混配杀虫剂对烟蚜的毒力测定

选用氰戊菊酯乳油为底药,与其它3种药剂分别按有效成份进行不同比例的混配,测定其对烟蚜的毒力差异.实验结果表明:氰戊菊酯乳油与辛硫磷乳油按3:2进行混配时,其共毒系数最大,为825.96;其次是按1:1进行混配时,其共毒系数为462.45;最小的为2:3进行混配时,其共毒系数为244.62.氰戊菊酯乳油与灭多威乳油按1:1进行混配时,其共毒系数最大,为367.09;其次是按3:2进行混配时,其共毒系数为297.08;最小的为2:3进行混配时,其共毒系数为157.32.氰戊菊酯乳油与吡虫啉按2:3进行混配时,其共毒系数最大,为1558.28;其次是3:2进行混配时,其共毒系数为603.01;最小的为1:1进行混配时,其共毒系数为326.13.各个配比的共毒系数均大于100,均表现出增效作用.     

白菜叶片挥发成分多样性及对黑斑病菌孢子萌发的影响

本文选取对白菜黑斑病具有不同抗性的白菜品种甜脆绿、瓢儿白、83-1和优早四号,采用GC-MS联用技术对白菜叶面漂洗物的挥发性化学成分进行分析,并用孢子悬滴培养法测定白菜叶面漂洗物对白菜黑斑病菌孢子萌发的影响.结果表明:当叶面漂洗物浓度＞10 μL时,四种白菜叶面漂洗物对病原菌抑制活性的顺序为:瓢儿白＞甜脆绿＞优早四号＞ 83-1,且各品种漂洗物对黑斑病菌孢子萌发的抑制率存在显著差异.甜脆绿漂洗物中含量最高的挥发性化学成分为2,2,4,6,6-五甲基庚烷(17.15％),瓢儿白、83-1和优早四号漂洗物中含量最高的挥发性化学成分为反-3-己烯醇(15.76％、10.87％、7.21％).根据本实验结果发现,2,2,4,6,6-五甲基庚烷、反-3-己烯醇及仅在感病品种83-1漂洗物中检测到的2,4,6,8-四甲基十一烯和2,4,6-ritert-butyl-4-methyl-2,5-cyclo-hexa-dien-1-one可能与黑斑病菌孢子萌发有关.     

八种常用农药与蜡蚧轮枝菌JMC-01的相容性及对烟粉虱若虫的毒力测定

【目的】为明确8种常用农药与蜡蚧轮枝菌的相容性及对烟粉虱Bemisiatabaci若虫的毒力。【方法】该试验采用涂板法和浸渍法分别测定了8种常用农药对蜡蚧轮枝菌菌丝生长、孢子萌发和产孢量以及对烟粉虱若虫的LC50和共毒系数。【结果】结果表明,随着农药稀释倍数的增加,蜡蚧轮枝菌菌丝生长抑制率、孢子萌发抑制率和产孢抑制率依次降低。其中,生物源农药乙基多杀菌素、藜芦碱、印楝素与蜡蚧轮枝菌的相容性和协同增效作用最好。乙基多杀菌素、藜芦碱、印楝素在10倍稀释浓度下,孢子萌发抑制率分别为20.02%、16.41%、15.38%;产孢抑制率分别为17.77%、15.90%、14.96%;菌丝生长抑制率分别为9.96%、8.87%、9.74%。蜡蚧轮枝菌与印楝素、藜芦碱混合后协同增效作用最好,CTC最大值分别为315和302。【结论】因此,应用蜡蚧轮枝菌防治烟粉虱,选择相容性好、共毒系数高的农药以低剂量与蜡蚧轮枝菌复配使用,可以大幅度减少农药的用量,对温室大棚烟粉虱的生物防治提供参考依据。     

丁布对小麦赤霉病菌和玉米小斑病菌的抑制作用

采用菌丝生长速率法和孢子萌发试验法检测了抗菌化合物丁布对小麦赤霉病菌和玉米小斑病菌的抑菌作用。结果表明,丁布在PDA培养基中浓度为0.2-1.0 mg/ml时对两种供试病菌的菌丝生长无抑制作用;丁布浓度为0.4-1.0 mg/ml时对两种供试病菌孢子悬浮液中孢子的萌发具有显著抑制作用;1.0 mg/ml丁布药液中培育15h的小麦赤霉病菌和培育5h的玉米小斑病菌的孢子萌发抑制率分别达到100%和83.6%。     

强力安对食用菌生产中杂菌的毒力测定

试验利用滤纸片、管碟抑菌圈法测定了强力安杀菌剂对木霉TrichodermaviridePers.exFr、链孢霉MoniliasitophilaMont等食用菌生产上的杂菌的毒力,结果表明强力安具有明显的抑菌、杀菌作用。试验还测定了强力安对食用菌的作用,结果表明强力安对平菇Pleurotusostreatus(JacexFr)Quel、金针菇Flammulinavelutipes（Fr）Sing具抑制力,而对黑木耳Auriculariaauricula(l.exHook)Underw、香菇Lentinulaedodes(Berk)Pegler则未发现抑制作用。根据强力安对供试菌的最低抑制浓度,作者提出了生产实际上的用药浓度,以供参考。     

几种杀菌剂对黄瓜疫霉菌的毒力测定

采用菌丝生长速率法检测60%嘧菌酯悬浮剂、80%代森锰锌可湿性粉剂、75%百菌清可湿性粉剂、60%唑醚·代森联水分散粒剂、2%蛇床子素微乳剂、64%杀毒矾可湿性粉剂等6种杀菌剂对黄瓜疫霉菌的室内毒力。结果表明,唑醚·代森联和蛇床子素对黄瓜疫霉菌的毒力最高,EC50值分别为3.4143 mg·L-1和10.4641 mg·L-1。将两种原药混配后,表现出增效作用,在两者混配比为1∶2时增效最明显,EC50值为5.8178 mg·L-1。     

绿僵菌与白僵菌对黑翅土白蚁的室内毒力测定

白蚁是世界性的主要害虫之一,世界各大洲都有分布,其为害面积约占全球总面积的50％,尤其在热带、亚热带地区,白蚁为害更为突出(李桂祥等,1989)。福建省的白蚁种类之多位居全国第三。     

7种杀虫剂对烟蚜的毒力测定

烟蚜是危害烟草的主要害虫之一,为寻找防治烟蚜的高效低毒药剂,本文采用浸叶法和浸渍法比较了藜芦碱、吡虫啉、啶虫脒、噻虫嗪、吡蚜酮、除虫菊素和双丙环虫酯7种药剂对烟蚜的毒力.结果表明,浸叶法处理后,噻虫嗪和吡虫啉对烟蚜的毒力较高,LC₅₀值分别为2.220 mg/L和2.619 mg/L;而浸渍法处理后吡虫啉和藜芦碱对烟蚜的毒力较高,LC₅₀值分别为1.203 mg/L和2.554 mg/L.吡虫啉在两种不同处理方法的试验中都显示对烟蚜有较高毒力,可以作为防治田间烟蚜的推荐使用药剂,在吡虫啉被限制使用的情况下,可选用噻虫嗪或藜芦碱防治烟蚜。研究结果可为烟蚜的有效防治提供科学的参考依据.     

阿维灭幼脲对马尾松毛虫幼虫的毒力测定

运用阿维灭幼脲生物复合剂对3-4龄的马尾松毛虫幼虫进行毒力测定,用机率分析法求得马尾松毛虫的死亡率与阿维灭幼脲剂量对数—机率直线,建立毒力回归线。研究表明,25%阿维灭幼脲悬浮剂对3-4龄幼虫的致死中稀释浓度为49.6倍液,即LC50=5.04 mg.L-1;阿维灭幼脲悬浮剂与尿素混合剂对3-4龄的致死中稀释浓度为52.5倍液,即LC50=4.76 mg.L-1;25%阿维灭幼脲悬浮剂10倍稀释液对3-4龄马尾松毛虫幼虫的LT50为0.57 d,到50倍稀释液时LT50为7.35 d;25%阿维灭幼脲悬浮剂与尿素混合剂10倍稀释液对3-4龄马尾松毛虫幼虫的LT50为0.71 d,到50倍稀释液时LT为6.13 d,随着浓度稀释倍数的增加,致死中时间延长。研究结果可为今后马尾松毛虫的林间防治提供科学依据。     

室内测定6种化学杀虫剂对草地贪夜蛾幼虫的毒力

2019年草地贪夜蛾Spodoptera frugiperda入侵我国多个省份和地区,对我国农业生产造成重大影响。化学防治是应对入侵害虫的主要措施,因此,本研究测定了6种不同作用机制杀虫剂对草地贪夜蛾初孵和3龄幼虫的生物活性。结果表明,对初孵幼虫具有较高毒力作用的为氯虫苯甲酰胺、多杀菌素、茚虫威、阿维菌素和甲氧虫酰肼;对3龄幼虫具有较高毒力作用的为氯虫苯甲酰胺、多杀菌素和茚虫威;与初孵幼虫相比,阿维菌素、茚虫威、多杀菌素和甲氧虫酰肼的LC 50分别提高了78.06、1.70、11.73和23.09倍。本研究筛选出了对草地贪夜蛾初孵幼虫和3龄幼虫杀虫效果较好的药剂,证明了低龄幼虫对部分农药抵抗力较弱,而3龄后的幼虫抵抗力显著增加,为田间草地贪夜蛾的化学防治提供了科学的用药指导。     

First Report of Alternaria Leaf Spot on Gerbera (Gerbera jamesonii H. Bolux ex J. D. Hook) in Bulgaria

Alternaria leaf spots of gerbera (Gerbera jamesonii H. Bolus ex J. D. Hook) were observed on plants from different greenhouses on commercial plants in Bulgaria. The symptoms of the disease on the leaves were characterized by the development of brown, small, scattered dots, which gradually enlarged and coalesced to form large, oval, circular or irregular, brown to black lesions with concentric rings. Affected plants showed lower vitality, suppressed development and fewer, smaller, distorted in shape flowers. Alternaria isolates, obtained from infected leaf tissues were grown in pure culture and the morphological characteristics of the colony and sporulation apparatus were determined. DNA, extracted from the fungal isolates was subjected to polymerase chain reaction (PCR) with primers ITS1/ITS4, amplifying the internal transcribed spacer (ITS) regions. The resulting products were sequenced and compared for homology with other species in the GeneBank. The isolates showed 94% homology of the ITS region with either Alternaria alternata, A. arborescens, A. tenuissima, A. longipes, A. lini or A. smyrnii. None of the studied isolates was amplified with the A. alternata specific primers AAF2/AAR3, indicating that they are pathogenic varieties of it or belong to another species. Pathogenicity tests on 10 gerbera cultivars revealed that all of them were susceptible to Alternaria leaf spot. Additional tests on nine other crops (Solanum lycopersicum, Calendula officinalis, Capsicum annuum, Celosia argantea, Pelargonium spp., Petunia hybrida, Nicotiana tabacum, Cucurbita moscata and Raphanus sativus var. radicina) and on tomato or pepper fruits, potato tubers and carrot roots also indicated that all tested plant species were potential hosts of the disease. This is the first report of highly virulent isolates of Alternaria spp. in Bulgaria that cause leaf spots on gerbera in greenhouses.     

不同老化程度的不结球白菜种子活力指标变化及其相关分析

以不结球白菜品种‘高梗白’种子为材料,采用高温(42℃)高湿(相对湿度100%)人工加速老化处理,研究不同老化程度下种子活力指标的变化及其相关性。结果显示:(1)发芽指标(除不正常苗率)和出苗指标均随种子老化程度的加深而显著下降,不正常苗率显著上升。(2)随老化程度的加深,种子中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性显著下降;种子的超氧阴离子(O2.-)产生速率先增高后降低,过氧化氢(H2O2)含量逐渐增加,丙二醛(MDA)含量下降,种子浸出液相对电导率升高;种子的可溶性糖含量、可溶性蛋白含量和脱氢酶活性下降,α-淀粉酶活性先升高后降低。(3)老化种子的发芽势、发芽率、SOD活性、H2O2含量、相对电导率和可溶性糖含量与出苗指标间均存在极显著相关性。研究表明,不结球白菜种子的发芽势、发芽率、SOD活性、H2O2含量和可溶性糖含量随老化程度加深的变化规律一致,且指标间以及与出苗指标均有极显著相关性,可以作为检验不结球白菜种子活力的候选指标。     

大白菜相对于结球甘蓝连锁群特异SSR标记的筛选

以9个大白菜品种和10个结球甘蓝品种为试材,对位于芸薹属A基因组10个连锁群的207对SSR引物进行PCR筛选,共筛选出33个大白菜相对于结球甘蓝的特异SSR标记,涉及了大白菜的10个连锁群,其中位于A1连锁群3对,A2连锁群4对,A3连锁群5对,A4连锁群2对,A5连锁群3对,A6连锁群4对,A7连锁群2对,A8连锁群1对,A9连锁群2对,A10连锁群7对。为进一步利用SSR标记鉴定结球甘蓝—大白菜异附加系奠定了基础。     

Production of phytotoxic spore germination liquids by Alternaria brassicae and A. brassicicola and their effect on species of the family Brassicaceae

Experiments assessed the susceptibility of Brassica spp. and non-Brassica spp. in the family Brassicaceae to infection by Alternaria brassicae and A. brassicicola, and determined the sensitivity of the host species to spore germination liquids (SGLs) produced by the pathogens on B. napus leaves. There was a wide range of sensitivity to the pathogens. Brassica spp. were generally more susceptible, and some non-Brassica spp. (Barbarea vulgaris and Capsella bursa-pastoris) were immune to A. brassicicola. Measurable damage was caused by SGLs but with significant variation between host species. Non-hosts and weak hosts also showed necrosis. It was concluded that, in the case of both pathogens, the toxic factors in these SGLs were host-selective. Selectivity in toxin production was also demonstrated in relation to the host surface or growing medium in which spores germinated. A substantial amount of toxin was produced on all Brassicaceae tested but not on unrelated species (Triticum aestivum, Pisum sativum and Lycopersicon esculentum). Neither pathogen produced measurable amounts of toxin when cultured in Czapek (Dox) broth.     

盐胁迫对不同品种小白菜种子萌发特性的影响

采用5个小白菜(Brassica chinensis)品种(‘七宝青’、‘夏冬青’、‘四月慢’、‘南京中杆’和‘605’),用100 mmol/L NaCl对种子发芽作盐胁迫处理,从发芽势、发芽率、发芽指数、盐害指数、胚长和胚鲜重等指标比较了5个小白菜品种的抗盐性。结果表明,‘七宝青’种子的耐盐性优于其它品种。     

Screening of chilli germplasm for resistance to Alternaria leaf spot disease

Chilli is one of the spices used to enhance the flavour and taste of cooked food. Fungal diseases are the main biological constraints in chilli production, and Alternaria leaf spot disease caused by Alternaria alternata is one of the most devastating diseases of chilli. One of the effective and environmentally friendly ways to control this disease is introgress resistance from wild relative/varieties to the cultivated one. The first step towards introgression of resistance genes is to screen the chill germplasm for leaf spot resistance. In the current study, we screened the chilly germplasm and identified the sources of leaf spot resistance, which can be harnessed in resistance breeding programmes.     

Establishment of seed-borne nature of Alternaria alternata causing leaf spot and fruit rot of chilli

Study on seed-borne nature of Alternaria alternata in chilli seeds indicated that in Standard blotter method, the incidence of A. alternata was 5.7–15.3% (average, 9.5%) and 16.5–28.4% (average, 21.7%) with unsterilsied seeds collected from general fields and diseased fields, respectively. The incidence for surface sterilised seeds from general and diseased fields was 2.6–7.2% (average, 4.9%) and 7.8–13.0% (average, 9.6%), respectively. In agar plate method with potato dextrose agar medium, the incidence of A. alternata was 4.0–10.5% (average, 7.4%) and 11.0–24.0% (average, 18%) with surface sterilised.     

玉米弯孢叶斑病菌的形态学分类与RAPD分析

对16个供试弯孢分离株根据其分生孢子的形态进行分类,其中12个为新月弯孢(Curvularia luna-ta),其余4个是画眉草弯孢(C.eragrostidis)。对这些分离株基因组DNA进行RAPD分析发现,一些分属于两种不同弯孢菌的分离株间比同种弯孢的分离株间具有更近的遗传距离,即具有更近的亲缘关系。因此,根据弯孢菌的形态分类和利用RAPD标记的分类结果存在不一致现象。     

Antifungal Activities of N-Arylbenzenesulfonamides against Phytopathogens and Control Efficacy on Wheat Leaf Rust and Cabbage Club Root Diseases

A set of N-arylbenzenesulfonamides with various substituents at the arylamine and benzenesulfonyl positions were prepared, and their antifungal properties were measured in vitro against such plant pathogenic fungi as Pythium ultimum, Phytophthora capsici, Rhizoctonia solani, and Botrytis cinerea. Compounds 3, 4, 8, 9, 10, 14, 16, 18, 20, 21, 24 and 27 had antifungal activity over a broad spectrum of the phytopathogenic fungi tested, where 50% of inhibition (ED₅₀) was in the range of 3-15 μg/ml. Based on the in vitro activity, six derivatives (3, 4, 10, 18, 21 and 27) were selected and tested further for their fungicidal efficacy in vivo. The fungicidal efficacy of 10, 21 and 27 had a disease control value of over 85% at 50 μg/ml against wheat leaf rust, while that of 4 was selective against cabbage club root disease.