Bombax ceiba is a deciduous tree belonging to the Genus Bombax in the Malvaceae family. It holds significant importance as an ornamental plant of economic, medicinal and edible value in southern China. It is the city flower of Guangzhou and Panzhihua. The traditional propagation methods for B. ceiba are seed sowing and grafting. However, the seeds are difficult to preserve and easily deteriorate, leading to decreased germination rates. Grafting results in even lower survival rates. Therefore, this experiment aimed to study the tissue culture techniques for the rapid propagation of B. ceiba. In this study, B. ceiba seeds were used as the experimental materials, and different disinfection methods were tested to determine the most suitable method for seed disinfection, aiming to obtain sterile seedlings. Using the sterile seedlings as the explants, various basic culture media, combinations of shoot-inducing hormones, induction and proliferation media for apical and adventitious buds, as well as rooting media, were tested and optimized. Additionally, seedling acclimatization experiments were conducted to explore the optimal basic culture medium, hormone combination, induction and proliferation medium, rooting medium, and seedling acclimatization methods. The results showed that the optimal basic culture medium for B. ceiba tissue culture was MS medium supplemented with 30 g/L sucrose and 7.5 g/L agar. The best disinfection method for B. ceiba seeds was 75% ethanol treatment for 1 min, followed by five rinses with sterile water, 4-hour sterilization with a 50% H₂O₂ solution prepared from 30% H₂O₂, and another five rinses with sterile water. The optimal plant growth regulators for inducing differentiation of apical buds into young shoots were a combination of 6-benzylaminopurine (6-BA) and naphthaleneacetic acid (NAA). The best induction and proliferation medium was MS medium supplemented with 0.5 mg/L 6-BA, 0.5 mg/L indole-3-butyric acid (IBA), 30 g/L sucrose, and 7.5 g/L agar. The optimal rooting medium was half-strength MS medium supplemented with 0.5 mg/L IBA, 30 g/L sucrose, 7.5 g/L agar, and 0.2 g/L activated charcoal. The recommended substrate for seedling acclimatization was a mixture of sand, peat soil, and vermiculite in a ratio of 1∶1∶1. Through the optimization of seed disinfection methods, culture media selection, hormone combinations, and seedling acclimatization experiments, an efficient tissue culture system for B. ceiba was established. This would provide technical support for the in vitro preservation of B. ceiba seedlings, propagation of superior individuals, healthy seedling breeding, and the industrialized production of seedlings, and lay a foundation for the genetic transformation system of B. ceiba.

Grey mold is a common disease in tomato production caused by Botrytis cinerea, a necrotrophic pathogen, which often leads to dramatic reduction of tomato yield. Sucrose catabolism plays an important role in plant defense against pathogen infection by providing carbon skeleton and energy for plant defense responses and/or regulating the expression of defense-related genes through signaling pathway. Previous studies have shown that cell wall invertase (CWIN), a kind of sucrose-degrading enzyme, can enhance plant resistance to several necrotrophic pathogens. However, no research has been conducted to study the role of CWIN in tomato resistance to B. cinerea. In this study, wild type tomato (W) and its transgenic line (R) with elevated CWIN activity were used as materials to study the effect of CWIN on tomato resistance to B. cinerea (Bc) via in vitro inoculation. In addition, inoculated leaves were sampled 12 h and 60 h post inoculation (hpi) for RNA-Seq to elucidate possible molecular mechanisms underlying the regulation of CWIN to tomato resistance against B. cinerea. The results are as follows: (1) Elevated CWIN activity enhanced tomato resistance to B. cinerea; (2) KEGG annotation showed that DEGs (W-Bc-12 h-vs-R-Bc-12 h) from 12 hpi were significantly enriched in five pathways, including biosynthesis of secondary metabolites, metabolic pathways, DNA replication, starch and sucrose metabolism, and steroid biosynthesis; No significant enrichment pathway was found for DEGs (W-Bc-60 h-vs-R-Bc-60 h) from 60 hpi. (3) By mapping DEGs to plant-pathogen interaction pathway, it was revealed that the LRR-receptor serine/threonine-like kinase gene FLS2 and heat shock protein gene HSP90 involved in hypersensitive response and defense-related gene induction were up-regulated in RNAi leaves after inoculation, indicating the two genes may participate in the regulation of CWIN to tomato resistance to B. cinerea. (4) The analysis of plant hormone signal transduction pathways and MapMan mapping showed that the signal pathway of jasmonic acid (JA) and ethylene (ET) was enhanced in RNAi leaves after inoculation, while the signal pathway of salicylic acid (SA) was weakened, indicating that the hormones might work together to improve the resistance of RNAi tomato to B. cinerea. In addition, the signal transduction of growth-promoting hormone auxin (IAA) and cytokinin (CTK) was also enhanced in RNAi leaves after inoculation, but that of senescence-promoting hormone abscisic acid (ABA) was weakened. The changes in signal pathways of IAA, CTK and ABA could inhibit the cell death in host during bacterial infection, thus preventing the necrotrophic pathogen B. cinerea from obtaining necessary nutrients from the dead host cells for its infection. In addition, MapMan mapping also revealed that cell wall thickening, proteolysis, reactive oxygen species (redox state and peroxidases) and secondary metabolites were also greatly enhanced in RNAi leaves after inoculation, which all contribute to improving the disease resistance of tomato. In conclusion, this study showed that elevated CWIN activity enhanced tomato resistance to B. cinerea. Transcriptome analysis not only verified the existing molecular mechanisms underlying the regulation of CWIN to plant resistance to microbial pathogens, such as cell wall thickening, accumulation of reactive oxygen species (ROS) and hypersensitive response (HR), accumulation of resistance hormones (SA and JA/ET), biosynthesis of pathogenesis-related protein (e.g. PR and HSP proteins) and secondary metabolites (such as phytotoxins and phenolics), but also revealed several possible new mechanisms including the signal transduction of growth-promoting hormone (IAA and CTK) and senescence-promoting hormone (ABA) and proteolysis. This study can provide theoretical guidance for the improvement of tomato resistance to B. cinerea by using modern biotechnologies such as genetic engineering and molecular breeding.

Biochar was modified with different concentrations of hydrogen peroxide, and the differences in its structural characteristics were analyzed to study the modification effect of hydrogen peroxide on biochar obtained from banana stem and the effect of modified biochar on Cr absorption of maize under Cr stress. The effects of modified biochar on the growth, Cr uptake and accumulation of maize under Cr stress were studied. With the increase of hydrogen peroxide concentration, the number of oxygen-containing functional groups on the surface of biochar increased, while the aromatics decreased and the polarity increased. After the modification, the surface of biochar was smooth, the pore diameter increased, and the specific surface area and pore volume decreased with the increase of hydrogen peroxide concentration. Modified biochar by 20% and 30% hydrogen peroxide mainly fixed heavy metals through the adsorption of functional groups, reduced its biological activity, and reduced the Cr absorption and accumulation by corn. The study showed that 20% and 30% hydrogen peroxide significantly changed the surface structure of biochar, which was conducive to alleviating the toxicity of heavy metal Cr to corn plants. 30% hydrogen peroxide modified biochar promoted the growth of corn under Cr stress.

Fenjiaren is a new Dendrobium variety bred by Sanming Academy of Agricultural Sciences for both ornamental and edible purposes. In factory seedling cultivation, it was found that Fenjiaren had slow cluster bud proliferation, low proliferation coefficient, underdeveloped root system of tissue culture seedlings and other problems, which affecting the large-scale production of this variety. To improve the efficiency of factory seedling cultivation of the variety, the sterile seedlings were used as the explants, the effects of plant growth regulators including 6-BA, NAA, and additives such as banana puree and AC on the proliferation of stem segments and the rooting of seedlings were studied using L₉(3³) orthogonal experiments. The suitable culture medium for the proliferation of stem segments of Fenjiaren was 1/2 MS+6-BA 3 mg/L, banana puree 100 g/L, white sugar 30 g/L, activated carbon AC 1 g/L, and agar powder 5.6 g/L. After 4 months of cultivation, the proliferation coefficient of the stem segment was 5.08. Range analysis indicated that the primary and secondary relationship of the factors was 6-BA>NAA>banana puree. The inter subject effect test showed that 6-BA had a significant impact on the growth rate coefficient (P<0.05). The most suitable culture medium for rooting was 1/2 MS+NAA 1 mg/L+banana puree 100 g/L+white sugar 15 g/L+agar powder 5.6 g/L. After 2 months of cultivation, the growth rate coefficient of the rooting was 12.82, the average plant height of the seedling was 12.66 cm, the average leaf length was 4.02 cm, the average number of roots was 11.80, and the average plant weight was 1.67 g. Range analysis indicated that the primary and secondary relationship of the factors was NAA>AC>banana puree. This study optimized the proliferation and rooting conditions of a new variety of Fenjiaren, which could provide technical reference for the seedling breeding of new varieties of Dendrobium and other Orchid plants.

Leaf photosynthesis is the energy source of plant life activities. However, some macadamia varieties (Macadamia integrifolia) planted in southern China are prone to generate the etiolated leaves under the continuous high temperature in summer, which seriously affects the shoot growth and fruit production of macadamia trees. In order to explore the mechanism of photosynthetic energy generation in the etiolated leaves of macadamia, the genes related to photosynthetic energy metabolism were identified and screened in this study, based on the previously obtained transcriptome sequencing data from the leaves of HAES344 macadamia at different yellowing stages, and the expression changes of the key genes in photosynthetic energy metabolism were analyzed during leaf yellowing of HAES344 macadamia by qRT-PCR. 96 genes with differential expression in the etiolated leaves of HAES344 macadamia were identified to be related to energy metabolism according to KEGG functional annotation and enrichment analysis, and the number of the differentially expressed genes enriched in the oxidative phosphorylation pathway was the highest, followed by carbon fixation pathway, and the least genes were enriched in the antenna proteins. After screening (RPKM>0.5), a total of 43 genes related to photosynthetic energy metabolism were obtained. Among these genes, the expression level of 27 genes decreased significantly in the yellowed leaves, while the remaining 16 genes did the opposite. Through the qRT-PCR analysis of the relative expression level of key functional genes in the photosynthetic energy metabolism, the CAP10A gene encoding photosystem Ⅱ (PSⅡ) antenna protein, the ATPC and ATPF genes encoding ATPase subunit protein, the enzyme genes related to carbon assimilation (GAPA, GPD, At4g2652 and rbcL), the Os05g0200100 and CXXS1 genes encoding thioredoxin, and the TIC32 gene associated with plastid protein transmembrane transport showed a significant lower transcription level in the etiolated leaves of HAES344 macadamia compared with the normal leaves, while the SIR and APR3 genes related to sulfur metabolism and the PGR5, ndhB and ndhD genes mediating cyclic electron transfer did the opposite, which suggested that the greatly changed expression patterns of genes related to photosynthetic energy metabolism affected the production of photosynthetic energy in the macadamia yellowing leaves. The results of this study would provide a reference for further exploring the mechanism of photosynthetic energy metabolism-related genes in the etiolated leaves of macadamia.

Phalaenopsis-hybrid Dendrobium is an important ornamental plant in tropical area and has high market values, with beautiful flower appearance and abundant flower colors. In this study, the protocorms and young seedling’s stem segments of commercial varieties, Den. Yaya Victoria, Den. Swirl and Den. Sonia Hiasakul, were used as the explants. The effects of different phytohormone combination on embryogenic callus induction, adventitious bud differentiation and plantlet regeneration were investigated. During the embryogenic callus (EC) induction stage, the best induction explants were protocorms and 2-month-old seedling stem segments and EC could be obtained after 30 days culture in dark condition. The best medium for EC induction of was MSD (MS+30 g/L glucose+1 g/L Hyponex+8 g/L agar) as the basic medium with 0.5 mg/L KT and 0.2-0.5 mg/L 2,4-D. The highest average induction rate of EC was 31.11%, 22.78%, and 50% for Den. Yaya Victoria, Den. Swirl and Den. Sonia Hiasakul, and the induction time for Den. Yaya Victoria was only 15 days from explants to EC. The best proliferation medium was MSD+0.5 mg/L IBA+0.5 mg/L KT, which maintaining EC in good condition without differentiation and the multiplication rate was 0.9. The best medium for differentiation was 1/2 MS+0.5 mg/L IBA+0.15 mg/L KT under light condition of 16 h one day, EC quickly differentiating and forming 2-3 leaf adventitious buds within 30 days, and finally regenerating into plantlet after 60 days in the same medium. The best rooting medium was 1/2 MS+30 g/L sugar+0.5 mg/L NAA+8 g/L agar, with rooting rate 100% and five roots in length 1.3 cm per plantlet. In this research, the EC induction, proliferation and differentiation media have a wide-spectrum and the EC regeneration pathway could lay a solid foundation for further molecular breeding of Phalaenopsis-hybrid Dendrobium.

The study was aimed to investigate the effects of litchi orchard intercropping Stylosanthes guianensis on soil physicochemical properties and soil bacterial community structure, and to provide theoretical basis for litchi orchard intercropping S. guianensis. Soil samples from litchi orchard intercropped with S. guianensis and litchi monocropping modes were used to determine soil physicochemical properties and analyzed by bacterial amplicon sequencing. After intercropping S. guianensis in litchi orchard, in the soil layer depth of 0-20 cm, nitrate nitrogen content significantly increased by 47.52%, available phosphorus content highly significantly increased by 141.53% and available potassium content highly significantly reduced by 125.59%; in the soil layer depth of 20-40 cm, nitrate nitrogen content highly significantly increased by 76.02%, available phosphorus content highly significantly increased by 48.52%, and available potassium content highly significantly reduced by 188.57%. In terms of alpha bacterial diversity, there were no significant changes in Chao1 index, AEC index, Simpson index and Shannon index in 0-20 cm soil layer and 20-40 cm soil layer after intercropping S. guianensis in litchi orchard. In terms of soil bacterial community structure, the main dominant phyla in the soil samples were all Acidobacteriota, Proteobacteria, Firmicutes, Chloroflexi, Bacteroidota, Verrucomicrobiota, Actinobacteriota, Gemmatimonadota, Myxococcota, Crenarchaeota, and Crenarchaeota were soil-specific relative abundances greater than 1% of the phyla after intercropping S. guianensis at 0-20 cm soil depth; at the genus level, in the 0-20 cm soil layer, Candidatus_Nitrosotalea was the genus with soil-specific relative abundance greater than 1% after intercropping S. guianensis, and at the 0-40 cm soil level, Nitrospira was the genus with soil-specific relative abundance greater than 1% after intercropping S. guianensis, Proteobacteria, Verrucomicrobiota, and Gemmatimonadota increased at all soil depths after intercropping S. guianensis; the results of the redundancy analysis showed that the soil bacterial community was mainly affected by effective phosphorus, nitrate nitrogen, and organic matter. In summary, intercropping litchi orchard with S. guianensis would improve the physicochemical properties and change the structure of soil bacterial community in litchi orchard soil, and play a certain role in optimizing the environmental conditions of litchi orchard soil.

The germplasm resources of Amomum tsao-ko (AT) at different altitudes in Nujiang, Yunnan were used as the materials to explore the genetic diversity of the agronomic phenotypic traits of AT germplasm resources at different areas. The genetic diversity of the agronomic phenotypic traits of AT was analyzed by measuring 8 agronomic phenotypic traits, using coefficient of variation, genetic diversity index, variance analysis, correlation analysis, cluster analysis, principal component analysis and comprehensive evaluation. The results showed that there were large variations in the agronomic phenotypic traits, and the variation coefficient was 7.63%-32.51%, among which the variation coefficient of tiller number was the largest. The traits showed good diversity, H' (diversity index) was 1.933-2.355, with an average of 2.024. There were significant differences in the agronomic phenotypic traits among different germplasms. There was a significant positive correlation between fruit longitudinal diameter and fruit shape index and fruit weight. There was a significant positive correlation between fruit transverse diameter and fruit weight. There was a significant negative correlation between fruit shape index and leaf width. Cluster analysis divided the AT germplasm resources at different areas into two groups, among which the AT germplasm resources from the areas of Lushui and from Fugong were clustered into one group. Three principal components were extracted from eight agronomic phenotypic traits, and the cumulative contribution rate reached 76.940%, which could comprehensively reflect most of the information of agronomic phenotypic traits of AT. The comprehensive evaluation results showed that SD12, SD20, SD7, SD17, SD18 and SD5 were ranked in the top six, and the comprehensive performance was better. The genetic diversity of the agronomic phenotypic traits of 24 AT germplasm resources in different areas of Nujiang, Yunnan is relatively rich, and the variability of AT germplasm resources in different areas is obvious. Among them, the agronomic phenotypic traits of SD12, SD20, SD7, SD17, SD18 and SD5 AT are better, which are more suitable for breeding.

KOH was used as the activator combined with ultrasonic treatment to treat rubber seed shell to prepare activated carbon, and the best preparation conditions were optimized. The surface structure of the chemical carbon was regulated by controlling the preparation and processing conditions. The physical and chemical properties of the active carbon were characterized by specific surface area voidness analyzer, FT-IR, SEM, element analyzer, and TGA. The adsorption capacity of methylene blue and iodine was investigated. The optimal preparation conditions were reagent∶material ratio 1∶1, ultrasonic action for 60 minutes, activation time for 60 minutes, and activation temperature of 700 ℃. Activation temperature had the greatest impact on the adsorption capacity of activated carbon, followed by the reagent to material ratio and ultrasonic time, with the activation time having the smallest impact. The absorption of methylene blue was 400 mg/g, and iodine was 1340.2 mg/g, respectively. The yield was 25.9%, the specific surface area was 1034.5009 m²/g, and the total pore volume was 0.9511 cm³/g with ultrasonic pretreatment (UAC). The adsorption value of methylene blue was 300 mg/g, iodine adsorption value was 894.0 mg/g, yield was 20.8%, specific surface area was 690.2461 m²/g, total pore volume was 0.6830 cm³/g without ultrasoni pretreatment (NAC). Both contained hydroxyl, alcohol hydroxyl and carbonyl functional groups. This is conducive to the enhancement of adsorption performance, and the characteristics of cellulose, hemicellulose and lignin were obvious. The nitrogen adsorption isotherm of the rubber seed shell activated carbon was type Ⅰ. Activated carbon contained a large number of microporous structures with uniform distribution. There was no pore structure on the surface of the rubber seed shell, and there were a large number of pore structures on the activated carbon surface after KOH activation. The surface of UAC activated carbon was smooth and flat, with many rich and regular pore structures. In contrast, the pore surface of NAC had many small pores, and the surface was rough. The carbon (C) content in the rubber seed shells was rich. After KOH activation, the C content of the activated carbon prepared by ultrasonic treatment and activated carbon prepared without ultrasonic treatment increased from 56.81% to 75.97% and 64.89%, respectively. However, the content of hydrogen (H) and nitrogen (N) decreased, making it an excellent raw material for activated carbon. The TGA results indicate that the sample activated by KOH was more stable than the rubber seed shell, and the total weight of UAC and NAC samples tended to stabilize after losing 62% and 68%, respectively. In conclusion, the better performance of the samples prepared by ultrasonic pretreatment indicates that the cavitation effect of ultrasonic wave acts on the structural surface of the activated carbon, causing it to undergo structural changes, thus, the adsorption capability of the active carbon, the specific surface area, etc. are enhanced.

The wood of most tree species of Dalbergia L. f. is well-known in the world. The research on wood anatomy mainly focus on tree species, while the research on vine or climbing plant species is rare. This paper discussed the macroscopic and microscopic wood structures of seven species of vines or climbing plants of Dalbergia L. f., and summarized systematically, and compared with the tree species of D. odorifera, so as to provide a scientific basis for wood identification, species identification, protection, breeding, development and utilization of this genus. The macrostructure showed that the difference between heartwood and sapwood was not obvious, and had little glossy, aromatic and oily when rich in gum. The growth ring was not obvious. The pores were obvious and common rich in gum, which were smaller and sparsely distributed in primary xylem, larger and densely distributed in secondary xylem. Included phloem was round. The microstructures indicated that they were all diffuse-porous wood, single pores, radial multiple pores, pores arrangement dispersed, single perforation, inter-vessel pitting alternate, vestured pitting, elliptical to nearly round, and obvious on the tangential section. Axial parenchyma was abundant and overlapped, paratubular banded, annular tubular. The wood rays were non overlapping, more fine and dense. D. odorifera was diffuse-porous wood to near semi-ring-porous wood, included phloem was absent, pith was smaller, axial parenchyma was mainly winged and polymerized-winged (paratubular banded type) or minimal banding (off tube type), low pores density. To sum up, there are many similarities in the wood anatomical structures of the seven vines or climbing plants of Dalbergia L. f., but there are also significant differences mainly in wood rays, wood rays width and pith core inclusions. Wood rays were mainly homotypic multiple columns, occasionally homotypic uniseriate of D. tsoi and D. yunnanensis. D. pinnata and D. benthamii were similar with homotypic single or multiple columns, while the former also had heterogeneous Ⅲ type rarely. D. hancei and D. peishaensis were similar with mainly heterogeneous uniseriate, occasionally heterogeneousⅠ type, while the former also had heterogeneous Ⅲ type rarely. D. candenatensis was mainly heterogeneous Ⅱ type, followed by heterogeneousⅠtype and heterogeneous uniseriate. The wood rays width of D. hanei and D. peishaensis was 1-2 cells, that of D. pinnata, D. benthamii and D. candenatensis was 1-3 cells, that of D. yunnanensis was 1-4 (mostly 2-3) cells. that of D. tsoi was 1-5 (mostly 3-4) cells. The pith core inclusions was mainly golden yellow, but that of D. tsoi was silver white, and that of D. pinnata was absent or not obvious.