Lycopene is an intermediate metabolic product of the capsanthin biosynthesis pathway in pepper fruits and is one of the strongest antioxidants found in plants. During the ripening of pepper fruits, lycopene is almost completely transformed into the downstream metabolic product capsanthin as well as other substances. As a result, lycopene cannot be enriched in ripe pepper fruits; however, the lycopene content can be increased by 2-(4-chlorophenylthio) ethylamine hydrochloride (CPTA) treatment, using the optimal concentration at the optimal development stage of pepper fruits. The current study tested different CPTA concentrations and fruit developmental stages to increase the lycopene content in pepper fruits. The results showed that the lycopene content was significantly enriched in pepper fruits treated with 0.1% CPTA applied at the turning stage. Real-time quantitative polymerase chain reaction analysis showed that CPTA treatment significantly promoted the expression of the upstream genes (Psy and PDS) involved in the anabolic metabolism of lycopene; however, CPTA treatment had a significant inhibitory effect on the downstream gene (Lcyb) of lycopene synthesis. Therefore, in pepper fruits, CPTA inhibits the normal expression of the Lcyb gene downstream of lycopene, thus achieving notable lycopene enrichment.

Chrysanthemum lavandulifolium (Fischer ex Trautv.) Makino is a diploid plant belonging to the Asteraceae family, with typical capitula composed of female ray florets and bisexual disc florets. The differentiation and development of these two types of florets have long been important research focuses; however, the potential epigenetic mechanisms governing these processes have not been elucidated. In the present study, methylation-sensitive amplification polymorphism method was used to trace the dynamic changes of DNA methylation during capitulum development in C. lavandulifolium. DNA methylation patterns and levels were detected in the whole capitula during seven developmental stages, and the obtained results revealed that DNA demethylation was dominant during this process. In addition, DNA methylation patterns and levels showed significant differences between ray and disc florets. Moreover, the expression patterns of candidate genes potentially involved in the development processes of two types of florets were analyzed by real-time quantitative reverse transcription polymerase chain reaction, and correlation analysis indicated that the expression levels of ClPI, ClAG2, ClSEP1, ClCYC2c, ClCYC2d, and ClCYC2e were highly correlated with DNA methylation levels. These results indicate that DNA methylation may be involved in the differentiation and development of ray and disc florets. This study provides epigenetic insights into the capitulum development in C. lavandulifolium.

Peach trees bear an abundance of flowers which produce a surplus of fruit that the tree is unable to support. A self-regulatory mechanism enhances the abscission of immature fruitlets leading to a reduced fruit load, but this is often insufficient to achieve fruit of marketable size. Supplementary manual fruit thinning is typically required to optimize economic fruit load. This 2-yr study investigated the response of ‘Redhaven’ peach trees to sprays of 300 and 600 mg L⁻¹ 1-aminocyclopropane carboxylic acid (ACC) during the phenological stages of full bloom, shuck split, and ˜20 mm fruitlet diameter. The objective was to determine the efficacy of ACC on fruit set, fruit size, and yield at harvest and the amount of hand-thinning required at “June drop”. Although the response to ACC varied between the 2 yr, 600 mg L⁻¹ ACC spray at full bloom (2018) and at ˜20 mm fruit size (2019) reduced fruit set, the need for hand-thinning by 59%–66%, and crop load. Treatments also had varying but significant effects on leaf yellowing and leaf drop when measured shortly after application. ACC reduced total yield and number of fruit per tree in both study years and increased fruit weight in 2019. Overall, peaches were responsive to ACC at a range of timings from bloom to ˜20 mm fruit size. This study enhances our understanding of ACC on fruitlet abscission of peaches and is one of few studies to demonstrate the effectiveness of a chemical fruitlet thinner for peaches.

Herbicide tolerance is commonly associated with reduced absorption and translocation of the herbicide; we hypothesized that the mechanism of dicamba tolerance in wild tomato (Solanum lycopersicum L.) accessions is due to these characteristics. The absorption and translocation of dicamba were investigated at a drift rate of 2.8 g a.e. ha⁻¹ in three predetermined dicamba-tolerant (DT) wild accessions (TOM199, TOM198, and TOM300) and compared with two dicamba-susceptible (DS) commercial tomato cultivars [Money Maker (MM) and Better Boy (BB)]. Dicamba was quantified in three different parts of the tomato plant: two upper leaves, two lower leaves, and the roots at 1, 3, and 7 d after treatment. Both MM and BB absorbed more dicamba then all the three DT accessions. The overall translocation pattern of dicamba was similar between DS cultivars and DT accessions, thus suggesting that tolerance to dicamba in wild accessions may not be associated with reduced translocation but instead with reduced uptake of the herbicide. Additionally, reduced dicamba absorption in DT accessions may be attributed to their leaf characteristics, such as the presence of narrower leaves (3.42 leaf length/width ratio) and higher trichome density (20 no. mm⁻²) in DT accessions, than compared with DS cultivars (1.92 leaf length/width ratio and 8 no. mm⁻² trichome density).

Demand is increasing for locally grown malt barley (Hordeum vulgare L.) in northeastern North America, driven primarily by growth in the craft beer sector. A multi-site experiment was conducted to evaluate how variety (V), seeding rate (S), and nitrogen (N) fertilizer affect malt quality in the northeast. Two barley varieties (Cerveza and Newdale), two seeding rates (200 and 400 seeds m⁻²), and five rates of actual applied N fertility (0, 30, 60, 90, and 120 kg ha⁻¹) were tested at Charlottetown, PE, Canada, Ithaca, NY, US, Princeville, QC, Canada, and New Liskeard and Ottawa, ON, Canada. Basic agronomic data were collected from all environments including yield, thousand kernel weight, and hectoliter weight. Barley of suitable quality was micromalted and subjected to malt quality analysis. Both V and S resulted in small effects on malt quality, however, N had the greatest effect on most measured variables. Increased rates of N application resulted in increased yield, hectoliter weight, and thousand kernel weight but had a negative effect on most quality traits, especially with increased protein content, reduced fine extract, Kolbach index, and friability, though it increased wort β-glucans. This study shows that for most years at most sites, it is possible to achieve malt quality in the northeast; however, excessive protein and the prevalence of preharvest sprout damage are the main barriers. The results of this study have implications for increased malt barley production for the craft sector as well as potential access to commodity markets for northeastern producers.

Sclerotinia blight is a destructive disease of peanut caused by Sclerotinia sclerotiorum (Lib.) de Bary and Sclerotinia minor Jagger. Crop management practices are routinely used to control Sclerotinia blight, however, development of resistant cultivars together with crop management practices may provide a lasting solution to control the disease in peanut fields. In this study, 95 accessions of United States’ peanut mini-core collection were evaluated using detached leaflet and whole plant inoculation methods under greenhouse conditions. The area of detached leaflet infected was scored using a scale from 0 (no disease) to 4 (76%–100% leaflet area infected). Whole plants were evaluated based on disease severity index (DSI) from 0% (no disease) to 100% (entire plants infected). In the detached leaflet inoculation method, accessions PI-268586, PI-268696, PI-356004, PI-372305, and PI-429420 had the lowest average disease score of 2.7. In the whole plant inoculation method, accessions PI-200441, PI-259658, PI-319770, PI-323268, and PI-337293 had the lowest DSI from 86% to 90%. The two inoculation methods resulted in different set of accessions with the lowest disease level. These results may reflect differences in disease pressure between the two screening methods.

The foliar chemicals in potatoes (Solanum tuberosum L.) could affect the growth and development of agricultural pests, such as Colorado potato beetle Leptinotarsa decemlineata (Say) and aphid Macrosiphum euphorbiae (Thomas). Thus, altering the chemical composition of potato leaves could potentially supplement integrated pest management (IPM). In this study, field experiments were conducted in Quebec, Canada, to investigate the effects of nitrogen (N) rate and source on foliar sugar, glycoalkaloid, and amino acid concentrations and tuber yield of potato cultivar Russet Burbank. Three N fertilizer sources of ammonium nitrate, ammonium sulfate, and polymer-coated urea were used at four rates of 60, 120, 200, and 280 kg N ha⁻¹ plus an unfertilized control in a randomized complete block design. The fourth leaves from the top of 20 randomly selected plants in each plot were collected at 54, 68, and 82 d after planting for sugar, glycoalkaloid, and amino acid analysis. Tubers were collected at harvest, and the total and marketable yields were determined. Results showed that N fertilization linearly decreased sugar concentrations and these reduced sugars were conveyed and stored in tubers as starch. Glycoalkaloid concentrations in leaves were influenced by N source and rate. Both total and marketable yields quadratically varied with increasing N rates regardless of N sources, with average values of 36.4 and 28.3 Mg ha⁻¹, respectively. As N rate affected potato foliar chemical composition and tuber yield, N fertilization could be considered as a supplemental tool to the IPM strategy for potato pest control.

Pathogenic fungi cause significant yield losses and quality reductions to many crops including canola, wheat, and barley. Toxic metabolites produced by fungal pathogens, along with excessive application of synthetic fungicides, can also pose risks to human and livestock health. Hydroxy unsaturated fatty acids (HUFAs) are novel alternatives to commonly used fungicides. Here, the antifungal activities of two HUFAs, coriolic acid (CA) and ricinoleic acid (RA), were assessed in vitro and in planta for their activity against the important phytopathogens Fusarium graminearum Schwabe, Pyrenophora tritici-repentis (Died.) Drechsler, Pyrenophora teres f. teres Drechsler, Sclerotinia sclerotiorum (Lib.) de Bary, Leptosphaeria maculans Ces. & De Not., and Aspergillus niger Tiegh. on selected media, monocots or dicots. The results in vitro indicated that both CA and RA showed the strongest inhibitory activity against L. maculans and A. niger, but their activities varied with different fungi. On wheat and barley, CA but not RA reduced disease severity caused by Pyrenophora spp.; on canola, treatment with high levels of CA and RA led to oxidative damage of the plant tissues, and treatment with low concentrations of CA and RA did not reduce disease severity caused by L. maculans or S. sclerotiorum on canola. Our findings suggest that the utility of HUFAs in reducing disease severity caused by pathogenic fungi depends on the dosage and the plant and fungus targeted. High concentrations of HUFA can be phytotoxic on certain plants. In addition to their direct antifungal properties, additional mechanisms may be involved in the disease reduction of CA, suggesting the need for further evaluation of its potential use in crop protection.

Skotomorphogenesis occurs after germination and before excavation in plants. It inhibits excessive absorbed energy in cells and can prevent the lethal photooxidative damage caused by transitioning from skotomorphogenesis to photomorphogenesis for light energy utilization. To investigate the mechanisms underlying photoreactions in soybean [Glycine max (L.) Merr.], we identified and isolated soybean phytochrome-interaction factor 1 (GmPIF1). A yeast two-hybrid (Y2H) assay showed that GmPIF1 interacted with photoactive PHYTOCHROME A (PHYA) and B (PHYB) in both soybean and Arabidopsis (GmPHYA, GmPHYB, AtPHYA, and AtPHYB). To analyze its function, we ectopically over-expressed GmPIF1 in wild type and pif1 mutant Arabidopsis. In etiolated seedlings, GmPIF1 caused hypocotyl elongation, cotyledon closed, apical hooks folded, and less accumulation of protochlorophyllide. In Y2H, GmPIF1 interacted with AtHDA15 that inhibited chlorophyll synthesis under dark conditions. After transition from darkness to white light, GmPIF1 promotes the reduction of photobleaching and induced de-etiolation. Moreover, GmPIF1 inhibited PHYA- and PHYB-mediated seed germination. Our findings increase our understanding of the regulatory network of light response in soybean and provide useful gene resources for soybean breeding in programs and genetics engineering.

On-tree maturation was monitored in a commercial ‘Royal Gala’ apple orchard in two separate years (2016 and 2017) and was found to advance more quickly in 2017 as compared with 2016. Dry matter was predicted using a handheld infrared spectrometer and dry matter content (relative to fresh weight) was 18.2% in 2016 and 14.7% in 2017. The lower average dry matter content in 2017 was hypothesized to be associated with accelerated maturation on the tree. Apples were harvested for storage testing, in both years, at a target maturity at which internal ethylene levels had reached approximately 1 μL·L⁻¹, starch clearing index was between 2 and 4 on the Cornell starch chart, and I_AD value (measure of relative chlorophyll content in the peel) was approximately 0.5. Consequent, instrumentally measured flesh quality changes were monitored after ultra-low oxygen, controlled atmosphere (CA) storage (0.7 kPa O₂+1.0 kPa CO₂) at 0.5 °C for 3 and 6 mo. The firmness, soluble solids, and titratable acidity were much higher in the apples from the 2016 harvest. While these quality measures declined during 3 and 6 mo of storage, they were consistently higher in the apples from the 2016 season. These results show that when dry matter contents were higher for ‘Royal Gala’ apples from this orchard, harvest maturity was delayed and fruit were much firmer and had higher contents of soluble solids and somewhat higher titratable acidity at harvest and after ultra-low oxygen CA storage for up to 6 mo.

Furrow sowing could significantly decrease salt damage to wheat; however, the molecular mechanism in wheat is not well known. In this study, a split-root system was used to simulate non-uniform root zone salinity. Our hydroponic experiments showed that wheat seedlings under non-uniform salt stress probably use a salt avoidance strategy to ensure growth. RNA sequencing analysis showed that 1648 and 3245 differentially expressed genes were identified in 0/150 and 75/75 salt treatments, respectively, with an intersection of 690 genes. Gene ontology terms representing normal growth were specifically enriched by upregulated genes in the 0/150 treatment and downregulated genes in the 75/75 treatment, and terms representing phytoremediation were specifically enriched by upregulated genes in the 75/75 treatment and downregulated genes in the 0/150 treatment. Differentially expressed genes that are probably associated with salt stress and transcription factors showed significantly higher expression in the 75/75 treatment than in the 0/150 treatment. These findings suggest that a uniform salt treatment causes wheat to initiate a more complex salt tolerance mechanism for salt stress. In addition, the expression of 11 genes annotated as peroxidase was higher in the 0/150 treatment than in the 75/75 treatment, and the enzyme activity showed the same trend, indicating that peroxidase probably played a role in the better performance of wheat plants under non-uniform salt stress. Pot culture experiments showed that wheat plants under non-uniform salt stress produced higher yields than those under uniform stress, further indicating that inducing unequal salt distribution in soil could significantly improve wheat cultivation.

Des équations précédemment développées prédisent la valeur nutritive de la luzerne ou de mélanges luzerne–graminée avant la récolte. Cette étude valide cinq de ces équations avec des échantillons de luzerne pure cultivée sous conditions québécoises. Ces équations de prédiction ont été évaluées en utilisant les statistiques associées aux régressions linéaires. Parmi les équations évaluées, celle du Wisconsin et de New York semblaient les plus appropriées. Cependant, la présence de biais limite leur utilisation. Le développement d’une équation québécoise devrait donc être considéré afin d’aider les producteurs à identifier le moment de récolte de toutes les cultures à base de luzerne.

Soybean [Glycine max (L.) Merr.] is an important source of health-beneficial compounds, including soyasaponin I. A field study was conducted for 11 yr in Ottawa, ON, Canada, to assess the impacts of temperature and precipitation during specific growth stage intervals on soyasaponin I concentration in three soybean cultivars. Soyasaponin I concentration response to air temperature and precipitation variables were observed at specific growth stage intervals for some cultivars. The response was complex and cultivar specific. Overall, reproductive stages were more responsive and 20 °C appeared to be a critical threshold in determining soybean soyasaponin I concentration response to air temperature.

Moderate levels of calcium or magnesium were applied to two cultivars of subirrigated, potted, pinched chrysanthemums during vegetative growth. Market-quality plants were produced with sufficient leaf-calcium or leaf-magnesium even though the delivery of the respective nutrient could be reduced by approximately 87.5%, compared with industry standards. This practice could contribute to low-input production of floricultural crops.

Fusarium head blight (FHB) is a devastating wheat disease with a significant economic impact. Fhb5 is an important quantitative trait loci (QTL) conferring type I resistance to FHB. In this study, we accessed the usability of a Kompetitive allele-specific polymerase chain reaction (KASP) marker for the QTL on Fhb-5AS. The KASP clustering results were compared with the linked simple sequence repeat marker, wmc705 for Qfhb-5AS. Our results indicate that the single-nucleotide polymorphic locus wsnp_Ra_c24707_34262900 (IWA7777) provides reliable information for Qfhb-5AS-based resistance and would be amenable to masker-assisted selection, introgression of the resistance loci, and pyramiding of FHB resistance in wheat cultivars.

Evolve is the world’s first ogu INRA (Institut national de la recherche agronomique) CMS (cytoplasmic male sterility) hybrid summer rape (Brassica napus L.) Roundup Ready^® high erucic acid, low glucosinolate cultivar. On average, Evolve yielded 12.4% more seed, 6 g kg⁻¹ more seed oil, and 5 g kg⁻¹ less meal protein than Red River 1861, an open-pollinated Roundup Ready^® high erucic acid, low glucosinolate summer rape. Evolve has an erucic acid content of 52.3% in isolated field trials of high erucic acid rapeseed genotypes and is adapted to the southern B. napus growing regions of western Canada.

CO474 is a mostly Stiff Stalk (BSSS), yellow, semi-dent inbred with early-medium maturity (75 d to flowering). It has moderate resistance to eyespot and rust and intermediate reactions to Fusarium stalk rot, northern leaf blight, and goss’s wilt. This inbred combines well with several testers in many different locations.