Background: Protocorm-like bodies (PLBs) represent a major morphogenic pathway in orchids and are characterized by cellular reprogramming, tissue differentiation, and developmental reorganization. Although PLB formation is widely explored for orchid micropropagation, endopolyploidy dynamics during PLB morphogenesis remain poorly understood. Aims: This study aimed to characterize endopolyploidy patterns and evaluate nuclear DNA content maintenance during PLB morphogenesis and plant regeneration in Cattleya tigrina. Methods: Basal leaf explants were cultured under PLB-inducing conditions in vitro. Morphological and histological analyses were performed throughout PLB development, while nuclear DNA content was estimated by flow cytometry in leaf regions, PLBs at successive developmental stages, and regenerated plants. Results: The leaf base was the most responsive region for PLB induction, showing intense cell proliferation and meristematic activity. Flow cytometric profiles consistently revealed 2C, 4C, and 8C nuclear DNA peaks, indicating endopolyploidy in somatic tissues. PLBs exhibited transient shifts in ploidy distribution during active proliferation phases, particularly at intermediate developmental stages, when 4C nuclei became predominant. Regenerated plants maintained nuclear DNA contents comparable to the original explants. Conclusions: Endopolyploidy is an intrinsic and developmentally regulated feature of PLB morphogenesis in Cattleya tigrina. PLB-mediated regeneration maintained overall nuclear DNA content under the evaluated in vitro conditions.

Background: RAB Guanine Nucleotide Dissociation Inhibitors (RAB GDIs) are important vesicle transport regulators in eukaryotes, participating in the functional cycle of RAB GTPases by stabilizing their non-active GDP-conformation. Aims: We address the importance of the three Arabidopsis thaliana RAB GDI paralogs by genetic and developmental analyses and put these results into the seed plants evolution context. Methods: We use methods of genetics, microscopy, and phylogenetics. Results: Our genetic analyses of Arabidopsis T-DNA insertional mutants confirm recent CRISPR alleles data indicating lethality of double gdi1 gdi2 mutants, and our microscopic data point to embryo development arrest in double mutant seeds. We also confirm the involvement of GDI2 and GDI3 in pollen tube growth. Moreover, our data show that GDI1 also contributes to proper pollen function. Our phylogenetic analysis reveals independent diversification of RAB GDIs in Gymnosperms and Angiosperms, with early specialization of an Angiosperm reproduction- and gametophyte-related clade. Conclusions: In Arabidopsis, RAB GDI1 and 2 are important for the vegetative growth while RAB GDI2 and 3 are vital for reproduction. Evolution of the RAB GDI family reflects the evolution of seed plants.

Background: The Viola plants have important value for theoretical and applied research. Agrobacterium-mediated transient expression enables rapid target protein production in plants, yet this system remains poorly established in Viola. Aims: To establish an efficient Agrobacterium-mediated transient expression system in Viola. Methods: By employing two types of A. tumefaciens strains (EHA105 and LBA4404) and green fluorescent protein (GFP) as a reporter, we demonstrated the transient expression in the leaves of four Viola species, including Viola philippica, V. prionantha, V. tricolor, and V. dissecta. Results: GFP transient expression peaked at 4 dpi in all four Viola species. Agrobacterium at OD₆₀₀ = 0.3 yielded optimal expression, and strain EHA105 was superior to LBA4404; V. philippica showed the highest GFP accumulation. In the optimal system, exogenous indole-3-acetic acid (IAA) improves GFP transient expression with maximum promotion at 50 ng/mL, while methyl jasmonate (MeJA) has no facilitating effect. This system enables transient expression of FMDV VP1, whose expression is also markedly increased by 50 ng/mL IAA. Conclusions: This study successfully established a transient expression system for Viola and identified factors affecting Agrobacterium-mediated transient expression efficiency in this genus.

Background: The tomato brown rugose fruit virus (Tobamovirus fructirugosum, ToBRFV) is an emerging tobamovirus that has quickly become a significant obstacle to the production of tomatoes and peppers worldwide. It is now classified as a regulated quarantine pathogen. Effective containment requires rapid, reliable, inexpensive, and safe diagnostic protocols for routine screening in laboratories and production systems.
Aims: We aimed to thoroughly evaluate integrated molecular and serological diagnostic methods for ToBRFV and develop biosafe positive controls suitable for high-throughput and decentralized applications.
Methods: We evaluated the following methods: conventional RT-PCR, one-enzyme RTX-PCR, immunocapture RT-PCR, recombinase polymerase amplification, loop-mediated isothermal amplification with colorimetric detection, Western blotting, dot blot, and tissue blot immunoassay. The non-infectious positive control was prepared using the GoldenBraid 3.0 cloning system. We developed a single-seed assay that enables direct testing of tomato seed stocks.
Results: Among the evaluated molecular methods, RTX-PCR was particularly advantageous due to its minimal sample handling, reduced cost, and ability to bypass RNA extraction. The tissue blot immunoassay enabled high-throughput, low-cost screening of hundreds of samples per day using only basic equipment. Although ToBRFV was frequently detected in seeds harvested from infected plants, no systemic infection was observed in progeny seedlings, confirming the low rate of true vertical transmission. A non-infectious positive control was prepared and successfully employed in molecular methods.
Conclusions: Our findings provide an integrated diagnostic framework combining molecular, serological, and biosafety tools to effectively monitor and contain ToBRFV in commercial production and phytosanitary settings.

Background: Cymbidium faberi Rolfe is an ornamental orchid of high economic value, however, an efficient genetic transformation system has not yet been reported for this species. Aims: This study aimed to establish an Agrobacterium tumefaciens-mediated genetic transformation system for C. faberi and to optimize the key factors affecting transformation performance. Methods: Rhizomes, calli, and inflorescences were used as explants. The pCAMBIA3301-EGFP vector was introduced using Agrobacterium strain GV3101. Explant type, pre-culture duration, bacterial density (OD₆₀₀), infection time, co-cultivation period, and antibiotic selection were systematically optimized. Putative transformants were screened by green fluorescence and verified by polymerase chain reaction (PCR). Results: Calli pre-cultured for 3 d were the most suitable recipient material. The optimal transformation conditions were an Agrobacterium suspension of OD₆₀₀ = 0.2, infection for 5 min, and co-cultivation for 2 d; under these conditions, explant survival reached 72.22%. Two independent transgenic plantlets with stable integration of the enhanced green fluorescent protein gene were obtained and confirmed by PCR. Conclusions: This study provides an Agrobacterium-mediated transformation protocol for C. faberi and offers a technical basis for molecular breeding and gene function studies in this orchid.

Background: Stem base rot disease poses a serious threat to the Cyclocodon lancifolius industry, yet its causal agent remains unidentified. Aims: In this study, we aimed to identify the pathogenic fungi responsible for this disease and to screen for effective biocontrol strains against the causal agent. Methods: We isolated and identified the fungal pathogen from the stem base of diseased plants and confirmed its pathogenicity by fulfilling Koch's postulates. Multilocus sequence analysis identified the pathogen as Stemphylium lycopersici. Results: An antagonistic strain, Bacillus subtilis YHYS1, exhibited significant inhibition (51.8%) of S. lycopersici growth in a plate confrontation assay. Volatile compound analysis further confirmed the fungistatic potential of YHYS1. These findings highlight the promise of YHYS1 as an eco-friendly alternative to chemical fungicides for controlling stem base rot disease in C. lancifolius caused by S. lycopersici. Conclusions: Our characterization of this novel disease in C. lancifolius has elucidated the pathogenic features of Stemphylium species, an essential yet understudied group of plant pathogens. These findings provide valuable references for the diagnosis and control of diseases affecting C. lancifolius.

Background: In the last decades, vacuum infiltration had been applied for the Agrobacterium-mediated transient expression of foreign gene in plants. However, the relevant influencing factors have not been fully studied yet. Aims: This study aimed to evaluate the effects of vacuum infiltration pressure, time of vacuum infiltration, concentration of Agrobacterium tumefaciens (A. tumefaciens), and incubation time post infiltration on the transient expression of foreign gene in leaves of Nicotiana benthamiana (N. benthamiana). Methods: Two A. tumefaciens strains, LBA4404 and EHA105, carrying a reporter gene of green fluorescent protein (GFP), were used to infiltrate leaves of N. benthamiana via vacuum infiltration. The changes of GFP expression with changes of vacuum infiltration pressure, time of vacuum infiltration, concentration of A. tumefaciens, and incubation time post infiltration were measured. Results: Increase of vacuum pressure from 0.03 to 0.07 MPa increased the GFP expression in the leaves infiltrated with either LBA4404 or EHA105, and the vacuum pressure at 0.07 MPa made almost all of area of the infiltrated leaf express GFP. The increase of the time of vacuum infiltration from 10 to 20 min significantly enhanced the GFP expression in either the LBA4404 or EHA105-infected leaves. Among the different concentrations of Agrobacterium (from OD600 0.1 to 0.9), the concentrations of LBA4404 strain suspension at OD600 0.5 and EHA105 strain suspension at OD600 0.3, respectively, were most effective concentrations for enhancing the GFP expression in the infected leaves. The increase of incubation time post infiltration from 2 to 4 days largely enhanced the intensity of GFP expression in the either LBA4404 or EHA105-infected leaves. However, further increase of incubation time post infiltration from 4 to 6 days decreased the GFP expression in the infected leaves. Conclusions: Vacuum infiltration pressure/time, concentration of A. tumefaciens, and the incubation time post infiltration were important factors affecting the level of transient expression by vacuum infiltration. Optimizing these factors is essential for improving the level of transient expression of foreign gene by vacuum infiltration.

Background and aims: Tire wear microplastics (TWMs) are emerging environmental contaminants, but their ecological risks to agricultural systems remain poorly understood. Methods: Rice seedlings were exposed to 0, 10, 100, and 1 000 mg L^-1 TWMs for 10 days. Growth parameters, chlorophyll fluorescence, and antioxidant enzyme activities were measured. Results: TWMs promoted growth; exposure to 1 000 mg L^-1 TWMs increased plant height and root length by 8.06% and 57.38%, respectively. Chlorophyll fluorescence analysis revealed that TWMs significantly suppressed rETR_max by 32.53 - 43.62% and altered qP and NPQ. TWMs inhibited Y(NPQ) while enhancing Y(NO) loss, indicating impaired photoprotective dissipation and aggravated photodamage. TWMs also inhibited SOD, POD, CAT, and APX activities in both leaves and roots, with root CAT and APX decreasing by up to 37.35% and 40.34%, reflecting a direct impairment of the antioxidant defense system. Conclusions: Rice seedlings achieve TWM-induced short-term growth at the expense of compromised photosynthetic efficiency and antioxidant defense, leading to an unsustainable compensatory state. This study provides physiological evidence for assessing TWMs phytotoxicity in agricultural systems.

Background: Idesia polycarpa var. vestita Diels is an oil-bearing woody plant of significant economic value. Aims: To accelerate the propagation of its elite germplasm, this study aimed to establish an efficient and stable in vitro rapid propagation system using one-year-old stem segments from elite plants. Methods: Young stem explants were disinfected with 75% ethanol for 40 s, followed by 0.1% HgCl₂ for 6 min. MS or 1/2 MS served as basal media, and various combinations of plant growth regulators were tested for axillary bud induction, proliferation, and rooting. Results: The optimal disinfection protocol yielded a 38.10% survival rate. The best axillary bud induction medium was MS + 1.5 mg/L 6-BA + 0.05 mg/L NAA + 0.08 mg/L TDZ, achieving 100% induction. For proliferation, MS + 1.5 mg/L 6-BA + 0.06 mg/L NAA + 0.01 mg/L TDZ (proliferation coefficient 5.81) was optimal. Rooting was best with 1/2 MS + 0.3 mg/L IAA + 0.1 mg/L NAA (100% rooting, 14 roots/plant). Conclusions: This study established a reliable micropropagation system for Idesia polycarpa var. vestita, providing technical support for the efficient production of high-quality seedlings.

Imported from Scholar: Original Article

Background: Many concerns have been raised about the extensive use of agrochemicals and their impacts on environment and soil. Some serious issues include increased soil salinization, toxicity and decrease in soil microbial biodiversity. Biostimulants have emerged as a promising ecofriendly alternative to agrochemicals. Humic substances (HSs) are biostimulants with many beneficial effects in plants physiology and productivity. Aims: This review aims to synthesize current evidence on the role of HSs in supporting sustainable agriculture that improves crop productivity while maintaining good soil health in changing environmental conditions. Methods: Relevant studies related to HSs and their effects on soil fertility, plant growth, stress tolerance and hormonal regulation were collected from major scientific databases including Scopus, Web of Science, and Google Scholar. The main outcomes of these studies were extracted and analyzed to provide an overview of the available evidence. Results: The literature shows that the integration of HSs into agricultural practices improves soil structure, increases water retention, maintains healthy microbial diversity and enhances plant productivity. Conclusions: This review highlights the importance of using HSs in enhancing soil health and plant physiology. However, further studies are required to integrating new technologies and diversify HSs sources, plants species, and different environments.

Background: Platycladus orientalis L. is a drought-tolerant conifer valued for its ornamental and medicinal properties. However, efficient regeneration systems for this species remain limited, hindering its propagation and conservation. Aims: The aim of this study was to develop a reliable protocol for indirect organogenesis of Platycladus orientalis under in vitro conditions, evaluating the influence of explant type, culture medium, light exposure, and pretreatment on regeneration efficiency. Methods: Cotyledon, hypocotyl, and radicle explants were cultured on different media formulations. The effects of light and darkness during callus induction and shoot elongation were compared. Seeds underwent or avoided vernalization and scarification treatments to assess their influence on germination and callus formation. Results: Cotyledon explants achieved the highest callus induction rate, reaching 74.06%, particularly under dark conditions. Exposure to light during elongation significantly enhanced callus proliferation and shoots differentiation. Quoirin and LePoivre medium promoted the greatest number of adventitious shoots, with an average of 7.9 shoots per explant, while other media tested showed lower effectiveness. Germination was higher in non-vernalized and non-scarified seeds cultured in Quoirin and LePoivre medium. Conclusions: The established protocol enables efficient indirect organogenesis and shoot regeneration of Platycladus orientalis using cotyledon explants and Quoirin and LePoivre medium. The finding provides a valuable tool for clonal propagation and conservation of this species, supporting both ornamental cultivation and the preservation of its genetic resources.

This study investigated the impacts of acid rain stress on Akebia trifoliata and the mitigation effects of exogenous curcumin (CUR) using integrated physiological, anatomical, and transcriptomic analyses. Acid rain stress significantly decreased chlorophyll content (total chlorophyll by 64.8%), leaf epidermal thickness (upper and lower epidermis by 58.9 and 35.6%), and starch content (by 63.9%), while increasing oxidative stress markers (MDA by 82.6%; ROS production by 345.8%) and content of osmolytes (proline by 64.4%). A. trifoliata counteracted acid rain stress by enhancing superoxide dismutase (SOD) and catalase (CAT) activities, and by modifying leaf anatomical structure (increased mesophyll tissue thickness). CUR application, particularly at 50 μmol/L (CUR50), effectively alleviated damage by maintaining leaf structural integrity and promoting growth recovery. Transcriptomic analysis revealed 993 differentially expressed genes between CUR50-treated vs. acid rain-stressed plants, primarily enriched in the plant hormone signal transduction and phenylpropanoid biosynthesis pathways. These results demonstrate that CUR mitigates acid rain stress through coordinated physiological adaptations and transcriptional reprogramming of stress-responsive pathways. This study provides a theoretical basis for cultivating A. trifoliata and implementing phytoremediation strategies in acid rain-affected regions.

With the drastic changes in global climate and the increasing frequency of extreme weather events, abiotic stress poses a significant threat to future food crop production and is a major contributor to crop yield reduction (Ahmad et al., 2010). Wheat, one of the world's primary food crops, is susceptible to both abiotic and biotic stresses at all stages of its growth and development. Numerous studies have indicated that drought stress severely limits the growth and productivity of wheat (Xue et al., 2014; Faran et al., 2019). Therefore, understanding the effects of drought stress on wheat grain germination and developing strategies to mitigate the inhibition of germination caused by drought are crucial for enhancing wheat yield.

Excess water is an abiotic stress in plants, but the level at which excess water becomes varies widely between plant species. We conducted a two growing season replicated excess flooding experiment that was planted with 24 accessions of perennial ryegrass which had been vegetatively propagated to ensure equal representation of genotypes within an accession, both cultivars and ecotypes, from various geographical origins. The excess water treatment applied over the winter periods was achieved with irrigation. Yields increased in the winter-flooded treatment in contrast to the non-artificial watered control treatment significantly in 2017. In 2018 the same trend could be seen, but was not significant. Differences in composition of macro- and micronutrient profiles were observed. Sulphur was the only element with highly significantly increased concentration (0.25%) in flooded samples compared to control. Phosphorus, copper, iron, manganese, and molybdenum decreased statistically significantly under flooded conditions. In conclusion, perennial ryegrass is coping extremely well with excess water supplied over the winter period and can utilise it effectively in spring.

In plant breeding, polyploidization is an established technique to obtain superior phenotypic characteristics. In seed propagated agricultural crops, seed treatments with antimitotic agents are often used to obtain chromosome doubling. Here, we developed a method to induce polyploidization in clonally propagated fodder grasses Lolium, Festuca, and the intergeneric hybrid Festulolium. The aim was to obtain specific genotypes at both the diploid and tetraploid levels. We evaluated different types of plant explants, and the effects of the type, concentration, and application mode of three antimitotic agents (oryzalin, colchicine, and trifluralin) on the survival rate and the polyploidization efficiency. The treatment of greenhouse-grown tillers with antimitotics only resulted in mixoploids, while tissue culture propagated plants were successfully polyploidized. A shock pretreatment, using a high concentration of an antimitotic agent during a short period, successfully induced tetraploids in all three genera. Additionally, supplementing the tissue culture medium with a lower dosage of an antimitotic agent during minimal four weeks after the shock pretreatment further promoted polyploidization. By our methods, we were able to generate diploid and tetraploid plants with an identical genomic constitution but different ploidy allowing investigation of the effects of polyploidization on plant physiology and gene regulatory networks.

Perennial ryegrass (PRG; Lolium perenne) remains the backbone of grass swards in Northern Ireland due to its improved digestibility persistence, and ease of management compared with other grass species. However, innovative breeding approaches are needed that include positive environmental outcomes, as well as improved productivity in ruminants. The objective of this study was to evaluate the feasibility of root-trait screening and selection using the in situ coring method under commercial grass breeding field conditions. 108 root cores were sampled over a 2-year period from a field trial sown in autumn 2021. Root cores were washed, scanned, and analysed using the open-access root scanning platform Rhizovision. A seasonal effect was noted whereby significant differences were detected in October for root volume, network area, and surface area, but no significant differences for any root parameter were detected in April. No association was observed between root volume, network area, or surface area at the October sampling with either dry matter (DM) yield at the 4^th cut (October) or annual DM yield. These results suggest that this method may be useful for identifying improved germplasm in PRG for root characteristics; however, being comparatively labour and time intensive this method may not be practicable for large-scale breeding programmes.

Lettuce is one of our most important leaf vegetables that can be cultivated safely in organic farming, which is not only pesticide-free, but also aims to maintain and stimulate the presence of naturally occurring beneficial organisms, such as algae, mosses, bacteria, or arbuscular mycorrhiza (AM) fungi. These organisms are all beneficial for soil life and nutrient decomposition. The positive effects of beneficial microorganisms could be enhanced by mulching which is a widely used practice in organic farming. Mulching may also increase soil nutrient substance after decomposition and inhibit weed growth. In our experiment, we sought to determine the effect of different mulching techniques (alfalfa, rye, black foil) on AM root colonisation, leaf chlorophyll (Chl) content, and on peroxidase (POD) activity in Lactuca sativa plants and observe whether there are correlations between these parameters. Results show natural mulching has a positive effect on mycorrhiza fungi root colonisation and therefore lowers the stress in lettuce plant. On the other hand, there was no significant correlation between root colonisation and Chl content. As POD enzymes are directly linked to enzymatic browning, the high colonisation rate of AM may consequently lower post-harvest browning in lettuce.

Mesembryanthemum crystallinum is a model halophyte that switches from C₃ photosynthesis to Crassulacean acid metabolism (CAM) upon extreme abiotic stresses. This study aimed to investigate alkalinity-induced root transcriptome profiling in M. crystallinum. M. crystallinum seedlings were treated with 50 mM sodium bicarbonate (NaHCO₃; pH 7.5) and 90 mM NaHCO₃ (pH 9.5) for 7 d, respectively. Alkalinity-induced differentially expressed genes (DEGs) were identified and annotated. Functional enrichment analysis was performed for DEGs. The expression of genes related to response to stress and CAM were analyzed and compared. Comparing with control, 50 and 90 mM NaHCO₃ treatments induced 4 027 and 25 403 DEGs in M. crystallinum roots, respectively. Among these DEGs, 832 and 131 DEGs were consistently upregulated and downregulated by both stresses, respectively. These genes were associated with multiple biological processes related to response to abiotic stresses. Alkaline stress upregulated genes encoding heat shock proteins and ethylene-related genes, but downregulated genes encoding glutathione S-transferases. Also, genes that encode phosphoenolpyruvate carboxylases, phosphoenolpyruvate carboxylase kinase 1, and malate dehydrogenases related to malate accumulation were upregulated by alkalinity. This study indicated that alkaline stress affected the genes related to stress responses, metabolism, and malate accumulation in the roots of M. crystallinum.

The intensification of agriculture is closely linked to high emissions of greenhouse gases. To address the challenges, the European Commission published the European Green Deal in 2019. The aim of our study was to compare the yield of maize genotypes bred in Martonvásár in three different cropping environments (organic, irrigated conventional, and non-irrigated conventional). The silage and grain yields of different maize hybrids and parental lines were evaluated in a three-replicate small plot experiments. The green mass yield of the organic area was 19 and 15% lower compared to the irrigated conventional and non-irrigated conventional treatments. The dry matter yield of the maize hybrids was 12.9 t ha^-1 in the organic area, 15.7 t ha^-1 in the irrigated, and 15.8 t ha^-1 in the non-irrigated environment. Hybrids had significantly better grain yield in the conventional systems (irrigated: 10.0 t ha^-1 and non-irrigated: 9.8 t ha^-1) than in the organic environment (7.6 t ha^-1). The difference in yield results was not as considerable for the parental lines as for the hybrids. In addition, our results indicated high presence of heterosis for yields. The heterosis of the grain yields was two times higher than for silage yields. Heterosis was highest at the non-irrigated conventional area.

The analysis of single nucleotide polymorphisms of 107 maize inbreds was performed on 384 special single nucleotide polymorphism (SNP) markers to receive their unique certificates and determine their degrees of affinity and heterotic potential. All inbreds were selected in the steppe zone of Ukraine; among them, 39 inbreds belonged to the Iodent and 28 inbreds to the BSSS germplasms. 40 inbreds of the Iodent/BSSS breeding group developed after hybridization of Iodent and BSSS, were also analysed by the same SNP markers. The average homozygosity of lines amounted to 98.05%, and the genetic diversity was 0.1746. According to pairwise SNP distances, lines of the Iodent and BSSS pedigrees formed two separate clusters, while the Iodent/BSSS lines were distributed among them. The allelic patterns of SNP markers specific for Iodent and BSSS inbred lines in comparison with each other and with the original inbreds P165, B14, B37, and B73 were formulated and discussed. Inbreds within the Iodent germplasm were on average much more closely related (GD = 0.2494) than those within the BSSS germplasm (GD = 0.3900) and the Iodent/BSSS breeding group (GD = 0.3967). The potential of the heterotic model Iodent×BSSS was assessed as high (mean GD = 0.4509). Based on SNP distances, inbreds have been recommended for the development of single cross heterotic hybrids, sister hybrids, and initial populations for subsequent breeding cycles.

Opportunities exist to accelerate genetic gain in forage breeding using genome-wide selection approaches. In this study, we evaluated rapid cycle recurrent genomic selection (GS) as a means of improving genetic gain for value of annual forage yield. A small population of tetraploid half-sib families was evaluated for seasonal forage yield over two years, and the maternal parent plants were genotyped and genomic prediction models developed. The GS model for value of annual forage yield had a predictive ability of 0.23. An initial round of among-family selection based on field evaluations and within-family selection using genomic estimated breeding values was performed. This was followed by two further GS cycles. New synthetics were produced after each round of selection and were established in a field trial alongside the starting population. A positive response to selection was observed in new synthetics after two successive rounds of rapid cycle recurrent genomic selection before declining in the third round. The genetic gain for the value of annual forage yield was 2.4% from C₀ SYN-1 to C₁ SYN-1 and 6.4% from C₁ SYN-1 to C₂ SYN-1_. In the case of C₀ to C₁, genetic gain was compounded by among-family selection based on field evaluations. The implementation of rapid cycle recurrent genomic selection offers an opportunity to increase genetic gain; however, the predictive ability is likely to decay rapidly as selection candidates become more distant from the training population.

Strigolactones (SL) are crucial plant hormones that regulate plant growth. We investigated genetic and metabolic changes in tobacco axillary flower buds following application of GR24 (SL synthetic analogue), administered 2 and 6 days later. The results indicated that GR24 effectively inhibited the growth of axillary buds. RNA sequencing revealed 1 781 differentially expressed genes in axillary buds after 6 days of GR24 treatment compared to untreated controls. Among them, 882 genes were up-regulated following GR24 treatment, suggesting substantial number of genes experienced significant changes in expression following GR24 treatment. Four carbohydrate metabolites exhibited altered abundance after 6 days of GR24 treatment; one increased and three decreased. In this study, GR24 induces substantial changes in the transcriptome and metabolome of tobacco axillary buds, with the starch and sucrose metabolic pathways and the phenylpropane biosynthesis pathway playing essential roles in the regulation of tobacco axillary bud development. Transcriptomic and metabolomic analyses highlighted that GR24 treatment significantly modulated the starch and sucrose metabolic pathways and the phenylpropane biosynthesis pathway. Our results suggest that the metabolic pathways of starch and sucrose and the biosynthesis pathway of phenylpropane play important roles in the regulation of growth and development of tobacco axillary buds by GR24.

Martaban camphor [Cinnamomum parthenoxylon (Jack) Meisn] is a woody tree in India, China, Indonesia, Thailand, and Vietnam and has been widely utilized for commercial purposes. It is threatened due to fragmented habitats, over-deforestation, and oil extraction. To conserve this species, the investigation of genetic diversity and population structure of this species is essential. Herein, we analyzed 192 adult trees from eight populations covering its natural distribution range in Vietnam using ten polymorphic EST-SSR markers. Medium levels of genetic diversity (R = 2.7, H_o = 0.399, H_e = 0.426) and genetic differences between populations (F_st = 0.223) were determined. Two populations, Cuc Phuong and Xuan Nha have undergone recent bottlenecks. These results indicated that anthropogenic activities may be the major factor for the low heterozygosity and influenced the number of alleles in all C. parthenoxylon populations. Clustering analyses revealed three genetic clusters that related to gene flow between different areas. We proposed in situ conservation for some populations with high levels of allelic richness, genetic diversity, or private alleles. The collecting of the seeds of the remaining populations for ex-situ conservation could be performed.

Dendrobium williamsonii and Dendrobium cariniferum (Orchidaceae) are endangered perennial herbs, and they are very similar in morphology. Chloroplast genome sequencing technology provides a powerful tool for molecular analysis to get more infomation for phylogenetic analysis and identification of Dendrobium species. In this study, the complete chloroplast genomes of Dendrobium williamsonii and Dendrobium cariniferum were assembled and characterized using Illumina NovaSeq 6000. The genome sizes are 159 695 and 159 479 bp, including pairs of inverted repeats (27 055 and 27 024 bp) each separated by small single-copy regions (18 451 and 18 488 bp) and large single-copy regions (87 134 and 86 943 bp). The chloroplast genome overall GC content was 37.11% and 37.13%, respectively. Each chloroplast genome encoded the same number (147) of genes, including 88 protein-coding genes, 51 tRNA genes, and 8 rRNA genes. Comparative analysis of chloroplast genomes revealed the high degree of divergence included accD-psaL and ycf4 -cemA. The phylogenetic tree showed the two Dendrobium species formed only one small clade. A pair of primers that could effectively identify the two Dendrobium species were also screened. This study will provide theoretical basis for species identification, genetic breeding, and evolution of Dendrobium.

Bacterial diseases of vegetable crops cause significant losses of yield and substantially decrease food quality. For sustainable development of agriculture, it is highly important to use the most effective strategies for the protection of vegetable crops from bacterial diseases which allows the creation of resistant cultivars and their introduction in regions with an increased risk of damage by phytopathogenic bacteria. This paper reviews the most widespread bacterial diseases of tomatoes, the mechanisms of interaction of plants with phytopathogenic bacteria, and the advantages of the biotechnological strategies over traditional and marker-associated breeding for creation of the resistant tomato cultivars. The current research progress on the use of biotechnological approaches such as cell selection, genetic engineering, genome editing, and gene silencing is summarized, with a special emphasis on the advantages and limitations of these methods.