To address the limitation of conventional rubber plantation suitability assessments that overlook geographical environmental heterogeneity, this study proposes a suitability evaluation approach based on geographical zoning modeling. Eight key indicators were selected from three dimensions, topographic conditions, hydrothermal conditions, and cold damage risk, to construct the evaluation index system. The weight of these indicators was determined by integrating the Analytic Hierarchy Process (AHP) with the GeoDetector method. Using the Ailao Mountains ridge as a geographical demarcation, the rubber plantation area in Yunnan province was divided into western and eastern zones, for which region-specific factor suitability grading standards were established and applied for factor reclassification. Subsequently, the reclassified factors were integrated through linear weighting to produce a comprehensive suitability evaluation, classifying the results into four categories, unsuitable, marginally suitable, moderately suitable, and highly suitable. Among the six prefecture-level regions engaged in rubber cultivation, highly suitable areas accounted for approximately 4.29% of the total land area, moderately suitable areas for 2.79%, and marginally suitable areas for 5.06%, totaling about 12.14%. These areas are mainly concentrated in Xishuangbanna, Pu'er and Honghe. Overlay analysis with 2024 rubber plantation distribution data revealed that about 47.80% of existing plantations in highly suitable zones, 22.09% in moderately suitable zones, and 19.29% in marginally suitable zones, accounting for a combined 89.18%. This distribution shows a high degree of spatial consistency with the actual planting patterns. The evaluation results, with a spatial resolution of 10 m, are capable of reflecting fine-scale variations in Yunnan's mountainous environments, and can thus provide valuable references for rubber plantation planning and adjustment in Yunnan province.

Internode length is a key factor determining sugarcane plant height, and appropriate promotion of sugarcane internode elongation can increase unit yield. The gibberellin insensitive dwarf (GID) gene is a core receptor in the gibberellin (GA) signaling pathway. Previous studies have shown that sugarcane GID1 is highly expressed during the vigorous internode elongation stage, and its overexpression can enhance GA signaling to promote internode elongation. In this study, using the sugarcane variety Guitang 42, Xintaitang 22, Guifu 98-296 as the material, the coding sequence (CDS) of ScGID2 (gibberellin receptor protein) was cloned and subjected to bioinformatics analysis. Besides, quantitative real-time PCR (qRT-PCR) was used to analyze the expression patterns of the gene in different tissues, different genotypic varieties, and under gibberellin (GA₃) treatment. Result showed that the cloned ScGID2 gene had a full-length CDS of 720 bp, encoding 239 amino acids, containing a conserved F-box domain. It shared high homology (>88.75%) with GID2 from gramineous plants such as sorghum and maize, and was mainly localized in the nucleus. Expression pattern analysis revealed that ScGID2 had the highest expression level in the shoot apex at the non-elongation stage, followed by the +2 internode at the vigorous elongation stage. There were differences in the expression patterns of ScGID2 among different sugarcane varieties. The expression of ScGID2 in Xintaitang 22, Guifu 98-296, and Guitang 43 showed a trend of first increasing, then decreasing, then increasing again, and then decreasing again. The expression level of ScGID2 in Guitang 43 was much higher than that in Xintaitang 22 and Guifu 98-296. The expression level of ScGID2 in Guitang 42 increased gradually, reaching the peak at 30 days. The expression peak of ScGID2 in long-internode varieties was significantly higher than that in short-internode varieties and lasted longer. After GA₃ treatment, the expression peak of ScGID2 in the short-internode variety Guitang 14-818 appeared earlier than that in the long-internode variety Guifu 98-296. Taken together, the present study provides a theoretical basis for elucidating the molecular mechanism of gibberellin-mediated sugarcane internode elongation, and ScGID2 could serve as a potential molecular target for sugarcane plant height improvement, since the expression of ScGID2 is induced by gibberellin and positively correlated with the internode elongation rate.

The heavy texture, acidification, compaction and water-air imbalance of red soils constrain crop yield enhancement. To investigate the combined effects of aerated irrigation and nitrogen application on maize yield and water-nitrogen use efficiency in red soil regions, this study employed a four-year (2021—2024) field-based design using Huiyu Sweet 3 corn as the test variety. Four treatments were established: no nitrogen application (CK), low nitrogen (N1, 150 kg/hm²), medium nitrogen (N2, 300 kg/hm²), and high nitrogen (N3, 450 kg/hm²) treatments. The study measured the effects of aerated irrigation technology on soil physicochemical properties, maize nitrogen use efficiency, and yield under different nitrogen fertilizer levels. Results indicated that aerated irrigation combined with nitrogen fertilization significantly improved soil bulk density in the plow layer (0–40 cm), with N2 and N3 treatments showing superior effects. Average soil bulk density decreased significantly by 3.87% and 5.23% compared to CK, respectively, while total soil porosity increased significantly by 5.40% and 6.27%, respectively. Under the N2 treatment, soil water storage capacity significantly increased compared to CK. Nitrogen application elevated soil organic carbon and total nitrogen content in the plow layer. The soil carbon-to-nitrogen ratio decreased with increasing nitrogen application rates, effectively promoting soil microbial growth, particularly bacterial biomass accumulation, with N2 treatment yielding the best results. Under aerated irrigation conditions, nitrogen fertilization improved maize yield traits, with N2 yielding the best results, achieving a significant average yield increase of 63.7% compared to CK. Fitting the relationship between maize yield and nitrogen application rate under aerated irrigation revealed that grain yield peaked at nitrogen application rates of 250–350 kg/hm². The agronomic efficiency (4.50–25.10 kg/kg) and nitrogen use efficiency (30.1%–41.9%) were higher under N1 and N2 treatments. In summary, considering nitrogen fertilizer reduction, corn yield maximization, and efficient nitrogen utilization, applying 250–350 kg/hm² of pure nitrogen improves soil physicochemical properties and enhances water retention capacity under aerated irrigation in Guangdong's red soil regions, effectively boosting corn yield and nitrogen utilization. These findings provide theoretical support and practical pathways for improving the aeration of clayey red soils in southern China.

Dalbergia odorifera is a rare perennial plant valued for both its medicinal and aromatic properties. However, its long growth cycle and slow maturation to meet traditional medicinal standards are major constraints for its rational utilization and development. To investigate the active components in its roots and facilitate the use, this study utilized aeroponic cultivation to rapidly obtain a substantial quantity of high-quality roots from one-year-old seedlings. Comparative transcriptome analysis between soil-cultivated roots and aeroponic roots was conducted using high-throughput sequencing to identify key genes and pathways involved in root secondary metabolite biosynthesis. The results revealed 7731 significantly differentially expressed genes (DEGs) between the two groups, with 4447 upregulated and 3284 downregulated. GO, KEGG and GSEA enrichment analyses indicated that the DEGs were primarily associated with defense signal transduction, amino acid metabolism, and the biosynthesis of secondary metabolites. Specifically, sesquiterpene and triterpene biosynthesis pathways and defense signal transduction pathways were highly expressed in soil-cultivated roots, whereas amino acid metabolism and flavonoid biosynthesis pathways were upregulated in aeroponic roots. Further analysis identified candidate key DEGs related to secondary metabolite synthesis: evm.TU.scaffold_100.907, MSTRG.3788, evm.TU.scaffold_233.200, evm.TU.scaffold_111.78 and evm.TU.scaffold_5.71 in the flavonoid pathway, and evm.TU.scaffold_36.788, MSTRG.8652, evm.TU.scaffold_40.382, MSTRG.27285 and MSTRG.28295 in the sesquiterpene pathway. This study preliminarily elucidates the differences in gene expression between soil-cultivated roots and aeroponic roots, uncovering genes and pathways regulating secondary metabolite synthesis. The findings would provide valuable data and references for the further development and utilization of D. odorifera root resources.

Calcium-dependent protein kinases (CPKs) are a class of plant-specific key signal transduction factors. In pineapple, an important tropical economic crop, the identification, classification, and functional characterization of the CPKs gene family are still in their infancy, and the molecular mechanisms by which they participate in stress responses remain unclear, which limits their application in the improvement of stress-resistant pineapple varieties. In this study, we systematically investigated the AcoCPKs gene family in pineapple by integrating genomic analysis, chromosomal localization, bioinformatic prediction, and qRT-PCR–based molecular approaches. A total of 18 AcoCPKs family members were identified at the whole-genome level in pineapple. Chromosomal mapping showed that these AcoCPKs genes are unevenly distributed across the nine chromosomes of pineapple. Bioinformatic analysis revealed that all AcoCPKs sproteins share similar conserved motifs and domain architectures. qRT-PCR expression profiling further demonstrated that the 18 AcoCPKs genes are expressed in multiple tissues, including fruits, leaves, fruit peduncles, and flower buds, with distinct tissue-specific expression patterns; moreover, the transcription levels of several AcoCPKs genes were markedly up-regulated under high-temperature, low-temperature, and NaCl salt stress treatments.Taken together, this study systematically elucidates the physicochemical properties, genetic characteristics, and stress-responsive expression patterns of members of the AcoCPKs gene family in pineapple. These findings not only provide an important theoretical basis for further dissecting the molecular mechanisms underlying AcoCPKs-mediated stress responses in pineapple, but also lay a solid foundation for the targeted improvement of stress tolerance and the breeding of high-quality, stress-resistant pineapple cultivars through gene editing, transgenic approaches, and other modern molecular breeding technologies.

The study systematically investigated the long-term regulatory effects of returning sugarcane organic materials to the field on soil physicochemical properties, microbial communities, and sugarcane growth to solve the problems of soil acidification, organic matter attenuation and structural degradation in sugarcane fields on dry slopes in China. Through a three-year barrel planting experiment (including one new planting season and two-year ratoon season), four types of sugarcane organic materials were returned to the field, including filter mud (T₁), sugarcane bagasse ash (T₂), sugarcane leaves (T₃), sugarcane bagasse (T₄), along with control (without organic amendment). Soil nutrients, physical structure, microbial diversity, root morphology, yield and sugar content were measured. The four sugarcane organic materials returned to the field reduced soil bulk density and improved soil mechanical properties and pore structure, but significant difference were observed in the effects of different materials. T₁ and T₂ significantly increased soil pH, total organic carbon (TOC), alkali-hydrolyzable nitrogen (AN) and available phosphorus (AP). T₁ consistently optimized deep soil structure, and T₂ had a significant effect on improving available potassium (AK) and water retention. T₃ and T₄ mainly increased soil TOC content, but T₄ aggravated soil acidification during the new planting season. T₃ and T₄ promoted the formation of highly stable large aggregates, with significant short-term effect. Although T₁ and T₂ promoted the formation of mechanically stable large aggregates, the water stability was poor. T₁ and T₂ had significant and long-lasting effects on improving the diversity and richness of soil bacteria and fungi, T₃ promoted microbial activity in the early stage but inhibited it in the later stages, and T₄ significantly restored microbial diversity in the later stages. T₁ had the most significant effect on increasing yield and sugar content, T₂ had an outstanding effect on promoting root development and had significantly effects on increasing yield and sugar content. T₃ had a certain yield-increasing effect in the later stages. T₄ led to a yield reduction and was not conducive to sugar accumulation. Overall, the effects of returning different sugarcane organic materials to the field varied significantly. Filter mud (T₁) proved to be the optimal material, combining long-term soil improvement, enhanced microbial diversity, and increased yield and sugar content. Sugarcane bagasse ash (T₂) was suitable for short-term water retention and root growth, but the risk of deep soil compaction must be controlled. Sugarcane leaves (T₃) should be accompanied by nitrogen fertilizer. Sugarcane bagasse (T₄) returning to field requires decomposition pretreatment. This study could provides theoretical support for the precise return of sugarcane organic materials to the field and the sustainable management of cultivated land in red soil areas.

Phosphorus (P), a crucial nutrient, has a significant impact on the growth, development, and productivity of sweetpotato. Establishing an evaluation system for low-phosphorus tolerance in sweetpotato and screening for low-phosphorus tolerant sweetpotato varieties can provide essential foundational support for the further development, breeding, and utilization of low-phosphorus tolerant sweet potato resources. In this study, 30 sweet potato varieties were selected. Field experiments with phosphorus deficiency were conducted, involving two phosphorus treatment conditions, no phosphorus application (0 kg/hm²) and normal phosphorus supply (110 kg/hm²). At the harvest stage, 14 characteristic traits were measured, including fibrous root fresh weight, lateral root of storage root fresh weight, single storage root fresh weight, storage root fresh weight per plant, storage root number per plant, fibrous root dry weight, lateral root of storage root dry weight, storage root dry weight, leaf fresh weight, stem fresh weight, leaf dry weight, stem dry weight, relative chlorophyll content and root/shoot ratio. The low-phosphorus tolerance coefficient for each index was calculated. Principal component analysis, correlation analysis, and cluster analysis were performed using the comprehensive membership function method to evaluate the low-phosphorus tolerance of each sweet potato cultivar. Principal component analysis showed that the cumulative variance contribution rate of the five principal components reached 80.36%, indicating these indicators fully reflected the low-phosphorus tolerance of sweetpotato varieties. The comprehensive low-phosphorus tolerance evaluation value (D) was calculated via the membership function method, with D values ranging from 0.30 to 0.79. The varieties were classified into four grades, high tolerance, medium tolerance, low tolerance, and non-tolerance. Through systematic cluster analysis, Qiongshu4 was identified as a high-tolerance variety, Silky, Fushu8, and Shanchuanzi were classified as medium-tolerance varieties, Yanshu25, Taishu14, and Xuzishu8 were low-tolerance varieties, and Annayu, Jinshu17, and Xinxiang were low phosphorus-sensitive varieties. The key evaluation indicators for low-phosphorus tolerance in sweet potato at harvest stage were determined to be the yield per plant (storage root fresh weight per plant), fibrous root fresh weight, lateral root of storage root fresh weight, fibrous root dry weight, leaf fresh weight, stem fresh weight, leaf dry weight, and stem dry weight. This study would provide a theoretical basis for breeding and utilizing new low-phosphorus-tolerant sweetpotato varieties.

The primary bottleneck restricting sugarcane harvesting mechanization in Chinaʼs hilly regions is fragmented terrain combined with narrow-row, high-density planting. This study was aimed to systematically analyze the effects of a two-step mechanical harvesting model on production efficiency, raw material quality, and farmer' income, thereby clarifying its application potential and promotion strategies in these regions. During the 2023/2024 and 2024/2025 harvesting seasons in Gengma, field experiments and cost-benefit analyses were conducted to compare four harvesting models, Combine Harvesting, Traditional Manual, Commissioned Processing, and Raw Cane Sale. Statistical methods, including ANOVA, were employed to analyze the effects of sugarcane growth stages and major cultivars on the impurity rate of raw materials. The Commissioned Processing model increased farmerʼs net income to 365.00 yuan/t over the Traditional Manual model (farmerʼs net income 318.00 yuan/t), an increase of 14.80%, while reducing harvesting costs 42.06%. The income was comparable to the Combine Harvesting model but effectively avoided the severe damage to sugarcane ratoons caused by the latter. Regarding raw material quality, genetic differences among cultivars had no significant effect on the impurity rate, whereas harvest time was the dominant factor. As the harvest period was extended from December to the following April, the net cane rate under Traditional Manual model significantly increased from 75.76% to 84.90%. Correspondingly, the impurity rate of two-step mechanized harvesting decreased from 6.42% to 4.52%, indicating that scheduling operations within the full maturity window after January effectively controls raw material impurities. The study also revealed a misalignment between the commercial impurity deduction standards of sugar mills and field-measured impurity rates. This discrepancy, characterized by significant inter-varietal differences, could hinder the fair promotion of this new technology. The two-step mechanical harvesting model is an optimal choice for Chinaʼs hilly regions, balancing economic benefits with ecological sustainability. Its promotion strategy should prioritize establishing a precise operational timetable based on sugarcane growth stages rather than developing differentiated harvesting systems for existing cultivars. This model would provide a quantifiable and scalable solution for mechanization in hilly sugarcane areas, holding significant practical value and strategic importance for enhancing the competitiveness of national sugar industry and ensuring sugar security.

Raffinose family oligosaccharides (RFOs) are the most widely distributed oligosaccharides containing galactose (-Gol) in higher plants. Raffinose (Raf) and stachyose (Sta) are the main members of this family, which are used as osmotic agents or active oxygen scavengers in many plants to maintain cell integrity. Glycosyl hydrolase 36 family (GH36) is a kind of α-galactosidase, which can catalyze oligosaccharides containing -Gol to produce RFOs. Hevea brasiliensis is an important plant for synthesizing natural rubber. After tapping and stimulation by exogenous ethylene, glycosyl hydrolases accumulate in latex and play an important role in maintaining latex stability. Eight genes (HbGH36-1-8) of glycosyl hydrolase 36 family (HbGH36) were successfully identified to search for functional hydrolases in the latex of H. brasiliensis. QRT-PCR analysis showed that five genes (HbGH36-1, HbGH36-4, HbGH36-6, HbGH36-7, HbGH36-8) were obviously expressed in latex. Among the five genes, HbGH36-4, HbGH36-6, HbGH36-7 and HbGH36-8 were highly expressed in response to tapping stimulation, and the expression levels of HbGH36-4 and HbGH36-7 changed more obviously. HbGH36-1, HbGH36-4, HbGH36-6 and HbGH36-7 expressed at high levels in response to exogenous ethylene stimulation, and HbGH36-6 expressed at high levels for a relatively long time after ethylene stimulation. Western blot of different components of H. brasiliensis latex confirmed that HbGH36-1 and HbGH36-8 were expressed in C-serum component of latex. The results indicate that H. brasiliensis HbGH36s may be involved in the regulation of latex stability and latex physiological metabolism in response to tapping and ethylene stimulation.