Seed priming is a presowing technique in which seeds are moderately hydrated to the point where pregermination metabolic processes begin without actual germination. Seeds are then redried to near their actual weight for normal handling. Seeds can be soaked in tap water (hydropriming), aerated low-water potential solutions of polyethylene glycol or salt solutions (KNO₃, KH₂PO₄, KCl, NaCl, CaCl₂ or MgSO₄; osmopriming), plant growth regulators, polyamines (hormonal priming), plant growth-promoting bacteria (biopriming), macro or micronutrients (nutripriming) or some plant-based natural extracts. Here, we review: (1) seed priming as a simple and effective approach for improving stand establishment, economic yields and tolerance to biotic and abiotic stresses in various crops by inducing a series of biochemical, physiological, molecular and subcellular changes in plants; (2) the tendency for seed priming to reduce the longevity of high-vigour seeds and improve the longevity of low-vigour seeds; (3) the advantages of physical methods of seed priming to enhance plant production over conventional methods based on the application of different chemical substances; (4) the various physical methods (e.g. magneto-priming and ionising radiation, including gamma rays, ultraviolet (UV) rays (UVA, UVC) and X-rays) available that are the most promising presowing seed treatments to improve crop productivity under stressful conditions; and (5) effective seed priming techniques for micronutrient delivery at planting in field crops. Seed priming as a cost-effective approach is being used for different crops and in different countries to improve yield, as a complementary strategy to grain biofortification and in genetically improved crop varieties to enhance their performance under stress conditions, including submergence and low phosphorus. Some of the challenges to the broad commercial adaption of seed priming include longevity of seeds after conventional types of priming under ambient storage conditions and a lack of studies on hermetic packaging materials for extended storage.

Winter wheat (Triticum aestivum L.) production in the North China Plain (NCP) is threatened by wheat lodging. Therefore, enhancing plant lodging resistance by improving stem quality traits is crucial to maintaining high stable yields of winter wheat. A consecutive 7-year field experiment was conducted to study the effects of stem traits on lodging resistance and the yield of four winter wheat cultivars (Bainong 418, Aikang 58, Wenmai 6 and Zhoumai 18). The results indicated that rainfall is often accompanied by strong winds that can cause lodging in the field. Stalk bending strength and wall thickness of the second internode showed significant negative correlations with lodging index, and a higher lodging index indicated increased lodging risk, which, in turn, could seriously affect the grain yield of wheat. Significant regression relationships were observed between lodging index and population lodging resistance strength, as measured using a crop lodging resistance electronic measuring device. Statistical analysis revealed that yield components and the grain yield of Bainong 418 were higher than those of the other cultivars; there was no significant difference between Bainong 418 and Aikang 58 in lodging index, stalk bending strength or single-stalk and population lodging resistance strengths at anthesis and the middle filling stages, but the mean plant height of Bainong 418 was significantly higher than that of Aikang 58. These results provide a new and reliable method for assessing lodging resistance capacity and indicate that greater lodging resistance, as determined by simultaneously considering plant height and basal stem strength, is an important way to achieve high, stable yield in winter wheat.

Multi-ovary wheat is a unique variety of wheat that has one to three pistils and three stamens, and can stably set one to three grains in each floret. By observing the developmental process of additional pistils, we found that the additional pistil was derived from a protrusion generated at the base of the main pistil, between the frontal stamen and lateral stamen. The additional pistil’s development was greatly delayed compared with the main pistil at an early stage. However, after the awn exposed stage, it developed very rapidly to a mature pistil within the maturity time of the main pistil. Generally, the grains originating from additional pistils were smaller than the grains from the main pistil. By studying the penetrance and germination conditions of multi-ovary wheat, we found that no matter which ovary the grains originated from, they had the same penetrance. However, the germination ability of grains generated from the main pistil was significantly higher than that of grains from additional pistils. Our results showed that multi-ovary wheat was an excellent variety, not only for studying the mechanisms of the multi-ovary trait and floral development in wheat, but also for improving the propagation coefficient and promoting the progress of wheat breeding. This paper lays a theoretical foundation for the practical application of multi-ovary trait in hybrid wheat; our results could be implemented in fostering future breeding activities focussed on the development of high yield wheat cultivars.

The use of cereals as forage crops is limited due to the high lignin content in the cell walls reducing nutrient digestibility. Recent research has focused on reducing lignification in forage crops through gene mutations. This study investigated the ruminal fermentation characteristics of a barley mutation (orange lemma), which is associated with a lower lignin content, using the in vitro ruminal fermentation system (RUSITEC). Two-rowed spring barley cv. ‘Optic’ and its ethyl methane sulfonate (EMS)-induced orange lemma (rob1) mutant line were harvested at both stem elongation and early fruit development and incubated in the RUSITEC system. Gas production, concentrations of short-chain fatty acids (SCFA) and ammonia and the nutrient degradation of the plants after 48 h incubation were investigated. Additional samples were analysed for microbial composition using MiSeq sequencing technology. In general, acid detergent lignin (ADL) was higher at early grain filling than stem elongation. ADL was lower in the mutant line than in the wild type at both stem elongation (13.9% vs 18.5%) and early grain development (26.0% vs 28.6%; dry matter basis). This was reflected in increased ruminal degradation of neutral detergent fibre (61.7% vs 53.7%; P < 0.001) when harvested at stem elongation, but not at the later stage. In contrast, methane formation was lower with rob1 than ‘Optic’ (P = 0.002), especially when harvested at stem elongation. No difference was seen in protein degradation between the barley genotypes. The fermentation SCFA profile did not differ between barley genotypes when harvested at stem elongation, but at early fruit development more acetate and less butyrate was produced with rob1. Microbial species richness was lower when barley was incubated at stem elongation compared to fruit development (P < 0.001), which was especially pronounced with rob1 (P = 0.026). The abundance of Bacteroidetes, Synergistetes and Tenericutes was lower when plants harvested at early grain development were incubated compared to the stem elongation stage, whereas the abundance of Cyanobacteria, Elusimicrobia, Fusobacteria, Lentisphaerae, Proteobacteria, Verrucomicrobia and WPS-2 was higher (P < 0.001). In conclusion, most fermentation parameters were affected by vegetation stage and related changes in nutrient composition. However, additional effects of barley genotype were seen on the rumen microbial community structure, SCFA profile and methane production.

Barley grass (Hordeum spp.) is a relatively short lived annual that provides high quality grazing early in the season, but its seed heads cause contamination of wool and carcasses, and may irritate the mouth, eyes and nose of sheep. Treatments were imposed on established subterranean clover (Trifolium subterraneum L.) annual pasture in the same plots for three consecutive years (2015 to 2017) to evaluate changes in barley grass content. Treatments included: grazing alone (G), herbicide followed by grazing (HG), or a forage conservation harvest in early October, late October or early November consistent with an early silage harvest (ES), late silage harvest (LS) or hay cut (H). Grazing plus herbicide markedly reduced (P < 0.05) barley grass numbers compared with all other treatments, but increased (P < 0.05) the growth of annual ryegrass (Lolium rigidum L.). ES reduced (P < 0.05) barley grass and increased (P < 0.05) subterranean clover compared with H, but broadleaf weed content benefitted by LS in contrast to either ES or H. Although herbicide application was the most effective method for barley grass control, forage harvest timing could be used to beneficially manipulate pasture composition.

Flax-leaf alyssum (Alyssum linifolium Steph. ex. Willd.) is a winter growing annual weed species widely distributed in many semi-arid cropping regions of Iran, especially in the Khorasan Razavi and East Azerbaijan provinces. The germination of two populations (one each from Khorasan Razavi and East Azerbaijan) of this weed was evaluated under different experimental conditions. Seeds of A. linifolium germinated over a wide range of day/night temperature regimes, with the highest germination percentage observed with a regimen of 20°C/10°C. Light was not required for germination for either population, and >70% seeds germinated under all photoperiods tested. Germination was affected by pH levels; seeds germinated over the pH range 4–9 and germination was maximum at pH 7. For the Khorasan Razavi and East Azerbaijan populations, ≥50% of seeds germinated at a water potential of –0.69 and –0.78 MPa and salinity of 12.64 and 11.7 dS m^–1 respectively. Maximum seedling emergence occurred when seeds were slightly covered with soil, but emergence decreased with increasing depth of soil cover, with no emergence at depths >3 cm. These results indicate that A. linifolium germinates in a wide range of climatic conditions and could invade into new regions. Burying the seeds through tillage may reduce their emergence.

One of the main challenges of using a silvopastoral system (SPS) is maintaining pasture and animal productivity over time. Our objective was to compare the productive characteristics and nutritive value of signal grass (Brachiaria decumbens cv. Basilisk) and the liveweight gain of dairy heifers in a SPS and open pasture (OP, signal grass under full sunlight) during the rainy seasons of four experiments between 2003 and 2016, which characterised systems from their 6th to 19th years after establishment in south-eastern Brazil when analysed together. The experimental design was a randomised complete block in a 2 × 4 factorial scheme (two production systems (SPS and OP) and four experiments (2003–2004, 2004–2007, 2011–2014 and 2014–2016)). From the 7th year onwards, the progressive reduction of photosynthetically active radiation negatively impacted the productive characteristics of the SPS pasture. Total forage mass was reduced by 19% in SPS compared with the OP in 2004–2007, 38% in 2011–2014 and 31% in 2014–2016. Crude protein content was 23% and 30% higher in the SPS than in the OP in 2011–2014 and 2014–2016, respectively. However, during the study period (until the 19th year), the liveweight gain of heifers was similar between systems since the higher crude protein content available in SPS contributed to improved forage nutritional value. From the 17th to the 19th year, weight gain per area was lower in the SPS compared with the OP (169 vs 199 kg ha^–1), although the difference between systems was small. Signal grass presents a high degree of phenotypic plasticity in response to changes in shade levels, which gives this species a high potential for use in SPS.