Horticulture Environment and Biotechnology最新文献

The ethylene inhibitor 1-methylcyclopropene (1-MCP) is widely used in the apple industry as a post-harvest fumigation application to slow down the ripening process and maintain fruit quality during storage. With the development of a sprayable formulation (Harvista™, Agrofresh Inc, USA), it is becoming increasingly common in the apple industry to apply 1-MCP as a pre-harvest spray. This study investigated the impact of pre-harvest 1-MCP applied 1 week prior to harvest as a foliar application at 11.4 L ha⁻¹ in 1000 L water, on the quality and respiration rate of ‘Scilate’ apples grown in the Huon Valley, Southern Tasmania, Australia. Two trials were undertaken, trial 1 examined fruit quality, flesh browning (FB) and fruit softening in 1-MCP treated and untreated fruit while trial 2 compared the respiration rate of 1-MCP treated and untreated fruit. Despite no effect on fresh fruit quality attributes, pre-harvest spray application of 1-MCP influenced post-harvest fruit quality, storability, and respiration rate of apples. Fruit treated with 1-MCP showed higher malic acid concentration (1.2 g L⁻¹ vs 0.9 g L⁻¹) and lower juice pH (4.6 vs 4.9) even after 7.5 months of regular air cold-storage along with a six-fold reduction in fruit softening in comparison to untreated fruit (2% vs 13%). Pre-harvest treatment of 1-MCP reduced respiration rate by 32%, and incidence of CO₂ injury by over 40%. The incidence of radial type (senescent related) FB was reduced by 100%. A significant proportion of treated apples still suffered from severe CO₂ injury. This study has demonstrated that pre-harvest application of 1-MCP to ‘Scilate’ fruit can be useful in maintaining long-term fruit quality during storage, reducing respiration rate, and lowering the incidence of FB in general. However, the risk of severe CO₂ injury remains, especially with larger fruit harvested from trees with lighter crop loads.

Hydrangeas with large inflorescences are widely used as cut flowers and in floral arrangements. However, the genetic diversity of commercially grown hydrangeas has been limited owing to the breeding focus on popular species. Therefore, this study was conducted to suggest interspecific breeding strategies for expanding the genetic diversity in Hydrangea L. by evaluating genetic diversity in the seven main species collected in Korea and analyzing cross compatibility via intra- and interspecific hybridization. Interspecific diversity evaluation using simple sequence repeat markers resulted in the segregation of 35 varieties accounting for seven species into five groups as follows: (1) Hydrangea paniculate group, (2) Hydrangea arborescnes group, (3) Hydrangea anomala and Hydrangea aspera group, (4) Hydrangea quercifolia group, and (5) Hydrangea macrophylla and Hydrangea serrata group. Cross compatibility was confirmed via intra- and interspecific crossing, and hybrids were obtained in 18 crossing combinations. Intraspecific hybrids tend to be easy to obtain, but interspecific hybrids are difficult to obtain due to a variety of factors. While most of the interspecific hybrids were obtained using ovule culture, the crossing between H. macrophylla and H. serrata created hybrids from seed sowing, indicating that H. serrata is a subspecies of H. macrophylla. Bilateral and unilateral incompatibilities were observed across the obtained hybrids. Particularly, weak bilateral compatibility was observed between H. serrata and H.paniculata. Accordingly, it was proposed that hybrids between H. macrophylla and H. serrata can be successfully used as parental materials in crossing with H. paniculata to improve cold tolerance. In addition, cross compatibility was improved in interspecific crossing using H. macrophylla and H. arborescens as maternal plants. It is anticipated that these finding will help improve the genetic diversity in commercial hydrangeas.

Ozone (O₃) absorption through leaf stomata disrupts plant physiological processes, prompting various defense mechanisms to mitigate O₃-induced harm. This study measured parameters including cell structure, gas exchange, carbon assimilation, lipid peroxidation, and biogenic volatile organic compounds (BVOCs) emissions to evaluate the physiological impact of Prunus × yedoensis under elevated ozone (E-O₃) exposure. The seedlings exhibited a slight stimulatory effect during the early phases of E–O₃ exposure; however, E–O₃ beyond a specific threshold significantly and negatively affected photosynthetic parameters, pigment content, and potential antioxidant capacity, and E–O₃ was significantly correlated with the BVOCs emission rate. After three weeks of E–O₃ exposure, no significant differences were observed in leaf stomatal appearance in the field emission scanning electron microscopy results, but according to the results of leaf mesophyll cell ultrastructure, grana degradation, membrane decomposition, cell wall thickening, wart–like protrusion formation, and increased plastoglobulus density within the chloroplasts were observed. Chlorophyll content significantly decreased by 38.71%, and solute leakage increased by 20.57% in the E–O₃ group. The net photosynthetic rate was almost two times lower with E–O₃. In contrast, there were no significant differences in stomatal conductance. In conclusion, E–O₃ can induce a hormetic stimulatory effect during the early exposure phase. However, when the critical threshold is exceeded, O₃ adversely affects the physiology of P. × yedoensis seedlings. Therefore, E–O₃ is a harmful air pollutant that hinders the growth of woody plants, and urban trees require the continuous management of O₃ phytotoxicity.

Reynoutria sachalinensis is an herbaceous plant that has gained attention as a promising functional ingredient in bio-health. However, information on the propagation of this plant remains limited, and information on the germination and dormancy characteristics of R. sachalinensis seeds native to Korea is yet to be established. This study aimed to determine the optimal method for breaking dormancy by classifying the dormancy types in R. sachalinensis seeds collected from Ulleungdo. Initial observations revealed that R. sachalinensis seeds exhibited water permeability and fully developed embryos. However, further investigation into seed dormancy was warranted due to the low germination percentage of less than 20%. To address this dormancy, a cold stratification treatment lasting four weeks was employed, which confirmed the presence of physiological dormancy (PD) in R. sachalinensis seeds. Additionally, prolonged after-ripening, without any special treatment, led to the loss of dormancy. Both treatments demonstrated that the dormancy of R. sachalinensis seeds could be overcome by alternative methods for non-germinated seeds. Accordingly, scarification was used to treat seeds whose dormancy was broken by after-ripening, and all viable seeds germinated. Therefore, it is assumed that R. sachalinensis seeds have two types of PD—non-deep and intermediate, exhibiting polymorphism as an adaptive strategy to thrive in challenging environments. Through this study, the scope of industrial use can be expanded based on stable and uniform seedling production by establishing conditions that efficiently break dormancy in R. sachalinensisseeds that exhibit polymorphism.

Interspecific hybridization in the genus Rosa (Rosaceae) is a common natural phenomenon. Hybrids often exhibit heterosis and new combinations of traits, which can provide raw materials for horticultural breeding. DNA barcodes and microsatellites have been proposed to facilitate species discrimination and hybrid detection. However, most SSR markers developed for roses have been found unapplicable to Rosa sect. Synstylae because of null alleles or failed amplification. In this study, we designed 15 pairs of microsatellite primers, along with four previously developed primers specifically for Rosa sect. Synstylae; we then analyzed 174 individuals of three closely related and sympatrically distributed Rosa species as a test case to evaluate the consistency between morphological and genetic hybrid identifications and to compare the discrimination efficiency of the DNA barcodes versus SSRs in detecting admixture. Principle coordinate analysis identified several individuals with intermediate phenotypes among the three rose species. Hybridization, intraspecific morphological polymorphism, and sample collection at different growth stages or phenological phases may have hindered species identification based on morphology and distorted the morphological clustering results. The molecular analyses showed that 12 (6.8%), 13 (7.4%), and 15 (8.6%) individuals were identified as admixed by STRUCTURE, NewHybrids, and nrITS sequences, respectively, of which only seven hybrids showed signs of admixture across all three methods. About 81% of the morphologically identifiable hybrids exhibited admixture based on SSRs. Meanwhile, approximately 69% of morphologically identifiable hybrids were detected, but four morphologically pure species individuals were identified as genetically admixed based on nrITS sequences. Some morphologically pure species individuals were genetically identified as hybrids while some morphological hybrids were identified as pure individuals based on certain molecular markers. Overall, EST-SSRs discriminated morphological hybrids more accurately than nrITS. We inferred that there is ongoing interspecific gene exchange among the three wild Rosa species that obscures morphospecies boundaries. Combining multiple data types and analytical approaches offers powerful utility for hybrid detection, regardless of the level of hybridization.

Kimchi cabbage, a staple in South Korean cuisine, exhibits taste variations depending on the season of cultivation, with significant implications for kimchi production quality. In this study, we conducted comprehensive metabolomic analyses of kimchi cabbage grown in diverse environments throughout the year. We identified 15 primary metabolites, 10 glucosinolates, and 12 hydrolysates, providing valuable insights into the metabolic composition of kimchi cabbage. Using this data, we developed predictive models for taste and quality differentiation in kimchi cabbage based on the season of cultivation. Three regression models, including Orthogonal Partial Least Squares regression (OPLS), Partial Least Squares (PLS) regression, and Random Forest regression, were employed to predict seasonal variation. The models exhibited high accuracy, with R² values ranging from 0.77 to 0.95, indicating their potential for distinguishing seasonal differences. Notably, hydroxyglucobrassicin, 5-oxoproline, and inositol consistently emerged as significant metabolites across all models. Additionally, we developed regression models for predicting sweetness and bitterness in kimchi cabbage. Metabolites such as malic acid, fructose, and glucose were positively correlated with sweetness, while neoglucobrassicin and glucobrassicin were negatively correlated. Conversely, metabolites like glucoerucin and glucobrassicin were positively correlated with bitterness, while malic acid and sucrose were negatively correlated. These findings provide a valuable foundation for understanding the metabolic basis of taste variation in kimchi cabbage and offer practical applications for improving kimchi production quality. By incorporating more varieties and multi-year data, future research aims to develop even more accurate predictive models for kimchi cabbage taste and quality, ultimately contributing to the consistency of kimchi production.

Graphical Abstract

BMI1 is the main component of the Polycomb Group Complex 1 (PRC1), which functions as an important epigenetic inhibitor of various regulatory genes associated with shoot apical meristem, embryonic development, flowering, senescence and so on. However, its role in the regulation of grapevine development is still unclear. In order to explore the function of VvBMI1a gene in the regulation of flowering in Vitis vinifera ‘Cabernet Sauvignon’, the subcellular localization, expression pattern, yeast two-hybrid, two-molecule fluorescence complementation and flowering time of transgenic Arabidopsis were analyzed. The results showed that VvBMI1a, a member of RING domain-containing proteins family from grapevine (Vitis vinifera), is involved in controlling plant flowering time. Expression of VvBMI1a was abundant in the shoot tips and inflorescence meristems of grapevine. VvBMI1a protein is localized in the nucleus. VvBMI1a could interact with VvRING1a protein which belonged to PRC1. Phenotypic analysis showed that VvBMI1a over-expression lines had earlier flowering time than wild-type plants under long-day (LD) conditions. Further analysis by qRT-PCR and transcriptome suggests that both the suppression of FLC and activation of FT, SOC1, SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 5 (SPL5), AGL8 were observed in VvBMI1a-overexpressing lines, resulting in early flowering. Our results provide the evidence demonstrating the effectiveness of manipulating VvBMI1a to alter the flowering time of plants. In a word, ectopic overexpression of VvBMI1a inhibited the expression of FLC, activated the expression of FT, SPL5, AGL8 to alter the flowering time of Arabidopsis plants.

The effects of preharvest or/and postharvest treatments with salicylic acid (SA) on the physicochemical quality of peach fruit, infection with the fungus Monilinia laxa and the phenolic response to infection in SA treatments in different peach peel tissues were evaluated. Preharvest SA treatments had an effect on the physical quality parameters only at harvest on three times SA-sprayed peaches, with which a lower hue angle and a higher percentage of red blush occurred, indicating better coloration of the fruit. It was found that the intensity of M. laxa infection was not affected by preharvest SA treatments, only by soaking peach fruit in SA solution after harvest. On SA soaked peach fruit, M. laxa spread between 1.8 and 3.9 mm/day slower than on non-soaked fruit, resulting in a 34% lower intensity of infection five days after infection. Peach fruit treated with SA after harvest also had a significantly lower percentage of sporulating fruit (7.8%) compared to non-soaked fruit (68.9%). The phenolic response differed between tissues, since the proportion of hydroxycinnamic acids and anthocyanins was higher in the healthy tissue of infected fruit, while the proportion of flavanols was higher in the boundary tissue of infected fruit. The strongest phenolic response to infection and treatments with SA was in higher levels of neochlorogenic acid, cyanidin-3-glucosides and cyanidin-3-rutinosides.

Improper handling degrades the quality of the produce and causes economic losses. Thus, to study the effect of post-harvest handling on essential oil content and chemical constitutions, different experiments were conducted on two aromatic grasses. The first experiment was conducted on lemongrass crop using three accessions (A1, A2, and A3) and three storage times (0, 24, and 48 h), the second experiment was conducted on palmarosa crop with five harvesting dates (12 October, 27 October, 10 November, 25 November, and 10 December) and three storage time (0, 24 and 48 h). The essential oil percentage of the major compound of lemongrass (citral) was recorded significantly higher in accession A1, while 46.49% higher EO content was recorded when processing the biomass after 48 h of storage as compared to 0 h. Significantly higher (93.84%) increase in essential oil content of palmarosa was recorded on the 25 November harvesting date, while 112.69% higher EO content was recorded for storage of 48 h than 0 h. The major chemical compound geraniol attained the highest percentage (88%) on the 10 December harvesting date and storage time of 48 h recorded 85.78% higher EO content than 0 h. The degradation of constituents, rearrangement, and disappearance results in variations in essential oil composition. Harvesting at proper maturity and quality stages with longer storage time of the plant resulted in quality essential oil when compared to early harvest and shorter storage time in both aromatic plants.

Graphical abstract

Harvesting at proper stages with longer storage time resulted in quality EO of aromatic grasses

Investigating agricultural traits and silymarin content variations in the domestic cultivation environment is necessary since the interest in milk thistle has increased as a high-income cash crop or plant capable of crop rotation. Therefore, this study selected six varieties cultivated for three years in Hwaseong, Gyeonggi-do, and one year in Haenam, Jeollanam-do, to analyze agricultural phenotypes and silymarin content variations. Among the varieties, M05 and M03 expressed the highest silybin and silymarin contents, maintaining a silybin ratio of over 15%. In addition, M03 and M05 exhibited no or minimal silydianin content in both regions, likely due to genetic factors. However, silydianin content tended to increase in most Haenam varieties, excluding M03 and M05. Compared to other varieties, M06 had a notably higher silydianin content and was further accumulated in Haenam, indicating a potential environmental influence.