Genotype and environment effects on the chemical composition and rheological properties of field peas.

BACKGROUND: The inclusion of pulses in traditional wheat-based food products such as bread, cakes, and pasta is increasing as the food industry and consumers are recognizing the nutritional benefits due to high protein, antioxidant activity, and good sources of dietary fiber of pulses. In all crops, including cereals, oilseeds, and pulses, variability in chemical composition is known to exist due to genetic differences and environmental effects. This study reports the effect of genotype and environment on seed composition and the rheological properties of field-pea genotypes for both field-pea flour and isolated starch. RESULTS: Genotype had a significant effect on the chemical composition (protein, total starch, water-soluble carbohydrates, and phenolic compounds), the mean starch granule size, and rheological properties (peak viscosity, breakdown viscosity, final viscosity, peak time, and pasting temperature) of the field peas. The growing environment also had a significant effect on starch granule size, phytic acid, water-soluble carbohydrates, some phenolic compounds, and pasting characteristics of field peas. Genotype × environment (G × E) interactions were observed for protein, some phenolic compounds, and some pasting characteristics. CONCLUSION: Genotype and the growing environment had a significant effect on the chemical composition and rheological properties of the field pea. The variability in composition and quality traits could be exploited through plant breeding and optimized agronomic practices to increase production of field peas with the desired quality traits. © 2019 Society of Chemical Industry.

Elevated atmospheric [CO2 ] can dramatically increase wheat yields in semi-arid environments and buffer against heat waves.

Wheat production will be impacted by increasing concentration of atmospheric CO2 [CO2 ], which is expected to rise from about 400 µmol mol(-1) in 2015 to 550 µmol mol(-1) by 2050. Changes to plant physiology and crop responses from elevated [CO2 ] (e[CO2 ]) are well documented for some environments, but field-level responses in dryland Mediterranean environments with terminal drought and heat waves are scarce. The Australian Grains Free Air CO2 Enrichment facility was established to compare wheat (Triticum aestivum) growth and yield under ambient (~370 µmol(-1) in 2007) and e[CO2 ] (550 µmol(-1) ) in semi-arid environments. Experiments were undertaken at two dryland sites (Horsham and Walpeup) across three years with two cultivars, two sowing times and two irrigation treatments. Mean yield stimulation due to e[CO2 ] was 24% at Horsham and 53% at Walpeup, with some treatment responses greater than 70%, depending on environment. Under supplemental irrigation, e[CO2 ] stimulated yields at Horsham by 37% compared to 13% under rainfed conditions, showing that water limited growth and yield response to e[CO2 ]. Heat wave effects were ameliorated under e[CO2 ] as shown by reductions of 31% and 54% in screenings and 10% and 12% larger kernels (Horsham and Walpeup). Greatest yield stimulations occurred in the e[CO2 ] late sowing and heat stressed treatments, when supplied with more water. There were no clear differences in cultivar response due to e[CO2 ]. Multiple regression showed that yield response to e[CO2 ] depended on temperatures and water availability before and after anthesis. Thus, timing of temperature and water and the crop's ability to translocate carbohydrates to the grain postanthesis were all important in determining the e[CO2 ] response. The large responses to e[CO2 ] under dryland conditions have not been previously reported and underscore the need for field level research to provide mechanistic understanding for adapting crops to a changing climate.

Copper fungicide residues in Australian vineyard soils.

Copper (Cu) concentrations were measured in Australian vineyard soils to assess the extent and magnitude of Cu accumulation resulting from the use of Cu-based fungicides and to indicate the likely risks to long-term soil fertility. Soil samples were collected from 98 vineyards across 10 grape-growing regions of Australia and analyzed for total Cu concentrations. Ninety-six percent of vineyards surveyed had elevated Cu concentrations in soil compared to the background Cu concentrations in nearby soil in its native state. Concentrations of total B, Co, Cr, Pb, and Zn were similar to background concentrations and below reported toxicity guideline values. Cu concentrations in Australian vineyard soils were generally much lower (6-150 mg kg (-1)) than those reported in the soils of vineyards in parts of Europe (i.e., 130-1280 mg kg (-1)). Concentrations of total Cu were generally below those concentrations reported to cause lethal effects to soil invertebrates; however, Cu exceeded concentrations known to cause sublethal effects (i.e., inhibit growth, affect reproduction, induce avoidance behavior) to those (or related) invertebrates.