Salinity is one of the major abiotic stresses that lead to loss of billions of dollars in crop production worldwide. The growth of rice plant is severely affected and subsequently the yield is generally low in salt affected areas. Salinity affects rice primarily at the early vegetative stage by interfering with biochemical and physiological processes governing its growth and development. This review aims at summarising various morphological, physiological, biochemical, and molecular-based methods that are currently used in screening salt-tolerant rice genotypes at different growth stages with particular emphasis on screening of breeding lines, and also the effectiveness of these methods. Field and laboratory-based methods are described including visual screening of salt-induced injuries as per the IRRI’s standard evaluation system, salt-induced accumulation of ions, changes in the levels of photosynthetic pigments, antioxidant, and image-based visual quantification of injuries, and molecular markers-based screening, which are lengthy and cumbersome. Among these methods currently available, this review highlights IC₅₀ (50% inhibition concentration) estimation of shoot growth inhibition as a rapid and accurate method that can differentiate genotypes with the IC₅₀ difference of only a few mm NaCl for the initial screening of a large number of rice germplasm and breeding lines.

A single measurement is useful for determining how far a crop has progressed through grain development, and whether it has reached physiological maturity. Grain development is commonly assessed by using subjective, qualitative methods that describe the look and feel of the kernel or the colour of the straw. Physiological maturity in cereal crops can be determined more accurately by the grain moisture content; however, the moisture content of whole spikes is potentially quicker and easier to assess than that of individual kernels, and with a greater degree of accuracy. This experiment aimed to characterise the moisture dynamics of whole intact wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) spikes during the grain development phase and identify the spike moisture content corresponding to physiological maturity for both species. The dry matter and water contents of whole spikes of five wheat and five barley cultivars sown over six dates were determined at weekly intervals throughout the period of grain development from anthesis to harvest ripeness. Use of regression analysis determined that the spike moisture content at physiological maturity was 43% (95% confidence interval 41–45%) for wheat and 50% (95% confidence interval 49–51%) for barley, irrespective of differences in cultivar morphology, phenology and growing conditions. We demonstrate that progression through kernel development in wheat and barley can be assessed objectively and quantitatively by using spike moisture content, and we provide guidelines for accurate determination of the grain development stage using spike moisture.

Stem strength is critical for lodging resistance in wheat. The present study utilised a high-density genetic map generated with a 50K single-nucleotide polymorphism (SNP) chip to map quantitative trait loci (QTLs) for stem-related traits. The analysis involved 198 recombinant inbred lines (RILs) derived from the cross between bread wheat (Triticum aestivum L.) varieties Xinong1376 and Xiaoyan81. The RILs were planted in randomised complete blocks with two replicates at three locations. The constructed genetic map contained 13571 SNP markers spanning 3605.53 cM across the 21 wheat chromosomes. The genetic and physical positions of SNP markers in 28 linkage groups were approximately the same. Twelve major QTLs related to stem strength were detected for eight traits and were distributed on chromosomes 2D (three QTLs), 3A, 4B, 4D (three QTLs), 5A, 5B, 5D and 6B. Each QTL explained 0.6-34.6% of the phenotypic variation. Taking full advantage of the available resources for fine-mapping of these stable QTLs will benefit molecular marker-assisted breeding and facilitate the dissection of molecular regulatory mechanisms underlying the mechanical properties of the wheat stem.

Improvement of the nutritional quality of wheat (Triticum aestivum L.) has been quite challenging, due, in part, to the limited variation found in modern cultivars and the strong effect exerted by the environment, which hinder the selection process. The aim of this study was to characterise the mineral profile of grains of 35 Argentinean-adapted, mostly spring wheat cultivars in two successive years. Concentrations of most mineral nutrients in grains spanned approximately a two-fold range. Our study revealed a strong effect of the environment, but also that some key differences among genotypes are maintained over years. Correlation and principal component analyses showed the existence of a strong and stable association of variables determining the global elemental profile in grains of the wheat lines under analysis. In this regard, some cultivars displayed, over successive years, opposite global patterns of elemental composition, suggesting the existence of a genotype dependent ionome signature. Important negative correlations were found for the concentration of most, but not all, nutrients with yield, thus indicating a potential compromise among beneficial traits. The genotypic variation characterised in the present study has potential to be used in breeding programs aimed at improving wheat grain quality.

ERECTAs are receptor-like kinases that regulate plant biomass and stress resistance. In this study, the wheat (Triticum aestivum) TaERECTA gene was used as a probe to identify the SbERECTA family genes (SbERs) in the sorghum (Sorghum bicolor) genome, analyse their subcellular localisation and characterise their expression. Results showed that the two SbER members, SbER10 with three copies (SbER10_X1, SbER10_X2, and SbER10_X3) and SbER4 with two copies (SbER4_X1 and SbER4_X2), were found on chromosomes 10 and 4 of sorghum, respectively. SbER10 had the highest expression level in the pedicel tissue and showed a remarkable response under treatment with abscisic acid, brassinolide, gibberellin and indole-3-acetic acid. SbER10_X1, functioning on the cell membrane and chloroplast, exhibited abundant transcript in only a few sorghum varieties that are grown in mountainous areas and receive strong light, heat, and water supply. Expression of SbER10_X1 was significantly and positively correlated with plant biomass of 32 sorghum germplasm resources. These results indicate that SbER10 genes have an important regulatory role in sorghum growth, and increasing SbER10 transcription level offers a potential strategic target for breeding or biotechnological approaches to enhance sorghum biomass and environmental adaptability.

Chickpeas (Cicer arietinum L.) are a high value crop for farmers, but price penalties will be imposed or grain rejected whenever the standards are not met by growers whose crops suffer grain defects in a particular season. Australian chickpeas are renowned for their high quality and are generally in high demand globally because of good farming practice and strict grain quality standards. However, small quantities of defective seed in grain loads can reduce the price paid to individual farmers, with significant financial impacts. Information is scarce on the types of defects causing price penalties and there is no information on the magnitude of those penalties. An online farmer survey was conducted to capture information on the types of grain defects, price penalties imposed and load rejections with respect to the delivery of their 2017 chickpea crop. Here we show that the cost to individual chickpea farmers affected by price penalties or load rejections ranged from AU$743 to $1 293 750. Furthermore, the total cost of seed defects was calculated to be $154.2 million in that season, equating to a revenue loss of 23.7% of gross value of production in Australia. Chickpea seed defects also contributed to additional costs including seed cleaning, further transport costs and harvest delays, with subsequent risk of yield losses and further quality defects. Too often, crop yields are the focus while seed quality is overlooked as an essential driver of farmer profitability. We demonstrate how important seed quality is to farmer profitability; if ‘yield is King’ then seed quality is certainly Queen. We suggest that farmers prioritise harvest of their chickpea crops ahead of harvest of cereal crops to minimise the risk of chickpea seed defects and seed loss, and to maximise profits from this higher value crop. Additional surveys over several seasons are warranted to refine information on the types of seed defects occurring in chickpea and their financial impacts on farmers, and they could be expanded to other crops and countries. We suggest that misclassification of seed defects needs further exploration, as does research into minimising the major causes of seed defects. Improvements to grain classification systems globally should be sought to provide better support for farmer profitability so that they can continue to feed the world.

The ability to quantify inoculum levels of the soilborne fungal pathogen Verticillium dahliae in field soil is essential for understanding potential disease pressure of Verticillium wilt in cotton and for making informed management decisions. Several semi-selective media and techniques for pathogen isolation have been developed for determining the inoculum levels of V. dahliae present in soil. The objective of this study was to gather data on soil plating techniques, media, sampling depths, and times of sampling for the detection and quantification of V. dahliae in field soils, in order to develop a V. dahliae isolation protocol for Australian cotton-growing soils. Two soil plating techniques (dilution plating or ‘wet plating’, and direct spreading by hand or ‘dry plating’) on four semi-selective media (Sorenson’s NP-10, potato dextrose agar, and acidified versions of each) were compared for their efficacy in quantifying soil inoculum as germinated microsclerotia propagules per gram soil. Soil was sampled from three depths to examine the vertical distribution of the fungus and so determine the ideal sampling depth. Field soil sampling was conducted pre-planting and post-harvest to examine differences in inoculum with sampling time. Based on the results of this study, a soil sampling protocol has been developed for Australian cotton farms that includes sampling soil before planting, at a depth of 2–24 cm, and using the direct dry plating method on Sorenson’s NP-10 media.

The aphid Aploneura lentisci is widespread in Australia and New Zealand, living all year round on roots of its secondary grass hosts. The fungal endophyte (Epichloë festucae var. lolii), strain AR37 in Lolium perenne is known to greatly reduce populations and was a likely reason for the superior growth and persistence of this association previously observed in the field. Aphid populations were quantified in a field trial near Ballarat, comparing yields of perennial ryegrass infected with eight different endophyte strains and an endophyte-free (Nil) control in a common ryegrass background (Grasslands Samson (G. Samson)). AR37 and another endophyte strain, AR5, had significantly fewer aphids than all other endophytes. These differences were significantly related to yield increases taken before and after sampling that persisted until the end of the trial. In a pot trial comparing commercially available ryegrass-endophyte combinations with equivalent Nil controls, aphid numbers were lower on G. Samson AR37 and Banquet II with AR5 (Endo®5) than on all other cultivar-endophyte combinations. Compared with Nil controls, the common toxic strain in G. Samson, and two strains in Trojan also reduced aphid numbers. The AR5 endophyte produces the alkaloid ergovaline but high concentrations of this in roots of potted plants could not account for differences in root aphid numbers. Root concentrations of epoxyjanthitrems, the only known alkaloids produced by AR37, were low and unlikely to be the cause of resistance to A. lentisci.