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.

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.

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 purpose of the study was to explore the relationship between Lvnonglin^® 41 compound microbial fertilizer (LNL41) and the occurrence of tomato Fusarium wilt and soil fungal communities and to provide theoretical basis for the prevention and control of tomato Fusarium wilt and the rational application of nitrogen fertilizers. Using plots with severe occurrence of tomato Fusarium wilt in previous years as experimental plots, four treatments were designed in field: water control (CK), LNL41, bacterial fertilizer nutrient substrate (NS), compound microbial (CM). The effects of different treatments on the concentrations of main soil nutrients of rhizosphere soil, plant growth, soil respiration rate, incidence of Fusarium wit disease were analyzed. Using 18S rDNA sequencing technology, the differences in the occurrence of tomato Fusarium wilt and the fungal community structure in rhizosphere soil under LNL41 were investigated. Compared with other treatments, the LNL41 treatment is the best. The treatments with LNL41 and CM had higher contents of organic matter and available phosphorus in tomato rhizosphere soil than other two treatments. Compared with the control, the plant height, stem circumference, leaf area, photosynthesis, chlorophyll, yield and water-soluble sugar treated by LNL41, CM and NS all increased by 8.87%-34.71%, 15.93%-67.62%, 13.37%-52.88%,3.17%-12.55%, 3.20%-20.49%, 4.38%-19.53%, 0.46%-8.79% respectively. The soil respiration rate increased by 59.52% in LNL41. The incidence and control effect of tomato Fusarium wilt disease in different growth stages reached 2.33%-16.33% and 80.50%-90.83% in LNL41, respectively. The Ace index and Chao1 index at the fungal genus level in the rhizosphere soil increased by 26.97%-57.71% and 24.89%-56.00%, respectively. The diversity indicators of the Simpson index and Shannon index of the CM treatment increased by 25.75%-29.45% and 39.04%-49.13%, while the diversity indicators of the NS treatment decreased. Hypocreaceae and Trichoderma treated with LNL41 were among the top five dominant families and genera (both abundances were 8.56%); Trichoderma was similar to Cladosporium, Uwebraunia, Aureobasidium and Fusarium in the four treatments, and was positively correlated with Aspergillus, Uwebraunia and Alternaria respectively. Chao1 index treated with LNL41 was significantly positively correlated with organic matter, available phosphorus, available potassium and soil respiration rate, and was significantly negatively correlated with salinity and disease incidence. The abundance of saprophytic functional groups treated with microbial fertilizer increased by 0.92-11.15 percentage, plant pathogen decreased by 2.55 percentage, and endophyte decreased by 7.95 percentage, while only two functional groups treated with NS and CM increased in abundance. LNL41 can significantly improve the ratio of soil nutrients, thereby improving the structure and functional characteristics of soil fungal communities, stimulating saprophytic functions of the fungal communities, promoting tomato growth, and reducing the rate of blight.

Species of Diaporthe have broad host ranges and are widely distributed in ecosystems, occurring as plant pathogens, endophytes or saprobes. In this study, the ingredients and contents of phytohormones, organic acids, and fatty acids in 16 strains of Diporthe fungi, collected and identified from Xisha islands, were detected by LC-MS and GC-MS methods. Cluster analysis by Ward method of Euclid Distance was used to classify the quality types of different strains. The results showed that four phytohormones, three organic acids, and five fatty acids could be detected. The phytohormones included abscisic acid (ABA, average yield 125.36 µg/kg), indole-3-acetic acid (IAA, average yield 40.28 µg/kg), salicylic acid (SA, average yield 6.63 µg/kg) and jasmonic acid (JA, average yield 4.95 µg/kg). the yield of ABA was significantly higher than other plant hormones, and the four phytohormones contents of different strains varied greatly. Organic acids were succinic acid (average yield 336.04 µg/g), succinic acid (Vc, average yield 10.03 µg/g), shikimic acid (average yield 0.58 µg/g). The succinic acid production of Diporthe fungus was significantly higher than those of other organic acids. The yield of organic acids varied greatly among the 16 strains. The fatty acids were trans linoleic acid (average yield 58.99 µg/g), linolenic acid (average yield 28.15 µg/g), stearic acid (average yield 21.35 µg/g), palmitic acid (average yield 17.07 µg/g) and oleic acid (average yield 15.22 µg/g). The production of trans linoleic acid were the highest, while the production of oleic acid the lowest, and the five organic acids contents of different strains varied remarkably. Cluster analysis using plant hormones, organic acids, and fatty acids of the 16 strains revealed D. biconispora D43 was independent group. The strain showed the highest production of ABA (average yield 443.86µg/kg), succinic acid (average yield 1115.98 µg/g), shikimic acid (average yield 1.21 µg/g), and oleic acid (average yield 60.75 µg/g), while the lowest production of linoleic acid (average yield 7.08 µg/g). Comprehensive analysis suggests that D. biconispora D43 had certain potential for the development and utilization of microbial derived succinic acid. This study would provide information for the research and appication of Diaporthe resources in the field of food, chemical industry, and other related fields.

Xyleborus affinis, a main pest of rubber trees, is effectively monitored and controlled using semiochemicals, a key method in rubber pest management. Chemosensory proteins (CSPs) are believed to play an important role in the process of binding and transporting odorants in insect. To elucidate the role of chemosensory proteins in semiochemicals recognizing by X. affinis, the XaffCSP1~XaffCSP5 genes were cloned and identified in this study. The characteristics of nucleotide and deduced amino acid sequences of the genes were analyzed using bioinformatics methods. The binding mode and ability with 15 different ligands (14 host plant volatiles and 1 aggregation pheromone) was analyzed using molecular docking technology. Results revealed that the length of the open reading frame (ORF) of the five XaffCSPs genes was 366-417 bp, encoding 121-138 amino acids. The predicted protein molecular weight was 13.95-16.08 kDa and all five XaffCSPs contained signal peptide composed of 17-20 amino acid residues at N-terminal. The secondary structure of the proteins was mainly composed of α-helix. All five XaffCSPs possessed four conserved cysteine residues, conforming to the typical characteristics of insect chemosensory proteins. Phylogenetic tree anaylsis indicated that except for XaffCSP5, XaffCSP1 to XaffCSP4 were clustered with CSPs of other bark beetle species. The three-dimensional models of the the five XaffCSPs were with good model quality according to model assessment results, and the models of the five XaffCSPs were composed of six α-helices. Molecular docking results demonstrated all five XaffCSPs had a strong binding affinity with (-)-α-copaene and (+)-longifolene. Additionally, XaffCSP4 showed strong binding to terpinolene and limonene, while XaffCSP5 showed strong binding to camphene, α-pinene, and β-pinene. The binding ability of the five XaffCSPs to (S)-cis-verbenol was relatively weak. The results demonstrated that the five XaffCSPs had good affinity with host volatiles and may be participated in the process of recognizing host plant volatiles by X. affinis. This study would provide a theoretical basis for elucidating the molecular mechanism of X. affinis in recognizing semiochemicals and is of great significance for the control of X. affinis.

Pineapple, an important tropical fruit, belongs to the family Bromeliaceae (Ananas Merr.), and its flower and fruit development theory and transcriptional regulation technology are one of the hot spots in the pineapple industry. Ethylene is one of the important hormones that regulate the flowering and fruit development of pineapple. In the study of watercore disorder in Bali pineapple varieties, it was found that two MYB transcription factors, AcMYB68 and Ac-MYB109, played an important role in fruit development. With the completion of pineapple genome sequencing, 94 pineapple R2R3-MYB transcription factors have been identified in the pineapple genome, which are divided into 26 subfamilies, and are differentially expressed by salt and other stresses and ABA hormones. In this study we proposed a scientific hypothesis that ethylene mediated MYB transcription factors to regulate the development of pineapple fruits. In order to elucidate the molecular regulatory mechanism, a MYB transcription factor AcMYB103 was cloned from the fruit of pineapple Tainong 17, with a total length of 1204 bp, a coding region of 1038 bp, and encoding 345 amino acids. The protein contains two typical SANT domains, localized to the nucleus, without transmembrane domain and signal peptide, and was a member of the plant R2R3 MYB transcription factor family. Cluster analysis of pineapple and Arabidopsis MYB family members showed that AcMYB103 had the highest similarity with Arabidopsis AtMYB80, At-MYB103 and AtMYB35, and belonged to the S19 subfamily. Furthermore, four ethephon concentrations (volume fraction) of 0%, 0.5%, 1.0% and 1.5% were used to treat the fruits at the small fruit stage, expansion stage and ripe stage of the three cultivars Tainong 17, Xiaomushousi and Damushousi, and the expression level of AcMYB103 was analyzed. The results showed that with the increase of ethephon concentration at the small fruit stage, the expression of AcMYB103 in Tainong 17 showed a down-regulated pattern, and upregulated in the Xiaomushousi and Damushousi mode. In the expansion stage, the downward adjustment pattern was shown in the Tainong 17 and Xiaomushousi varieties, and the upward pattern was shown in the fruit of Damushousi. AcMYB103 was not expressed in fruits at the ripening stage, indicating that the expression of AcMYB103 gene was specific in ethephon-treated varieties and fruit development periods, and played a differentiated regulatory role in the early stage of fruit development. This study would lay a foundation for in-depth study of the mechanism of AcMYB103 gene in the regulation of growth and development of pineapple fruit.

Chalcone synthase is a crucial enzyme in the initial stage of the flavonoid biosynthetic pathway. To explore the biological functions of our previously identified chalcone synthase coding gene DlCHS9 from longan, which is associated with anthocyanin accumulation, DlCHS9-SX and DlCHS9-HP from Shixia and Hongpi longan, were cloned respectively. Amino acid sequences of DlCHS9-SX and DlCHS9-HP were compared and found to differ only at position 328, which was not a key active site. Subsequently, an expression vector was created, and the Agrobacterium-mediated leaf disc method was used to introduce DlCHS9-SX into wild tobacco. The anthocyanin content in the petals of transgenic tobacco was notably higher than that in the wild type, suggesting that the DlCHS9-SX gene enhances anthocyanin accumulation in tobacco petals. The promoter sequences of the two DlCHS9 genes revealed a similarity of 96.2%. Compared to the promoter of DlCHS9-HP, the promoter of DlCHS9-SX had 32 SNPs, 14 base insertions, and 12 base deletions. Specifically, the DlCHS9-SX promoter contained an additional abscisic acid responsive element (ABRE), one fewer light-responsive element (Box4), one less low temperature-responsive element (LTR), and one less MYC transcription factor binding site. In conclusion, DlCHS9-SX plays a pivotal role as a structural gene in longan anthocyanin biosynthesis. The differences in the DlCHS9 promoter in Shixia longan may contribute to its lower expression level.

Phytochelatin synthase (PCS) is a key enzyme that catalyzes the synthesis of phytochelatin (PC). PC can reduce the toxicity of heavy metals to plants through complexation. Heavy metal pollution in soil increases the risk of cassava food safety. It is of great significance to study the reduction and control of heavy metals in cassava by analyzing the function of MePCS1 gene. In this study, the coding region of MePCS1 gene in cassava variety SC8 was cloned by PCR. The full length was 1512 bp, encoding 503 amino acids. Protein sequence analysis showed that MePCS1 protein was a hydrophilic protein, containing 41 phosphorylation sites and 2 glycosylation sites, without signal peptide. The phylogenetic tree showed that the cassava MePCS1 protein had the closest relationship with the PCS protein of the rubber tree. The qPCR analysis showed that the MePCS1 gene had the highest expression level in the stem. During the development of cassava roots, the expression level of MePCS1 gene was the highest in the root enlargement period. Lead (Pb) stress induced MePCS1 gene expression. MePCS1 gene can improve the tolerance of BY4741 yeast to Pb. The results of this study provide new information for further analysis of the functional characteristics of the MePCS1 gene and its mechanism for reducing Pb in cassava tuber roots.

Sugarcane mosaic disease is one of the main viral diseases threatening the production of sugarcane. Sugarcane streak mosaic virus (SCSMV), Sorghum mosaic virus (SrMV) and Sugarcane mosaic virus (SCMV) are the main pathogens. The occurrence of sugarcane mosaic disease seriously affects the quality and yield of sugarcane. The most economical and effective way to control the disease is the application of resistant varieties. In this paper, the damage and controlling ways of sugarcane mosaic disease were summarized. The recent research progress on identification of resistance germplasm resources, resistance inheritance, molecular markers, mining and application of the resistance gene, and breeding of disease-resistant varieties were reviewed. Moreover, the problems existing in sugarcane disease resistance breeding were pointed out, and some suggestions were put forward to strengthen the research on sugarcane mosaic disease resistance breeding.