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  • Author or Editor: He Li x
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Leaf stomata are the main channels for water loss of plants including cut flowers. In this study, we investigated the organographic distribution, morphological characteristics, light–dark response, and water loss contribution of stomata in cut carnations (Dianthus caryophyllus L. ‘Master’), which are prone to typical water deficits despite a few and small leaves. Stomata were observed in the upper and lower leaf epidermis, stem surface, abaxial bract epidermis, and abaxial sepal epidermis. Stomatal density (SD) on the stem surface was the highest and significantly greater than that on the upper and lower leaf and abaxial bract epidermis. The sepal epidermis had the lowest SD and the smallest stomata whereas the upper leaf epidermis had the largest stomata. Changes in the water loss rate increased in the light and decreased in the dark in both intact and leaves-removed cut carnations. The water loss rate of the former was greater than that of the latter. However, the water loss rate for the stem-only cut carnations had weak change rhythms and was much lower than that for the intact and leaves-removed cut carnations. These findings demonstrate the differential contributions of stomata in leaves, stems, and floral organs to water loss, and help to elucidate further the mechanism underlying postharvest water deficit in cut carnations.

Open Access

The use of grafted seedlings in vegetable crops has increased in recent years to enhance the resistance to biological and abiotic stresses, and improve yields. However, incompatibility restricts the wide application of grafting. In this study, two pumpkin (Cucurbita) cultivars, with great differences in grafting affinity and symbiotic affinity, were used as rootstocks and cucumber (Cucumis sativus) seedlings were used as the scion. The effects of compatibility or incompatibility on histological aspects, antioxidant enzyme activities, phenylpropanoid contents, and chlorophyll fluorescence were studied. The results showed that compatible graft combinations present a stronger resistance to the oxidative damage resulting from grafting and had relatively weak phenylpropanoid metabolisms. The results also indicated that the chlorophyll fluorescence levels of incompatible combinations were lower, except compared with the original fluorescence. Finally, a necrotic layer existed earlier in compatible graft combinations. These differences at the morphological, physiological, and cellular levels may govern compatibility and incompatibility, and may provide valuable information for determining the symbiotic affinity of grafted seedlings at an early stage.

Free access

GA20-oxidase (GA20-ox) is a key enzyme involved in the biosynthesis of gibberellic acid (GA). To investigate its role in plant growth and development, we suppressed MdGA20-ox gene expression in apple (Malus domestica cv. Hanfu) plants by RNA interference (RNAi). After 20 weeks of growth in the greenhouse, significant phenotype differences were observed between transgenic lines and the nontransgenic control. Suppression of MdGA20-ox gene expression resulted in lower plant height, shorter internode length, and higher number of nodes compared with the nontransgenic control. The expression of MdGA20-ox in transgenic plants was significantly suppressed, and the active GA content in transgenic lines was lower than that in the nontransgenic control. These results demonstrated that the MdGA20-ox gene plays an important role in vegetative growth, and therefore it is possible to develop dwarfed or compact scion apple cultivars by MdGA20-ox gene silencing.

Free access

The addition of pulverized grape pruning wood to grape soils has a positive effect on fruit quality. However, its effects on the soil microecology of the root zone and the growth of the grape plants are not fully understood. To address this, ‘Shine Muscat’ grapes were cultivated in media consisting of garden soil and crushed grape pruning material at different mass ratios [100:1 (T1), 50:1 (T2), 30:1 (T3), 20:1 (T4), and 10:1 (T5)] and in garden soil without the pruning material, as a control. The changes in the plant fresh weight, leaf area, soil and plant analyzer development (SPAD) value, root development, soil organic carbon, microbial biomass carbon, and soil enzyme activity were determined over time. High-throughput sequencing technology was used to determine the soil bacterial community structures. The pruning supplementation increased the grape plants fresh weight, leaf area, and SPAD values. The T2 and T3 treatments increased the grape root length, surface area, and the projected area and number of the root tips; the soil organic carbon content, microbial biomass carbon content, soil invertase activity, amylase activity, and β-glucosidase activity were also significantly increased. The addition of the grape pruning material was found to increase the bacterial diversity and richness 60 and 150 days after treatment. At the phylum level, Proteobacteria, Acidobacteria, and Actinobacteria were the dominant groups, and the grape pruning material increased the relative abundance of the Acidobacteria and Actinobacteria after 60 and 150 days. The relative abundance of the Actinobacteria in the T2 treatment was 1.7, 1.3, 1.5, and 1.3 times that of the control, after 60, 90, 120, and 150 days, respectively. The T2 treatment was identified as the optimal treatment for grapes in the field because it improved the soil microecology and promoted root and tree development the most compared with the other treatments tested.

Open Access

Dendrobium officinale Kimura et Migo is a famous traditional Chinese medicinal plant. It produces various phytochemicals, particularly polysaccharides, which have nutraceutical and pharmaceutical values. To increase its biomass production and polysaccharide content, our breeding program has generated a series of polyploid cultivars through colchicine treatment of protocorm-like bodies (PLBs). The present study compared two tetraploid cultivars, 201-1-T1 and 201-1-T2, with their diploid parental cultivar, 201-1, in an established in vitro culture system. Tetraploid ‘201-1-T1’ and ‘201-1-T2’ had shorter leaves and shorter and thicker stems and roots, and they produced higher biomass compared with the diploid cultivar. The length and width of stomata significantly increased, but stomatal density decreased in tetraploid cultivars. The PLB induction rates from the stem node explants of the tetraploid cultivars were significantly higher than those of diploid. However, the PLB proliferation of tetraploids was lower than that of the diploid. The mean number of plantlets regenerated from tetraploid PLBs was also lower than that of the diploid after 4 months of culture. Polysaccharide contents in stems, leaves, and roots of 6-month-old tetraploid plantlets were significantly higher than those of diploids. The polysaccharide content in the stem of ‘201-1-T1’ was 12.70%, which was a 2-fold increase compared with the diploid cultivar. Our results showed that chromosome doubling could be a viable way of improving D. officinale in biomass and polysaccharide production.

Free access

The procedure for Heuchera villosa ‘Caramel’ propagation was investigated, which involves shoot regeneration, rooting of regenerated shoots, and acclimation of regenerated plantlets. Petioles, as explants, were cultured on MS medium supplemented with 1-naphthylacetic acid (NAA), benzylaminopurine (BA), thidiazuron (TDZ) and callus formed on all media. Shoots were observed to proliferate from callus on media with BA and NAA, whereas no shoots regenerated on media with TDZ and NAA. On media containing 0.5 or 1.0 mg·L−1 BA in combination with NAA, the regenerated shoots showed severe hyperhydricity, whereas on media containing 0.1 mg·L−1 BA in combination with NAA, the regenerated shoots grew normally. The highest shoot induction rate, 90.6%, was obtained on media containing 0.1 mg·L−1 BA and 0.01 mg·L−1 NAA. The effects of indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), and NAA on rooting of H. villosa ‘Caramel’ was explored. The highest rooting rate (95%) was obtained on 1/2 MS medium containing 0.2 mg·L−1 NAA. In the subsequent acclimation experiments, about 85% of rooted plantlets survived and grew normally.

Free access

Accurate estimation of the nutrient requirements of Chinese onion is essential to increase its nutrient utilization efficiency and yield. In this study, the yield and nutrient uptake data were collected from major Chinese onion growing regions during 2001 to 2018, and the relationship between Chinese onion yield and nutrient uptake was evaluated using the Quantitative Evaluation of the Fertility of Tropical Soils (QUEFTS) model. The QUEFTS model predicted the linear-parabolic platform curve of the balanced nutrient uptake of Chinese onion and estimated the demand of nitrogen (N), phosphorus (P), and potassium (K) for the potential target yields ranging from 40 t/ha to 120 t/ha. The nutrients required for the target yield increased linearly before reaching 60% to 70% of the potential yield. Nutrient requirements for producing 1 t of Chinese onion were 1.91 kg N–0.28 kg P–1.71 kg K. The corresponding nutrient internal efficiency (IE, yield per unit nutrient uptake) was 524.6 kg/kg, 3585.7 kg/kg, and 584.3 kg/kg for N, P and K, respectively. Subsequently, a nutrition decision-making software, Nutrient Expert (NE), for the Chinese onion was developed based on the improved QUEFTS model. Field verification studies for NE fertilizer recommendation were conducted in multiple Chinese onion growing plots for 2 consecutive years. Results showed that the QUEFTS model can be used to accurately estimate the nutrient requirements for Chinese onion within a defined range of target yield.

Open Access

The use of resistant rootstocks is an inevitable trend in the development and production of grapes (Vitis sp.). The present study analyzed differences in the metabolites in grape seeds of different rootstock combinations (1103P, 5C, SO4, 3309C, 140R, and control) grafted onto ‘Cabernet Sauvignon’ (CS) wine grape (Vitis vinifera) scions (control, CS/CS, self-rooted grafting vines) using liquid chromatography–mass spectrometry (LC-MS) and nontargeted metabolomic techniques. Principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal-partial least squares discriminant analysis identified 30 significant metabolites and 22 metabolic pathways in the seeds of CS that differed significantly from the control seeds. This study revealed that rootstocks influence metabolite concentrations and metabolic pathways (alanine–aspartate–glutamate pathway, arginine-proline pathway, and the tricarboxylic acid cycle) in the scion onto which they are grafted. The rootstocks increased the concentration of delphinidin-3-(6-acetylglucoside), peonidin 3-(6-p-coumarylglucoside), L-threonine, and D-tartaric in CS seeds. Appropriate rootstock combinations can be used to improve the quality of grape seeds by changing the concentrations of amino acids, organic acids, polyphenols, and vitamin B. This study provides a theoretical basis for selecting grape rootstocks and provides important insights for improving the quality of commercial products derived from grape seeds.

Open Access

Extrapyramidal symptoms (EPSs) are common adverse reactions to antipsychotics in patients with schizophrenia. The purpose of this study was to investigate the effects of edible horticultural therapy (EHT) on EPSs in schizophrenic patients. This study assessed the changes in psychopathological symptoms and extrapyramidal symptoms in patients with schizophrenia before and after participating in a six-session EHT. Forty schizophrenic patients, recruited from Wuhan Wudong Hospital, were randomly assigned to the EHT group (average age: 45.40 ± 13.960 years) or the control group (average age: 49.30 ± 12.516 years). The EHT program held weekly sessions from May 2020 to June 2020. A psychiatrist assessed the psychopathological symptoms and extrapyramidal symptoms of schizophrenic patients in both groups with the Chinese version of the Positive and Negative Syndromes Scale (PANSS) and the Rating Scale for Extrapyramidal Side Effects (RSESE). After six courses of horticultural therapy, the terms of positive, negative, and general symptoms on the PANSS significantly improved in the EHT group. Moreover, the EPSs were also significantly improved in the EHT group. However, there was no change in the PANSS and RSESE scores in the control group. This study shows that EHT has the potential to improve not only psychopathological symptoms but also EPSs in psychiatric patients. This adds new evidence for EHT as an adjunct to treatment for schizophrenia.

Open Access