A rapid propagation system via tissue culture for Rosa multiflora was established using the stem segments with buds of the current-year as the experimental material. The results showed that the best explants were stem segments with axillary buds. The best disinfection method was to soak the explants in 75% ethanol for 30 seconds, and then soak them in 10% sodium hypochlorite solution for 20 minutes. The survival rate can reach 96%. The optimal bud-induction medium was MS+1.0 mg∙L^-1 6-BA+0.01 mg∙L^-1 NAA+0.1 mg∙L^-1 GA₃. The budding rate can reach 98% after 30 days of cultivation. WPM was the best basal medium for the proliferation of sterile regenerated plantlets, and the proliferation coefficient was 2.87. The best medium for rooting was 1/2MS+1.0 mg∙L^-1 6-BA+0.1 mg∙L^-1 NAA, and the rooting rate can reach 93%. The transplanting survival rate of sterile regenerated plantlets was 98%. On this basis, the transient expression system of R. multiflora was established. The results showed that the optimal transformation conditions for transient expression were OD₆₀₀ of 0.8 for the bacterium culture medium, vacuum negative pressure of -0.10 MPa and vacuum suction twice for 15 minutes each time. The transient expression efficiency can reach 96%. The results of this study laid a foundation for the establishment of regeneration and genetic transformation system of R. multiflora, and also provided technical support for studying on the gene function of Rosa plants.

Due to the long flowering cycle, unpredictable flowering period and low seed setting rate of most bamboo plants, bamboo breeding has been a challenge in the research of bamboo plants. Polyploid breeding, as a common mean of plant breeding, is able to obtain progeny with excellent traits through artificial induction. In bamboo breeding, there are fewer studies on polyploid breeding. In this study, based on the existing regeneration system of Dendrocalamus asper, the embryonic calluses of D. asper were treated with colchicine using the liquid suspension method and the solid medium mixed culture method, respectively. The results showed that, based on the differentiation and browning rates of the calluses, the better results were obtained by treating the calluses with 50 mg∙L^-1 colchicine for 48-72 hours using the liquid suspension method. A total of 54 regenerated plants, including 7 control plants, and 16 chromosome doubled plants were successfully obtained from D. asper using flow cytometry to test all the regenerated plants. In terms of chromosomal doubling, treatment with 100 mg∙L^-1 colchicine for 48 h produced the highest number of chromosome-doubled plants with a polyploidy rate of 54.54%. Compared with 6-ploid plants, the 12-ploid plants presented larger and thicker leaves, and larger lower epidermal stomata, implying their superiority in stress tolerance physiology. This study provides an efficient polyploid breeding technique based on the in vitro indirect regeneration system of bamboo, and offers a new solution for breeding new polyploid germplasm of bamboo.

A large number of software applications for plant identification based on plant images have been developed in recent years. However, those applications are mostly used for identifying the common species countrywide, and thus cannot meet the needs of identifying region-specific vegetation types. In this study, we developed an artificial intelligence model for identifying the dominant plants in Hulunbeier and Xilinhot grassland in Inner Mongolia, based on the image datasets in the Plant Photo Bank of China. The Top5 accuracy of this model reaches 94.6% in the actual field identification tests. Our model provides a new method for the intelligent identification of the major plant species in a specific area.

Cereal starch endosperm is the main source of human staple food, but the methods for observing its mature cell structure are not well developed. Micro CT technology, a non-destructive three-dimensional imaging technique, is a powerful tool for studying plant morphology. However, due to the uniform density of cereal starch endosperm, whose cell structures cannot be distinguished clearly by conventional micro CT techniques. In this study, we used phosphotungstic acid to treat ten different kinds of cereal seeds of seven crops, and then dried them by CO₂ critical point dryer. We found that the cell structure of the treated endosperms can be clearly displayed by micro CT. Our method provides a new way for studying the structures and functions of cereal starch endosperm cells.

Membrane microdomains, which are highly dynamic structures rich in sterols and sphingolipids on the plasma membrane, play crucial roles in various biological processes such as signal transduction, vesicle transport, endocytosis, and exocytosis. Consequently, the investigation of membrane microdomain dynamics is an important area of research in plant cell biology. Fluorescence probes combined with fluorescence microscopy are widely used to monitor the status of living plant cells. The PA probe (push-pull pyrene) is a novel, highly efficient and stable fluorescence probe based on pyrene: however, its application in imaging studies of living plant cells is limited. In this study, we used PA probes and laser scanning confocal microscopy, combined with image processing and the polar normalized value mapping method, to quantitatively analyze the order of the plasma membrane in Arabidopsis root cells. The results revealed that the emission spectrum of the liquid-ordered phase in the plasma membrane of Arabidopsis root cells labeled with the PA probe ranged from 500-550 nm, whereas the emission spectrum of the liquid-disordered phase ranged from 580-700 nm. Treatment of wild-type plants with the sterol extraction agent MβCD resulted in a decrease in plasma membrane order. In the smt2/smt3 double mutant lacking the key methyltransferase in sterol synthesis, the plasma membrane order was consistent with that of the wild-type plants after treatment with MβCD. In the smt2/smt3 mutant, the plasma membrane order of the root hair cells was lower than the plasma membrane order of the wild-type root hair cells, indicating that sterols, as key components of membrane microdomains, play an important role in regulating the order of the plasma membrane. This study provides a straightforward and rapid detection method for monitoring the dynamic characteristics of living plant cell membranes and changes in membrane microdomains.

In this study, the seed embryos of Pyrus calleryana cv. ‘Cleveland’ were used as materials to systematically study the sterilization of seed embryo explants, callus induction, adventitious bud proliferation and rooting medium. The results showed that the germination rate of young embryos stored at 4°C for 21 d was the highest (67.23%) The suitable sterilization treatment of seed embryo explants was 75% alcohol (30 s)+10% H₂O₂ (10 min)+0.1% HgCl₂ (14 min)_. The most suitable medium for seed embryo germination was 1/2MS+4.0 mg·L^-1 6-BA+0.5 mg·L^-1 NAA, and the germination rate was 89.67%. The optimum culture medium for callus induction was 1/2MS+1.0 mg·L^-1 IBA+1.0 mg·L^-1 6-BA, and the callus induction rate was 93.33%. The best differentiation medium was 1/2MS+0.2 mg·L^-1 IBA+2.0 mg·L^-1 6-BA, and the regeneration frequency was 87.44%. Best transgenerational proliferation medium was 1/2MS+1.5 mg·L^-1 6-BA+0.1 mg·L^-1 IBA, and the proliferation rate was 100%. The most suitable medium for root formation was 1/2MS+ 20 g·L^-1 sucrose+1.0 g·L^-1 active carbon+1.5 mg·L^-1 IBA+0.05 mg·L^-1 NAA, and the rooting rate was 82.63%. In summary, the seed embryo regeneration system of P. calleryang cv. ‘Cleveland’ was established, which provides scientific basis and guidan-ce for the efficient reproduction of high-quality pear germplasm resources.

To establish a tissue culture regeneration system for cultivated Chinese yam (Dioscorea polystachya), the effects of different concentrations of plant growth regulators, and stem segments on axillary bud induction and plant regeneration were investigated with different concentrations of plant growth regulators, media types, and shoot tips and stem segments at four different positions under the shoot tip as explants. The results revealed that MS+1.0 mg∙L^-1 6-BA+0.5 mg∙L^-1 KT hormone ratio and 12-20 cm stem segment under the stem tip were the best formulas for the induction of adventitious buds in D. polystachya, and the induction rate reached 90.0%. In the subculture, the optimal concentration was MS+0.5 mg∙L^-1 6-BA+0.05 mg∙L^-1 NAA+0.1 mg∙L^-1 KT, and the proliferation coefficient increased with increasing of 6-BA within a certain range when the low concentration of NAA was constant. With the same concentration of exogenous hormones, DKW medium was significantly better than the conventional 1/2MS medium, and the rooting rate is significantly improved, reaching 92.86%. Adding 1 mg PVP (polyvinylpyrrolidone) and increasing the number of transfers can significantly reduce browning. This study effectively solved the problem of optimizing the explant position for the stable of in vitro propagation of cultivated yam germplasm resources, laying a good foundation for the large-scale production of their high-quality virus-free seedlings.

Atomic force microscopy (AFM) is a powerful tool for studying the ultrastructure and mechanical properties of plant cell walls, while good sample preparation is essential for AFM data acquisition. As micron-scale plant samples, pollen tubes are typical experimental materials for studying the structure and function of cell walls. Due to the difficulty in sample preparation, it is hard to obtain in situ AFM data in physiological state of pollen tubes as pollen tubes are hard to attach to the substrate firmly in fluid. In this study, the AFM preparation and detection methods are optimized using Nicotiana tabacum pollen tubes as the experimental materials. Thin solid medium is used as the adhesive, thereby pollen tubes are attached to the glass slide during germination and elongation in fluidic environment. Compared with the conventional drying-rehydration method, the optimized liquid-attaching method allows observation directly in fluid without drying treatment, which avoids the shrinkage and denaturation of pollen tubes caused by drying-rehydration process. Accordingly, liquid-attaching method can be applied for pollen tubes of different species and sizes, providing support to obtain high-resolution in situ AFM data of pollen tube cell walls in native physiological state under aqueous conditions.

Agropyron mongolicum is a perennial shrub grass in the Triticeae tribe of Poaceae family. It has high forage quality and tolerance to cold, drought, salt and sandstorm. Therefore, it is an excellent grass species for mining stress tolerant genes and restoring deteriorated grasslands. However, a highly efficient transformation system has yet to be established in A. mongolicum. It restricts the identification of genetic resources and the application of genetic improvement of this species. Here, we report an embryogenic callus line (ECL) #89 that was induced from the seeds of A. mongolicum cultivar Mengnong No. 1. Our studies showed the ECL #89 had high regeneration and Agrobacterium-infection efficiencies. An Agrobacterium-mediated transformation system with a transformation efficiency up to 30% was established by infecting the ECL #89 with EHA105. Additionally, we found that subcultures could decrease severely the regeneration capacity of ECL #89, which could be partially restored by adding (1 mg·L^-1) ABA or high concentration (45 g·L^-1) sucrose in the regeneration medium, from 5% to 35% and 42%, respectively. Our work will facilitate the developing of genome editing system, gene function characterization, and molecular breeding in A. mongolicum.

Dracocephalum rupestre is an important medicinal plant. However, its leaf explant regeneration system has yet to be established. Here we investigated the impact of plant growth regulators on callus induction, differentiation, adventitious bud proliferation, and rooting using field planted leaves and tissue-cultured seedling leaves of D. rupestre as explants. We found that the optimal medium for inducing callus from field planted leaves was MS+1.0 mg·L⁻¹ 6-BA+ 0.1 mg·L⁻¹ 2,4-D+1.0 mg·L⁻¹ IAA, achieving an induction rate of 84.51%. For adventitious bud differentiation, the preferred medium comprised MS+3.0 mg·L⁻¹ 6-BA+0.5 mg·L⁻¹ TDZ+0.5 mg·L⁻¹ IAA, resulting in a differentiation rate of 66.37%. Similarly, for inducing callus from tissue-cultured seedling leaves, the optimal medium included MS+2.0 mg·L⁻¹ 6-BA+0.1 mg·L⁻¹ 2,4-D+0.5 mg·L⁻¹ IAA, with an induction rate of 86.73%. The medium conductive to adventitious bud differentiation consisted of MS+2.0 mg·L⁻¹ 6-BA+2.0 mg·L⁻¹ TDZ+0.05 mg·L⁻¹ IAA, yielding a differentiation rate of 53.48%. Furthermore, the appropriate medium for adventitious bud proliferation was MS+2.0 mg·L⁻¹ 6-BA+0.05 mg·L⁻¹ NAA, achieving a proliferation rate of 83.57%. The rooting medium was 1/2MS+0.1 mg·L⁻¹ NAA+0.1 mg·L⁻¹ IBA, resulting in a rooting rate of 86.97%. Tissue-cultured seedlings exhibited optimal growth in a mixed substrate of peat and vermiculite at a ratio of 1:1 (v/v). This study successfully established a leaf explant regeneration system for D. rupestre, providing valuable technical support for the conservation and rapid propagation of its germplasm resources.

Using two different genotypes of Pinguicula cyclosecta and P. ‘Sethos’ as explants, an efficient system for adventitious bud regeneration of Pinguicula was established by studying the factors affecting regeneration. The results showed that the two kinds of Pinguicula had the same requirements for the disinfection scheme and basic medium, but the regeneration ability differed. The best medium for P. cyclosecta leaf regeneration was MS+1.0 mg∙L^-1 6-BA+0.2 mg∙L^-1 NAA, with a regeneration rate of 92.22% and a regeneration coefficient was 4.84. On MS+0.6 mg∙L^-1 6-BA+0.1 mg∙L^-1 NAA media, the proliferation coefficient of adventitious buds reached 4.98. The best medium for the leaf regeneration of P. ‘Sethos’ was MS+2.0 mg∙L^-1 6-BA+0.2 mg∙L^-1 NAA, with a regeneration rate of 77.78% and a regeneration coefficient of 6.12. On the MS+0.3 mg∙L^-1 6-BA+0.1 mg∙L^-1 NAA media, the proliferation coefficient reached 4.84. After root culture (1/2MS+0.1 mg∙L^-1 IBA), the root state of the two kinds of Pinguicula was the best. This study solved the problems of a low reproduction coefficient and difficulty in factory breeding of Pinguicula and provided technical support for its large-scale production and breeding improvement.