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Violets (Viola) are potential candidates for aroma-focused breeding research. Though most Viola species and modern hybrids lack fragrance, the genus contains a famously scented species, Viola odorata L. This species and its cultivars are genetic resources of aroma traits that could be used to investigate the selection for and transmission of fragrance during the breeding process. Despite its famous scent, however, the floral volatile emissions of V. odorata have not been characterized using modern headspace techniques. Using static and dynamic headspace volatile collection methods and gas chromatography–mass spectrometry, the floral volatile emissions of V. odorata were temporally and developmentally characterized. Floral volatiles were also sampled from 10 V. odorata cultivars, three Parma violet cultivars, five violet species, and one hybrid, and variation in scent among these violets was investigated. Total volatile emissions in V. odorata were highest from 0600 HR to 1900 HR, suggesting a diurnal pattern of emission. Volatile emissions also varied over the developmental lifespan of the flower, with the highest emission of individual and total volatiles occurring, in general, from stages 0 or +1 to stages +3 or +4. Floral scent qualitatively and quantitatively differed among assorted violets. The floral volatile emissions of V. odorata exhibit temporal and developmental variation. Compared with the other violet species in this study, sweet violets are intensely fragrant. The quantity and quality of floral scent differs among V. odorata cultivars, providing genetic variation from which selections could be made in a fragrance-focused breeding program.
Temporal separation of red (R) and blue (B) (alternating R/B) photons has been reported to increase leaf area, photon capture, and yield of lettuce compared with delivering both colors together (concurrent R+B). We grew three diverse lettuce cultivars (Grand Rapids, Rex, and Red Sails) under concurrent R+B photons (9/1 ratio) and alternating R/B photons (9/1 ratio) under an equal daily light integral (DLI) of either 8.6 or 23 mol⋅m−2⋅d−1. Contrary to five previous studies, we found no increase in either leaf area or fresh mass and dry mass in any of the alternating R/B photon treatments compared with concurrent R+B photons. In fact, at a DLI at 8.6 mol⋅m−2⋅d−1, alternating R/B photons decreased the dry mass of ‘Grand Rapids’ and ‘Rex’ lettuce by 38% and 17%, respectively. Two previous studies reported that photosynthetic rates increased with alternating R/B photons; however, we found that the net assimilation rate was generally decreased by alternating R/B photons. An analysis of images obtained from automated digital photography revealed that the relative expansion rate of leaves was 61% higher during intervals of pure B rather than intervals of pure R photons at the same photosynthetic photon flux density; however, this did not result in a higher leaf area compared with concurrent R+B photons. Overall, our studies do not indicate that alternating R/B photons increase lettuce leaf area or yield compared with concurrent R+B photons.
Blueberries are small perennial evergreen or deciduous shrub berries of the genus Vaccinium in Ericaceae family. Pollination with different parental genotypes has significant effects on fruit size, fruit harvest time, fruit firmness, and chemical composition, such as soluble solids, titratable acids, anthocyanins, fructose, sucrose, glucose, flavonoids, and total phenols, showing an evident xenia effect. To understand the molecular mechanism and biosynthetic pathways involved in the xenia effect in rabbiteye blueberry, we employed transcriptome profiling by RNA sequencing to identify differentially expressed genes (DEGs) during fruit development of the variety ‘Premier’ produced by self and cross-pollination with ‘Brightwell’ and ‘Powderblue’. On the basis of the transcriptomic sequences, DEGs related to plant hormone signal transduction were identified through bioinformatics analysis, screening of DEGs, and functional enrichment analysis. The results showed that the single fruit weight and the contents of anthocyanins fructose, glucose, and sucrose showed significant differences between self- and cross-pollinated fruits, demonstrating a distinct xenia effect. High-throughput sequencing was conducted on the transcriptomes of young fruits harvested at six developmental stages (at 10-day intervals from 40 to 90 days after self- and cross-pollination). After screening and identification, 16.37 million to 25.52 million raw reads were generated and 4,937,201,302 to 7,709,896,920 clean bases were obtained. The comparison group of 80-day-old fruits generated through self-pollinated ‘Premier’ and those crossed with ‘Brightwell’ (PBR-80 vs. PPR-80) showed the largest number of DEGs (6377), of which 3052 were upregulated and 3325 were downregulated. Through further screening, 174 DEGs were found related to plant hormone signal transduction, comprising 147 known genes and 27 new genes and that 76 genes were downregulated and 98 genes were upregulated. Of the eight DEGs randomly selected for quantitative real-time polymerase chain reaction verification, their expression patterns were consistent with those revealed by high-throughput sequencing. The results elucidated the underlying mechanism of xenia, thereby providing a solid theoretical foundation for the targeted breeding, quality control, and improvement of economic benefits of blueberry, which are of important theoretical value and practical significance.
Green care activities are associated with lower intensity and a lower risk of injury than agricultural activities aimed at producing agricultural and livestock products; however, the risk of health problems cannot be completely ruled out. To implement green care interventions to improve physical health, it is essential to identify the green care activity levels and biomechanical characteristics of the movements that are appropriate for each subject’s physical functions and goals. Thus, this study was conducted to determine the muscle activation of the upper and lower limbs during 19 green care farming activities. We used electromyography signals, which are biomedical signals that measure the action potentials generated in the muscles and nervous system when the muscles contract, to evaluate the muscle activation. Twenty adults (aged 29.9 ± 9.6 years) participated in this study. Participants performed 19 green care farming activities, including horticultural activity, animal-mediated, and off-farming activities. The participants performed each activity three times. The electromyography data were assessed using surface electromyography during activities to measure muscle activation. As a result, 16 upper and lower limb muscles were activated during the green care farming activities, which showed significantly different muscle activation by care farming activity. As a result of the comparison of muscle activity according to each muscle, many of the muscles of the upper and lower limbs were most activated during organizing a garden plot, transplanting plants, and collecting natural objects. In conclusion, the electromyography data obtained during this study suggest that green care farming interventions may be effective for training specific muscles of the upper and lower limbs.
Citrus microcarpa is a popular nutritious fruit that is widely cultivated in China. In recent years, many compounds with significant pharmacological activities have been isolated successfully from the pericarp of C. microcarpa. However, to date, there are no reports on the activity of C. microcarpa pericarp against root-knot nematodes. This study used the ethanolic extract from the pericarp of Hainan C. microcarpa and the impregnation method to determine its activity on J2 Meloidogyne enterolobii specimens and on single-egg hatching. The results showed that when J2 individuals were treated with 50 mg⋅mL–1 of the extract, the lethal concentration 50 values after 24 and 48 hours were 17.124 and 8.858 mg⋅mL–1, respectively. The mortality rate of nematodes after 48 hours of treatment was 100%, and the inhibition rate of single-egg hatching after 24 hours was 89.29%. The ethanolic extract of C. microcarpa peels showed high inhibitory and lethal activity against the M. enterolobii. The analysis of the chemical composition of the extract revealed 28 substances with insecticidal and antibacterial effects, including lignans, flavonoids, fatty acids, organic acids, terpenoids, and imidazole. The formulas of the chemical structures and pharmacological effects of these potential insecticidal and antibacterial substances were elucidated to provide a scientific basis and a theoretical reference for the use of C. microcarpa pericarps as a raw material for the development of new, natural plant nematicides.