Banana is a typical respiration fruit. MaERF15 is a transcription factor located in the nucleus and has the effect of regulating postharvest ripening of banana fruits. MaACO8 is a key ethylene biosynthesis-ACC oxidase gene expressed at high levels during postharvest ripening of banana fruits. But the molecular interaction mechanism between the two has not been clarified. To explore the transcriptional regulation mechanism of ethylene response factor MaERF15 on the key genes of downstream ethylene synthesis was to provide a theoretical basis for the innovation of postharvest preservation technology of banana fruits. In this study, the promoter sequence of MaACO8 was isolated from banana DNA, and the promoter activity of MaACO8 was studied by bioinformatics analysis and GUS staining. Yeast monohybridization, EMSA, dual fluorescein reporter system and in vivo imaging system were used to study the interaction mechanism between MaERF15 and MaACO8 promoter. The results showed that there were 11 GCC-boxes in the promoter sequence of MaACO8 that bind to AP2/ERF transcription factors, which had strong priming activity. MaERF15 could specifically bind to the GCC-box of the MaACO8 promoter, activate the expression of MaACO8, promote the biosynthesis of ethylene, and regulate fruit ripening. The results further improved the theory of postharvest ethylene biosynthesis regulating fruit ripening of banana fruits, and would provide genetic resources and theoretical basis for the research and development of new technologies for storage and transportation tolerance breeding and maturity regulation of bananas, respectively.

The fruit of Aquilaria sinensis contains a class of tetracyclic triterpenoids known as cucurbitacins, which exhibit anti-inflammatory, hepatoprotective, and antitumor activities. Cytochrome P450s (CYP) are key enzymes in the biosynthesis pathway of cucurbitacins. The P450 genes for cucurbitacin synthesis in A. sinensis have not been extensively studied. In this study, a P450 gene (AsCYP131) was cloned based on A. sinensis transcriptome data. The complete open reading frame (ORF) of AsCYP131 gene was 1491 bp, encoding a protein of 496 amino acids with a molecular weight of 55.39 kDa. The theoretical isoelectric point (pI) of the protein was 7.65, with an average hydrophilicity coefficient of –0.053, and an instability index of 47.16, classifying it as an unstable protein. The protein contained 40 potential phosphorylation sites, and its secondary structure was predominantly composed of α-helix and random coil. The results of multiple sequence alignment and phylogenetic tree analysis showed that the protein encoded by the AsCYP131 gene clustered into a single unit with CsCYP, CmCYP, and ClCYP, which have been reported to be involved in the biosynthesis of cucurbitacins. The sequence of the functional structural domains at the C-terminal showed high consistency. At the same time, the expression levels of AsCYP131 in different tissues of A. sinensis detected by real-time fluorescence quantitative PCR (RT-qPCR). The results indicated differential expression levels of AsCYP131 across various tissues, including roots, stems, leaves, flowers, fruits, and seeds, with the highest relative expression observed in fruits. This study would serve as a valuable reference for the subsequent validation of the functional role of the AsCYP131 gene in cucurbitacin biosynthesis.

Rice (Oryza sativa L.) is one of the most critical staple crops worldwide, and enhancing its yield is fundamental to ensuring global food security. Shanlan rice, a prominent upland rice variety in the southern regions of China, particularly in the mountainous areas of central Hainan province, is highly valued by farmers for its strong adaptability, drought resistance, and superior stress tolerance. However, traditional Shanlan rice varieties often suffer from challenges such as excessive plant height, vulnerability to lodging, and yield instability, which restrict the broader application in modern agriculture. This study focused on four local Shanlan rice varieties: Wuzhishan Nandui Village Shanlan rice, Huangke Shanlan Nuo, Shanlan Nuo and Shanlan Hong. The varieties were subjected to mutagenic treatment using ethyl methanesulfonate (EMS). After treatment, superior mutants were selected through screening across M₁ to M₃ generations based on significantly reduced plant height and either stable or enhanced single-plant yield. The results revealed the successful induction of multiple dwarf, high-yield mutants in all four varieties via EMS mutagenesis. For instance, in Wuzhishan Nandui Village Shanlan rice (WZSNDCSLD2), plant height was reduced by 9.6%, while single-plant yield increased by 52.8%; in Huangke Shanlan Nuo (HKSLN31), plant height decreased by 11.5%, and single-plant yield rose by 46.0%; in Shanlan Nuo (SLN8), plant height was reduced by 15.4%, with a 37.0% increase in single-plant yield; and in Shanlan Hong (SLH6 and SLH9), plant height was reduced by 22.2% and 15.5%, respectively, while single-plant yield increased by 49.6% and 36.8%. The superior mutants also exhibited significant improvements in agronomic traits, including total grain number, spikelet number per panicle, filled grain number per panicle, thousand-grain weight and seed setting rate. The findings of this study demonstrate that EMS mutagenesis is an effective approach for improving both plant height and yield-related traits in Shanlan rice. This research would provide new genetic lines and a solid theoretical foundation for the genetic improvement and molecular breeding of Shanlan rice.

The effect of gibberellin (GAs) on the fruit size of longan using the F₁ generation of a stable hybrid population, FD 52 (big-size fruit) and FD 114 (small-size fruit), which derived from the cross between ‘Fengliduo’ and ‘Dawuyuan’, were studied. Three concentrations of gibberellin (50 mg/L, 100 mg/L, and 150 mg/L) were applied to the inflorescences of small-fruit longan at four time points: 3 days before anthesis (–3 d), on the day of anthesis (0 d), 3 days after anthesis (3 d), and 6 days after anthesis (6 d). The endogenous GAs contents in the treatments were measured, and fruit quality traits were mature at the ripening stage. Additionally, the endogenous GAs content, cell size, and the number of cell layers in untreated large-fruit and small-fruit longan were compared. Results showed that exogenous gibberellin application significantly increased endogenous GAs levels and promoted fruit enlargement, with the most pronounced effect observed when 100 mg/L gibberellin was applied 3 days after anthesis. Early in fruit development, GA₄ was the predominant active gibberellin in longan fruit, with higher levels of GA₄, larger cell size, and more cell layers observed in big-size varieties compared to small-size ones. The findings suggest that GAs application and the differential accumulation of GA₄ along with cellular factors such as cell size and layer number, contribute to the variation in fruit size. This study would provide valuable insights for improving longan fruit size through the application of gibberellin in cultivation practices.

Sucrose phosphate synthase (SPS) plays a crucial role in the sucrose synthesis process, and investigating the biological functions of the SPS family in durian (Durio zibethinus Murr.) can contribute to enhancing fruit quality. In the durian genome, 10 SPS members were identified and designated as DzSPS1 to DzSPS10. The results indicated that the average hydrophobicity coefficient was less than 0, with isoelectric points ranging from 5.70 to 6.68, suggesting that they are hydrophilic acidic proteins. Subcellular localization predictions primarily placed them on the cell membrane and nucleus. Analysis of conserved motifs within the gene family revealed variations in the number and distribution of motifs among durian SPS members, although all contained motif 3, indicating that motif 3 is a significant conserved domain within the durian SPS gene family. Gene structure analysis showed that durian SPS genes were structurally similar, containing 8 to 15 exons and 7 to 13 introns. Phylogenetic tree analysis demonstrated that durian SPS genes could be divided into two subfamilies, with subfamily Ⅱ comprising nine members and subfamily Ⅰ containing one member. Compared to SPS genes in horticultural fruit trees such as cacao and citrus, durian SPS genes exhibited closer phylogenetic relationships with Arabidopsis and rice SPS genes. Seven members of the durian SPS family shared high spatial structural similarity, with secondary structures predominantly consisting of α-helices and random coils. Cis-acting element analysis suggested that durian SPS genes may be readily induced by response elements related to light, low temperature, drought, and gibberellin. This study detected that the primary soluble sugars in durian fruit are sucrose, fructose, and glucose, with sucrose content significantly higher than that of fructose and glucose, and notable differences observed among different varieties. Fluorescence quantitative analysis revealed significant variations in SPS expression levels among different durian varieties, with the expression patterns of DzSPS3 and DzSPS7 correlating with changes in total sugar content between varieties, suggesting that DzSPS3 and DzSPS7 may be key members involved in sugar accumulation. By analyzing the structure and physicochemical properties of durian SPS genes and exploring the SPS accumulation characteristics in different varieties, this study would provide a reference for further investigation into the biological functions of the SPS family in durian.

Natural rubber (NR) is an important industrial material and strategic resource. Its composition, structure, and properties are influenced by factors such as the rubber tree cultivar and processing methods, leading to significant variations in quality stability. By studying the changes in particle size and molecular weight of natural rubber prepared through different centrifugation cycles, this research explored the effects on rubber composition and performance, which is crucial for obtaining high-quality rubber. In this study, two rubber cultivars, Reyan 73397 and PR107, were selected to investigate the impact of different centrifugation cycles on the particle size of latex, molecular weight, physicochemical properties of raw rubber, and vulcanized rubber properties. After centrifugation, the particle size of the latex from both cultivars increased with the number of centrifugation cycles, and the particle size distribution became more concentrated, with Reyan 73397 having a larger particle size than PR107. The molecular weight decreased, and the molecular weight distribution narrowed as the centrifugation cycles increased. With more centrifugation cycles, the ash content, gel content, nitrogen content, and Mooney viscosity of both cultivars decreased, the vulcanization time extended, but the resistance to storage hardening increased. However, the tensile strength and tear strength were reduced. The aging resistance of the vulcanized rubber from both cultivars decreased with the increase of centrifugation cycles. Furthermore, centrifugal treatment increased the glass transition temperature (T_g) of the rubber, enhanced its resistance to wet sliding, and increased the rolling resistance and heat build-up of the rubber.

The residue of nitrogen fertilizer in soil is an important destination after nitrogen fertilizer application. Under tropical acidic soil conditions, it is hypothesized that the lack of carbon may further limit soil retention of nitrogen fertilizer in rubber plantation. A field micro-experiment utilizing ¹⁵N isotope tracer technology was conducted to investigate the soil nitrogen residual characteristics in rubber plantations with different nitrogen application levels (0 kg/hm², N₀; 100 kg/hm², N₁₀₀; 200 kg/hm², N₂₀₀; 400 kg/hm², N₄₀₀) under the addition of exogenous carbon (100 kg/hm²). The results showed that the soil residual rate of nitrogen fertilizer was 8.8%-17.6% in the first year and 6.6%-16.5% two years later after adding carbon. Notably, the residual rate of nitrogen fertilizer showing a downward trend was observed with the increasing of nitrogen application; compared with the treatment without nitrogen fertilizer, the lower nitrogen application level (100 kg/hm²) under carbon addition had a significant effect on enhancing both soil total nitrogen and organic carbon content. The 2-year field trial revealed that the residual rate under different nitrogen application with carbon addition was higher than that without such addition. Variance analysis showed that exogenous carbon addition had a significant positive effect on the residual rate of nitrogen fertilizer; and carbon addition could effectively enhance the soil retention of nitrogen fertilizer. In conclusion, the deficiency of soil carbon emerged as a critical factor contributing to the low nitrogen residue rates in rubber plantations; therefore, it is imperative to combine chemical fertilizers with organic fertilizers during the fertilization process in rubber plantations, while the nitrogen application rate remains moderate.

Taraxacum grypodon Dahlst. is an important medicinal and edible perennial herb. To study the effects of light intensity on the growth and secondary metabolites of T. grypodon can lay a foundation for revealing the formation mechanism of its secondary metabolites, and provide crucial reference for its subsequent comprehensive development and utilization, and also provide guidance for establishing high-quality and high-yield dandelion artificial cultivation system. In this study, four shading gradients (the light transmittance was 100%, 80%, 50%, 30%, respectively) were set up in the greenhouse to cultivate T. grypodon. At the time of harvesting, the growth related indicators were measured, and the sugar, flavonoids, total phenols, and lignin components in the aboveground leaves and underground roots were analyzed. 100% light transmittance was conducive to the growth and photosynthetic efficiency of T. grypodon. Under this light condition, leaf length, root length, aboveground and underground biomass were the highest (P<0.05), and the SPAD value of leaves was the largest. The total sugar and polysaccharide contents of leaves and roots were the highest when the light transmittance was 100%, and the total sugar content in roots was significantly higher than that in leaves (P<0.05), and the polysaccharide content in roots was significantly higher than that in leaves. The content of reducing sugar in leaves and roots both was the highest when the light transmittance was 50%. The content of reducing sugar in leaves and roots both had significant difference under different shading treatment. The flavonoids content in the leaves was significantly higher than that in the roots (P<0.05), and reached to the highest content in 100% light transmittance. The total phenolic content in leaves was significantly higher than that in roots (P<0.05), and reached to the highest at 100% light transmittance, but decreased significantly after shading. The lignin content in roots was significantly higher than that in leaves (P<0.05), and both reduced under shading. In conclusion, the flavonoids and phenols of T. grypodon are mainly accumulated in leaves, while total sugars and polysaccharides were mainly accumulated in roots. Sufficient light is more conducive to the accumulation of the metabolites and plant growth. Proper shading is beneficial to the accumulation of reducing sugar, reduces the content of total phenol and lignin, and increases the taste quality of T. grypodon. In production, both medicinal and edible quanlity should be taken into account, so the cultivation conditions of T. grypodon are suitable for no shaded or slightly shaded habitats.

The present work aims to provide references for differentiated nutrient management of litchi cultivars, and enhance the cultivation promotion of the new quality cultivars via clarifying the differences in nutrient content, nutrient transfer capacity and nutrient accumulation in different parts of litchi fruits among the main and the new quality cultivars in South China. A total of 73 litchi fruit samples belonging to 25 main and new quality litchi cultivars were collected from 29 litchi orchards in South China. The contents of 12 nutrients in pericarp, flesh and kernel of litchi fruits were determined to compare the discrepancies in nutrient transfer and accumulation among cultivars. Further, the types of nutrient accumulation in litchi fruit were categorized through cluster analysis. The results show that, most cultivars of litchi had the highest K content in the pericarp and the flesh, whereas the highest N content were observed in the kernel. The average transfer factors of P, S, Fe, Cu and Zn from pericarp to kernel ranged from 1.09 to 1.58, with strong transfer ability. N, K, Mg, B and Mo had medium transfer ability, with the average transfer factors within 0.53-0.99. The average transfer factor of Ca and Mn was only 0.35 and 0.481 respectively, with relative low transfer capability. With regard to the transfer capability from pericarp to flesh, N, K, Mg, S, Fe, Zn, B and Mo were figured by average transfer factors of 0.49-0.87, and Cu and P by high average transfer factors (5.91 and 1.32). However, Ca and Mn were characterized by extremely low average transfer factors of 0.069 and 0.112, respectively. Among the 25 cultivars, the content of Ca, Mg and Mn in Xiantaoli peel was higher than that of all the other cultivars, which was 6.13 g/kg, 3.34 g/kg and 233.52 mg/kg, respectively. Moreover, the ability of the three elements transferring from peel to kernel or flesh was lower than that of all the other cultivars, leading to excess accumulation in the peel. The requirement of N and K in 25 litchi cultivars was categorized into seven types: low N and high K, medium N and low K, medium N and medium K, medium N and high K, high N and low K, high N and medium K, high N and high K. The accumulation of Ca, Mg, B and Mo was divided into three groups including the low-, medium- and high-types, respectively. Ca and Mn were difficult to transfer in litchi fruit, being an obstacle to the development of litchi fruit. Conclusively, the nutrient accumulation of litchi fruit is cultivar dependent, therefore, elaborate nutrient strategy for litchi can be made to meet the nutrient demand for fruit development. The fertilization strategy for the new quality varieties of litchi can be referred to the traditional cultivars belonging to the same nutrient requirement type.

The study was aimed to breed new varieties of fresh-eating sweet potato with high yield and high quality to meet the market demand of fresh-eating varieties. A new fresh-eating variety Guishu No. 15 was successfully bred with Yuzishu No. 7 as the mother and Guiziweishu No. 1 as the father. The variety is spindle-shaped with purple skin and white heart. Guishu No. 15 is centralized and neat, with an average number of 5.10 storage roots per plant. The proportion of commodity sweet potato is high, with a medium and large storage roots rate of 94.20%. The cooked has excellent quality, with β-carotene 27.70 µg/100 g, anthocyanin 67.40 mg/100 g, soluble sugar 5.39%, reducing sugar 1.90 g/100 g, and protein 0.94 g/100 g. The average fresh storage roots yield, dry storage roots yield, and starch yield in the two-year regional trial was 30 303.00 kg/hm² 8187.90 kg/hm² and 5195.99 kg/hm², respectively, significantly increased by 11.95%, 23.10% and 27.81% compared to CK. Guishu No. 15 has good high and stable yield, excellent cooked food quality, and moderate resistance to Fusarium wilt, bactrium wilt, stem nematode, and root rot disease, which is suitable for planting in Guangxi and its similar ecological areas.