought-stress adaptation. BSPs were accumulated at different developmental stages in a cultivar- and stage-dependent manner. The induced expression of different BSPs under drought conditions in tolerant cv. PBW 175 implies the relevance of these BSPs under drought conditions. Notably, the different BSPs were also expressed under normal growth and developmental stages at 57 and 76 days post-anthesis, implying their key role in earlier stages and maturity of grain development.

The high carotenoid content in tritordeum (×Tritordeum Ascherson et Graebner) grains is derived from its wild parent, Hordeum chilense Roem. et Schulz. Phytoene synthase 1 (Psy1) is located on chromosome 7H^chS and plays a major role in this trait. This study investigates the impact of the introgression of chromosome 7H^ch into common wheat background on carotenoid composition, including xanthophylls esterified with fatty acids (monoesters and diesters). All of the genetic stocks carrying Psy1 from H. chilense increased their carotenoid content relative to common wheat. In addition, significant changes in the carotenoid profile were detected in different genetic stocks. The most relevant was the increase in content of lutein diesters when both 7H^ch and 7D were present, which indicates the existence of genes involved in the esterification of xanthophylls in both chromosomes. Furthermore, our results suggest that 7H^ch genes preferentially esterify lutein with palmitic acid, whereas 7D is either indifferent to the fatty acid or it prefers linoleic acid for lutein esterification. The involvement and complementarity of 7H^ch and 7D are highly significant considering the scarcity of previous results on lutein esterification in wheat.

Responses in spikelet fertility and grain weight to high temperature (HT) at anthesis and the relation to floral positions within a panicle were investigated using two HT-susceptible cultivars (Xieqingzao and Gang46) and two HT-tolerant cultivars (Qianjiang3 and Haunghuazan) under well-controlled climatic conditions. Results showed that effects of HT at anthesis were more adverse for spikelet fertility than for grain weight. The cultivar-dependent difference in spikelet fertility response to HT was mainly attributed to the extent of decrease in pollen viability for HT exposure. HT at anthesis impelled the flowering date of the florets on the middle and lower parts within a panicle, thereby resulting in shortened duration to floret-opening date and relatively concentrated floret-blossoming date. Change in spikelet fertility induced by HT was more notable than that caused by different grain positions, and the effect of HT on pollen viability was independent of the floret positions on the rachides within a panicle. Positional differences in spikelet fertility and grain weight under the HT regime were closely associated with the duration of HT exposure, in addition to differences in competing ability for supply of assimilates after successful fertilisation.

Transgenic glyphosate-resistant canola was first commercially grown in Western Australia (WA) in 2010, providing an opportunity to obtain important baseline data regarding the level of glyphosate resistance in weeds following the exclusive use of glyphosate for in-crop weed control. In this study, two surveys (2010 and 2011) were conducted across the 14 Mha of the grainbelt of WA. The 2010 survey was carried out at the late-flowering stage of glyphosate-resistant canola, whereas the 2011 survey was conducted at an earlier growth stage (6–8 leaves), ∼2–3 weeks after the second in-crop glyphosate application. During the surveys, 239 fields were visited, representing an estimated combined area of 24 000 ha. The 2011 survey alone represented a subsample of 23% of the total glyphosate-resistant canola planting in the WA grainbelt for that season. Glyphosate resistance was identified in one population of wild radish (Raphanus raphanistrum L.) and in eight annual ryegrass (Lolium rigidum L.) populations. None of the tested capeweed (Arctotheca calendula (L.) Levyns) populations were glyphosate-resistant. In this survey, no populations of barley grass (Hordeum spp.), brome grass (Bromus spp.), wild oat (Avena spp.) or small-flowered mallow (Malva parviflora L.) survived glyphosate application. Despite a long history of pre-seeding and fallow glyphosate use in WA, this survey found that glyphosate still provides excellent in-crop control of most species; however, some resistance is evident, requiring diverse weed control techniques to limit their spread.

The use of a TIMERITE^® spring spray to control redlegged earth mite (RLEM), Halotydeus destructor (Tucker) (Acari: Penthaleidae), in annual pastures was evaluated on farms across Australia. RLEM populations in autumn in the treatments sprayed in spring 1998 and 1999 were 97% lower in 1999 and 97% in 2000 in the western region (Western Australia), and 93% lower in 1999 and 93% in 2000 in the eastern region (Victoria, New South Wales and South Australia). At sites in the west, control of RLEM resulted in significant increases in subterranean clover seed yield in 1999 and in clover seedling numbers in autumn 1999 and 2000. Penthaleus major (blue oat mite) populations in autumn were 60% lower in sprayed treatments, but Sminthurus viridis (lucerne flea) populations were not affected. Differences in weather between the west (where there is a hot, dry summer) and the east (where temperature and rainfall regimes are more variable in spring and early summer) seem to cause greater RLEM control and greater benefits in subterranean clover seed yield and seedling numbers with a spring spray in the west.

Variety selection in perennial pasture crops involves identifying best varieties from data collected from multiple harvest times in field trials. For accurate selection, the statistical methods for analysing such data need to account for the spatial and temporal correlation typically present. This paper provides an approach for analysing multi-harvest data from variety selection trials in which there may be a large number of harvest times. Methods are presented for modelling the variety by harvest effects while accounting for the spatial and temporal correlation between observations. These methods provide an improvement in model fit compared to separate analyses for each harvest, and provide insight into variety by harvest interactions. The approach is illustrated using two traits from a lucerne variety selection trial. The proposed method provides variety predictions allowing for the natural sources of variation and correlation in multi-harvest data.

This research was carried out to determine stable genotypes and investigate genotype × environment interaction (GE) effects on the forage yields of 24 tall fescue genotypes (Lolium arundinaceum, syn. Festuca arundinacea Schreb.) across 14 test environments (combination of year, location and moisture conditions). The GGE biplot method was used to evaluate the phenotypic stability of forage yield in the studied genotypes. The GGE biplot analysis accounted for 75% of the G   GE variation. According to GGE biplot, in terms of performance, the genotypes were divided into two groups. The first group, with more than the average yield, included G20, G24, G04, G01, G22, G14, G10, G17 and G02. The second group included the remaining genotypes with below-average performance. From the seven foreign genotypes evaluated, G10 and G22 fell in the first group and the rest were clustered in the second group. In the first group, the performance of G24 (from Semnan province) was the most variable (the least stable), whereas the G20 and G14 (both from Isfahan province) were highly stable. In the second group, except for G08 and G16, the performance of genotypes was highly stable. The genotype G20 (from Isfahan province) had superior performance under all of the test environments, suggesting that it has a broad adaptation to the diverse environments. The results obtained in this study demonstrated the efficiency of the GGE biplot technique for selecting genotypes that are stable, high yielding, and responsive.

Italian ryegrass (Lolium multiflorum Lam.) is one of the most important temperate forage grasses on a global basis. The present study estimated trait variance, inter-trait correlation and broad-sense heritability (H²) for herbage yield, nutritive values and morphological characteristics of Italian ryegrass, and analysed associations between these traits and single nucleotide polymorphism (SNP) markers. A field-based, spaced-plant nursery experiment was conducted to assess 960 genotypes from seven cultivars and breeding lines, in a randomised complete block design with four replicates. Significant correlations, broad ranges of variation and significant genotypic variance components were identified for 18 measured phenotypic traits. Moderate H² estimates (0.36–0.52) were obtained for nutritive values, compared with low to high H² estimates (0.20–0.69) for yield over five cuttings, and moderate to high H² estimates (0.40–0.78) for morphological traits. Within- and among-cultivar variation ranged from 40.0% to 95.1% and 4.9% to 60.0%, respectively, depending on different traits. Association analysis identified 65 significant SNP–trait gene associations involving multiple genomic regions, which warrant further validation. The implications of trait correlation and heritability for selection and improvement are discussed.

Increasing lease and purchase costs for irrigated pasture are encouraging producers to use herbicides to control broadleaf weeds and maximise forage production on their current land base, as opposed to seeking out additional pastureland. There are two challenges to using herbicides to control broadleaf weeds in irrigated pasture. One challenge is that producers often encounter weed species for which herbicide information is limited or non-existent. Another challenge is that broadleaf herbicides tend to damage desirable legumes. We evaluated the efficacy of several broadleaf herbicide options for Symphyotrichum divaricatum, a species not previously the subject of research in irrigated pasture. Additionally, we monitored herbicide impacts on desirable legumes, principally Trifolium repens. We also evaluated control of Convolvulus arvensis and Plantago lanceolata, subjects of considerable herbicide research. Our goal was to identify herbicide options that controlled all three weeds while causing the least damage to legumes. Several rates and combinations of dicamba, diflufenzopyr, triclopyr, MCPA, and 2,4-D provided statistically indistinguishable control of C. arvensis and P. lanceolata, with point estimates suggesting 66–88% control in 2011 and 43–86% control in 2012. 2,4-D   triclopyr appeared to provide the best control of P. lanceolata and C. arvensis, with point estimates for high rates indicating nearly 100% control in both years. However, this combination was particularly damaging to legumes. Based on these findings, we recommend 2,4-D   triclopyr where desirable legumes are absent. Where desirable legumes are present, we recommend 2,4-D alone. Whereas 2,4-D alone appeared not to perform as well as 2,4-D   triclopyr at controlling S. divaricatum in 2012, it was less damaging to desirable legumes.