This study was conducted to clarify the long-term effects of biochar application on the structure and function of the fungal community in continuous cropping watermelon soil.Taking watermelon root soil as the research object,Illumina NovaSeq high-throughput sequencing and FUNGuild platform were used to analyze the differences in soil fungal community composition,diversity,and function after 3-year biochar additions of 7.5,15.0,and 30.0 t·hm-2 and to explore the correlation between soil environmental factors and fungal community structure under the control of biochar.The results showed that compared to that in the absence of biochar(control),the soil pH,available phosphorus,available potassium,total nitrogen,organic matter,and cation exchange capacity increased,but available nitrogen decreased with biochar addition.High-throughput sequencing results showed that biochar amendment improved the fungal community structure in continuous cropping watermelon soil and increased the richness and diversity of soil fungi.A total of 922 OTU were obtained from all soil samples,and the species annotation results indicated that the dominant fungal groups were Ascomycota,Basidiomycota,Mortierellomycota,Chytridiomycota,and Glomeromycota,with these phyla accounting for 85.70%-92.45%of the total sequences.The relative abundance of Ascomycota and Basidiomycota decreased,whereas the abundance of Mortierellomycota and Glomeromycota increased with biochar addition.At the genus level,the application of biochar increased the relative abundance of Mortierella and Rhizophlyctis but decreased the abundance of Fusarium.The Mantel test showed that soil available potassium,available nitrogen,organic matter,and pH were the main environmental factors leading to the shift in the soil fungal community composition.The functional prediction with FUNGuild showed that the many nutrient types among the different treatments were saprotrophic,pathotrophic,and symbiotrophic.The relative abundance of pathotrophs significantly decreased,but the abundance of symbiotrophs significantly increased with the medium and high doses of biochar treatment.In conclusion,the application of biochar changed the soil physicochemical properties,promoted the development of soil fungal community structure and functional groups in a healthy and beneficial direction,and improved the quality of continuous cropping watermelon soil.

为了明确0.1％噁霉灵颗粒剂对西瓜枯萎病的防治效果,以70％噁霉灵可溶粉剂525 g/hm2(有效剂量)为药剂对照,以清水为空白对照,0.1％噁霉灵颗粒剂有效剂量分别设450、525和600 g/hm2,2020～2021年连续2 a开展了0.1％噁霉灵颗粒剂防治西瓜枯萎病的田间药效试验.结果表明:0.1％噁霉灵颗粒剂对西瓜枯萎病具有较好的防治效果,且防效稳定,但不同有效剂量处理的防效差异较大,其中,有效剂量600g/hm2处理的防效显著高于对照药剂和其他剂量处理,有效剂量525g/hm2处理的防效与对照药剂相当,而有效剂量450g/hm2处理的防效显著低于对照药剂.0.1％噁霉灵颗粒剂对西瓜和其他有益生物安全,是一种防治西瓜枯萎病的理想药剂.生产上建议使用0.1％噁霉灵颗粒剂525～600 g/hm2防治西瓜枯萎病.

探明采前喷施氯化钙对苹果叶片光合特性、叶绿素荧光特性和果实品质的影响特征,为苹果的钙肥施用技术及苹果高效吸收钙素的生理机制研究提供理论支撑.以矮砧密植富士苹果为试验材料,设置0.5％CaCl2(Tl)、1.0％CaCl2(T2)、2.0％CaCl2(T3)、4.0％CaCl2(T4)、6.0％CaCl2(T5)、0％CaCl2(CK)5 个不同氯化钙浓度处理,利用主成分分析结合隶属函数综合评价方法明确苹果采前最佳钙肥施用量.结果表明,采前喷施不同浓度氯化钙对叶片光合功能和果实品质的促进效果有差异,采前喷钙处理均可显著提升苹果叶片叶绿素指数、果实硬度、果实可溶性固形物含量;与CK处理相比,T2处理叶片净光合速率提高7.68％、叶片水分利用效率提高55.14％、叶片羧化效率提高8.36％、叶片最大光化学量子效率提高11.56％、叶片实际光化学量子效率提高8.63％、叶片光合有效辐射提高21.63％、叶片光合电子传递效率提高32.05％、果实质量提高5.83％、果形指数提高4.26％、果实固酸比提高16.42％、叶片蒸腾速率降低30.58％、叶片气孔导度降低30.00％;主成分分析结合隶属函数表明,采前喷施氯化钙各处理对叶片光合功能影响的综合得分排序为1.0％CaCl2＞0.5％CaCl2＞2.0％CaCl2＞0.0％CaCl2＞4.0％CaCl2＞6.0％CaCl2,对果实品质影响的综合得分排序为 1.0％CaCl2＞2.0％CaCl2＞0.5％CaCl2＞0.0％CaCl2＞4.0％CaCl2＞6.0％CaCl2.研究认为,采前喷施适宜的氯化钙浓度对富士苹果光合功能和果实品质有显著影响,苹果采前氯化钙最佳施用浓度为1.0％CaCl2,采前喷施氯化钙浓度不宜大于2.0％.

以生物熏蒸、微生物菌剂和化学熏蒸(棉隆)为处理,对3年连作西瓜生长发育和枯萎病的防治效果进行研究.结果表明:(1)试验条件下,各处理对西瓜出苗率无显著影响,且未出现药害现象;(2)生物熏蒸配施微生物菌剂或棉隆对西瓜生长发育均具有一定的促进作用,增加了株高(蔓长),提高了叶绿素含量;(3)生物熏蒸配施微生物菌剂或化学药剂棉隆两个处理对西瓜枯萎病均有良好的防效,且持效期较长;(4)生物熏蒸配施微生物菌剂处理显著提高了西瓜的品质和平均单果重.结论:生物熏蒸配施微生物菌剂不仅能有效防治西瓜枯萎病,还可以促进西瓜的生长发育,提高西瓜单果重,同时显著改善西瓜品质.

以富士苹果为试材,采用主成分分析结合隶属函数分析进行综合评价,研究了不同浓度氯化钙结合低温处理对苹果不同贮藏时间果实失重率、硬度、可溶性固形物含量、可滴定酸含量、维生素C含量等品质指标的影响,以期为采后苹果高效、低成本低温贮藏提供参考依据.结果表明:随着贮藏时间的延长,苹果果实的失重率上升,硬度下降,可滴定酸含量与维生素C含量总体呈降低趋势,可溶性固形物含量先减少后升高,固酸比升高,贮藏120 d内果实品质指标变化幅度较缓;与对照相比,不同浓度的氯化钙浸泡处理均能减缓贮藏期间苹果果实失重率的上升,提升果实硬度、可滴定酸含量、维生素C含量和可溶性固形物含量;相关性研究表明除可溶性固形物含量与失重率、硬度、固酸比无显著相关性外,其余果实品质指标间均呈现不同程度的显著相关性;主成分分析结合隶属函数分析表明150 d贮藏时间内2％氯化钙结合4 ℃低温处理对延缓富士苹果果实衰老过程、保持果实贮藏品质效果最好.综上,采后浸泡氯化钙处理可减缓贮藏期苹果果实失重率的增加和硬度的降低,抑制贮藏期可溶性固形物、可滴定酸和维生素C含量的降低,较好地保持苹果果实外观品质和营养品质.最适采后浸泡氯化钙浓度为2％,适宜的贮藏期在120 d左右.

土壤微生物区系变化引起的土传病害一直是制约西瓜产业健康发展的重要因素,为揭示土壤真菌群落对生物熏蒸及配施微生物菌剂的响应机制,本研究在连续种植两年的西瓜田设置生物熏蒸(R)、生物熏蒸配施微生物菌剂(RB)和空白对照(CK)处理,于西瓜初花期采集土样,采用Illumina HiSeq高通量测序技术,分析生物熏蒸及配施微生物菌剂对连作西瓜土壤真菌群落组成和多样性的影响及其与土壤环境因子间的相关性.结果表明:与CK相比,R和RB处理均提高了土壤碱解氮、有效磷、速效钾、全氮及有机质含量,降低了土壤pH;Alpha多样性指数显示,R和RB处理显著降低了土壤真菌群落丰富度和多样性,表现为R<RB<CK.3个处理的西瓜连作土壤样本共获得794个OTU,其中含有一些未知真菌;在已知的真菌群落中,子囊菌门、担子菌门和被孢霉门为3个主要菌门,其相对丰度占总丰度的95.14％～96.17％;R处理增加了土壤中子囊菌门和担子菌门的相对丰度,RB处理提高了子囊菌门的相对丰度,显著降低了担子菌门的相对丰度;R和RB处理均显著提高了土壤中毛壳菌科和小囊菌科相对丰度,此外,RB处理显著增加了从赤壳科真菌相对丰度,并降低了柔膜菌科真菌相对丰度.聚类分析表明,RB处理与CK的真菌群落结构相似.RDA分析可知,有机质、全氮、速效钾和pH是驱动土壤真菌群落结构变化的关键因子.综上所述,生物熏蒸配施微生物菌剂不仅能够提高土壤质量,相比于单独生物熏蒸,还可提高土壤真菌群落丰度和多样性,调节西瓜连作土壤真菌群落结构向有益方向发展.

为确定噻虫胺拌种对瓜蚜的防治效果,以西瓜蚜虫为防治对象,开展了室内、盆栽及田间条件下的药剂拌种试验.结果表明:在室内条件下,10％噻虫胺种子处理悬浮剂各处理对西瓜发芽率无显著影响,发芽势和发芽指数随着噻虫胺用量的增加呈现先升高后降低的趋势;在盆栽条件下,西瓜出苗15、30、45d后,接虫12 h和24 h时,西瓜成蚜的死亡率均随着噻虫胺用量的增加而升高;在田间条件下,在供试剂量范围内,噻虫胺拌种对西瓜出苗安全,对西瓜蚜虫的防效随用量的增加而升高.

中国梨喀木虱是梨树上一种重要的刺吸式寡食性害虫,本文于2018-2019年对山西省运城市酥梨产区中国梨喀木虱消长动态进行系统调查,明确其种群消长规律.结果表明,中国梨喀木虱卵量出现3次高峰,分别为3月上旬、5月上中旬和6月下旬至7月上旬;若虫盛发期出现两次,为4月中下旬和6月上中旬,其中以6月中旬为害最为严重;越冬代出蛰期在3月上中旬;第一代成虫发生高峰期为5月上中旬.针对中国梨喀木虱的种群消长动态,本文提出以"两防一控"为核心的防控对策,为山西运城地区中国梨喀木虱的防控治理提供指导依据.

农业管理实践会干扰土壤生态系统,对土壤微生物特别是根系周围微生物产生不同影响,保护性耕作被认为是对土壤扰动较小的耕作方式,在全球范围内应用广泛,但其可持续性受到了秸秆覆盖可能会增加土壤病原微生物的挑战,对土壤微生物多样性的影响仍存在争议.因此,为全面了解黄土高原旱作麦田长期保护性耕作对土壤生态系统的影响,本研究依托山西省临汾市长达27年的保护性耕作试验平台,采用高通量测序技术,开展了土壤真菌群落结构和多样性对传统耕作(TT1)、免耕覆盖(NTS)、深松+免耕覆盖(SNTS)的响应分析.结果表明:与TT1相比,NTS和SNTS处理小麦根围土壤真菌组成及相对丰度发生了显著变化,NTS处理出现了未知真菌类群;各处理土壤真菌的主要优势菌门为子囊菌门、担子菌门和接合菌门;从属水平物种分布热图可以看出,与传统耕作相比,该地区多年的保护性耕作会加大小麦赤霉病发生的风险;UPGMA(非加权组平均法)分析表明,2种保护性耕作土壤真菌群落组成相似;TT1中具有显著差异的关键优势物种属担子菌门,NTS和SNTS处理的属子囊菌门;NTS处理土壤真菌丰富度和系统发育多样性最高,SNTS处理土壤真菌多样性最高;但土壤真菌多样性和丰富度指数在各处理间并无显著差异.综上,长期保护性耕作显著改变了土壤真菌群落结构及组成,提高了土壤真菌的丰富度和多样性,但不存在显著差异.同时该地区多年的保护性耕作可能会加大小麦赤霉病发生的风险.本研究对黄土高原旱作麦田区推广保护性耕作及土壤管理具有一定的指导意义.

以二十年生苹果品种“红富士”为试材,采用人工气候室模拟低温冻害的方法,研究不同外源钙不同浓度对苹果花器官丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性及过氧化氢酶(CAT)活性的影响,并用隶属函数法进行抗寒性综合评价.结果 表明:低温胁迫下不同外源钙各浓度处理MDA含量较对照降低了10.7％～53.6％,且均呈极显著差异;不同外源钙除28 mmol·L-1 CaCO3处理外各浓度处理均提高了SOD活性,除14 mmol·L-1 Ca(NO3)2处理外均与对照呈极显著差异;不同外源钙各浓度处理均提高了POD活性,除14、28 mmol·L-1 Ca(NO3)2处理外均与对照呈极显著差异;不同外源钙各浓度处理CAT活性较对照提高了8.7％～22.7％,且均与对照呈极显著差异.综上所述,丙二醛含量、过氧化氢酶活性、过氧化物酶活性和超氧化物歧化酶活性4个生理指标可作为苹果抗寒性的鉴定指标.通过隶属函数值分析表明21 mmol·L-1 CaCl2处理后的苹果花器官抗寒性效果最佳.

中国梨喀木虱是梨树上一种重要的专食性刺吸式害虫.为明确中国梨喀木虱卵的分布及变化规律,本文对梨生育期中国梨喀木虱卵的空间格局及时序动态进行了调查研究.结果 表明:中国梨喀木虱在叶片上的产卵量有2次高峰,分别在5月下旬和7月上旬,单叶卵量分别达到18.1头/叶和22.8头/叶;卵集中分布在叶片主脉两侧、叶柄凹槽处内以及叶缘缺刻处,叶面较少,各处所占比例呈现动态变化;在树冠上、中、下3个垂直高度层和同一水平不同方位叶片的着卵量差异并不显著.

Quinoa black stem is a new disease that affects the stems of quinoa plants and is more likely to develop under cool conditions (15 to 25°C, RH = 55 ± 2%). The typical symptoms include the formation of black necrotic lesions on the stem, which can completely wrap around the stem, causing lodging and blanking (development of 'empty' and sterile grain on the panicle). Furthermore, the pycnidia form small round protrusions on the surface of the lesions. Phylogenetic analysis revealed that representative isolates LMHS-3 and LMHS-5 were closely related to Ascochyta caulina (teleomorph: Neocamarosporium calvescens). Comprehensive morphological and molecular characterizations confirmed A. caulina as the pathogen that caused quinoa black stem. A. caulina mainly infected quinoa stems and could produce many pycnidia, but it rarely infected quinoa leaves. Pathogenicity testing showed that the most suitable temperature for the onset of quinoa black stem was from 15 to 25°C. When the temperature was increased above 30°C, the conidial germination of A. caulina became malformed, and when the temperature was decreased below 5°C, mycelium growth of A. caulina became extremely slow; thus, both extreme high and low temperatures affected the pathogenicity of A. caulina. Mancozeb and azoxystrobin fungicides were revealed to have had the strongest inhibitory effects on the conidial germination of A. caulina, and in some cases caused malformations in conidial germination. Tebuconazole and difenoconazole had the strongest inhibitory effects on A. caulina mycelial growth and less on the effects on the conidial germination. The results of the present study provide a basis for the recognition and management of quinoa black stem.

为探究梨木虱的研究历史、研究趋势和发展动向,基于中国知网数据库,利用主题文献计量分析方法系统分析1964年至2020年11月的国内梨木虱研究主题文献资料.结果 显示,国内发表梨木虱主题研究论文共875篇,源于302种期刊;发表论文年度数量呈现逐年增加,后趋于稳定趋势;《河北果树》发文量最多;李大乱以第一作者发表梨木虱论文数量最多,魏巍等撰写的《梨园芳香植物间作区中国梨木虱与其天敌类群的相互作用》论文被引频次最高;以梨木虱为主题发表的研究论文主要以该虫发生规律和防治技术为主.

为明确12％虱螨·虫螨腈悬浮剂对为害甘蓝的甜菜夜蛾的防效,以其为供试药剂,设置高、中、低剂量处理,并以5％虱螨脲悬浮剂和10％虫螨腈悬浮剂为对照,开展了田间药效试验.结果 表明,12％虱螨·虫螨腈悬浮剂3个处理对甜菜夜蛾均有较好的防治效果,且持效期较长,药后3d的防效为68.17％～90.34％,药后10d的防效达85.31％～100％.12％虱螨·虫螨腈悬浮剂的中剂量(72 g/hm2)处理防效与对照药剂相当,高剂量(90 g/hm2)处理防效显著高于对照药剂,3个处理均对甘蓝及其他非靶标生物安全.

枯草芽孢杆菌LF17是分离自苹果树枝干的1株对苹果树腐烂病具有良好防效的生防菌株,为研究其对环境的适应度,通过测量吸光度值,平板涂布等,测定菌株LF17对温度、pH的敏感度并筛选最佳培养基配方.结果 表明:菌株LF17在35 ～85℃均生长良好,致死温度为96℃、处理8 min;最适pH范围为6～7,致死pH为小于4或大干10;最佳产孢及成膜的培养基配方为牛肉膏5 g、蛋白胨10 g、NaCl 5 g、葡萄糖20 g、甘油10 g、MnCl25 mg.本研究可为菌株LF17生防菌剂产业化生产及田间应用等提供理论依据.

藜麦(Chenopodium quinoa)是藜科藜属1年生双子叶植物[1],作为一种新型粮食作物在南美洲、欧洲、大洋洲、亚洲等90多个国家种植或试种[2].2014年以来,在我国的山西、青海、甘肃、河北等省份开始规模化种植[3];山西省静乐县是我国藜麦规模化种植最早的基地[3],随着种植面积的扩大及连作栽培导致病害日趋严重,尤其是叶部病害.2015～2017年间,本课题组在静乐县藜麦种植区调研时发现一种藜麦叶部病害,该病害发病初期,在叶片上形成圆形或近圆形病斑;严重时病斑连片造成叶片枯黄脱落.近年来,该病害的发病率约35%,严重地块约70%左右、减产约25%,并呈加重趋势.

为明确来自苹果树上的1株生防菌LF17对腐烂病菌的抑制作用及其发酵液对腐烂病的防治效果,采用形态学结合16S rDNA和gyrA基因序列分析对菌株LF17进行了鉴定,并通过滤纸法测定了发酵液对腐烂病菌的抑制率,利用涂抹发酵液的方法测定了发酵液对腐烂病的防效.结果 表明,菌株LF17发酵液对腐烂病菌的抑菌率为93.80％,与甲基硫菌灵(94.20％)抑菌率相当,显著高于嘧菌酯(42.60％)、辛菌胺(52.80％)和苯醚甲环唑(81.30％);离体枝条防治结果表明,发酵液水剂和膏剂对腐烂病的防效为78.59％～80.40％,与甲基硫菌灵(76.93％)相比差异不显著,与嘧菌酯(44.15％)、辛菌胺(68.25％)、苯醚甲环唑(74.45％)相比差异显著;田间试验表明,涂有发酵液的伤口愈合面积为9.37～9.79 cm2,病疤复发率为3.82％～4.56％,与其他4种药剂相比差异显著.研究表明菌株LF17发酵液对腐烂病菌有明显抑制作用,且可促进伤口的愈合并显著降低腐烂病的复发.

藜麦原产于南美洲的安第斯山地区,具有适应恶劣环境的特性,在美洲、欧洲、亚洲、澳洲等地都有种植[1].联合国粮农组织推荐为适宜人类食用的“全营养食品”[2,3].我国的藜麦产业起步晚,2008年山西省最早实现了规模化种植藜麦[4].2016年山西省藜麦面积约5 307 hm2,其中山西省忻州市静乐县种植面积约3 538 hm2,被誉为“中国藜麦之乡”.随着种植面积的扩大及连作栽培,藜麦病害日趋严重,严重影响藜麦产业的发展.

The pink mold rot on traditional fruit tree Ziziphus jujube was observed in plantation of Shanxi pro vince.At the beginning,pink mold rot appeared as white mold on the fruit surface.As the disease progressed,it changed to thick and larger powdery mildew lesion with variation in the size.The appearances were punctiform,mottling,patching,ellipse and so on.The morphological characteristics,pathogenicity test and molecular identification method were used to confirm the pathogen of pink mold rot.Two representative strains of Trichothecium roseum were identified in this study based on morphological and physiological tests in addition to the ITS se quence comparison.The conidia of T.roseum germinated with optimal conditions at 20℃-25℃,pH 4-10,and over 75％ relative humidity.The lethal temperature for conidia of T.roseum was 48℃ for 10 minutes.The germ tube of T.roseum grew with an optimal condition at 20℃-25℃,pH 6,more than 75％ relative humidity.The results of this research provide the theoretical basis for disease diagnosis and control measures.

Objective]The strain DS-9 was an endophyte bacteria from Salvia miltiorrhiza which can good control the Bortytis cinerea .To effectively inhibit pathogenic fungus,[Methods]Its medium composition and fermentation condi-tions were optimized by the method of single factor and orthogonal design.[Results]The results indicated that the best basic culture medium was NYBD,the optimum carbonsource was glucose,the nitrogen source was the combination of pancreatic peptone and beef extract,the optimum fermentation conditionswere as following:pH 9.0,shaking flask volume at 200 mL/500 mL,proper inoculation 10%,130 r·min-1 for 24 h,the antibacterial substance had higher yield and bacteriostatic effect was the best.[Conclusion]The test for the Salvia miltiorrhiza endophytic bacteria provides the theory basis for the development and application of biological agents.