Acta Scientiarum Polonorum Hortorum Cultus

Mutual effects of humic acid content and nitrogen sources for vegetative development and flowering of snapdragon (Antirrhinum majus L.)

2024-03-08T16:18:24+01:00

Snapdragon (Antirrhinum majus L.), a garden plant cherished for its unique and colorful flowers, is widely used in bouquets and wreaths as a cut flower. The purpose of this study is to examine the effects of nitrogen sources (ammonium sulfate, AS; ammonium nitrate, AN; and urea) and humic acids from lignite sources (TKI-Humas and HUM-Zn) on the growth and flower production of snapdragon that are grown in pots under controlled conditions. It has been observed that plants started to flower during applications of HUM-Zn with AN and urea, whereas they remained at the vegetative stage during the application of HUM-Zn with AS. Furthermore, it has been determined that the two humic acid sources with AS usage prolonged the vegetative development and did not induce flowering of plants. Simultaneous application of humic acid and nitrogen sources has caused an increase in the leaf width, peduncle diameter, floret weight, chlorophyll content, and biomass of the snapdragon. Results show that the application of HUM-Zn with AN and urea has been effective on the plant’s vegetative organs, flowering, and dry weight. It indicated that HUM-Zn contains zinc, which is effective in flowering and biomass development. In conclusion, it was concluded that the simultaneous application of humic acid with AN or urea rapidly affected the flowering process of snapdragon.

In vitro propagation, cold preservation and cryopreservation of Taxus baccata L., an endangered medicinal and ornamental shrub

2024-03-08T16:18:10+01:00

In vitro propagation, cold preservation, and cryopreservation are three essential approaches to preserve the genetic resources of red-listed plants, including English yew (Taxus baccata L.). Different concentrations of plant growth regulators (PGRs) and different pre-treatments of cold preservation and cryopreservation are the prerequisites of these three approaches. Apical bud as explant and Murashige and Skoog (MS) as the culture medium for all three sections of the research, kinetin (Kin) and indole-3-butyric acid (IBA) as PGRs for the micropropagation section, and encapsulation-dehydration as pre-treatment for the sections of cold preservation and cryopreservation were used. The results of the micropropagation section indicated that the highest number of shoots (5.40 per explant) and roots (5.98 per explant) were obtained from the culture of the explants on the media containing 1 mg L^–1 IBA together with 1 and 2 mg L^–1 Kin, respectively. The results of the cold preservation section revealed that the highest percentage of survival of germplasms (100%) after storage in the refrigerator was observed in the apical buds pre-treated by dehydration of encapsulated explants with 0.75 M sucrose for two hours, followed by dehydration under a laminar airflow cabinet for two hours. The results of the cryopreservation section demonstrated that the highest percentage of survival of germplasms (100%) after storage in liquid nitrogen was obtained in the apical buds pre-treated by encapsulation-dehydration under a laminar airflow cabinet for two hours. At the acclimatization stage, 100% of the plantlets acclimatized suitably with ex vitro conditions.

Metabolomic analysis of Chinese yam (Dioscorea polystachya Turczaninow) bulbils at different germination stages by UPLC-Q-TOF-MS

2024-03-08T16:18:22+01:00

Bulbil germination is crucial to the survival of Chinese yam plants, the preservation of germplasm resources and the worldwide supply of food and natural medicine. There are still some unknowns regarding bulbil biochemical variations associated with germination. The metabolic changes during the germination of Chinese yam (Dioscorea polystachya Turczaninow) bulbils were studied using ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) at eight-time points covering all four phases of germination. It was determined that 27 metabolites, including organic acids, amino acids, sugars, lipid metabolites, phenolics and steroids, were responsible for the variation in the Chinese yam bulbil groups. A metabolomics pathway was proposed based on the identified metabolites. The main processes affected during germination were those related to carbohydrate metabolism, the TCA cycle, lipid metabolism, nitrogen metabolism, lipid metabolism and polyphenol metabolism. It is one of the earliest reports on the metabolite identification and profiling of Chinese yam bulbils at different germination stages.

Effects of summer pruning on the growth and photosynthetic characteristics of pepper (Capsicum annuum L.)

2024-03-08T16:18:13+01:00

The objective of the study is to investigate the mechanism by which summer pruning enhances the growth of pepper plants, as indicated by growth and fruit appearance indicators, photosynthetic rate and gas exchange parameters, rapid light response and induction kinetics curves and the related chlorophyll fluorescence parameters. The results indicated that the leaf growth rate, the individual pepper fruit weight, and the fruit longitudinal and cross diameters of the pruned group were significantly higher than those of the control. The stomatal conductance (G_s), intercellular CO2 concentration (C_i) and transpiration rate (T_r) of the pruned group were significantly higher than those of the control. The initial slope of the rapid light response curve, which represents light energy utilisation efficiency (α), the maximum electron transfer rate (J_max) and saturated light intensity (PAR_sat) were all higher in the summer pruning group than in the control group. The F₀ of the pruned group decreased by 16.83%, F_v/F₀ increased by 23.69%, PI_abs increased by 58.33%, and DIo/RC decreased by 22.09% compared to the control group. In summary, summer pruning significantly improves the leaf growth rate and fruit appearance quality of pepper, effectively promotes the photosynthesis of functional leaves, and reduces the degree of stress under adverse environmental conditions.

Effect of brassinosteroids on rooting of the ornamental deciduous shrubs

2024-03-08T16:18:16+01:00

Brassinosteroids are a developing group of growth regulators. They are a group of steroid hormones involved in plants’ physiological and developmental processes. Among other things, they are responsible for cell wall regeneration or cell elongation. This experiment aimed to examine the effect of rooting stimulants on rhizogenesis in cuttings of two deciduous shrub species: Philadelphus ’Virginal’ and Hydrangea paniculata ’Limelight’. Aqueous solutions of indole-3-butyric acid (IBA) at 200 mg·L^–1, Brassinolide (BL) at 0.05% and 24-epibrassinolide (24epiBL) (0.05%) were used in this study. The results obtained showed that both auxin and both of the brassinosteroids used increased the percentage of rooted cuttings almost twice, the degree of rooted cuttings and root length – for BL + IBA – longer roots than the control by 41% in jasmine and by 59% in hydrangea. The growth regulators applied during the rooting of cuttings also caused changes in the organic compound content of plant tissues and the activity of oxidative stress enzymes. The studies and results suggest that brassinosteroids may soon replace the popular rooting stimulants.

The effects of high temperature and low humidity on crop water stress index of seed pumpkin plants (Cucurbita pepo L.) in semi-arid climate conditions

2024-03-08T16:18:05+01:00

This study aimed to evaluate the effects of high temperature and low humidity on the crop water stress index (CWSI) of seed pumpkin plants grown under semi-arid climate conditions to determine the optimum irrigation time. This research unveils the critical impact of high temperature and low humidity on seed pumpkin growth, emphasizing the vital role of the CWSI in optimizing irrigation strategies and seed yield. Moreover, the relationship between CWSI, physiological parameters, and seed yield of the pumpkin was investigated. The mean CWSI values in the I70 (0.40) and I35 (0.56) treatments were 42% and 100% higher, respectively than those in the full irrigation (I100) treatment (0.28). While the I70 treatment showed manageable water stress with minimal impact, the I35 treatment experienced severe stress, significantly reducing crop growth and yield. The mean seed yield (SY) in the I70 treatment increased to 1245.2 kg ha^–1 compared to I35 (903.3 kg ha^–1) but remained lower than I100 (1339.3 kg ha^–1). The CWSI had negative correlations (p ≤ 0.01) with seed yield, chlorophyll content, and leaf area index, while it had positive correlations with water use efficiency and irrigation water use efficiency (p ≤ 0.01). This study showed that pumpkins could be grown successfully at 30% water deficit conditions, and a water deficit higher than 30% may cause a significant seed yield loss in semi-arid climate conditions. In addition, the results highlight the importance of optimal irrigation and CWSI monitoring for informed irrigation decisions and sustainable agricultural practices. Therefore, moderate water deficit (I70) can be adopted in pumpkin cultivation as an alternative to full irrigation.

Supplement of a commercial mycorrhizal product to improve the survival and ecophysiological performance of olive trees in an Arid region

2024-03-08T16:18:18+01:00

Rainfed olive groves in arid Tunisia face severe water scarcity and a low abundance of native arbuscular mycorrhizal fungi (AMF). We investigated if a supplement of commercial AMF-product at transplantation would improve olive plant survival and ecophysiological performance in an arid region. The commercial AMF product was added to two olive tree cultivars, ‘Meski’ and ‘Zarrazi’. There was an increase in the mycorrhizal intensity in the roots of ‘Meski’. Mycorrhizal symbiosis seems to have improved the survival of ‘Meski’ and the growth rate of ‘Zarrazi’. Plant water status and gas exchanges were enhanced in ‘Meski’. Mycorrhization helped maintain a higher photosynthetic assimilation rate and stomatal conductance in ‘Zarrazi’. AMF-symbiosis exhibited an inter-cultivar difference in the enhancement of the ecophysiological performance of olive trees under aridity. It also improved pre-existent indigenous defense strategies. It reinforced the avoidance strategy of ‘Meski’ but strengthened the tolerance strategy of ‘Zarrazi’.