Salinity stress, driven by high-chloride saline water (HCW), poses a significant threat to global agriculture by impairing plant growth and altering the soil microbial communities. Although the role of microbiomes in enhancing plant salt tolerance is well documented, the specific responses of walnut (Juglans regia) root and soil microbiomes to HCW remain unexplored. This study investigated the effects of HCW on walnut leaf mineral elements, soil physicochemical properties, and the diversity and composition of bacterial and fungal communities in the root, rhizosphere, and bulk soil compartments. The results showed that HCW significantly reduced essential leaf nutrients (N, P, K, Fe, and Ca) while increasing Cl- accumulation, resulting in leaf necrosis. Soil electrical conductivity, Cl-, and Na+ levels were elevated under HCW, with notable reductions in nitrate nitrogen and increases in exchangeable calcium. Microbial analysis revealed decreased bacterial diversity in roots and rhizosphere soils under HCW, along with a shift in community composition characterized by a decline in Proteobacteria (e.g., Rhizobium) and an increase in Actinobacteria (e.g., Arthrobacter, Streptomyces). The fungal diversity remained stable, but the community structure changed, with an increased abundance of Mortierellomycota. Co-occurrence network analysis indicated simplified bacterial interactions and enhanced fungal competition in HCW. Mantel tests demonstrated that bacterial community composition was strongly correlated with Cl-, Na+, and Ca2+, whereas fungal community composition was significantly associated with NO3 -, Na+, and Ca2+. These findings highlight the targeted reshaping of walnut-associated microbiomes under chloride-dominated salinity and suggest the potential of leveraging salt-tolerant microbes to improve crop resilience in saline agriculture.

Walnut (Juglans regia L.) is an important oilseed crop, and salt stress threatens the growth of walnut tree. In this study, NO3− or NH4+ was applied at three concentrations (4, 32, and 100 mM) to investigate the effect of NO3−-N and NH4+-N on walnut seedlings under 100 mM NaCl stress. Results showed that moderate (32 mM) NO3−-N application alleviated the effect of salt stress. Moreover, plants treated with 32 mM NO3−-N showed no significant morphological difference from those subjected to the nonstress treatment. The treatment of 32 mM NO3−-N application enhanced plant growth, increased antioxidant enzyme activities (superoxide dismutase and catalase), and restricted Na⁺ and Cl⁻ uptake and transport. Additionally, it might induce beneficial shifts in the rhizosphere microbiome. Low-concentration (4 mM) NO3⁻ or NH4⁺ treatment individually induced the minor alleviation of salt stress. By contrast, 100 mM NO3⁻ and all tested concentrations of NH₄⁺ further inhibited biomass and root growth, thereby exacerbating salt injury. Notably, 100 mM NH₄⁺ caused severe defoliation and seedling mortality. Furthermore, in contrast to its NO3− counterpart, 32 mM NH4⁺ shifted the root microbiome and impaired microbial diversity, likely contributing to increased salt sensitivity. This study demonstrates that moderate NO3⁻ application can effectively mitigate salt stress during walnut growth, offering a potential strategy for fertilizing walnut plantations under saline conditions.

Accurately evaluating the water status of walnuts in different growth stages is fundamental to implementing deficit irrigation strategies and improving the yield of walnuts. The crop water stress index (CWSI) based on the canopy temperature is one of the most commonly used tools for current research on plant water monitoring. However, the suitability and effectiveness of using the CWSI as an indicator of the walnut water status under field conditions are still unclear. This paper focuses on walnut orchards in Northwest China using synchronous monitoring of the canopy temperature, meteorological parameters, and water physiological parameters of walnut trees under both full irrigation and deficit irrigation treatments. The aim is to test the effectiveness of the simplified crop water stress index (CWSIs) and the theoretical crop water stress index (CWSIt) in tracking the diurnal and daily variations of the water conditions in walnut orchards. The CWSIs can reflect the diurnal and daily changes in the water status of walnut orchards. It was found that the CWSIs at 12:00 local time had the best performance in tracking the daily changes in the water status. Compared to the daily averaged CWSI calculated using the measured transpiration (CWSITr_day), the correlation coefficient, index of agreement, and root mean squared error between the CWSIs and CWSITr_day were 0.82, 0.94, and 0.11, respectively. However, due to the calculation errors of the aerodynamic resistance in walnut trees, the CWSIt was unable to track the diurnal variations in the water status in walnut orchards and the degree of water stress was underestimated. In addition, the variations in minimum canopy resistance in the various growth stages of walnut orchards may also affect the accuracy of the CWSIt in terms of indicating the seasonal changes in the water status. The CWSIs provides a non-destructive, quickly and effective method for monitoring the water status of walnuts. However, the results of this study suggest that the effects of aerodynamic resistance parameterization and variations in minimum canopy resistance in the various growth stages of walnut orchards in the CWSIt calculation should be noted.

Agronomic crops can benefit from the application of nanoscale materials in order to control phytopathogens and improve plant growth. Bipolaris sorokiniana, a soil-and seed-borne fungus, causes severe yield losses in wheat. In order to determine the physio-chemical changes in wheat under biotic stress of B. sorokiniana, the current study aimed to synthesis silver nanoparticles (AgNPs) using Allium sativum bulb extract. Herein, we applied the silver nanoparticles (AgNPs) as a foliar spray on two wheat varieties (Pakistan-2013, and NARC-2011) at the con-centrations of 10, 20, 30, and 40 mg/L to suppress B. sorokiniana. Among all the applied concentrations of AgNPs, the 40 mg/L concentration demonstrated the most effective outcome in reduction of the intensity of spot blotch and improved the morphological, physiological, biochemical parameters, as well as antioxidant activity in wheat plant. Foliar application of AgNPs at 40 mg/L Pakistan-2013 and NARC-2011 wheat varieties significantly increased chlorophyll a 84.8% and 53.4%, chlorophyll b 28.9% and 84.3%, total chlorophyll content 294.3% and 241.2%, membrane stability index 7.5% and 6.1%, relative water contents 25.4% and 10.5%, proline content 320.5% and 609.9%, and soluble sugar content 120% and 259.4%, respectively, compared to control and diseased plant. This is the first study provides important insights into the role of phyto-mediated AgNPs in increasing resistant of wheat infected with B. sorokiniana. These findings offers valuable new insights that may be useful for reducing disease incidence in wheat fields.

为提高烟叶品质寻求一条解决途径,以"云南 87"为材料,通过田间喷施试验(山梨醇、葡萄糖酸钠、甘氨酸和糖醇螯合钾)研究喷施小分子有机物及配施水溶性钾肥对烤烟生长及品质的影响.结果表明,与CK处理相比,SOM1、SOM2、SOM3、SOM4 和SOM5 处理均增大了烤后烟上部烟叶外观质量评价得分,增幅分别达7.63%、2.66%、4.57%、9.53%和 4.57%;且SOM1、SOM2、SOM3、SOM4 和SOM5 处理提高了烤后烟上部烟叶上等烟率,增幅分别达 16.57%、68.71%、26.99%、26.39%和 43.09%;另外,喷施小分子有机物改善了烟叶内在化学成分协调性,主要体现在提高了烟叶总糖、钾、糖碱比和钾氯比等常规化学成分指标.因此,在烤烟生产上选择喷施小分子有机物可作为一种提高上部烟叶品质的途径.

Walnut is one of the world’s four largest nuts. Currently, the bottleneck in walnut breeding is the production of resistant variants. Soil salinization is a global problem, and the use of salt-tolerant rootstocks is a basic strategy to overcome the challenge of sustained walnut production. Providing a scientific basis for the selection of walnut salt-tolerant rootstocks is possible by studying the physiological and biochemical response characteristics and salt tolerance variations of different walnut genotypes under salt stress. In the present study, seedlings of four genotypes of walnut rootstocks, including J1 (Juglans hindsii), J2 (J. mandshurica), J3 (J. regia × J. mandshurica), and J4 (J. regia × J. hindsii), were employed as test materials to conduct a 28-day pot experiment under NaCl stress with five NaCl concentrations (0, 50, 100, 200, and 300 mmol/L). Under different NaCl treatment concentrations, seedling morphology, growth indices, chlorophyll content, photosynthetic parameters, relative electrical conductivity (REC), malondialdehyde (MDA), proline (Pro), soluble sugar (SS), and the activity of superoxide dismutase (SOD) and peroxidase (POD) in the leaves were examined. Salt stress altered the morphological characteristics and growth indices of seedlings from four genotypes to varying degrees. In addition, according to the analysis of physiological and biochemical data, salt stress had a considerable impact on both the physiological and biochemical processes of seedlings. Salt stress decreased the chlorophyll content and photosynthetic parameters of four genotypes, the REC, MDA content, Pro content, and SS content of each genotype increased by different degrees, and the enzymatic activities showed different trends. The salt tolerance of rootstocks was evaluated thoroughly using principal component analysis and membership function analysis based on the 16 parameters. The results of a comprehensive evaluation of salt tolerance showed that the order of salt tolerance of the four genotypes was J4 > J1 > J3 > J2, which corresponded to the order of the morphological symptoms of salt injury. In conclusion, J4 has strong salt tolerance and is an important germplasm resource for walnut salt-tolerant rootstock breeding.

[目的]为探索WOX4b基因在核桃不定根发生过程中的调控作用提供理论支撑.[方法]以核桃品种'林早香'(Juglans?regia?'Linzaoxiang')的cDNA为模板克隆该基因CDS全长序列;利用生物信息学技术对其进行多重序列比对和系统进化分析;构建该基因与黄色荧光蛋白(Yellow?Fluorescent?Protein,YFP)标签的融合表达载体进行亚细胞定位分析;通过对银腺杨'84K'的遗传转化,分析其功能.[结果]JrWOX4b基因的编码序列(Coding?sequence,?CDS)长度为678?bp,编码226个氨基酸,分子量为25.42?KDa.所编码氨基酸序列的多重比对及系统进化分析结果显示:核桃JrWOX4b与山核桃属的长山核桃同源蛋白遗传关系最近,与壳斗科栎属白栎次之,而与禾本科的黍稷和二穗短柄草的亲缘关系最远.JrWOX4b基因过表达植株的表型分析结果显示:JrWOX4b的过表达和对照植株生长发育均正常,但在相同培养条件下,JrWOX4b基因的过表达能够显著增加杨树的不定根数量,2周龄过表达植株不定根数量为对照植株的3?～?4倍,不定根长度是对照植株的1/2.[结论]从核桃中成功克隆了WOX基因家族成员JrWOX4b基因,其过表达可显著增加转基因植株的不定根数量.研究结果不仅能够为不定根发生调控机制的研究提供理论支撑,同时也为其他难生根木本植物的快速繁殖提供优良基因资源.

Walnut (Juglans regia L.) is an important woody nut tree species, and its endopleura (the inner coating of a seed) is rich in many polyphenols. Thus far, the pathways and essential genes involved in polyphenol biosynthesis in developing walnut endopleura remain largely unclear. We compared metabolite differences between endopleura and embryo in mature walnuts, and analyzed the changes of metabolites in endopleura at 35, 63, 91, 119, and 147 days after pollination (DAP). A total of 760 metabolites were detected in the metabolome, and the polyphenol contents in endopleura were higher than those in embryos. A total of 15 types of procyanidins, 10 types of kaempferol glycosides, and 21 types of quercetin glycosides that accumulated during endopleura development were identified. The analysis of the phenylpropane metabolic pathway showed that phenylalanine was gradually transformed into proanthocyanidins and other secondary metabolites with the development of endopleura. A total of 49 unigenes related to polyphenol synthesis were identified by transcriptome analysis of endopleura. The expression patterns of PAL, C4H, 4CL, CHS, CHI, F3H, LDOX, and ANR were similar, and their expression levels were highest in endopleura at maturity. Transcriptome and metabolome analysis showed that endopleura rapidly synthesized and accumulated polyphenols during maturation. Moreover, the transcription factor MYB111 played an important role in synthesizing polyphenols in endopleura, and its expression pattern was positively correlated with the accumulation pattern of quercetin, kaempferol, and proanthocyanidins. MYB111 was co-expressed with NAP, NAC, ATR1, and other genes related to cell senescence and abiotic stress response. Our study analyzed the composition and molecular synthesis mechanism of polyphenols in walnut endopleura, and provided new perspectives and insights regarding the nutritional research of walnut nuts.

The practice of intercropping, which involves growing more than one crop simultaneously during the same growing season, is becoming more important for increasing soil quality, land-use efficiency, and subsequently crop productivity. The present study examined changes in soil physicochemical properties, enzymatic activity, and microbial community composition when walnut (Juglans spp.) was intercropped with tea (Camellia sinensis L.) plants in a forest and compared with a walnut and tea monocropping system. The results showed that walnut-tea intercropping improved the soil nutrient profile and enzymatic activity. The soil available nitrogen (AN), available phosphorus (AP), available potassium (AK), organic matter (OM) content, and sucrase activity were significantly boosted in intercropped walnut and tea than in monocropping forests. The interaction between crops further increased bacterial and fungal diversity when compared to monoculture tea forests. Proteobacteria, Bacteroidetes, Firmicutes, Chlamydiae, Rozellomycota, and Zoopagomycota were found in greater abundance in an intercropping pattern than in monoculture walnut and tea forest plantations. The walnut-tea intercropping system also markedly impacted the abundance of several bacterial and fungal operational taxonomic units (OTUs), which were previously shown to support nutrient cycling, prevent diseases, and ameliorate abiotic stress. The results of this study suggest that intercropping walnut with tea increased host fitness and growth by positively influencing soil microbial populations.

为提高上部叶的工业可用性,以NC102品种3个不同采收成熟度(BM1、BM2、BM3)的烤后上部烟叶为材料,分析了叶尖、叶中、叶基3个分切区段的外观质量、物理性状、化学成分及其可用性指数(CCUI)和感官质量的差异.结果表明,同一成熟度下,烟叶外观质量总分表现为叶中＞叶基＞叶尖;填充值在低、中成熟度时表现为叶尖高于叶中和叶基,其他物理指标差异不显著;还原糖含量和糖碱比在低、中成熟度下表现为叶尖＜叶中＜叶基,在高成熟度下差异不显著,淀粉含量在各成熟度下均表现为叶尖＜叶中＜叶基,钾含量和钾氯比在各成熟度下均表现为叶尖＞叶中＞叶基,总氮含量、烟碱含量及氮碱比在不同区段及不同成熟度间差异不显著;低、中成熟度下烟叶CCUI为叶尖＜叶中＜叶基,且低成熟度处理中叶基段与叶尖和叶中段差异达到显著水平,高成熟度下则无显著差异.随成熟度提高,不同区段烟叶外观质量、物理性状、化学成分及CCUI间的差异总体呈逐渐缩小的趋势.烟叶感官质量得分表现为:低、中成熟度下叶尖＜叶基＜叶中,高成熟度下叶尖＞叶中＞叶基.综上,采收成熟度影响叶片不同区段的质量,低、中成熟度烟叶的叶中和叶基段综合质量优于叶尖段,而高成熟度下叶尖段化学成分整体协调性和感官质量优于叶中和叶基段.

为验证密集烤房包式固定堆积装烟烘烤效果,以云烟97中、上部叶为材料,对烟夹装烟和包式固定堆积两种装烟方式装烟量、用工、烘烤耗能成本及烤后烟叶物理性状、化学成分、外观质量、经济性状、感官质量进行比较分析.结果表明,包式固定堆积装烟量及密度比烟夹装烟提高45.70％～49.50％,编装烟和卸解烟用时缩短,每千克干烟烘烤用工及耗能综合成本下降0.46～0.50元.烤后烟叶平衡含水率提高0.15～0.30百分点(p<0.05),总糖含量提高1.40～2.13百分点(p<0.05),油分、色度均得到显著改善.包式固定堆积装烟量大、减工效果明显、烤后烟质量较好,是一种值得示范推广的烟叶烘烤装烟方式.

为提高皖南烟区C2F等级质量,对本部位正组率偏低、等级合格率不高的问题进行了分析,并采取了针对性的解决措施.结果表明,2019年度较2018年度本部位正组率提升7个百分点,混部位和含青、挂灰烟叶明显减轻,混上部叶和下部叶比例下降3个百分点.

为改善商洛烟区土壤肥力,促进烤烟生长发育,开展了微生物不同菌剂与不同施用量双因素大田试验,对烤烟植物学性状和农艺性状进行分析.结果表明:(1)巨大芽孢杆菌和复合菌剂的低水平处理(A1、C1和C2)的植物学性状相对较优;(2)B4处理株高最高,平均为129.7cm,比对照高12.8％,适量应用微生物菌剂对烟株生长具有良好的促进作用;(3)烤烟茎围B1最大为13.9cm,与对照相比增加12.1％,低水平微生物菌剂的应用能够增加烤烟的茎围,但施用量过多不利于茎围的增加;(4)施用微生物菌剂的各处理烤烟节距均高于对照,其中C1最高为7.77cm;(5)各处理烤烟腰叶长度以C1最高为83cm,与对照相比分别增加12.2％,同一菌剂内不同水平处理表现出不同的增减趋势;(6)各处理烤烟腰叶宽度以C1最高为45.7cm,与对照相比增加15.7％.

为稳定保持湖南永州烤烟浓香型风格,进行了烤烟浓香型特色品种的适宜性研究,对云烟97、K326、云烟87、湘烟3号、云烟99等5个品种进行了大田比较试验,分析其各项产质指标.结果表明,植物学性状上,云烟87品种栽后50d的生长势强,云烟系列3个品种不挂灰;经济性状上,云烟87的产量、产值、均价和上中等比例为最高,分别达到3456.0kg/hm2、70243.2元/hm2、20.33元/kg、89.8％.

为提高烤烟C2F收购等级合格率与本部位正组率,抽检统计主要的问题,从分级、预检、收购、管理等方面分析问题症结,从培训、人力、流程、追溯、目标等方向探讨并实施收购质量提高的途径.结果表明,对策实施后烤烟C2F的等级合格率与本部位正组率得到明显提升,波动有所降低.

研究烤烟幼苗移栽后不同揭膜时间对烤烟根系生长、 品质及土壤氯离子含量的影响.结果表明,30 d揭膜处理可获得更好的地上部分干物质重,根系活力增加,利于产量的形成,土壤氯离子含量更低,烤烟内在化学成分更协调,烤后烟叶钾离子含量增加,氯离子和烟碱含量减少.揭膜时间越延迟,上述效果表现的越不明显.

Although the effects of fertilization and microbiota on plant growth have been widely studied, our understanding of the chemical fertilizers to alter soil chemical and microbiological properties in woody plants is still limited. The aim of the present study is to investigate the impact of long-term application of chemical fertilizers on chemical and microbiological properties of root-associated soils of walnut trees. The results show that soil organic matter (OM), pHkcl, total nitrogen (TN), nitrate-nitrogen (NO3−), and total phosphorus (TP) contents were significantly higher in non-fertilized soil than after chemical fertilization. The long-term fertilization led to excessive ammonium-nitrogen (NH4+) and available phosphorus (AP) residues in the cultivated soil, among which NH4+ resulted in soil acidification and changes in bacterial community structure, while AP reduced fungal diversity. The naturally grown walnut trees led to an enrichment in beneficial bacteria such as Burkholderia, Nitrospira, Pseudomonas, and Candidatus_Solibacter, as well as fungi, including Trichoderma, Lophiostoma, Phomopsis, Ilyonectria, Purpureocillium, Cylindrocladiella, Hyalorbilia, Chaetomium, and Trichoglossum. The presence of these bacterial and fungal genera that have been associated with nutrient mobilization and plant growth was likely related to the higher soil OM, TN, NO3−, and TP contents in the non-fertilized plots. These findings highlight that reduced chemical fertilizers and organic cultivation with beneficial microbiota could be used to improve economic efficiency and benefit the environment in sustainable agriculture.

水冲井窖器是推广水造法井窖移栽方式的关键,项目通过对手持式水冲井窖器在不同土壤类型条件下使用效果的对比研究,探讨形成一套成本低、功能多、适合于多种土壤类型的井窖器推广应用方案,为水造法井窖移栽方式的推广奠定基础.

为提高烟叶复烤选叶质量、提高烟叶复配可用性,选用四川凉山、重庆、皖南烟叶开展烟叶多分技术研究.结果表明,烟叶多分技术的应用能够提高选后烟叶质量和选后烟叶的合格率.此外,烟叶多分技术的推广能够实现不同类别烟叶的区分及内在质量的细化,提高烟叶的可用性.

综述了除肥料种类外的生产农艺措施调控烤烟营养吸收利用的研究成果,主要包括施肥方式、精准平衡施肥、高肥效品种、生理调控、轮作方式及其他农艺措施等对调控烤烟营养吸收利用的效果,指出了需关注的主要问题,并对未来的研究方向进行了展望.