Kiwifruit rot caused by the fungus Alternaria alternata occurs in many countries, leading to considerable losses during kiwifruit production. In this study, we evaluated the antifungal activity and mechanism of tetramycin against kiwifruit soft rot caused by Alternaria alternata. Tetramycin exerted antifungal effects through the suppression of mycelial growth, conidial germination, and the pathogenicity of A. alternata. Scanning electron microscopic observations revealed that tetramycin destroyed the mycelial structure, causing the mycelia to twist, shrink, and even break. Furthermore, transmission electron microscopy revealed that tetramycin caused severe plasmolysis and a decrease in cell inclusions, and the cell wall appeared thinner with blurred boundaries. In addition, tetramycin destroyed cell membrane integrity, resulting in the leakage of cellular components such as nucleic acids and proteins in mycelial suspensions. Moreover, tetramycin also caused cell wall lysis by enhancing the activities of chitinase and β-1,3-glucanase and inducing the overexpression of related chitinase gene (Chit) and β-1,3-glucanase gene (β-1,3-glu) in A. alternata. In field trials, tetramycin not only decreased the incidence of kiwifruit rot but also create a beneficial living space for kiwifruit growth. Overall, this study indicated that the application of tetramycin could serve as an alternative measure for the management of kiwifruit rot.

探求不同施肥量对猕猴桃产量及品质的影响,以明确最佳施肥量,分析施肥量对猕猴桃氮磷钾含量的影响.以"红阳"猕猴桃为研究对象,猕猴桃萌芽期一次性施入复合肥料0?kg/株(对照)、0.25、0.5、0.75、1?kg/株,研究了不同施肥量对"红阳"猕猴桃产量、品质(包括可溶性固形物、可溶性总糖、可滴定酸、可溶性蛋白、维生素C)及氮磷钾含量的影响.结果表明:(1)施肥可有效提高猕猴桃平均横、纵径,施肥量为0.75、1?kg/株的平均横、纵径与对照差异达到显著水平;不同施肥量均可提高猕猴桃果实平均单果质量,各处理与对照相比,分别提高了15.10％、12.55％、27.21％、13.08％,其中,施肥量为0.75?kg/株的处理与对照差异达到显著水平.(2)施肥能提高猕猴桃果实可溶性固形物、维生素C和可溶性总糖的含量;施肥量为1?kg/株的果实可溶性固形物与空白对照相比差异显著;施肥量为0.5?kg/株的果实维生素C含量最高,达145.29?mg/100?g;施肥量为0.75?kg/株的果实可滴定酸和可溶性总糖含量分别为1.18％和6.04％,均高于其他处理.(3)整个生育期间,猕猴桃果实干物质含量总体均呈"S"形上升的变化趋势,叶片及果实的氮磷钾含量随施肥量的增加呈"上升-下降"的变化趋势.(4)整个生育期内各器官氮含量顺序为叶>果,其中叶氮含量呈"上升-下降"的变化趋势,果实的氮含量总体呈下降的变化趋势;各器官磷含量顺序为叶>果,叶的磷含量总体呈"下降-上升-下降"的变化趋势,果实的磷含量总体呈下降的变化趋势;叶的钾含量呈波动下降的变化趋势,果实钾含量总体呈"下降-上升"的变化趋势.综上所述,不同施肥量可以不同程度地提高猕猴桃果实平均单果质量、可溶性固形物、维生素C和可溶性总糖的含量,改善果实营养品质,综合效果以施肥量为0.75?kg/株最佳;整个生育期间,果实干物质含量呈"S"形上升的变化趋势,各器官氮磷含量为叶>果,叶的钾含量呈波动下降的变化趋势,果实钾含量总体呈"下降-上升"的变化趋势.

以'贵长'猕猴桃为试材,多糖醇螯合富钠钙、无水氯化钙、硝酸钙、25％嘧菌酯SC为供试药剂,采用田间施药方法,研究了采前喷施钙+嘧菌酯对猕猴桃果实外观品质、营养指标、贮藏性及软腐病的影响,以期为猕猴桃果实品质改善和软腐病的防控提供参考依据.结果表明:采前喷施钙+嘧菌酯处理可提高猕猴桃平均纵径、平均横径、单果质量及单果体积,显著提高猕猴桃果实可溶性固形物、叶绿素、可溶性蛋白质含量,同时减缓猕猴桃果实硬度下降速率,有效延缓猕猴桃果实软化,延迟其货架期.采前喷施钙+嘧菌酯处理对猕猴桃软腐病均具有良好的防控效果,贮藏10 d后,对照平均发病率达57.80％,处理组平均病果率均低于对照,差异极显著;防效最好的为处理B,达67.24％.综合试验结果表明采前喷施钙+嘧菌酯可有效改善猕猴桃果实品质,延长货架期,同时还可有效防治猕猴桃软腐病.

Alternaria alternata is the main pathogenic species of various crops, including kiwifruit (Actinidia cinensis). In this study, an antagonistic fungus, J-1, with high antifungal activity against A. alternata was isolated from A. cinensis “Hongyang.” The strain J-1 was identified as Fusicolla violacea via morphological identification and DNA sequencing. This study aimed to evaluate the antifungal activity and potential mechanism of the strain J-1 against A. alternata. The strain J-1 exhibited antifungal activity against A. alternata, with an inhibition rate of 66.1% in vitro. Aseptic filtrate (AF) produced by the strain J-1 could suppress the mycelial growth and conidia germination of A. alternata at the inhibition rates of 66.8% and 80%, respectively, as well as suppress the spread of Alternaria rot in fresh kiwifruit. We observed that many clusters of spherical protrusions appeared at the mycelial tips of A. alternata after treatment with 200 mL L−1 AF of J-1. Scanning electron microscopy analysis results showed that the mycelial structures were bent and/or malformed and the surfaces were rough and protuberant. Variations in temperature, pH, and storage time had little effect on the antifungal activity of the AF. Moreover, the AF could damage the integrity of cell membranes and cause intracellular content leakage. Meanwhile, the chitinase and β-1,3-glucanase enzyme activities increased significantly, indicating that the function of A. alternata cell wall was seriously injured. Eleven antimicrobial metabolites were identified by gas chromatography–mass spectrometry (GC–MS). The strain J-I and its AF exhibited well broad-spectrum antifungal activity against Diaporthe eres, Epicoccum sorghinum, Fusarium graminearum, Phomopsis sp., and Botryosphaeria dothidea, with inhibition rates ranging from 34.4% to 75.1% and 42.7% to 75.2%, respectively. Fusicolla violacea J-1 is a potential biocontrol agent against A. alternata and other fungal phytopathogens.

为筛选出防治猕猴桃软腐病的有效药剂及药剂组合,采用菌丝生长速率法测定了不同杀菌剂以及效果较好产品组合对猕猴桃葡萄座腔菌的室内毒力,并对增效作用较强的复配组合进行田间防效验证.室内毒力测定结果表明:11种杀菌剂中对葡萄座腔菌抑制效果最好的为戊唑醇,其EC50为0.87 mg/L;戊唑醇和氨基寡糖素质量比为1:1、1:2、1:3、1:4、1:5、1:9、1:10组合均有增效作用,其中以配比1:1的增效作用最为显著,对葡萄座腔菌的EC50为0.12 mg/L,CTC达931.99.田间试验结果表明,戊唑醇和氨基寡糖素以质量比1:1混配对猕猴桃软腐病有较好的防治效果,较高施用浓度处理的病果率仅为6.48％,防效达87.90％;中、低浓度防效也在78％以上,显著高于对应的2个单剂处理,且戊唑醇和氨基寡糖素复配可促进猕猴桃果实外观品质的形成,提高产量.说明戊唑醇与氨基寡糖素复配能有效防治猕猴桃软腐病,改善外观品质,提高产量,可用于猕猴桃软腐病的田间防治.

[目的]为筛选猕猴桃叶斑病的防治药剂.[方法]采用菌丝生长速率法测定11种药剂对可可毛色二孢菌的室内生物活性,筛选6种抑菌效果较好的药剂进行田间药效试验.[结果]29％吡萘·嘧菌酯SC、36％喹啉·戊唑醇SC对该菌的抑制效果最强,EC50值分别为0.1826、0.6338 mg/L,田间防效分别为78.88％、77.94％,同时提高猕猴桃单果质量.[结论]29％吡萘·嘧菌酯SC和36％喹啉·戊唑醇SC可以作为有效药剂开展猕猴桃叶斑病的防治.

[目的]明确猕猴桃花腐病的致病病原及其防控药剂.[方法]从贵长猕猴桃发病花蕾中分离获得病原菌,通过致病性测定、形态学观察、生物学特性测定,以及16SrDNA、rpoD)、gyrB、gltA和dnaA基因联合分析鉴定,同时测定11种杀菌剂和组合药剂对该病原菌的抑制效果.[结果]从病样中分离获得的菌株G-2为猕猴桃花腐病病原,根据形态学观察、生理生化检测及分子鉴定将其鉴定为绿黄假单胞菌Pseudomonas viridiflava;毒力测定结果显示,供试11种药剂中四霉素对该病原菌的抑菌活性最高,EC50为1.24 mg`kg-1,其次为丙硫唑,EC50为9.62 mg·kg-1;四霉素与丙硫唑以有效质量比4∶1、3∶1时,共毒系数(co-toxicity coefficient,CTC)分别为272.70、129.86,具有增效作用.[结论]猕猴桃花腐病的病原菌为绿黄假单胞菌Pseudomonas viridiflava,对四霉素和丙硫唑及组合药剂均有敏感性.

为山地猕猴桃产业健康发展提供参考,分析了贵州省六盘水市水城区山地猕猴桃产地环境条件及土壤养分、山地建园方式、管护现状及存在的问题,从科学建园、修枝整形等方面提出山地猕猴桃种植建议.

以猕猴桃叶斑病典型症状叶片为试材,采用组织分离法分离、纯化并结合回接试验确定病原菌,结合形态学和分子生物学对病原菌进行鉴定,并通过不同培养条件对该病原菌的生物学特性进行探究,以期为该病害发生规律的探究和综合防治措施的制定提供参考依据.结果 表明:引起猕猴桃叶斑病致病病原为可可毛色二孢菌(L.theobromae);该病原菌在10～35℃内均能生长,最适温度为28℃,最适pH为5,光照条件为连续光照,适宜的碳、氮源分别为可溶性淀粉和酵母膏.

为有效防控'红阳'猕猴桃受褐斑病的危害,采用传统的组织块分离方法对发病叶片进行了病原菌分离纯化,并对病原菌开展了致病性测试、形态特征观察、多基因序列分析及系统发育树构建,明确分离获得的菌株为细极链格孢(Alternaria tenuissima).采用菌丝生长速率法测定6种药剂对病原菌的抑菌效果,结果发现,咪鲜胺和苯醚甲环唑抑菌活性最强,EC50分别为0.008 4、0.055 3 mg/L,可用于田间防治由链格孢菌引起的褐斑病.

红阳猕猴桃是猕猴桃品种中的红肉猕猴桃,其营养价值高,经济效益好,受到广大消费者和果农的青睐.随着种植的推广,红阳猕猴桃的种植技术也显著提高,从种植选址、苗木培植、棚架搭建到施肥授粉、疏花疏果、病虫害防治,都需要果农倾心浇筑.为加强果农对红阳猕猴桃的了解,结合红阳猕猴桃的特点和栽培技术进行阐述,以期得到更广泛的推广和运用.

猕猴桃是贵州精品水果产业发展的主要树种之一,通过对贵州山地猕猴桃产业发展现状分析,分析标准体系的构建、优良品种示范与推广、着力推进绿色发展、应用"大数据+猕猴桃"技术、示范采后贮藏与商品化处理技术等技术措施,总结应用与推广成效,剖析不同推广模式,为全省水果产业发展提供参考.

农药作为重要的农业生产资料,在防治农作物病虫草鼠害、保证农业持续发展方面起了举足轻重的作用.我国是个农业大国,每年平均发生病虫草害约27-28亿亩次,施用农药的防治面积为23亿亩次左右,挽回粮食损失200-300亿公斤.过去10年来粮食单产增加了3倍,到2040年粮食单产还要增加3倍才能满足全球日益增加的人口的需要,为达此目标,农药的作用功不可没.可以说,没有农药就没有农业生产的持续健康发展.

一、加入WTO对我省农药产业的影响 研究WTO与山东农药产业,必须从市场出发,落脚于市场,从变化的市场中分析把握加入WTO对山东农药消费、生产、销售以及政府监管的影响,进而及时采取应对策略.