[Objective]To address the scientific challenges of limited yield potential,inefficient resource use efficiency,and constrained economic benefits in equidistant maize planting in the Northwest oasis irrigation zones of China,this study investigated the effects of wide-narrow row planting patterns on maize density tolerance and yield potential.[Method]This experiment began in 2017 and the data were collected from 2019 to 2021,using a split-plot design.The main plot treatments comprised three line spacing configurations characterized by alternating wide-narrow line spacing:L1(7∶3 ratio,56 cm wide line spacing:24 cm narrow line spacing),L2(6:4 ratio,48 cm wide line spacing:32 cm narrow line spacing),and L3(5:5 ratio:40 cm wide line spacing,40 cm narrow line spacing).The split-plot treatments were four maize planting densities:D1(8.25×104 plants/hm2,local conventional planting density),D2(9.00×104 plants/hm2,increased density by 9.1%),D3(9.75×104 plants/hm2,increased density by 18.2%),and D4(10.50×104 plants/hm2,increased density by 27.3%).The effects of these spacing arrangements under increasing planting density on maize photosynthetic characteristics,yield,resource utilization,soil nitrogen content,and economic benefits were investigated.[Result]Both wide-narrow line spacing planting and increased maize planting density enhanced photosynthetic characteristics,yield,and resource utilization efficiency of maize in the Hexi Oasis Irrigation District.Compared with wide-narrow line spacing ratio of 5:5 treatment,wide-narrow line spacing ratio of 7∶3 treatment increased maize average leaf area index,light interception score at the big flare stage,grain yield,light use efficiency,water use efficiency,and nitrogen use efficiency by 9.7%,7.1%,8.8%,8.2%,12.7%,and 14.1%,respectively.Increased density by 9.1%and 18.2%treatments increased maize average leaf area index by 11.4%and 15.7%,light interception score at the big flare stage by 7.4%and 10.1%,grain yield by 9.6%and 11.3%,light use efficiency by 4.0%and 6.1%,and water use efficiency by 10.2%and 20.5%than that with local traditional planting density,respectively.Wide-narrow line spacing ratio of 7∶3 with an 18.2%density increase demonstrated significant potential for comprehensive improvement.Compared with wide-narrow line spacing ratio of 5:5 and traditional planting density,wide-narrow line spacing ratio of 7∶3 and increased density by 18.2%increased average leaf area index by 28.4%,enhanced light interception score at big flare and grain filling stages by 22.0%and 17.1%,respectively,and raised grain yield,biomass,and harvest index by 22.2%,13.1%,and 8.0%,respectively.Wide-narrow line spacing ratio of 7∶3 and increased density by 18.2%also improved average leaf area index,water use efficiency,and nitrogen use efficiency by 13.5%,39.6%,and 24.0%,respectively,while reducing soil total nitrogen,ammonium nitrogen,and nitrate nitrogen contents by 11.2%,18.0%,and 16.8%compared with wide-narrow line spacing ratio of 5:5 and traditional planting density,respectively.Additionally,wide-narrow line spacing ratio of 7∶3 and increased density by 18.2%treatment increased net profit and the ratio of benefit and cost by 50.1%and 23.3%,compared with wide-narrow line spacing ratio of 5:5 and traditional planting density,respectively.[Conclusion]The wide-narrow line spacing ratio cropping pattern of 7∶3 enhanced the comprehensive effects of densely planted maize by improving photosynthetic characteristics,resource use efficiency,and soil nitrogen supply.

Agricultural soils are the largest anthropogenic source of nitrous oxide (N2O), primarily due to excessive nitrogen (N) fertilization and inefficient N management. Mitigating N2O emissions from croplands without compromising productivity is therefore a major global challenge for climate and environmental sustainability. A three-year split-plot field experiment was conducted in an arid maize production region of northwestern China to examine how green manure intercropping combined with reduced chemical N input regulates N2O emissions and soil N residues. The main plots comprised maize monoculture (M), maize intercropped with common vetch (M/V), and maize intercropped with rape (M/R), while subplots consisted of local conventional N application (N1: 360 kg N ha(-1)) and a 25% reduced rate (N2: 270 kg N ha(-1)). Results indicated that intercropping with green manure can offset the reduction in maize grain yield caused by a 25% decrease in N supply. Green manure intercropping significantly decreased cumulative N2O emissions compared with monoculture maize, and the mitigation effect was further strengthened under reduced N input. The M/V system under reduced N input exhibited the strongest mitigation effect, reducing N2O emissions per unit of grain yield by 9.2-11.5% compared with the M/R system. This reduction was driven by the ability of M/V to stabilize soil mineral N availability. Notably, the independent maize growth stage contributed 52.6-66.9% of total seasonal N2O emissions, emphasizing it as a critical period for emission mitigation. Overall, integrating green manure intercropping with reduced chemical N input effectively mitigates N2O emissions while maintaining maize productivity in arid regions, providing a practical strategy for sustainable and environmentally responsible agricultural intensification.

Achieving sustainable intensification in resource-limited arid agroecosystems requires innovative planting models that balance high productivity with long-term stability. A six-year field experiment (2018–2023) was conducted to evaluate an annual cropping intensification gradient based on the number and coordination of crop cycles within a year. The gradient comprised single-harvest wheat (W) and maize (M) monocultures, double-harvest wheat–maize spatial intercropping (W||M) and wheat–common vetch green manure temporal multiple cropping (W-G), and a triple-harvest integrated spatiotemporal system combining wheat–maize intercropping with a subsequent common vetch green manure phase (W-G||M). System productivity and grain-yield stability increased along this gradient. Relative to W, total grain yield increased by 14.1% in W-G and 117.9% in W||M, while W||M exceeded M by 1.8%. W-G||M further increased total grain yield by 107.2% over W-G and 8.5% over W||M, and achieved the highest temporal stability of total grain yield. Land equivalent ratios remained above 1.0 in all multi-harvest systems, whereas the spatio-temporal resource intensification ratio was highest in W||M and declined with the inclusion of common vetch, indicating a trade-off between increasing annual crop cycles and absolute land–time-use efficiency. Complementarity effects were positively associated with grain and energy yields, whereas selection effects were not significantly associated with either productivity metric. From 2020 to 2023, the post-harvest growth rate of maize in W-G||M was 27.8%–92.6% higher than that in W||M. Structural equation modeling further showed that cropping intensification altered crop growth trajectories by advancing early-season crop development and strengthening post-harvest recovery of the late-season crop. These findings suggest that coordinating spatiotemporal integration to optimize annual cropping cycles effectively transforms early-season competitive constraints into late-season synergistic facilitation. This integrated approach provides a robust agronomic strategy for sustaining high-yield and resilient food production in arid environments.

Grapevine (Vitis vinifera L.) is highly sensitive to soil salinization, which severely restricts its cultivation in salt-affected areas. In this study, "Pinot Noir" (V. vinifera "Pinot Noir") was micro-grafted onto the salt-tolerant rootstock "Kangzhen No. 3" to explore the mechanisms by which rootstock-mediated micrografting enhances scion salt tolerance. Grafted seedlings, un-grafted scions, and rootstocks were irrigated with 200 mmol/L NaCl for 6 days. Physiological assessments and transcriptomic analysis revealed that grafted plants exhibited significantly improved salt tolerance compared to ungrafted "Pinot Noir." Differentially expressed genes were mainly enriched in plant hormone signal transduction, MAPK signaling, and phenylpropanoid biosynthesis pathways. Two key genes, VvFLS and VvGSTU14, were selected for functional validation. Overexpression in grapevine calli enhanced antioxidant capacity and significantly improved salt tolerance. These findings demonstrate that micrografting with a salt-tolerant rootstock can enhance scion performance under saline stress by modulating key signaling and metabolic pathways, providing a theoretical foundation for grapevine improvement and sustainable production on saline soils.

Glucoraphanin (GRA) and sulforaphane (SF) are potent anticancer compounds. Understanding their accumulation mechanisms is crucial for increasing their levels in broccoli. This study aimed to investigate the role of nitric oxide (NO) in GRA and SF accumulation and identify key genes involved in this process. Low NO concentrations were found to promote GRA and SF accumulation. Transcriptome sequencing and Weighted Gene Co-expression Network Analysis (WGCNA) identified BoNIA2b, a nitrate reductase (NR) gene, as a key regulator of NO-mediated GRA and SF accumulation. Silencing BoNIA2b reduced endogenous NO levels and NR activity in hairy roots, while exogenous treatment with sodium nitroprusside (SNP) restored NO levels without affecting NR activity. Overexpression of BoNIA2b increased NO content and NR activity. Silencing BoNIA2b decreased GRA content, but SF levels remained unaffected. SNP treatment enhanced both GRA and SF accumulation, with GRA being more dependent on BoNIA2b. In BoNIA2b-overexpressing roots, both GRA and SF levels were significantly higher than in controls. Moreover, the interaction between BoNIA2b and BoMYB28 protein was confirmed through Y2H and luciferase complementation assays. These findings underscore BoNIA2b's role in NO-mediated regulation of GRA and SF accumulation in broccoli hairy roots, offering insights to enhancing the production of these anticancer compounds.

Understanding the mechanisms that give rise to obstacles in the continuous cultivation of C. pilosula is essential for addressing or mitigating these challenges. The findings of this study suggest that repeated cultivation significantly reduced the content of polysaccharide in roots, and significantly increased the dead seedling rate in the field. The vascular bundles of the affected plant were extensively colonized by fungi. Furthermore, the root vascular bundles exhibit significant woodiness and corkiness, accompanied by cellular fractures and structural collapse. It was determined that the pathogenic endophyte is Fusarium oxysporum, and the exacerbated disease manifestation corresponds to an acute wilting type. Additionally, the root-zone soil microorganisms Cladosporium austroafricanum, Fusarium foetens, Fusarium petersiae, and Acaulium retardatum may significantly contribute to the yield-reducing phenomenon associated with continuous cropping. The proliferation of pathogenic bacteria during continuous cultivation initiates a complex interaction mechanism between the host plant and these pathogens. This process is characterized by a rapid increase in calcium ion (Ca2+) concentration, which subsequently leads to an upsurge in reactive oxygen species (ROS), particularly manifested as elevated levels of hydrogen peroxide (H2O2). Additionally, this response triggers thickening of cell walls and other immune mechanisms aimed at inhibiting the invasion of pathogenic bacteria. At the same time, to prevent ROS from inducing oxidative damage and triggering oxidative stress, there is a notable increase in both antioxidant enzyme activity and antioxidant substances content.

Salt stress is a typical abiotic stress in plants that causes slow growth, stunting, and reduced yield and fruit quality. Fertilization is necessary to ensure proper crop growth. However, the effect of fertilization on salt tolerance in grapevine is unclear. In this study, we investigated the effect of nitrogen fertilizer (0.01 and 0.1 mol L−1 NH4NO3) application on the salt (200 mmol L−1 NaCl) tolerance of grapevine based on physiological indices, and transcriptomic and metabolomic analyses. The results revealed that 0.01 mol L−1 NH4NO3 supplementation significantly reduced the accumulation of superoxide anion (O2.-), enhanced the activities of superoxide dismutase (SOD) and peroxidase (POD), and improved the levels of ascorbic acid (AsA) and glutathione (GSH) in grape leaves compared to salt treatment alone. Specifically, joint transcriptome and metabolome analyses showed that the differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) were significantly enriched in the flavonoid biosynthesis pathway (ko00941) and the flavone and flavonol biosynthesis pathway (ko00944). In particular, the relative content of quercetin (C00389) was markedly regulated by salt and nitrogen. Further analysis revealed that exogenous foliar application of quercetin improved the SOD and POD activities, increased the AsA and GSH contents, and reduced the H2O2 and O2.- contents. Meanwhile, 10 hub DEGs, which had high Pearson correlations (R2 > 0.9) with quercetin, were repressed by nitrogen. In conclusion, all the results indicated that moderate nitrogen and quercetin application under salt stress enhanced the antioxidant system defense response, thus providing a new perspective for improving salt tolerance in grapes.

Codonopsis pilosula (Franch.) Nannf. is an essential traditional medicinal herb in China. Soil sickness caused by continuous cropping is the main reason for the yield reduction of C. pilosula. However, because of the lack of systematic research on the mechanism of continuous cropping obstacles in C. pilosula, there is a lack of effective measures to reduce or even restrain the disorder of continuous cropping obstacles in C. pilosula. The root system, inter-root soil microorganisms and non-inter-root soil of C. pilosula under a continuous cropping system (e.g. crop rotation, two consecutive crops and three consecutive crops) as well as under different mulching methods (the mulched film and the uncovered) were used as experimental materials for the study. The plant growth of C. pilosula was significantly inhibited when continuous cropping reached 2 years. At the same time, the mulched film significantly (p < .05) promoted the development of C. pilosula under continuous cropping and considerably mitigated the plant death rate of C. pilosula in all fields. The content of soil nutrients, such as organic matter and inorganic nitrogen, decreased with increasing years of continuous cropping. In contrast, the mulched film improved this soil nutrient in continuous cropping. There was a tendency for the number of endemic operational taxonomic units (OTUs) to decrease in continuous cropping. Additionally, the mulched film altered the distribution of shared and endemic OTUs in the samples and had a recruiting effect on inter-root microorganisms in continuous cropping. Betaproteobacteriales flora abundance decreased with increasing years of continuous cropping, which showed a strong positive correlation with the immune system and environmental adaptation function. The mulched film increased the abundance of beneficial microorganisms, such as AKAU4049, Betaproteobacteriales and Gaiellales, to adapt and improve the continuous crop disorder of C. pilosula. In conclusion, mulching can enhance the soil environment and facilitate the growth and development of C. pilosula during continuous cultivation.

The integrated plant-metabolite-soil regulation model of C. Pilosula growth and lobetyolin synthesis in response to continuous cropping lacks systematic investigation. In this study, we investigated the regulatory mechanisms of growth and lobetyolin synthesis in C. pilosula under continuous cropping stress based on high-performance liquid chromatography, transcriptome, and microbial sequencing on the root system and rhizosphere soil of C. pilosula from one year of cultivation and five years of continuous cropping. The findings of this study revealed that continuous cropping significantly inhibited the growth of C. pilosula and led to a notable decrease in the lobetyolin content. An effort was made to propose a potential pathway for lobetyolin biosynthesis in C. pilosula, which is closely linked to the expression of genes responsible for glucoside and unsaturated fatty acid chain synthesis. In addition, soil physicochemical properties and soil microorganisms had strong correlations with root growth and synthesis of lobetyolin, suggesting that soil physicochemical properties and microorganisms are the main factors triggering the succession disorder in C. pilosula. This study provides an in-depth interpretation of the regulatory mechanism of acetylenic glycoside synthesis and offers new insights into the triggering mechanism of C. pilosula succession disorder, which will guide future cultivation and industrial development.

With the continuation of intensive and monoculture production in modern agriculture, the harm of continuous cropping obstacles is becoming more prominent. Pea has important nutritional and economic value, but it is easy to have continuous cropping obstacles in production. However, there is limited knowledge of the regulatory mechanisms of pea to cope with continuous cropping obstacles. In this study, we found that the number of differential expressed genes (DEGs) and differential metabolites (DAMs) increased in the pea roots with increasing continuous cropping times, and the number of DEGs and DAMs in roots of sensitive pea was more than that of continuous cropping tolerant pea. Comprehensive analysis of the omics data revealed that the flavonoid and isoflavonoid biosynthesis pathways play key roles in the response of pea roots to the continuous cropping obstacles. Most of the DEGs involved in these two pathways were up-regulated. Meanwhile, most of the flavonoid compounds and total flavonoid content increased. With increasing continuous cropping times, the isoflavones category in DAMs increased, and the isoflavones category in the roots of continuous cropping tolerant pea were higher than in sensitive pea. Additionally, the isoflavonoid (biochanin A, calycosin, genistein) in the roots of continuous cropping tolerant pea have the ability to inhibit the growth of fungi in pea soil and possess antioxidant activity. These findings revealed the important role of flavonoids in pea continuous cropping obstacles and laid a foundation for effectively alleviating pea continuous cropping obstacles in the future.

Abscisic acid (ABA) is a crucial signaling regulator governing plant growth and survival during adverse conditions. However, the mechanism by which ABA mediates grapevine tolerance to alkali stress has not yet been elucidated. Here, we investigated the role of ABA in regulating physiological characteristics and transcriptome of grapevines under alkali stress through the application of exogenous ABA and fluridone (an ABA biosynthesis inhibitor). The results revealed that alkali stress led to significant reductions in the net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO 2 concentration (Ci), transpiration rate (Tr), chlorophyll content, the maximum quantum yields of primary photochemistry of PSII (Fv/Fm), nonphotochemical quenching (NPQ), which were greatly alleviated by exogenous ABA (50 and 100 mu M) application. Specifically, the application of exogenous ABA (50 mu M) increased Pn, chlorophyll content and Fv/Fm by 28.39 %, 30.45 % and 17.29 %, respectively, compared with alkali stress alone. Furthermore, exogenous ABA treatment reduced alkali stressinduced superoxide anions (O 2 center dot - ) and hydrogen peroxide (H 2 O 2 ), malondialdehyde (MDA), and electrolyte leakage, as well as higher proline content and activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). Additionally, exogenous ABA (50 mu M) decreased O 2 center dot , H 2 O 2 , MDA, electrolyte leakage by 38.64 %, 28.16 %, 39.29 % and 39.42 %, respectively, respect to alkali stress alone. Moreover, exogenous ABA reduced the Na + , increased K + and K + /Na + ratio, as well as the phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), chalcone isomerase (CHI) activities and flavonoid content, and increased zeaxanthin epoxidase (ZEP) and 9-cis-epoxy carotenoid dioxygenase (NCED) activities and endogenous ABA levels in alkali stress-treated grapevines. Exogenous ABA (50 mu M) increased flavonoid content and endogenous ABA content by 74.03 % and 20.84 %, compared with alkali stress alone, respectively. Conversely, exogenous fluridone exacerbated alkali stress-induced physiological damage in grapevine plants. Transcriptome analysis revealed that exogenous ABA (50 mu M) and fluridone significantly induced the 'Plant hormone signal transduction (ko04075)', the 'MAPK signaling pathway-plant (ko04016)', 'ABC transporters (ko02010)', 'Photosynthesisantenna proteins (ko00196)', 'Flavonoid biosynthesis (ko00941)', 'Phenylpropanoid biosynthesis (ko00940)' and other biological pathways and key gene involved in chlorophyll metabolism and ion transport. In conclusion, ABA markedly enhanced grapevines tolerance to alkali stress by modulating key biological pathways and physiological characteristics.

Soil autotoxic chemosensory substances have emerged as the predominant environmental factors constraining the growth, quality, and yield of Codonopsis pilosula in recent years. Among a vast array of chemosensory substances, benzoic acid constitutes the principal chemosensory substance in the successive cultivation of C. pilosula. However, the exploration regarding the stress exerted by benzoic acid on the growth and development of C. pilosula remains indistinct, and there is a scarcity of research on the mechanism of lobetyolin synthesis in C. pilosula. In the current research, it was discovered that exposure to benzoic acid at a concentration of 200 mmol/L conspicuously attenuated the plant height, root length, total length, fresh weight, root weight, root thickness, chlorophyll content, electrolyte osmolality, leaf intercellular CO2 concentration (Ci), net photosynthesis rate (Pn), transpiration rate (Tr), and leaf stomatal conductance (Gs) of C. pilosula. Benzoic acid (200 mmol/L) significantly enhanced the activity of root enzymes, including superoxide dismutase (SOD), malondialdehyde (MDA), and peroxidase (POD), as well as the accumulation of polysaccharides and lobetyolins (polyacetylene glycosides) in the roots of C. pilosula. In this study, 58,563 genes were assembled, and 7946 differentially expressed genes were discovered, including 4068 upregulated genes and 3878 downregulated genes. The outcomes of the histological examination demonstrated that benzoic acid stress augmented the upregulation of genes encoding key enzymes implicated in the citric acid cycle, fatty acid metabolism, as well as starch and sucrose metabolic pathways. The results of this investigation indicated that a moderate amount of benzoic acid could enhance the content of lobetyolin in C. pilosula and upregulate the expression of key coding genes within the signaling cascade to improve the resilience of C. pilosula lobetyolin against benzoic acid stress; this furnished a novel perspective for the study of C. pilosula lobetyolin as a potential substance for alleviating benzoic acid-induced stress.

Conservation tillage is widely recognized as an important way to improve soil quality, ensure food security and mitigate climate change. However, relatively little attention has been paid to the subject in terms of sustainable evaluation of environmental and economic benefits of the combination of no tillage and straw returning for maize production in arid irrigated areas. In this study, grain yield (GY) and water use efficiency based on grain yield (WUEGY), soil carbon emission characteristics and economic benefits were investigated, and a sustainability evaluation index based on the above indicators was assessed in maize production under a wheat–maize rotation system from 2009 to 2012. Four wheat straw returning approaches were designed: no tillage with 25 to 30 cm tall wheat straw mulching (NTSMP), no tillage with 25 to 30 cm tall wheat straw standing (NTSSP), conventional tillage with 25 to 30 cm tall wheat straw incorporation (CTSP), and conventional tillage without wheat straw returning (CTP). The results showed that NTSMP treatment could effectively regulate water consumption characteristics of maize fields and meet the water conditions for high grain yield formation, thus gaining higher GY and WUEGY. NTSMP increased GY and WUEGY of maize by 13.7–17.5% and 15.4–16.7% over the CTP treatment, and by 5.6–9.0% and 2.3–11.2% over the CTSP treatment, respectively. Meanwhile, compared with CTP, the NTSMP treatment could effectively reduce carbon emissions from maize fields, where average soil carbon emission fluxes (ACf), carbon emission (CE) and water use efficiency based on carbon emission (WUECE) were reduced by 17.7–18.9%, 11.1–11.2% and 8.8–12.8% and carbon emission efficiency (CEE) was increased by 10.2–14.7%. In addition, the NTSMP and NTSSP treatments could effectively increase total output and reduce human labor and farm machinery input, resulting in higher economic benefit. Among them, the NTSMP treatment was the most effective, net income (NI) and benefit per cubic meter of water (BPW) were increased by 16.1–34.2% and 19.1–31.8% over the CTP treatment, and by 13.2–13.3% and 9.8–15.6% over the CTSP treatment, respectively. The sustainability analysis showed that the NTSMP treatment had a high sustainability evaluation index and was a promising field-management strategy. Therefore, no tillage with 25 to 30 cm tall wheat straw mulching is a sustainable maize-management practice for increasing economic benefits and improving environmental impacts in arid irrigated areas.

Plant acclimation to salt and alkali stress is closely linked to the ability of the antioxidant system to mediate the scavenging of reactive oxygen species (ROS). In this study, we investigated the effects of salt stress and alkali stress on ROS, antioxidant enzymes, transcriptome, and metabolome. The results showed that the levels of superoxide anions, hydrogen peroxide, malondialdehyde, and electrolyte leakage increased under salt and alkali stress, with higher concentrations observed under alkali stress than salt stress. The activities of superoxide dismutase (EC 1.15.1.1), peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6), ascorbate peroxidase (EC 1.11.1.11), glutathione reductase (EC 1.6.4.2), dehydroascorbate reductase (EC 1.8.5.1), and monodehydroascorbate reductase (EC 1.6.5.4) varied under salt and alkali stress. The transcriptome analysis revealed the induction of signal transduction and metabolic processes and differential expression of genes encoding antioxidant enzymes in response to salt and alkali stress. The metabolome analysis demonstrated increased ascorbic acid and glutathione under salt stress, while most phenolic acids, flavonoids, and alkaloids increased under salt and alkali stress. Integrative analysis of the metabolome and transcriptome data revealed that the flavonoid biosynthesis pathway played a key role in the grapevine's response to salt stress. The total flavonoid content increased under salt and alkali stress, but the accumulation of flavonoids was higher under salt stress than alkali stress. In conclusion, our findings indicate significant differences in the antioxidant defense of grapevines under these two stresses, providing insight into distinct acclimation mechanisms in grapevine under salt and alkali stress.

【Objective】Aiming at the problems of large nitrogen input, single fertilizer source, low nitrogen utilization rate, and poor quality of wheat in spring wheat cultivation in Hexi areas of Gansu Province, the objective of this study is to explore the effects of suitable green manure and reduced nitrogen fertilizer cultivation techniques on grain yield and quality, and nitrogen absorption and utilization of spring wheat, and to provide a theoretical basis for high yield, high quality, and green production of wheat in Hexi irrigation areas.【Method】A split plot experiment was conducted from 2019 to 2021 in the Hexi oasis irrigation areas of Gansu Province. Two cropping patterns of multiple green manure after wheat (W-G) and sole wheat (W) were set in the main plot. There were five N fertilizer levels in the sub-plot: 100% of conventional N fertilizer by the farmer (180 kg·hm-2, N4), 85% of conventional N fertilizer (N3), 70% of conventional N fertilizer (N2), 55% of conventional N fertilizer (N1), and no N fertilizer (N0).【Result】Multiple green manure after wheat combined with 85% N application (W-G-N3) was effectively increased wheat grain yield and biomass. The grain yield of W-G-N3 was increased by 16.7%-18.4% and 13.6%-34.4%, respectively, compared with the 85% N application (W-N3) and conventional N application (W-N4) treatments for the sole wheat. The biomass of W-G-N3 was increased by 11.3% (2020) and 5.2%-11.6% (2020 to 2021), respectively, compared with the W-N3 and W-N4 treatments. The increase of grain yield was greater than that of biomass, thus, the W-G-N3 treatment had higher harvest index, which was 4.9%-15.9% and 8.0%-20.5% higher than that of W-N3 and W-N4 treatments. Meanwhile, the W-G-N3 treatment improved grain quality of wheat by increasing protein content, sedimentation value, and wet gluten content, among which, the protein content, sedimentation value, and wet gluten content of W-G-N3 were increased by 12.3%-16.1%, 28.7%-47.2%, and 10.7%-11.1%, respectively, compared with W-N3; The protein content of W-G-N3 was increased by 8.9%-12.4% compared with W-N4, but the differences in sedimentation value and wet gluten content between W-G-N3 and W-N4 were not significant. In addition, the W-G-N3 treatment was beneficial to promote nitrogen uptake and conversion to grain yield in wheat compared with W-N3 and W-N4 treatments, in which the N uptake was increased by 42.2%-58.9% and 35.2%-45.0%, N use efficiency was increased by 12.0%-20.6% and 5.9%-20.4%, respectively, and N partial factor productivity was increased by 3.6%-18.3% and 28.1%-58.1%, respectively. The W-G-N3 treatment could compensate for the reduction of N agronomic efficiency, which was 74.2%-80.0% higher than W-G-N4 treatment. The correlation analysis showed that multiple green manure after wheat combined with moderate reduction of N fertilizer increased grain yield by promoting efficient nitrogen uptake and utilization, and also significantly improved grain nutritional quality.【Conclusion】The combination of multiple green manure after wheat with 85% (153 kg·hm-2) nitrogen application is the suitable cropping pattern and nitrogen application level to boost wheat yield, improve wheat grain quality, and increase nitrogen use efficiency in Hexi oasis irrigated areas.

实验教学是高校教学体系的重要组成部分,是大学生实践培养的关键环节.随着高等教育改革的不断深化,实验教学越来越成为教学改革的重中之重.自 2016 年以来,甘肃农业大学在大幅度增加植物生理学实验仪器设备、优化实验教学场所设置的基础上,从加强实验室建设,深化实验课程体系改革,修订实验教材,完善实验教学课程考核制度,以及录制实验操作视频等方面,对我校《植物生理学实验》课程进行了多方位的改革探究.这一系列改革措施的实施不仅提升了《植物生理学实验》课程规范化教学深度,也在教师和学生中收到了良好的教学反馈,为培养创新创业人才提供了有力的保障.

Background Continuous cropping is a significant obstacle to sustainable development in the pea ( Pisum sativum L.) industry, but the underlying mechanisms of this remain unclear. In this study, we used 16 S rDNA sequencing, transcriptomics, and metabolomics to analyze the response mechanism of roots and soil bacteria to continuous cropping and the relationship between soil bacteria and root phenotypes of different pea genotypes (Ding wan 10 and Yun wan 8). Results Continuous cropping inhibited pea growth, with a greater effect on Ding wan 10 than Yun wan 8. Metabolomics showed that the number of differentially accumulated metabolites (DAMs) in pea roots increased with the number of continuous cropping, and more metabolic pathways were involved. Transcriptomics revealed that the number of differentially expressed genes (DEGs) increased with the number of continuous cropping. Continuous cropping altered the expression of genes involved in plant-pathogen interaction, MAPK signal transduction, and lignin synthesis pathways in pea roots, with more DEGs in Ding wan 10 than in Yun wan 8. The up-regulated expression of genes in the ethylene signal transduction pathway was evident in Ding wan 10. Soil bacterial diversity did not change, but the relative abundance of bacteria significantly responded to continuous cropping. Integrative analysis showed that the bacteria with significant relative abundance in the soil were strongly associated with the antioxidant synthesis and linoleic acid metabolism pathway of pea roots under continuous cropping once. Under continuous cropping twice, the bacteria with significant relative abundance changes were strongly associated with cysteine and methionine metabolism, fatty acid metabolism, phenylpropanoid biosynthesis, terpenoid backbone biosynthesis, linoleic acid, and amino sugar and nucleotide sugar metabolism. Conclusion Ding wan 10 was more sensitive to continuous cropping than Yun wan 8. Continuous cropping times and pea genotypes determined the differences in root metabolic pathways. There were common metabolic pathways in the two pea genotypes in response to continuous cropping, and the DEGs and DAMs in these metabolic pathways were strongly associated with the bacteria with significant changes in relative abundance in the soil. This study provides new insights into obstacles to continuous cropping in peas.

Autotoxicity is one of the main problems in continuous cropping. The aims of this study were to identify potential autotoxins in soil where pea（Pisum sativum） had been cultivated and to explore their autotoxic effects. We collected rhizosphere soil from two pea genotypes（cultivars Ding wan 10 and Yun wan 8） in the field, and used gas chromatography-mass spectrometry（GC-MS） to identify potential autotoxins in these soil samples. Then, the effects of potential autotoxins at different concentrations on the seed germination, seedling growth, and physiological indexes of pea（cultivars Ding wan 10 and Yun wan 8） were evaluated using a hydroponic system. Erucamide was detected as a potential autotoxin in both pea genotypes. Erucamide at a concentration of 0. 1 mmol·L -1 promoted the germination of Ding wan 10 seeds, and erucamide at concentrations of 0. 10, 0. 25 and 0. 50 mmol·L -1 promoted the germination of Yun wan 8 seeds. It was found that erucamide at different concentrations significantly decreased the activities of superoxide dismutase（SOD） and peroxidase（POD）, and increased the malondialdehyde（MDA） content in Ding wan 10. A high concentration of erucamide significantly increased the MDA content in Yun wan 8, and decreased the proline（Pro） content and POD activity in pea roots. These analyses of the allelopathic effects of potential autotoxins on pea plants revealed that erucamide inhibited the growth of two pea genotypes, with a stronger inhibitory effect on Ding wan 10 than on Yun wan 8. Thus, erucamide is a potential autotoxin in pea rhizosphere soil, and its effects depend on its concentration. A low concentration can promote seed germination but higher concentrations can inhibit seed germination and plant growth. The degree of promotion and inhibition varies among different pea genotypes.

Legumes have important nutritional and economic values, but their production faces continuous cropping obstacles that seriously affect their yield formation. In order to reduce the negative impact of the continuous cropping obstacles of legumes, it is necessary to understand the response mechanisms of legumes to continuous cropping, the causes of continuous cropping obstacles and the measures to alleviate continuous cropping obstacles. This review aimed to identify the current knowledge gap in the field of continuous cropping obstacles of legumes and provide direction and focus for future research. The continuous cropping obstacles of legumes start with soil degradation, leading to oxidative stress in the plants. This triggers the expression of plant-hormone- and signal-molecule-related genes, activating the defense system and causing continuous cropping obstacles. Although there has been progress in researching these challenges in legume crops, many questions remain. We believe that the exploration of molecular mechanisms of legume crops responding to continuous cropping, rhizosphere signal exchange and soil environment repair mechanisms after long-term continuous cropping of soybean, and the excavation of candidate genes and functional loci related to continuous cropping obstacles in legume crops are breakthroughs for proposing effective continuous cropping obstacle management strategies in the future.

[目的]针对目前残膜累积导致农田生态环境污染和服务功能下降等问题,探究不同厚度聚乳酸可降解地膜对绿洲灌区玉米产量和农田水热特性的影响.[方法]在石羊河流域进行田间试验,本研究选取0.006 mm(PLA1)和0.008 mm(PLA2)厚度聚乳酸生物可降解地膜以及0.010 mm厚度的普通聚乙烯地膜(PE)覆盖种植玉米,探究不同厚度聚乳酸可降解地膜对绿洲灌区玉米产量和农田水热特性的影响,并采用填埋试验探究不同厚度可降解膜的降解性能.[结果]与PE相比,PLA2覆盖下玉米农田土壤温度、土壤含水量、作物耗水量和水分利用效率无显著差异,水分利用效率达24.6 kg/(hm2·mm),其叶面积指数、干物质累积量及产量构成因素与PE无显著差异,籽粒产量达13533.3 kg/hm2.此外,PLA2覆盖下农田水热特性和玉米产量均显著高于PLA1.在降解性能方面,PLA1降解率显著高于PE和PLA2,90 d后超过50％;PLA2填埋后60 d降解程度显著增大,150 d后成为碎屑,降解率达50.9％,降解性能优良.[结论]从生产上看,0.008 mm聚乳酸可降解地膜降解性能优良,与普通PE地膜具有相同的增温保墒和增产效应,可代替0.010 mm普通PE地膜应用于干旱绿洲灌区玉米生产中.