Crop rotation has been considered a potential solution to mitigate the negative effects of the continuous cropping of sorghum, including soil quality issues, inadequate plant development, and diminished yield and quality. A two-year field experiment was conducted to compare the effects of sorghum–sorghum continuous cropping and quinoa–sorghum rotation on soil properties and sorghum yield. The treatments were arranged in a randomized complete block design with three replicates. Sorghum seeds (Jinza 22) and quinoa seeds (‘Jiaqi 1’ variety) were used. Soil samples were collected before and during the experiment for the analysis of physicochemical properties. The yield traits of sorghum were measured at maturity. The results showed that soil nutrients and organic matter were higher in the top 0–20 cm soil depth compared to 20–40 cm depth, with significant differences observed between cropping systems. Sorghum–quinoa cropping increased soil total N and organic matter, particularly at the jointing and maturity stages of sorghum. However, the available phosphorus was higher under continuous cropping at all growth stages. Crop rotation significantly improved sorghum yield traits, including spike fresh weight, spike dry weight, grain weight per spike, and grain yield per hectare. A correlation analysis revealed positive relationships between soil total N, organic matter, and sorghum yield. Overall, sorghum–quinoa rotation demonstrated potential for improving soil fertility and enhancing crop productivity compared to continuous cropping, although further studies are needed to explore the long-term effects and optimize management practices.

The kafirin derived from Jin Nuo 3 sorghum underwent a high-hydrostatic-pressure (HHP) treatment of 100, 300, and 600 MPa for 10 min to investigate alterations in its physicochemical attributes. The findings exhibited a reduction in protein solubility, declining from 83% to 62%, consequent to the application of the HHP treatment. However, this treatment did not lead to subunit-specific aggregation. The absorption intensity of UV light diminished, and the peak fluorescence absorption wavelength exhibited a shift from 342 nm to 344 nm, indicating an increased polarity within the amino acid microenvironment. In an aqueous solution, the specific surface area expanded from 294.2 m²/kg to 304.5 m²/kg, while the average particle-size value in a 70% ethanol solution rose to 26.3 nm. Conversely, the zeta-potential value decreased from 3.4 mV to 1.3 mV, suggesting a propensity for aggregation in ethanol solutions. A notable rise in the intermolecular β-sheet content to 21.06% was observed, along with a shift in the peak denaturation temperature from 76.33 °C to 86.33 °C. Additionally, the content of disulfide bonds increased to 14.5 μmol/g. Collectively, the application of the HHP treatment not only enhanced the thermal stability but also induced a more ordered secondary structure within the kafirin.

Forage scarcity in semi-arid regions necessitates the identification of optimal sorghum cultivars for high-quality silage production. This study systematically evaluated varietal differences in agronomic characteristics, nutritive value, fermentation quality, and bacterial community structure of whole-plant sorghum silage. A completely randomized design was implemented with four sorghum cultivars representative of semi-arid northwestern China: Liaotian1 (LT1), Jinnuo3 (JN3), Jinza2001 (JZ2001), and Jinza1531 (JZ1531). Five quadrats per cultivar in experimental fields were randomly designated as biological replicates for silage production. The plants were harvested at the dough stage, chopped, and ensiled in laboratory-scale silos (n = 20, 4 cultivars × 5 replicates) for 120 days. Analyses included agronomic measurements, chemical composition, fermentation parameters, microbial plate enumeration, and bacterial community profiling via 16S rRNA gene amplicon sequencing of the V3–V4 hypervariable region. The results showed that cultivar significantly influenced (p < 0.01) all agronomic traits and most nutritional parameters. The forage-type cultivar LT1 showed the highest biomass yield but the lowest nutritional quality, with higher neutral detergent fiber (47.77% vs. 29.21–32.35%; p < 0.05) and lower starch (10.94% vs. 18.10–24.30%; p < 0.05) contents as well as higher dry matter losses (1.39% vs. 0.91–1.23%; p < 0.05) than grain-type cultivars. In contrast, the grain-type cultivar JN3 exhibited balanced yield-quality traits with the highest (p < 0.05) starch (24.30%) and crude protein (7.50%) contents. Most fermentation parameters differed significantly (p < 0.01) among cultivars, with JN3 showing elevated ammonia-nitrogen (0.24 g/kg) but within acceptable ranges. Microbial diversity analysis revealed cultivar-driven differences in bacterial communities, with JN3 enriched in Leuconostoc and early-colonizing taxa (p < 0.05 and LDA Score > 4). It is concluded that the grain-type cultivar JN3 is the most suitable cultivar for whole-plant sorghum silage production in water-limited regions due to its optimal yield-quality balance. The findings underscore the importance of integrated cultivar evaluation and suggest the potential of targeted microbial inoculants for enhancing silage quality.

The author Wenbin Bai has been changed to the second corresponding author

Introduction: Dark septate endophytes (DSE) are root-associated fungi that can enhance host stress tolerance, yet their diversity and function in sorghum remain unclear. Here, we investigated the culturable DSE community across 29 sorghum varieties and evaluated the symbiotic potential of key isolates. Methods: Culturable DSE were isolated from sorghum rhizosphere soil and roots via plate isolation, microscopy, and colonization assessment to screen efficient colonizers. Pot experiments then analyzed symbiotic compatibility with major Chinese cultivars to identify strains with high colonization efficiency. Finally, the selected strain was evaluated for salt tolerance and its effects on drought resistance, growth promotion, and low-fertility tolerance in seedlings. Results and discussion: A total of 94 DSE isolates were obtained, accounting for 30.72% of the total fungal isolates, and were classified into 30 morphotypes. The genus Alternaria emerged as the dominant group, comprising 46.67% of the isolates. Among them, strain HN16G1, isolated from Hongnuo 16 and identified as Alternaria destruens via internal transcribed spacer sequencing, demonstrated superior root colonization capability. Strain HN16G1 established stable symbiosis with all 10 commercial cultivars tested, maintaining colonization rates and intensities above 50.0 and 16.0%, respectively. Physiologically, HN16G1 exhibited moderate halotolerance, with low NaCl concentrations (0.1–0.2 mol/L) promoting mycelial growth, whereas high salt stress (0.6 mol/L) induced adaptive responses including enhanced sporulation and reduced hyphal septal distance. The strain also displayed substantial indole-3-acetic acid production, reaching 181.56 μg/mL. Inoculation with HN16G1 (5.0 × 10 ⁵ CFU/mL) significantly improved seedling emergence and early vegetative growth in sorghum under combined drought stress (40% field capacity) and low-nutrient conditions. Notably, varieties “Hongnuo 16” and “Jinnuo 3” exhibited the most pronounced responses, with growth parameters approaching optimal levels. Colonization parameters (rate and intensity) correlated positively with plant height, root length, and biomass. Overall, these findings highlight the rich DSE diversity in sorghum roots and identify A. destruens HN16G1 as a broad-compatibility, multifunctional endophyte with promising potential for the development of microbial inoculants to enhance stress tolerance in sorghum production systems.