Search Results (11)

Plant propagation is a labor-intensive process in the nursery and greenhouse industry, with labor accounting for 41.4% of expenditures in 2019—$4.8 billion of the $11.6 billion total. Labor availability remains a critical issue, and current methods of applying root-promoting compounds to cuttings often yield inconsistent rooting responses. This research investigated honey as a rooting adjuvant and its effects on rooting in Red Cascade™ miniature rose (Rosa ‘MOORcap’), common camellia (Camellia japonica), and southern magnolia (Magnolia grandiflora ‘Little Gem’). For Red Cascade™ rose, adding honey to water-soluble indole-3-butyric acid (IBA) solutions did not improve root counts compared to IBA alone. However, 1000 µL∙L⁻¹ IBA produced more roots than 250 µL∙L⁻¹ IBA. Camellia and magnolia cuttings were treated with multiflora, Manuka, or commercial honey, alongside IBA rates of 0 to 4500 µL∙L⁻¹. In camellia, honey type or auxin rate did not significantly affect rooting, but local and multiflora honey combined with higher IBA rates increased root counts. For magnolia, multiflora honey improved both root number and quality, outperforming other treatments. While honey showed limited benefits for camellia and rose, multiflora honey demonstrated potential economic advantages for magnolia propagation, enhancing root quality and quantity for producers. Full article

Roses, a popular ornamental crop, often face various abiotic stresses during growth and development, such as cold, drought, and salinity. Rosa multiflora is a commonly used rootstock and exhibits strong resistance to both biotic and abiotic stresses, making it an ideal material for studying mechanisms for resistance. Among the largest plant families, MYB transcription factors play a crucial role in plant abiotic stresses. Our previous research has indicated that RmMYB44 could be involved in the low-temperature response of R. multiflora. This study further investigated RmMYB44, revealing that its expression levels were upregulated in response to chilling, drought, and salt stress. The results suggested its potential role as a key transcription factor in plant resistance to abiotic stresses. Additionally, RmMYB44 encoded a nuclear-localized protein without the self-activating function. The overexpression of RmMYB44 in tobacco plants enhanced the resistance to cold, drought, and salt stresses, as evidenced by the improved growth compared to wild-type (WT) plants under conditions of 4 °C, 30% water-holding capacity, and 200 mM of NaCl, respectively. Moreover, in overexpression tobacco plants, the levels of hydrogen peroxide and malondialdehyde (MDA) were significantly reduced; and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT); as well as the proline content and the expression levels of NtPOD, NtCAT, and NtCBF; were significantly elevated under abiotic stresses. We assumed that the resistance to abiotic stress in plants conferred by RmMYB44 was associated with the regulation of cell membrane integrity. This study aimed to elucidate the role of the RmMYB44 gene in the resistance mechanism of R. multiflora against abiotic stress, thereby providing a candidate gene for the molecular breeding of abiotic stress resistance in roses and related species. Full article

WRKY transcription factors are important players in plant regulatory networks, where they control and integrate various physiological processes and responses to biotic and abiotic stresses. Here, we analysed six rose genomes of 5 different species (Rosa chinensis, R. multiflora, R. roxburghii, R. sterilis, and R. rugosa) and extracted a set of 68 putative WRKY genes, extending a previously published set of 58 WRKY sequences based on the R. chinensis genome. Analysis of the promoter regions revealed numerous motifs related to induction by abiotic and, in some cases, biotic stressors. Transcriptomic data from leaves of two rose genotypes inoculated with the hemibiotrophic rose black spot fungus Diplocarpon rosae revealed the upregulation of 18 and downregulation of 9 of these WRKY genes after contact with the fungus. Notably, the resistant genotype exhibited the regulation of 25 of these genes (16 upregulated and 9 downregulated), while the susceptible genotype exhibited the regulation of 20 genes (15 upregulated and 5 downregulated). A detailed RT–qPCR analysis of RcWRKY37, an orthologue of AtWRKY75 and FaWRKY1, revealed induction patterns similar to those of the pathogenesis-related (PR) genes induced in salicylic acid (SA)-dependent defence pathways in black spot inoculation experiments. However, the overexpression of RcWRKY37 in rose petals did not induce the expression of any of the PR genes upon contact with black spot. However, wounding significantly induced the expression of RcWRKY37, while heat, cold, or drought did not have a significant effect. This study provides the first evidence for the role of RcWRKY37 in rose signalling cascades and highlights the differences between RcWRKY37 and AtWRKY75. These results improve our understanding of the regulatory function of WRKY transcription factors in plant responses to stress factors. Additionally, they provide foundational data for further studies. Full article

Flower scent is an important trait of ornamental roses and has been an important character in the selection processes. In the present study, the composition of the volatile organic compounds (VOCs) emitted by both petals and pollen of 21 garden roses (Chinensis, Climber, English rose, Floribunda, Hybrid Tea, Multiflora, Damascena, Musk rose, Polyantha, Rugosa and Shrub) was investigated through the GC-MS Static Headspace method. A total of 19 different VOCs were detected, and for each identified compound, an odorant description was included. In petals, the most common VOCs were 2-phenylethanol, methyl eugenol, and hexanal, present in 95%, 86% and 86% of garden roses, respectively. While, in pollen were methyl eugenol, methyl-1-butanol, and hexanal (present in 100%, 95%, and 90% of the genotypes, respectively), even if in lower content. The comparison between the petals and pollen profile shown that, even with less quantity, the main compounds characterizing the scent of the studied roses are present both in the petals and in the pollen (19 and 17 compounds, respectively), with different magnitude. Overall, the content of VOCs emitted by petals was more than five times higher than that produced by pollen. Different and characteristic VOCs profiles were emitted by petals and pollen of the studied garden roses. Full article

Cut roses are ornamental crops that are produced year-round, and the quality and yield of these cut flowers vary depending on the temperature and light intensity of the four seasons. Grafting improves productivity by increasing adaptability to negative environments, such as high temperature and low light intensity. The effectiveness of grafting depends on the type of the scion and rootstock. In order to confirm the effectiveness of stenting on roses, two varieties of cut roses (Rosa hybrida cv. Pink Beauty and Pink Shine) were grafted onto three rootstocks (R. multiflora Natal Briar, R. indica Major, and Rosa multiflora Hort. No. 1), which are widely used in cut rose, and the quality and yield of the cut flowers were investigated year-round according to the four seasons; then, principal component analysis (PCA) was performed. The Rosa hybrida cv. Pink Beauty (PB) used as the scion showed high yield and excellent growth in autumn when the light intensity was high and the temperature was low. The PB grafted onto the R. multiflora Natal Briar (NA) rootstock showed improved growth in spring, autumn and winter, excluding summer, and had the effect of lengthening the stem. The growth of PB grafted onto R. indica Major (RI) rootstock was also improved in spring, autumn, and winter, except summer, and in particular, the stem was lengthened and thickened. The rosa hybrida cv. Pink Shine (PS) was a variety whose yield of cut flowers increased in summer when the temperature was high. The PS grafted onto the three rootstocks gave a higher yield of cut flowers than the PS scion. The graft of PS/Natal Briar gave longer stems than the PS scion, and the graft of PS/Major gave thicker stems than the PS scion. PS grafted onto the Rosa multiflora Hort. No. 1 (N1) rootstock gave more petals than the PS scion. As such, cut roses grafted onto the Rosa canina cv. Natal brier (NA) improved the stem length, increasing the adaptability to relatively high temperatures, and the Rosa indica cv. Major (RI) improved the stem length and stem diameter, enhancing the adaptability to relatively low temperatures. Full article

Rosa lucieae is one of the famous wild ancestors of cultivated roses and plays a very important role in horticultural research, but there is still a lack of research on the R. lucieae chloroplast genome. In this study, we used the Illumina MiSeq platform for sequencing, assembly, and annotation to obtain the R. lucieae chloroplast genome sequencing information and compared genomics, selection stress analysis, and phylogenetic analysis with 12 other chloroplast genomes of Rosa. The R. lucieae cpDNA sequence has a total length of 156,504 bp, and 130 genes are annotated. The length of all 13 studied chloroplast genomes is 156,333~157,385 bp. Their gene content, gene sequence, GC content, and IR boundary structure were highly similar. Five kinds of large repeats were detected that numbered 100~116, and SSR sequences ranged from 78 to 90 bp. Four highly differentiated regions were identified, which can be used as potential genetic markers for Rosa. Selection stress analysis showed that there was significant positive selection among the 18 genes. The phylogenetic analysis of R. lucieae and R. cymose, R. maximowicziana, R. multiflora, and R. pricei showed the closest relationship. Overall, our results provide a more comprehensive understanding of the systematic genomics and comparative genomics of Rosa. Full article

Cut roses are grown throughout the four distinct seasons of spring, summer, autumn, and winter in Korea. Especially in the very hot or cold seasons of summer or winter, the temperature and light environments inside a greenhouse cause abiotic stress on the growth of horticultural crops. In a greenhouse where shade cultivation is performed in summer, the temperature is high and the light intensity is low, whereas in winter when shade cultivation is not performed, both temperature and light intensity are low. This experiment investigated the year-round growth and yield changes of cut roses grafted onto three rootstocks. The root activity of rootstocks was generally higher than that of the scion. The stomata of the grafted cut roses showed morphological changes according to the seasons. Compared with the scion, the stomata of grafted cut roses became smaller and their number increased in summer, whereas only the stomata size increased in winter. The grafted cut roses had characteristics of high photosynthetic efficiency such as photosynthesis rate, stomatal conductance, transpiration rate from rootstocks under harsh environmental conditions including temperature and light intensity, and thus the photosynthetic efficiency was higher than that of the scion. There was no significant change in the yield of grafted cut roses, but flower quality parameters such as the stem height, stem thickness, and weight of grafted cut roses were improved according to the rootstocks compared with those of the scion. In particular, in cut roses grafted with R. multiflora cv. Natal Briar and Rosa indica ‘Major’ rootstocks, the weight increased as the stem lengthened and thickened in spring, autumn, and winter. Therefore, grafting is effective in improving the quality of cut roses grown under abiotic stress caused by harsh temperature and light intensity conditions during winter. Full article

Powdery mildew disease caused by Podosphaerapannosa is the most widespread disease in global cut-rose production, as well as a major disease in garden and pot roses. In this study, the powdery mildew resistance of different wild rose varieties was evaluated. Rose varieties with high resistance and high sensitivity were used for cytological observation and transcriptome and expression profile analyses to study changes at the morphological and molecular levels during the interaction between Rosa multiflora and P. pannosa. There were significant differences in powdery mildew resistance among three R. multiflora plants; R. multiflora ‘13’ had high resistance, while R. multiflora ‘4’ and ‘1’ had high susceptibility. Cytological observations showed that in susceptible plants, 96 and 144 h after inoculation, hyphae were observed in infected leaves; hyphae infected the leaf tissue through the stoma of the lower epidermis, while papillae were formed on the upper epidermis of susceptible leaf tissue. Gene ontology enrichment analysis showed that the differentially expressed genes that were significantly enriched in biological process functions were related to the secondary metabolic process, the most significantly enriched cellular component function was cell wall, and the most significantly enriched molecular function was chitin binding. Changes in the transcript levels of important defense-related genes were analyzed. The results showed that chitinase may have played an important role in the interactions between resistant R. multiflora and P. pannosa. Jasmonic acid and ethylene (JA/ET) signaling pathways might be triggered in the interaction between susceptible R. multiflora and P. pannosa. In the resistant R. multiflora, the salicylic acid (SA) signaling pathway was induced earlier. Between susceptible plants and resistant plants, key phenylpropanoid pathway genes were induced and upregulated after P. pannosa inoculation, demonstrating that the phenylpropanoid pathway and secondary metabolites may play important and active roles in R. multiflora defense against powdery mildew infection. Full article

Gamma (γ)-irradiation can induce changes in plant morphology, cellular physiological activities, and genetic material. To date, there has been limited research on the molecular basis of leaf morphological abnormalities and physiological changes in irradiated rose plants. In this study, Rosa multiflora ‘Libellula’ plants were treated with ⁶⁰Co γ-rays. The irradiation resulted in the distortion of blade morphology. Additionally, the leaf chlorophyll content decreased, whereas the accumulation of reactive oxygen species increased. The differentially expressed genes between the control and 2–3 plants irradiated with 50 Gy were analyzed by RNA-seq technology, which revealed genes related to chlorophyll metabolism were differentially expressed. The expression levels of genes related to the regulation of antioxidant enzyme synthesis were downregulated. An RNA-seq analysis also identified the differentially expressed regulatory genes involved in leaf morphology development. Four genes (RcYABBY1, RcARF18, RcARF9, and RcWOX8) were selected, and their expression patterns in different leaf development stages and in various plant organs were analyzed. Furthermore, virus-induced gene silencing technology was used to verify that RcYABBY1 is involved in the morphogenesis of R. multiflora ‘Libellula’ leaves. The results of this study are useful for clarifying the molecular, physiological, and morphological changes in irradiated rose plants. Full article

Determination of the mass diffusion coefficient for dried, inhomogeneous material is difficult as it depends on the drying agent temperature and the moisture content and physical structure of the material. The paper presents a method for efficient determination of the water diffusion coefficient for wood solid cuboids dried using convective drying methods. In this work, the authors define a theoretical dependence of the Fourier number on reduced water content in a convectively dried cuboidal solid, based on a simplified theoretical solution of the diffusion equation for such a body. The material for drying included shoots of common osier, robinia (false acacia), multiflora rose, and energy poplar, dried at temperatures of 40, 50, 60, 70, and 80 °C, in free convection. The obtained results differ from the theoretically anticipated changes of the coefficient. Full article

Invasive plants are a concern in many forest ecosystems because they can impact tree regeneration and recruitment, alter hydrology, and degrade wildlife habitats. Management efforts are generally planned locally, based on the severity of the infestation, species involved, and characteristics of the forest stand. A broad, landscape-level context can provide additional information and help with planning efforts but is often lacking. In this study, we estimated landscape-level priorities for the management of five invasive forest plants in Minnesota. We used a multi-criteria decision analysis approach to integrate plant distribution models and data with geographic information about areas of conservation concern, recreational areas, and the economic benefits of treatment. The results varied across Ecological Classification System provinces and Minnesota native plant community classes. Four of the five invasive plants considered demonstrated an abundance of Medium- and High-priority areas for management in the Eastern Broadleaf Forest province of Minnesota. The average priority was generally lower in the Prairie Parklands and Tallgrass Aspen Parklands provinces, with Rhamnus cathartica as the only species demonstrating Medium or higher priorities in the latter. The mean priorities were Medium or higher for R. cathartica and Frangula alnus in mesic hardwood community types across the state, in addition to several fire-dependent systems. The priority distribution was most limited for Rosa multiflora, where the only Medium or higher priority results were found in a mesic hardwood system in the southeastern corner of the state. The results presented here highlight broad-scale patterns that can provide a synoptic overview of invasive plant priorities at the landscape scale. Full article