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.

The induction of adventitious roots (AR) is a key step for successful clonal propagation in plants. Previous studies have shown that the auxin polar transport carrier MiPIN1 plays an important role in AR formation from mango cotyledon segments, yet its upstream regulatory mechanisms remain unclear. In this study, a 2 112 bp promoter sequence of MiPIN1 isolated using FPNI-PCR. Bioinformatic analysis revealed that the promoter region contained various cis-acting elements, including those involved in light response, MYB binding, abscisic acid response, and low-temperature stress. A bait vector, pAbAi-MiPIN1, was constructed, and the minimal concentration of Aureobasidin A (AbA) required to suppress autoactivation in the yeast system was determined to be 500 ng/mL. Furthermore, a yeast cDNA library was constructed from mango cotyledon segments during AR formation. Using the yeast one-hybrid (Y1H) system, 62 upstream proteins that potentially bind to the MiPIN1 promoter were identified, including auxin-binding protein ABP19a-like, zinc finger protein CCCH, MYB308, 8-hydroxygeraniol dehydrogenase, and chlorophyll a-b binding protein LHCII. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses indicated that the proteins were mainly involved in biological processes such as cellular processes, metabolism, response to stimuli, and biological regulation. They were also enriched in metabolic pathways related to secondary metabolite biosynthesis, energy metabolism, and the metabolism of amino acids, lipids, and carbohydrates. The findings would lay a foundation for unraveling the molecular regulatory network underlying adventitious root formation in mango.

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.

Plants are prone to low inorganic phosphorus (Pi) abiotic stress, which has adverse effects on the growth, development and physiological metabolic processes. Camellia hainanica, a local variety in Hainan, mostly grows in low-phosphorus environments. C. hainanica has unique genetic characteristics that distinguish it from C. oleifera. In this study, a tropical cultivar Haida Oil-tea 4 (H4) was used as the research object to screen reference genes suitable for quantitative real-time polymerase chain reaction (qRT-PCR) analysis of C. hainanica under low Pi stress. The expression levels of six candidate reference genes, EF1α1, GAPDH, Actin, UBQ, ETIF3H and TUB2, were detected by qRT-PCR. The stability of each reference gene was comprehensively evaluated using ΔCt, geNorm, NormFinder, BestKeeper software and RefFinder online analysis tools, and ETIF3H was identified as the optimal reference gene. Using ETIF3H as the reference gene, we validated the expression levels of three low Pi responsive genes. The results showed that the target genes were differentially expressed in response to low Pi, indicating that ETIF3H is suitable as a reference gene for detecting gene differential expression under low Pi stress conditions. This work would provide appropriate reference genes for transcript normalization in H4 under low Pi stress, which will facilitate subsequent study of phosphorus signal-response gene expression in C. hainanica.

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.

Long-term subculture preservation significantly impacts somatic embryogenesis (SE) in various plant species. Studies on its effects in litchi (Litchi chinensis Sonn.) remain scarce. This study aimed to investigate the effects of subculture times on SE in litchi embryogenic callus (EC) and to uncover the metabolic basis for its decline, thereby providing a theoretical foundation for improving SE efficiency. Using 'Feizixiao' litchi EC materials from different subculture times (denoted as J11, J22, J48, J65 and J86). Somatic embryo induction rate, phenotypic characteristics, and dynamic changes in soluble sugars, organic acids, free amino acids, and energy-related substances were measured. The results showed that subcultures times significantly influenced SE in litchi EC. The embryo induction rate initially increased and then decreased with increasing subculture times, while the yield of normal somatic embryos (monocotyledonous, dicotyledonous, and polycotyledonous embryos) was also significantly affected. Among the five groups, J22 exhibited the highest induction rate (257.33%) and the greatest number of milky-white embryos. Sucrose content showed a significant positive correlation with SE, highlighting its role as the key carbon source for litchi SE. Fluctuations in soluble sugar content were primarily attributed to variations in sucrose. Low-subculture materials (J11 and J22) showed significant decreases in citric acid, succinic acid, and malic acid during the middle-late SE induction stages, indicating a stronger tricarboxylic acid (TCA) cycle flux compared to high-subculture materials (J48, J65, J86). The total amino acid content in EC initially increased and then stabilized during SE induction, with low-subculture materials maintaining higher overall amino acid levels. The contents of two major amino acids (glutamine and alanine) were significantly more abundant in low-subculture materials. Furthermore, the contents of adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) initially increased and then decreased, with AMP being the most abundant. Low-subculture materials maintained significantly higher AMP levels during the first 49 days of SE induction, particularly in J22. The results demonstrate that subculture times is a critical factor influencing SE in litchi EC. Long-term subculture induces embryogenic decline by impacting energy supply and amino acid metabolism.

The study was aimed to explore the effects of reducing chemical fertilizer application combined with microbial fertilizer on the quality of cempedak [Artocarpus champeden (Lour.) Spreng.] and soil nutrients. 7-year-old Duoyi No.1 cempedak was used as the material and 6 treatments, 100% compound fertilizer treatment (CK, 2 kg), 20% reduction in compound fertilizer + 20% microbial fertilizer (T₁), 40% reduction in compound fertilizer + 40% microbial fertilizer (T₂), 60% reduction in compound fertilizer + 60% microbial fertilizer (T₃), 80% reduction in compound fertilizer + 80% microbial fertilizer (T₄), and 100% microbial fertilizer treatment (T₅, 5 kg) were set up. The effects of different fertilization treatments on cempedak quality, the effects of soil nutrients, and the correlation between cempedak quality index and soil nutrient index were analyzed. Compared with CK and T₅ treatments, other treatments increased the fruit weight, edible rate, single aril pit weight, single aril weight, and soluble solids content of cempedak, reduced the fruit wall thickness. The T₃ and T₄ treatments significantly increased the single fruit weight and single aril weight of cempedak. The combined application of microbial fertilizer had a certain promoting effect on soil nutrients. The T₄ treatment significantly enhanced soil total nitrogen, available phosphorus, available potassium, organic matter, and pH, while also increasing the levels of six metal elements in the soil: Ca, Mg, Fe, Mn, Cu, and Zn. The T₃ treatment was second only to T₄ treatment. Correlation analysis showed that the combined application of microbial fertilizer improved the single fruit weight and single aril weight of cempedak mainly by increasing available phosphorus, available potassium, Fe and Mn in the soil. In conclusion, the treatments of T₃ and T₄ not only improved the yield and quality of cempedak, but also improved the soil environment and ecological benefits, which are the optimal combined application modes for green and efficient cultivation of cempedak.

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 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.