Cultivar Differences Research Articles

Cultivar Differences on Nutraceuticals of Grape Juices and Seeds

In this study, nutraceutical properties of fruit juice and seeds, which are important for human health, of green (Kabarcik, Cavus), red (red Globe) and black (Honusu, Yildiz, Yediveren and Helvani) skin colored grape cultivars grown in same ecological conditions were investigated. Harvest period, number of seeds, cluster form, cluster weight, berry weight, berry color and usage area were determined as morphological parameters. The Folin-Ciocalteu method was used for total phenol content analysis. The total antioxidant status of juices and seeds of grape cultivars have been determined by 2,2–diphenyl−1–picryl-hydrazyl–hydrate (DPPH), ferric reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity (TEAC) assays. Seeds of all grape cultivars exhibited higher nutraceuticals than fruit juices. Total phenolic content of seed samples was found to be quite variable in range of 1.90 mg GAE/g (cv. Yildiz)–3.46 mg GAE/g (cv. Honusu) fresh weight base (FW), indicating 2 folds of differences between green and black grape cultivars. Green and black cultivars also showed the lowest and the highest total phenolic content in juices between 1.69 (cv. Yediveren) and 2.45 (cv. Honusu mg GAE/g FW). Seeds and fruit juices of all cultivars analyzed showed high antioxidant capacity and total phenol content. Of all different colored cultivars, black peel-colored cultivars had the highest values and combined better morphological and nutraceutical traits with an excellent berry qualitative profile for cv. Honusu and Helvani.

Integrated transcriptomic and metabolomic analysis of cultivar differences provides insights into the browning mechanism of fresh-cut potato tubers

The quality of fresh-cut potato tubers is usually impacted by surface browning, which affects food quality. Here, four potato cultivars that differed in their sensitivity to postcutting browning were evaluated with transcriptomics and untargeted metabolomics to investigate the molecular mechanism underlying postcutting browning. The results revealed that the cultivar Yunshu 505 (YS505) was most susceptible to postcutting browning, while Kexin 13 (KX13) was the least susceptible. Compared with KX13, YS505 showed higher PPO (2.5-fold) and POD (32.8-fold and 2.2-fold) mRNA accumulation but lower CAT (0.4-fold) and ACLY (0.4-fold) mRNA accumulation. Transcriptomic analysis also revealed that lipid metabolism and amino acid metabolism were critical to postcutting browning sensitivity, and reactive oxygen species and respiration contributed to browning. Moreover, metabolites related to signal transduction, such as jasmonic acid, glutamate and gibberellins, were found to be enriched in the browning-resistant cultivar KX13. L-aspartic acid and kynurenic acid were inferred to slow browning. Overall, the present study provides novel insights into the browning mechanism of postcutting potato tubers.

Cooler canopy leverages sorghum adaptation to drought and heat stress

In the present study, individual and combined effects of drought and heat stress were investigated on key physiological parameters (canopy temperature, membrane stability index, chlorophyll content, relative water content, and chlorophyll fluorescence) in two popular sorghum cultivars (Sorghum bicolor cvs. Phule Revati and Phule Vasudha) during the seedling stage. Estimating canopy temperature through pixel-wise analysis of thermal images of plants differentiated the stress responses of sorghum cultivars more effectively than the conventional way of recording canopy temperature. Cultivar difference in maintaining the canopy temperature was also responsible for much of the variation found in critical plant physiological parameters such as cell membrane stability, chlorophyll content, and chlorophyll fluorescence in plants exposed to stress. Hence, the combined stress of drought and heat was more adverse than their individual impacts. The continued loss of water coupled with high-temperature exposure exacerbated the adverse effect of stresses with a remarkable increase in canopy temperature. However, Phule Vasudha, being a drought-tolerant variety, was relatively less affected by the imposed stress conditions than Phule Revati. Besides, the methodology of measuring and reporting plant canopy temperature, which emerged from this study, can effectively differentiate the sorghum genotypes under the combined stress of drought and heat. It can help select promising genotypes among the breeding lines and integrating the concept in the protocol for precision water management in crops like sorghum.

The Infestation of Olive Fruits by Bactrocera oleae (Rossi) Modifies the Expression of Key Genes in the Biosynthesis of Volatile and Phenolic Compounds and Alters the Composition of Virgin Olive Oil.

Bactrocera oleae, the olive fruit fly, is one of the most important pests affecting the olive fruit, causing serious quantitative and qualitative damage to olive oil production. In this study, the changes induced by B. oleae infestation in the biosynthesis of volatile and phenolic compounds in olive (cvs. Picual, Manzanilla, and Hojiblanca) have been analyzed. Despite cultivar differences, the oils obtained from infested fruits showed a significant increase in the content of certain volatile compounds such as (E)-hex-2-enal, ethanol, ethyl acetate, and β-ocimene and a drastic decrease of the phenolic contents. The impact of those changes on the inferred quality of the oils has been studied. In parallel, the changes induced by the attack of the olive fly on the expression of some key genes in the biosynthesis of volatile and phenolic compounds, such as lipoxygenase, β-glucosidase, and polyphenol oxidase, have been analyzed. The strong induction of a new olive polyphenol oxidase gene (OePPO2) explains the reduction of phenolic content in the oils obtained from infested fruits and suggest the existence of a PPO-mediated oxidative defense system in olives.

Postharvest Spoilage Incidence and Prestorage Treatment in Chinese Chestnut and Complex Hybrid Cultivars

U.S. chestnut (Castanea sp.) production is expanding as knowledge of seedling cultivation and germplasm advances. Chestnuts have high starch and water content, making them highly perishable; therefore, they require cold storage immediately following harvest. Postharvest spoilage remains a significant area for improvement. Several postharvest fungi (including Fusarium sp. and Penicillium sp.) can infect chestnuts during storage, leading to spoilage and nonsellable nuts. The annual crop losses can reach up to 10%, thereby affecting trees differently. Our research objectives were to 1) evaluate spoilage incidence on the interior (i.e., pellicle, kernel) and exterior (i.e., nutshell) of the nut over the course of 200 days of cold storage on eight cultivars and 2) assess the impact of food contact-approved chlorine solution and 2% peracetic acid (PAA) with 27% hydrogen peroxide prestorage treatments for spoilage suppression on ‘Qing’ nuts. Fourteen timepoints were observed during the study period, each with four replications of 16 nuts. An additional four replicates of 16 ‘Qing’ nuts were treated prestorage and observed over seven time points. The incidence of spoilage was reported as the percentage of nonsellable nuts for each treatment and cultivar at four timepoints. The nut interior showed the highest spoilage incidence after 200 days, with four cultivars having >30% nonsellable nuts. Overall, the cultivars had an average of 10% nonsellable nuts from interior spoilage after 60 days in storage. ‘Hong Kong’ had the highest percentage of nonsellable nuts by the end of the study at 60%, whereas ‘Qing’ and ‘Mossbarger’ had the lowest rates, with only 14% nonsellable nuts. Spoilage of the exterior, although less frequent, is visible to buyers and impacts nut marketability. ‘Kohr’ had the highest percentage of nonsellable nuts because of exterior spoilage (35.9%). ‘Mossbarger’ had the lowest percentage of nonsellable nuts because of exterior spoilage (3.1%). ‘Qing’ nuts treated with 500 ppm chlorine and 100/200 ppm PAA demonstrated reduced exterior spoilage with longer storage times. Prestorage treatment did not show efficacy for reducing interior spoilage. This study provides a preliminary report of evidence that cultivar differences influence the spoilage incidence and supports taking nuts to market within 60 days of harvesting. These preliminary data also inform breeding parent combinations and studies of inheritance for postharvest spoilage tolerance at the University of Missouri Center for Agroforestry breeding program.

Varietal differences in the phytochemical components’ accumulation and aroma profile of three Humulus lupulus cultivars

Humulus lupulus (hop) cone is a key ingredient in beer, which determines its taste and aroma. The impact of ripening on the bitter acids, aroma compounds, and polyphenols of hops has been reported separately, there is no systematic study on all three components. Here, three hop varieties (‘TP1’, ‘TP2’, and ‘QTF’) in China were sampled to investigate the correlation between the harvest maturity and these three components, which indicated that polyphenols synthesized earlier than hop bitter acids, followed by the aroma compounds. Variety differences of the hop cultivars prompted the obvious separation in the partial least-squares discriminant analysis (PLS-DA). Among three hop cultivars. ‘TP1’ with the highest contents of aroma compounds contributed to flower aroma, and with higher contents of bitter acids which contributed to bitter taste. In contrast, ‘TP2’ has been reported to be rich in caffeic acid, salicylic acid, syringaldehyde, (+)-catechin, and (−)-epicatechin. To analyze the hop aroma characteristics, two matrices of hop tea and late-hopped beer were prepared and used for sensory evaluation. Compared to ‘TP2’ and ‘QTF’, the hop tea with ‘TP1’ scored best for ‘strong’ (P < 0.01), ‘herbal’ (P < 0.05) and ‘citrus’ (P < 0.01). While the ‘strong’ and ‘herbal’ characteristics from terpene compounds receded in the late-hopped beer, the ‘citrus’ and ‘fruity’ notes from terpenol compounds remained noticeable.

Evaluation of Barley Cultivars for Competitive Traits in Southern New South Wales.

The potential of multi-purpose barley (Hordeum vulgare L.) cultivars to suppress weeds while maintaining optimal yield and grain quality has been reported but not recently evaluated in replicated field trials performed under southern Australian field conditions. Therefore, to investigate this potential, aboveground competitive traits were assessed in nine genetically diverse commercial barley cultivars in 2015, 2016 and 2017, in two locations in the Riverina region of NSW in replicated field trials performed in the absence of pre-emergent herbicide treatment. Crop and weed establishment, early vigour, leaf area index, photosynthetically active radiation (PAR) and biomass were assessed at various crop growth stages, including early growth, vegetative, flowering, grain fill and harvest. Cultivar differences in crop and weed biomass accumulation at ~50, 100 and 150 days after planting were noted at both locations. Early barley biomass accumulation was inversely related to weed biomass in both locations and most years, suggesting strong (over 90%) potential for heritable competitive barley interference against weeds. The current study also observed a positive relationship between PAR light interception and crop biomass in all three years at both locations, suggesting that PAR light interception contributed positively to crop biomass accumulation by directly increasing photosynthesis (50–70%) and growth or indirectly influencing weed biomass accumulation (10–15%) and weed interference (50–75). Partial least squares modelling was performed with 2015 and 2016 datasets to assess the interactions between crop developmental traits and weed suppression. Cultivars exhibiting enhanced early vigour and PAR light interception were generally more weed suppressive under optimal higher soil moisture conditions. Our results indicate that the choice of barley cultivar has a significant impact on weed establishment, fecundity and seedbank dynamics. The use of competitive barley genotypes is, thus, a cost-effective strategy to reduce weed seedbank numbers over time and may reduce potential herbicide use.

The Role of Water Relations and Oxidative Stress in the Vase Life Response to Prolonged Storage: A Case Study in Chrysanthemum

Long storage periods have been associated with decreased vase life. In this study, the processes underlying the vase life response to prolonged storage were investigated, along with the potential of light reflectance profiles to estimate storage duration. Three cut chrysanthemum cultivars were exposed to four cold (5 °C) storage periods (0, 7, 14, and 21 d). Stomata were present on the leaves (either side) and stem, but not on petals. As compared to the leaves, stomata on the stem were non-functional, smaller, and less dense. Floral transpiration was a small portion of the whole-cut flower transpiration, with the major contributor being the leaves or stem depending on the cut flower hydration. Storage duration linearly decreased vase life, with the rate of decrease being cultivar specific. Storage duration (0–21 d) did not affect leaf stomatal functioning, non-leaf tissue transpiration, or the relative contribution of each organ to the whole-cut flower transpiration. Cut flower hydration was generally enhanced by storage, while water uptake restoration ability was not impaired. Membrane lipid oxidation increased in response to storage duration owing to enhanced H2O2 accumulation. A strong correlation between membrane lipid oxidation level and the vase life response to cold storage was apparent. By examining the light reflectance profiles (400–1050 nm) of leaves (either side) and flowers (top view), an indication of the storage period could not be deduced. In conclusion, cultivar differences in vase life response to cold storage were attributed to variation in oxidative state, whereas cut flower water relations are clearly not involved.

Watermelon Rind and Flesh Volatile Profiles and Cultivar Difference

Watermelon rind is treated as agricultural waste and commonly discarded, causing environmental issues and biomass loss. This study aimed to identify volatile profiles of watermelon rind and flesh and their cultivar difference. Volatiles were analyzed using solid-phase microextraction–gas chromatography–mass spectrometry (SPME-GC-MS). A total of 132 volatiles were identified, including aldehydes, alcohols, ketones, terpenes/terpenoids, esters, lactones, acids, and sulfides. In both rind and flesh, the most dominant compounds in numbers and abundance (peak area) were aldehydes and alcohols, which accounted 94–96% of the total volatile abundance in the rind and 85–87% in the flesh. Total volatile in watermelon rind was only 28–58% of the corresponding flesh samples. Both rind and flesh shared nine-carbon aldehydes and alcohols, though the rind lacked additional diversity. Volatile difference between rind and flesh was greater than the difference among cultivars, although volatiles in the rind could be two times difference between Fascination and other three watermelons (Captivation, Exclamation, and Excursion). This study provides the first-hand knowledge regarding watermelon rind volatile profiles and cultivar difference and shows the potential use of rind in food or beverages due to its naturally contained nine-carbon compounds.

The effect of plant biostimulants on the macronutrient content and ion ratio of several lettuce (Lactuca sativa L.) cultivars grown in a plastic house

Plant biostimulants have been identified as one of the most important agronomic factors that scientists have been looking for in a range of natural sources over the last few decades. The purpose of these experiments was to see how plant biostimulants (Willow bark extract, Bistep, and the combination of Willow+Bistep (W+B)) affect macronutrient content and ion ratio in three lettuce cultivars (May King, Kobak, and Great Lakes) from 2019 to 2021. Willow bark extract was diluted to 3% and applied to the plants through irrigation with the amount of 50–60 mL plant−1, whereas Bistep was sprayed every two weeks from transplanting in accordance with the manufacturer's recommendations at 0.05% with the amount of 20 mL plant−1.The data demonstrate that over the grown seasons, the treatments W+B and Willow bark extract were the most effective biostimulants impacting macronutrient content and ion ratio, whereas Bistep was the least effective. In comparison to untreated plants, the amount of macronutrients (Ca2+, Mg2+, and P) in lettuce leaves rose by 18%, 13%, and 9%, respectively, in plants treated with W+B over a period of years, while, potassium (K+) significantly reduced by 15%. Sodium level, on the other hand, was significantly improved using plant biostimulants of Bistep, Willow and W+B by 33%, 57% and 72%, respectively. Ca2+ and Mg2+ levels in lettuce cultivars were substantially higher in the season of 2019 when the climate was cooler and the air humidity was higher, but Na+, K+, and P levels were higher in 2020 when the temperature was somewhat warmer and dryer. Among the lettuce cultivars, Great Lakes lettuce has a greater level of macronutrient content (Ca2+, Mg2+, Na+, and K+), however, Kobak contained much higher phosphorus (P) content at 301.41 (mg kg−1 DM).Plant biostimulants enhanced the ion ratios of Na+: Ca2+ and Na+: Mg2+, but the only substantial improvement in Ca2+: P ratio was in plants treated with W+B from 2019 to 2021, particularly in the Kobak variety by 20%. Biostimulants, on the other hand, decreased the mass ratio of (K++Na+): (Ca2++Mg2+) in lettuce cultivars. Among plant biostimulants, Willow and the combination of W+B had the highest influence on nutritional absorption and ion ratio, although Bistep had the least. The macronutrient composition and ionic ratios of lettuce cultivars varied according to the cultivar differences and climate conditions. In our 3-year experiments, we discovered that the Great Lakes variety had a higher macronutrient content in the season of 2020, whereas the Kobak variety had a higher ion ratio.

Cultivar differences in the operation of the photosystem II of barley leaves

Differences between nine spring barley cultivars on structural and functional parameters of PSII operation are shown. Variability of the parameters used changed from 2.2…2.5 (oxidized quinones pool and maximum photochemical efficiency) to 24.6% (performance index PIABS_total). Parameters characterizing the values of excitation energy fluxes (ABS/RC; TRo/RC; ETo/RC) varied to a small extent - 3.1...6.5%, while the lost energy (DIo/RC) much stronger - 14.6%. The efficiency of electron transport from quinine QB and the entire PSII until the PSI’s primary acceptors varied even more - 18.1 and 17.4%, respectively. The PIABS integral performance index combined cultivars into two groups only; PIABS_total index showed more clear differences in cultivars. Cv. Novichok and Fermer were significantly inferior to cv. Forward, Belgorodsky 100, Boyarin and Bionic in most of the studied parameters. However, according to the results of a cluster analysis, cv. Novichok and Forward turned out to be similar to each other, as well as cv. Fermer, Boyarin and Bionic, which separated into the same cluster. Probably, the action of PSII in cultivars of the same cluster differs only quantitative but not qualitative. Therefore, for breeding work on pyramidizing the genes controlling operation of this photosystem, it is advisable to crossing cultivars belonging to different clusters.

Genotypic differences in root traits to design drought-avoiding soybean ideotypes

Soybean (Glycine max (L.) Merr.) may contribute to the agro-ecological transition of cropping systems in Europe, but its productivity is severely affected by summer drought. The crop is mainly grown in southern and continental parts of Europe, whereby increasing drought and heat waves are expected in the near future. Agronomic strategies, such as early sowing, require cultivars with enhanced early plant growth traits under suboptimal conditions. Moreover, efficient water uptake by root delays dehydration and promotes drought avoidance. In general, changes in root morphology and root architecture are important pathways for plant adaptation to water stress conditions. This paper reviews the cultivar differences in soybean for root morphological and architectural traits especially during early growth stage. Previous works reported cultivar differences for root traits in soybean but they did not deal with cultivars commonly grown in Europe on which little information is available to date. Genotypic differences in available early-stage root traits can be used as a framework to design soybean ideotypes less vulnerable to drought. To this aim, high-throughput phenotyping supported by digital methods and crop modelling offer new avenues for the exploration of target root traits involved in drought avoidance.

Evaluation of Damping-Off Tolerance in Spinach Cultivars in Field Soils and in a Standardized Lab Assay with Pythium ultimum

Spinach growers face increasing problems of damping-off in the production of fresh-market (baby-leaf) spinach due to increasing restrictions on chemical treatments. Damping-off-tolerant cultivars are increasingly important, requiring proper evaluation methods. From three locations in The Netherlands with a history of spinach cultivation and from one location in France, potential damping-off pathogens were isolated from the soil, identified to species or genus, and tested for their pathogenicity. Pythium ultimum was the most prevalent pathogen in those fields, causing spinach pre- and postemergence damping-off. Eight spinach cultivars with two or three seed lots each were evaluated at the same field locations and in a greenhouse with soil sampled from one of the Dutch field sites. Preemergence damping-off was more discriminating for differences among the cultivars than postemergence damping-off. Variation in levels of infection among trials, replicates, and seed lots of the same cultivars emphasized the need for a more standardized phenotyping assay. For such an assay, a cornmeal-sand-based inoculum with a pathogenic P. ultimum isolate was added to a substrate mixture of sand, perlite, and vermiculite and moistened until 50% water-holding capacity, in which spinach seeds were incubated for 10 days in a dark climate cabinet at 15°C, including a control treatment without P. ultimum inoculum. The assay showed reproducible results for discriminating differences in preemergence damping-off tolerance levels among seed lots. However, cultivar differences in preemergence damping-off tolerance levels could not be confirmed due to a large variation among seed lots that needs further investigation.

The molecular events underpinning cultivar differences in melatonin counteracting salt damage in Phaseolus vulgaris.

Melatonin (N -acetyl-5-methoxytryptamine) plays important roles in multiple stress responses, especially under salt stress. However, cultivar differences in melatonin mediated salt stress tolerance are unclear. Phaseolus vulgaris L. (common bean) cultivars Jiyin 1 (JY, salt-tolerant) and Xuliyabai (XL, salt-sensitive) were used in this study. Exogenous melatonin significantly improved root growth under salt stress in JY, but had little effect on XL. Physiology analysis showed significant differences in activities of antioxidant enzymes (superoxide, SOD; and catalase, CAT) and malondialdehyde content between JY and XL. Meanwhile, the change of ABA content in JY and XL root was opposite in salt plus melatonin treatment. Comparative root transcriptomes of JY and XL revealed 3505 and 668 differentially expressed genes (DEGs) regulated by salt stress and melatonin. The most enriched melatonin-responsive genes under salt stress are mainly involved in regulation of transcription, oxidation-reduction process, transcription factor activity, oxidoreductase activity. In addition, melatonin induced more obvious changes of DEGs in JY than that in XL under salt condition. Melatonin also significantly induced 41 DEGs only in JY, including signal transduction genes, transcription factors, ubiquitin protein ligases, ion homeostasis and osmotic adjustment genes etc. This study uncovered the molecular mechanism of cultivar difference of melatonin response under salt stress in common bean.

On the foaming properties of plant proteins: Current status and future opportunities

Aerated food products are becoming increasingly popular among consumers due to their visual appeal and peculiar sensory properties. Foam formation and stabilization are typically achieved using clean label surface-active molecules such as proteins. In recent years, the need to address pressing global challenges like food security and sustainability has steered the attention of food companies towards the replacement of animal proteins with plant-based ones. This trend has promoted the development and commercialization of a variety of plant protein-enriched ingredients that differ widely in their techno-functionality. The aim of this study was to provide a review of the foaming properties of selected plant proteins and to describe how these are influenced by the extraction processes as well as by physical, chemical and enzymatic treatments. The characterization of the foaming properties of plant proteins has been the subject of extensive research over the past couple of decades. However, drawing general conclusions based on the outcomes of different studies is a complex endeavor, even for protein ingredients derived from the same plant species. This is not only due to differences in terms of cultivars, environmental factors, farming practices and extraction processes, but also in the methods and conditions used to generate and analyze foams. Nevertheless, this review highlights the potential of different approaches to improve the foaming properties of plant proteins, including the optimization of extraction conditions, the use of physical, chemical and enzymatic treatments, and the modulation of their interactions with other food components. • Foaming properties of plant proteins have been extensively investigated in recent years. • A review of the foaming properties of selected plant proteins is provided. • Differences in cultivars and extraction processes complicate comparison between studies. • Foaming performance is closely related to the protein profile of the protein source. • The influence of physical, chemical and enzymatic treatments on foaming is described.

Physicochemical Characterization of Selected Pomegranate (Punica granatum L.) Cultivars

The physical and chemical characteristics of five pomegranate cultivars (Mridula, Ganesh, White muscut, G-137 and Jalor seedless) were examined in the present investigation. Physical properties of different cultivars were determined such as major diameter (85.05 to 91.62 mm), intermediate diameter (76.85 to 87.83 mm), minor diameter (79.86 to 90.01 mm), sphericity (0.903 to 0.937), fruit weight (294.4 to 404.14 g), fruit volume (289 to 387 mL), number of arils per fruit, weight of 100 arils were evaluated and analysed for the varietal difference. In addition, properties such as peel moisture content (68.72 to 74.15% w.b.), aril moisture content (78.25 to 81.82% w.b.), peel ash content (0.81 to 1.51%), aril ash content (0.29 to 0.53%), juice pH (3.47 to 3.96), total soluble solids (11.60 to 13.00 °Brix), titratable acidity (0.42 to 0.58%), total phenolic content, juice yield per fruit (104 to 186 mL) juice turbidity (142.20 to 364.50 NTU) and textural properties, like fruit compressive strength/firmness of arils (23.09 to 34.54 N), cutting strength of peel (84.33 to 111.35 N) and aril skin puncture force (0.28 to 0.38 N) were also investigated. Overall results suggested that the measured physico-chemical properties were quite different by the cultivar differences.

Systematic cultivar selection for weed biological control risk assessment

Classical biological control is important for long-term, sustainable management of invasive species such as weeds. To be acceptable for introduction, new biocontrol agents must not damage crops, native plants, or other valued non-target species. Host-specificity experiments inform risk assessment of new biocontrol agents by prioritising and testing non-target plant species. Susceptibility to damage can also vary between cultivars of the same species, yet current protocols for the selection of test plant species inadequately address cultivar differences. Poor selection increases the risk of failing to detect non-target damage. We developed criteria for prioritising cultivars and a process chart (the ‘decision support tool’) to guide the selection of cultivars for biological control host-specificity testing. We reviewed and documented current cultivar selection practice published in prominent biological control journals and government documents to further explore current best practice for cultivar selection. To demonstrate the utility of the tool, we then applied the decision support tool to a complex host-specificity testing case study. In our review, most papers either did not mention cultivars of the cultivated plant species being tested, or they provided incomplete descriptions of cultivars without explaining omissions. Only one of 29 papers fully described the method for selecting and prioritising cultivars and reported the results for each cultivar tested. Our application of the process chart to a potato testing case study generated a feasible short-list of cultivars which can be scrutinized and updated. We showed how selections could be made through a collaborative and transparent process involving key stakeholders and decision makers. We have identified an example of under-reporting in classical biological control which, if not addressed, could impede progress in the sustainable management of invasive species. The decision support tool we developed has broad application in weed biological control risk assessment. We demonstrated that the decision tool is easy to use, can account for uncertainty, is adaptable to different species, and is suitable for both small and large cultivar groups irrespective of complexity. Our approach will result in more transparent, defensible, and reproducible cultivar selection practices, leading to greater confidence in biological control risk assessments.

English

In Ethiopia, barley selection has focused on grain yield traits. Limited information is available on straw yield and its nutritive value. The aim of this study was to screen cultivars for grain and straw yield and nutritive value using forty cultivars of food and malt barley types at two locations in Ethiopia (Bekoji and Kofele) in 2018. Food-fodder quality traits investigated were crude protein (CP), neutral detergent fibre (NDF) and metabolizable energy (ME) of grain and straw. Location, cultivar and their interaction affected the performance in malt as well as food barley types. Wide cultivars differences were observed within food and malt types respectively: Grain CP: 10.2-12.2% and 11.4.1-13.3%, grain NDF: 40-2-52.7% and 38-42.9%, grain ME: 9.9-12.3 MJ/kg and 12.1-14.5 MJ/kg, straw CP: 4.1-5.7% and 4.9-6.2%, straw NDF: 73.5-76.7% and 72.9-76.1%, straw ME: 5-5.6 MJ/kg and 5.3-5.8 MJ/kg. Across locations, IBON174/03 produced most grain (6.95 t/ha), traveller produced most straw (9.1t/ha) and HB1963 was relatively high in both straw 8.4 t/ha and grain yield 6.4 t/ha, making it an interesting food-feed cultivar. Therefore IBON174/03, traveller and HB1963 are promising barley cultivars for the study area. Key words: Food-feed, cultivar, barley, straw.

Technological and nutritional properties of amaranth-fortified yellow cassava pasta.

Yellow cassava is an affordable starting material to design a healthy food, having high β‐carotene content. White and yellow cassava functional pasta were fortified with 50 g/kg (w/w) amaranth dry leaf powder and analyzed to evaluate the impact of cultivar difference, processing, and addition of amaranth leaf powder on the physicochemical, functional, pasting, antioxidant, and cooking properties of the white and yellow cassava pasta samples. Significant differences were observed among the cassava pasta samples. Leaf powder addition significantly enhanced the dietary fiber (7.6–9.1 g/100 g) and protein (1.41–4.69 g/100 g) contents of formulated cassava pasta. Yellow cassava‐amaranth pasta had higher β‐carotene (2.07 µg/g), iron (59 mg/kg), and zinc (9 mg/kg) contents than the white cassava‐amaranth pasta. The addition of amaranth leaf powder also enhanced the antioxidant capacities of pasta products. Cooking time and gruel solid loss were reduced upon the addition of amaranth leaf powder, which is beneficial to the consumers. Data showed the potential of amaranth‐fortified yellow cassava pasta in contributing to a healthy diet in low‐ and middle‐income countries by combining a biofortified crop with leafy vegetables via food‐to‐food fortification. Practical Application: This work demonstrates the feasibility of a cassava‐based pasta fortified with amaranth vegetables as an affordable and nutritious food to benefit micronutrient deficient consumers in countries with high cassava consumption but low vegetable intake. The inclusion of amaranth leaf powder enhanced the developed pasta's nutritional and technological properties, thus presenting a healthy food choice with the potentials for scaling up commercially.

Benefits of the Phytotoxic Ozone Dose (POD) index in dose-response functions for wheat yield loss

A central topic of recent research in ground-level ozone (O3) effects on plants is the shift from exposure based on concentrations to a physiologically more realistic approach based on O3 uptake. Critical test of the evidence for the benefits of the latter approach is of utmost importance for the development of O3 risk assessment. We explored the variability in O3 sensitivity in the wheat response function used for risk assessment by the Convention on Long-Range Transport of Air Pollution (LRTAP). The variation in O3 sensitivity among individual experiments was a factor of six larger when using the concentration-based index AOT40 compared to stomatal O3 uptake based Phytotoxic Ozone Dose (POD). Thus, consideration of environmental variables affecting stomatal conductance, such as solar radiation, air humidity and temperature, explained a substantial part of the variation in O3 response among experiments regardless of cultivar differences. Response-functions based on daytime O3 concentrations for the experiments of the POD response function was compared with the corresponding response function including available global data for O3 effects on field grown wheat yield. On average, there was no difference in O3 sensitivity between the two data sets, although the variation in response was substantially larger for global data. We conclude that POD represents a strong improvement over AOT40. The strength and representativeness of the POD approach highlighted is significant for the development and application of models used for risk assessment of ozone impact on crops.