Meloidogyne enterolobii is one of the most devastating pathogens in tomato (Solanum lycopersicum) production. Grafting with resistant rootstocks could help superior cultivars gain root-knot nematode resistance straightly. Previously, we identified a medium-resistant tomato rootstock cultivar Guizhen 1. In order to deepen the understanding to its resistance mechanism, we inoculated Guizhen 1 and susceptible cultivar Yala with M. enterolobii, and measured the proportion of root knots and nematode numbers in roots once every four days within 28 days. The root knot proportion of Yala reached 71.7%, which was kept under 36.0% in Guizhen 1. The root knot proportions between resistant and susceptible cultivars were significantly different on day 12, 16, 20, 24 and 28 after inoculation. Whereas the differences of nematode numbers between resistant and susceptible cultivars were not significant except on day 20. Thus it can be seen that the resistance of Guizhen 1 was not reflected by limiting the invasion of nematodes. The LC-MS based non-targeted metabolome of resistant and susceptible roots on 5th day after inoculation were measured. With the threshold of VIP>1 and P<0.05, 415 significantly different metabolites were gained, among which 280 were up-regulated and 135 were down-regulated. The top 8 classes of metabolites with largest number of metabolites were amino acid and its metabolites, heterocyclic compounds, benzene and its derivatives, organic acid and its derivatives, aldehyde, ketone and ester, fatty acyls, glycerol phospholipids, alcohol and amines. KEGG dataset were employed to do the metabolite pathway enrichment analysis. Glycerophospholipid metabolism, ascorbate and aldarate metabolism, nicotinate and nicotinamide metabolism, betalain biosynthesis and flavonoid biosynthesis pathways had relatively high level of enrichment, with the glycerophospholipid metabolism having the highest enrichment level. In glycerophospholipid metabolism pathway, there were several metabolites with significant differences between resistant and susceptible cultivars, which were phosphocholine, phosphatidylcholine, lysophosphatidylcholine, sn-glycero-3-phosphocholine, triethanolamine and diethanolamine. It was speculated that glycerophospholipid metabolism pathway might enhance the M. enterolobii resistance of Guizhen 1 at certain level. In this study, the histological and metabolomic fundamentals of M. enterolobii resistance were explored in tomato rootstock cultivar Guizhen 1, which would provide certain basis for the in-depth study on resistance mechanism in the future.

In view of the deficiency of calcium (Ca), magnesium (Mg), zinc (Zn) and boron (B) in the production of macadamia in Yunnan province, the accumulation characteristics of Ca, Mg, Zn and B in litter, pruned branch and nuts harvest were analyzed to provide a theoretical basis for the optimal management of Ca, Mg, Zn and B nutrients and help the quality and efficiency production of macadamia. In 2021 and 2022, high-yielding trees of macadamia nut variety A16 were used as the test materials to study the quality of dry matter, the content of Ca, Mg, Zn and B nutrients and their cumulative distribution during litter, pruned branch and nuts harvest. The average dry matter weight of litter, pruned branch and nuts harvest of macadamia t was 35.77 kg/plant, among which litter, pruned branch and nuts harvest accounted for 19%, 32% and 49% of the total dry matter weight, respectively. There were significant differences in the content of Ca, Mg, Zn and B nutrients in different tissues, and the overall performance was Ca>Mg>B>Zn. The average cumulative amounts of Ca, Mg, Zn and B in 2 years was 126.13, 23.39, 0.25 g/plant and 0.89 g/plant, respectively. The cumulative distribution of Ca and Mg in litter, pruned branch and nuts harvest was 45%, 48% and 7%, and 26%, 33% and 41%, respectively. The cumulative distribution of Zn was 25%, 28% and 47%, and the cumulative distribution of B was 44%, 36% and 20%, respectively. Among them, leaves (senescent leaves and pruning leaves) were the main accumulation and distribution parts of Ca and B, while pruning leaves and nuts were the main accumulation and distribution parts of Mg and Zn. The estimated apparent nutrient balance indicated that the total nutrient taken by Ca, Mg, Zn and B was 45.41, 8.42, 0.09 kg/hm² and 0.32 kg/hm². After removing some nutrients returned by litter, in the absence of exogenous Ca and Mg input and the input of Zn and B 0.08 kg/hm², Ca, Mg and B nutrients were deficient in macadamia. The results would provide the basis for nutrient optimization management of macadamia.

Biogenic volatile organic compounds (BVOCs) serve as a critical link between the biosphere and the atmosphere, playing a vital role in atmospheric chemistry, ozone formation, and the creation of secondary organic aerosols. Volatile emissions from urban forest parks and greenery can have a significant impact on local and regional air quality. In this study, two common Ficus spp. plants with a high planting rate in Haikou were selected, and the BVOCs emissions of F. elastica and F. altissima were measured using the dynamic headspace bagging collection method and identification and analysis by gas chromatograph. The chemical components and emission characteristics of the BVOCs were also investigated. Meanwhile, the experiment continuously monitored environmental factors [temperature (T), photosynthetically active radiation (PAR)] and physiological parameters [stomatal conductance (G_s), intercellular CO₂ concentration (C_i), transpiration rate (T_r)] to further analyze the driving factors of BVOCs emissions in Ficus spp. The results showed 19 and 12 compounds identified for F. elastica and F. altissima. BVOCs emissions from Ficus spp. were dominated by isoprene and terpenoids. Among them, the relative content of isoprene emission from F. elastica increased by 1.82 times in the rainy season compared to the dry season, indicating that F. elastica has a significant potential for isoprene emission. The terpene compounds α-pinene and Caryophyllene made significant contribution. The daily variation of BVOCs in Ficus spp. showed a single-peak emission pattern of “low in the morning and low in the evening, high in the middle of the day”, with the maximum emission of BVOCs occurring at 12：00 or 14：00 noon, when the temperature or photosynthetically active radiation was the highest. BVOCs emissions from Ficus spp. were significantly higher in the rainy season than they were in the dry season. In addition, the BVOCs emissions of Ficus spp. were positively correlated with the temperature and with the photosynthetically active radiation. BVOCs emissions were positively correlated with the physiological parameters, T_r and G_s, and negatively correlated with C_i. This study expands the research field by investigating the emission characteristics of BVOCs from tropical Ficus spp. It provides essential data for enriching the database of BVOCs emission inventories in tropical and subtropical regions and for assessing their environmental impact.

The study was aimed to provide technical support for risk management, risk analysis and risk assessment of pests carried by banana seedlings in China. By consulting domestic and foreign literature (mainly including China’s National Pest Quarantine Information System, etc.), a total of 68 species of pests that may be transmitted to bananas exported to China were identified, including 32 species of insects, 19 species of fungi, 9 species of nematodes, 4 species of bacteria, 1 species of mollusca, and 3 species of mites (including spiders). Based on the distribution in China (undistributed or not widely distributed), whether they are officially controlled, and the possibility of being carried with banana seedlings, 9 potential quarantine pests were identified that require further evaluation, including 7 species of fungi and 2 species of bacteria. The 9 potential quarantine pests were qualitatively and quantitatively analyzed one by one in terms of entry, colonization, diffusion possibility, economic impact and multi-index comprehensive evaluation, and 5 species of medium-risk pests and 4 species of high-risk pests were identified. Finally, it was determined that the nine pests including Botryotinia fuckeliana were quarantine pests that require attention when banana seedlings were exported to China, and the corresponding risk management measures were put forward.

Plant protection unmanned aerial vehicle (UAVs) operational parameters have remarkable effects on droplet distribution in UAVs spraying, which significantly affects pesticide utilization rate and treatment effectiveness. The study was aimed to explore the effects of operating parameters of electric UAVs on droplet deposition distribution in mango trees canopy and to enhance the efficiency of targeted deposition by UAVs. The DJI T40 multi-rotor electric plant protection UAV was used and the main operational parameters including droplet sizes (80, 100, 120 μm), flight height (2.0, 2.5, 3.0 m) and flight speed (3.0, 4.0, 5.0 m/s) were optimized by an orthogonal test. When the droplet size was 80 μm with 2.0 m of flight height and 3.0 m/s of flight speed, the droplet deposition density, coverage rate and uniformity in each canopy of mango trees were significantly larger than those of the other groups. There was a negative correlation between droplet deposition density, coverage rate and flight height, flight speed. The results of range analysis showed that droplet size was the main factor affecting the deposition density of droplet in mango canopy. The flight height was the main factor affecting the coverage rate of spray droplets on the front side of the lower canopy leaves and the back side of the inner canopy leaves of mango trees. The flight speed was the main factor affecting the coverage rate of spray droplets on the back side of the upper canopy leaves of mango trees. The spray diameter of the front and back of the leaves of the other layers was the main factor affecting the droplet coverage rate. The droplet distribution within mango canopy exhibited significant variation, with droplet size being the primary factor determining uniformity, followed by flight speed and flight height. In our current study, according to the droplet deposition density, coverage rate and uniformity in mango canopy, the best operating parameters of T40 multi-rotor electric plant protection UAV were obtained as follows: droplet size of 80 μm, operation height of 2.0 m, and operation speed of 3.0 m/s. It could provide fundamental guidance of the operation of small UAVs for the aerial spraying of mango trees and other similar orchards.

Sugarcane pokkah boeng disease (PBD) is a major disease of sugarcane in China, which severely affects the yield of sugarcane and causes significant economic losses. Selection and cultivation of PBD resistant sugarcane germplasms is the most economical and effective control method. In this study, a three-year field experiment was conducted in Dingdang of Guangxi, and Dehong of Yunnan to analyze the natural disease data of sugarcane PBD from 2015 to 2017. The objective was to evaluate the disease resistance of 98 sugarcane germplasms in China and provide a reference for breeding disease-resistant sugarcane. The results indicated significant difference between different regions, with the average incidence and disease index higher in Dingdang than Dehong. Joint analysis of variance (ANOVA) showed that germplasms, year, location, month, germplasms×year, germplasms×location and location×month had a significant impact on the incidence and disease index of tip rot (P<0.001). Among them, genotype and year had the greatest impact, indicating that PBD is mainly controlled by genetic and environmental factors. A comparison of meteorological conditions at various locations revealed a positive correlation trend between the PBD occurrence, air temperature, and annual rainfall. The 98 sugarcane germplasms were categorized into five groups, out of which 16 (16.33%) were highly resistant, 32 (32.65%) were resistant, 18 (18.37%) were moderately susceptible, 24 (24.49%) were susceptible, and 8 (8.16%) were highly susceptible. Highly resistant germplasms such as CP94-1100, Q202, ROC21, ROC23, Yuetang 93-159, Guitang 02-1247, Guitang 02-208, Guitang 02-761, Guitang 03-1403, Yuegan 16, Guitang 05-3846, Guitang 05-827, ROC22, Yuetang 00-236, Yuetang 89-240, and Yuetang 94-128 are recommended as the parents for disease resistance breeding. Conversely, highly susceptibility germplasms such as CP72-2086, PINDAR, ROC26, Guitang 02-619, Guitang 05-2743, Guitang 05-322, Liucheng 03-182, and Shuidian 25, should be used with caution. This study distinguished germplasms with stable resistance in different environments, which is significant for germplasm utilization and the breeding of resistant germplasms.

The introduction and evaluation of foreign clones play an important role in promoting the development of rubber trees in China. In order to evaluate the adaptability of Indonesian rubber tree clone Reshi 11-107, the stem circumference growth, dry rubber yield, rubber production and discharge characteristics, and natural rubber quality were examined in the clone trail test, which was arranged according to the breeding technical regulations. The average annual stem girth of Reshi 11-107 increased by 7.6 cm before tapping, and increased by 3.0 cm after tapping, and the fast-growing characteristics were obvious. The average yield was 58.41 g and the dry gum content was 33.37% in the first 5 tapping years, which were significantly better than that of the control clone RRIM600. Reshi 11-107 has a large number of laticifers in the bark, the initial flow rate of rubber discharge is fast, the plug index is low, the thiol content is significantly higher than that of the control, and the sucrose content is equivalent to that of the control. It has good characteristics of rubber production and discharge, better potential for rubber production, and good adaptability to cold damage. Reshi 11-107 natural rubber has large molecular weight, high ash content, high initial plasticity value, high tensile strength, high tear strength and good physical and mechanical properties. In conclusion, the comprehensive characters of Reshi 11-107 are better, which could adapt to the planting environment in China, and could be expanded in the type I planting area.

The triose-phosphate/phosphate translocator (triose-phosphate/phosphate translocator, TPT) is a triose phosphate transporter that plays an important role in plant carbon metabolism pathways as well as abiotic stresses. Sucrose has a wide range of edible value and important economic value. Sugarcane is the main raw material for sugar production, and sucrose from sugarcane accounts for more than 80% of China's sugar production, so it is very important to achieve the goal of high yield and high resistance of sugarcane. In this study, the sugarcane variety ROC22 was used as the material to clone the sugarcane triose/phosphate transporter gene ShTPT, and the physicochemical properties, conserved domains, transmembrane structure prediction and protein sequence comparison of ShTPT were carried out by bioinformatics methods. The results showed that the CDS of ShTPT was 1221 bp, encoding 406 amino acids, the molecular weight of the protein was 43.63 kDa, and the isoelectric point (pI) was 9.80. It was rich in alanine and leucine, its instability coefficient was 42.51, and its hydrophilic coefficient was 0.583, which was an unstable hydrophobic protein. ShTPT did not contain signal peptides but had 9 transmembrane domains. Conserved domain prediction showed that ShTPT contained a tpt domain, which was consistent with the characteristics of the TPT family. The results of phylogenetic analysis showed that ShTPT was clustered with Sorghum bicolor SbTPT (XP_002454867.1) and Zea mays ZmTPT (NP_001105497.1) with homology of 97.04% and 94.13%, respectively. Further subcellular localization analysis of ShTPT showed that ShTPT was localized in chloroplasts. Tissue expression pattern analysis of sugarcane showed that ShTPT was mainly expressed in leaves, and the expression level in roots and stems was very low. Under the drought stress conditions simulated by PEG, the expression of ShTPT showed an upward trend, indicating that it responded to drought stress. The results of this study suggest that ShTPT is a chloroplast-localized transmembrane transporter, which may be involved in the transport of primary carbon metabolic compounds in sugarcane leaves and responsive to drought stress. This study preliminarily determined that ShTPT gene plays an important role in the transport of carbon assimilates in leaves and abiotic stress, which provides a theoretical basis for further study of its function.

Cold resistance and high-yielding are always the core breeding objectives of Yunnan rubber tree planting area in China. The superior clone was selected by artificial hybridization, and was systematically identified by nursery trial, advanced clonal trial and resistance test. The results showed that Yunyan 80-1983 was a fast-growing, high-yielding and early-maturing rubber tree clone which could be tapped 0.5-1 years earlier. In advanced clonal trials, the girth reached 52.7 cm in the seventh year, which was 122.6% of the control RRIM600 (43.0 cm). The dry rubber yield of 1-13 tapping year was 4.3 kg per tree and 1622.7 kg/hm², which was 130.3% and 122.5% of the control RRIM600 (3.3 kg per tree,1324.8 kg/hm²). The cold resistance was basically equivalent to that of RRIM600, lower than that of GT1 and Yunyan 77-4. It is recommended to be planted in the low-altitude and slight cold damage zone in Yunnan. This clone would provide variety support for optimizing the variety structure, increasing the yield and output value in Yunnan and other rubber planting areas.

Gibberellic acid is a typical plant growth regulator, which has the efficacy of increasing yield and fruit preservation for crops. The preparation process of gibberellic acid dry flowable is still lacking systematic exploration, and the fruit preservation test of this preparation on citrus still needs to be verified. The study was aimed to investigate the effect of the wet grinding process of sand mill on the performance of gibberellic acid suspension slurry and to determine the performance of dry flowable prepared by spray drying. The 3% gibberellic acid dry flowable was prepared by the wet sand mill and pressure spray drying equipment, and the final process was screened according to the determination of particle size, viscosity, the retention rate of gibberellic acid content, and other performance indexes of the suspension concentrate through the optimization of the number of wet grinding times, the wet grinding speed, and the size of the diameter of zirconia beads used for wet grinding. The effect of 3% gibberellic acid dry flowable on citrus fruit set, fruit thickness, single fruit weight and soluble solids were tested in field efficacy test. The results showed that the optimal grinding process was 1 mm in diameter of the zirconium beads used for grinding, the grinding speed was 2500 r/min and grould twice. The viscosity of the suspension concentrate before spraying was lower than 200 mPa/s, and the particle size was about 2 µm, and the particle size of the suspension concentrate after spraying was about 3 µm after rehydration, and the retention rate of gibberellic acid was more than 90% after this grinding process, and the low viscosity of the slurry could meet the production requirements. The 3% gibberellic acid dry flowable produced by this process has high suspension rate (>90%), fast wetting speed (10 s), high retention rate of gibberellic acid, and the performance indexes are in accordance with the regulations, and there is no precipitation of suspension slurry during the production process. The results of the field trial showed that the spraying of gibberellic acid dry flowable increased the transverse and longitudinal diameter of the citrus single fruit, the thickness of the peel decreased, the weight of the single fruit increased, the soluble solids increased, and the fruiting rate of the planting area increased. The results provide theoretical support for the industrial production of gibberellic acid dry flowable, and the field trial of gibberellic acid dry flowable prepared in this study in citrus trees can provide reference for the application of gibberellic acid in citrus fruit trees.