Induced Resistance of Acibenzolar-S-methyl (CGA 245704) to Cucumber and Japanese Pear Diseases

Antifungal activity of the novel compound acibenzolar-S-methyl (CGA245704: benzo[1,2,3]thiadiazole-7-carbothioic acid S-methyl ester) was examined in vitro. No remarkable activity was observed on mycelial growth and conidial germination of almost all fungi tested. Only melon isolates of Didymella bryoniae were sensitive to this compound. On potted plants, acibenzolar-S-methyl showed control efficacy on anthracnose and scab of cucumber and rust of Japanese pear but not on Fusarium wilt of cucumber. In field trials, the occurrence of both rust and scab on Japanese pear was suppressed with this compound. Based on these experiments, it was suggested that acibenzolar-S-methyl induced resistance to some but not all diseases on cucumber and Japanese pear. Induction of disease resistance in cucumber was rapidly triggered after treatment with acibenzolar-S-methyl.     

哈茨木霉NF9菌株对水稻的诱导抗病性

在温室条件下用哈茨木霉NF9菌株进行种子处理，诱导水稻感病品种原丰早幼苗对稻-瘟病和白叶枯病的抗病性，其抗性水平为中抗，对稻瘟病菌不同菌株(SYl、H16)以及对白叶枯病菌不同菌株(CRl、CR7)的抗性表现无显著差异。经木霉种子处理的水稻幼苗接种稻瘟病菌或白叶枯病菌后，过氧化物酶及苯丙氨酸转氨酶活性增强，在某一时段显著高于未经木霉种子处理的对照。诱导抗性可能是哈茨木霉NF9菌株的生防机制之一。     

植物诱导抗病性与诱抗剂研究进展

以糖、蛋白和糖蛋白三大类生物源激发子为重要的植物诱抗剂,本文分析了植物诱抗剂作用于植物后所发生的一系列信号识别与信号传导过程及植物典型的防卫反应,为植物诱抗剂的研发和植物诱导抗病性分子机理的探讨提供参考。     

油菜核盘菌对戊唑醇的敏感性及室内抗药性诱导

为了探明油菜核盘菌对戊唑醇的敏感性,对68株油菜核盘菌的戊唑醇室内敏感性进行了试验.同时通过室内诱导获得抗药性突变株,并分析了突变株的菌丝生长速率、产菌核能力及戊唑醇靶标酶基因,为戊唑醇的应用及其抗药性风险评估提供基础数据.结果表明,2016年和2018年从安徽、湖南、湖北、四川采集的68株油菜核盘菌对戊唑醇的EC50...     

落叶松毛虫对兴安落叶松6种挥发物的触角电位反应

利用触角电位技术(EAG)测定了落叶松毛虫未交尾雌蛾、已交尾雌蛾、未交尾雄蛾对R型α-蒎烯、S型α-蒎烯、罗勒烯、S型β-蒎烯、水芹烯、莰烯等6种兴安落叶松挥发物的触角电位反应.结果表明:不同生理状况的落叶松毛虫对6种挥发物的7个浓度的EAG反应中,除对0.1 μg·μL-1水芹烯的EAG反应值是未交尾雌虫＞已交尾雌虫＞未交尾雄虫外,对水芹烯的其它不同浓度以及其它挥发物的EAG反应值均是已交尾雌蛾＞未交尾雌蛾＞未交尾雄蛾.未交尾雌、雄蛾的EAG反应差异显著(P＜0.05),已交尾雌蛾与未交尾雌、雄蛾之间差异极显著(P＜0.01),表明已交尾雌蛾对寄主植物气味更为敏感.落叶松毛虫未交尾雌蛾、已交尾雌蛾、未交尾雄蛾对水芹烯的EAG反应均比较敏感.在暗周期内已交尾雌蛾与未交尾雄蛾的活跃期在20:00-4:00,与其羽化、交尾、产卵期一致.     

杨树Na+/H+反向运输蛋白基因(PtNHX1、PtNHX6)的克隆和检测

Na /H 反向运输蛋白基因(NHX)是在细菌、植物和动物体内普遍存在的一类膜蛋白基因家族.迄今已在模式植物拟南芥中分离出AtNHX1、AtNHX2、AtNHX3、 AtNHX4、 AtNHX5和 AtNHX6共6个成员,并发现部分成员对盐胁迫有不同程度的响应.以AtNHX1和AtNHX6的cDNA核苷酸序列为信息探针, 基于可利用的杨树EST数据库和毛果杨全基因组测序结果,通过电子杂交辅助的克隆技术,从毛白杨形成层cDNA中分离得到长度分别为1 635 bp和1 709 bp的2个cDNA,其分别含有编码544个和526个氨基酸残基的完整开放阅读框. 由它们所推导的蛋白质序列与拟南芥、水稻、小麦和玉米的NHX1和NHX6基因的蛋白质序列高度同源, 同源性分别为79%、76%、69%和74%以及82%、82%、27%和26%, 故将其命名为PtNHX1和PtNHX6(GenBank 注册号分别为AY660749和AY832912).Southern 杂交分析表明, PtNHX1和PtNHX6均为低拷贝基因(或有一些高度同源的基因),在杨树基因组中以1 ～ 4个拷贝形式存在.组织特异性RT-PCR结果显示, PtNHX1和PtNHX6基因在杨树根、茎和叶片中均有表达,但其表达模式稍有不同:PtNHX1在根部、形成层、未成熟木质部、成熟叶和嫩叶中均高度表达,在韧皮部和成熟木质部中有少量表达,而PtNHX6在根部、成熟叶和嫩叶中表达丰度较高,在韧皮部、形成层、未成熟木质部表达丰度较低,在成熟木质部中表达丰度极低.NaCl诱导的杨树叶片差异表达RT-PCR检测结果初步表明,PtNHX1和PtNHX6基因均受盐诱导表达,当溶液中NaCl浓度在100～400 mmol·L-1内,随着盐浓度的提高,PtNHX1和PtNHX6基因的表达丰度逐渐增强,但超过400 mmol·L-1后,其表达丰度均有所降低,这与所测定的叶片ABA含量匹配.     

柑橘溃疡病抗性SNP验证及其相关钙依赖性蛋白激酶基因诱导表达

【目的】前期根据转录组数据挖掘柑橘单核苷酸多态性(single nucleotide polymorphism,SNP)位点,通过关联分析获得14个与柑橘溃疡病耐/感性关联的SNP。以此为基础,本研究利用柑橘杂交群体验证这些位点与柑橘溃疡耐/感性的相关性,以期获得显著相关的SNP,并对其相关的基因进行柑橘溃疡病菌(Xanthomonas citri subsp. citri,Xcc)和植物激素诱导表达分析。【方法】以抗病和敏感柑橘品种及其杂交F1代群体共143个材料为试材,采用离体叶片针刺接种法进行溃疡病抗性鉴定;利用高分辨率熔解曲线(high resolution melting,HRM)技术,对F1群体进行SNP分型;使用DPS软件对F1群体的溃疡病耐/感性表型和SNP基因型进行相关分析;实时荧光定量PCR(quantitative real-time PCR,qRT-PCR)分析其中一个SNP相关的柑橘钙依赖性蛋白激酶基因(calcium-dependent protein kinase gene,CDPK)的诱导表达模式。【结果】供试杂交F1代群体的病斑面积在0.75—3.29...     

Preovulatory serum estradiol concentration is positively associated with oocyte ATP and follicular fluid metabolite abundance in lactating beef cattle

Cattle induced to ovulate a small, physiologically immature preovulatory follicle had reduced oocyte developmental competence that resulted in decreased embryo cleavage and day 7 embryo quality compared with animals induced to ovulate a more advanced follicle. RNA-sequencing was performed on oocytes and their corresponding cumulus cells approximately 23 h after gonadotropin-releasing hormone (GnRH) administration to induce the preovulatory gonadotropin surge suggested reduced capacity for glucose metabolism and oxidative phosphorylation in the cumulus cells and oocytes from follicles ≤11.7 mm, respectively. We hypothesized that induced ovulation of a small, physiologically immature preovulatory follicle results in a suboptimal follicular microenvironment and reduced oocyte metabolic capacity. We performed a study with the objective to determine the impact of preovulatory follicle diameter and serum estradiol concentration at GnRH administration on oocyte metabolic competence and follicular fluid metabolome profiles. We synchronized the development of a preovulatory follicle and collected the follicle contents via transvaginal aspiration approximately 19 h after GnRH administration in lactating beef cows (n = 319). We determined ATP levels and mitochondrial DNA (mtDNA) copy number in 110 oocytes and performed ultra-high-performance liquid chromatography–high resolution mass spectrometry metabolomic studies on 45 follicular fluid samples. Intraoocyte ATP and the amount of ATP produced per mtDNA copy number were associated with serum estradiol concentration at GnRH and time from GnRH administration to follicle aspiration (P < 0.05). mtDNA copy number was not related to follicle diameter at GnRH, serum estradiol concentration at GnRH, or any potential covariates (P > 0.10). We detected 90 metabolites in the aspirated follicular fluid. We identified 22 metabolites associated with serum estradiol concentration at GnRH and 63 metabolites associated with follicular fluid progesterone concentration at the time of follicle aspiration (FDR < 0.10). Pathway enrichment analysis of significant metabolites suggested altered proteinogenesis, citric acid cycle, and pyrimidine metabolism in follicles of reduced estrogenic capacity pre-gonadotropin surge or reduced progesterone production by the time of follicle aspiration.     

植物抗虫生理研究进展

害虫是严重影响农作物产量和品质的重要因素.深入研究植物与害虫间的相互作用,可为从业者探索农业生产中适用的抗虫措施提供理论参考.在对相关文献分析总结的基础上,从植物对害虫为害所采取的防御机制以及昆虫为适应植物防御反应采取的特定措施两个方面进行分析,综述了植物抗虫生理的研究现状:(1)植物可通过体内营养物质含量的变化降低对...     

非饱和砂质黏性紫色土崩解特性及MICP加固试验

砂质黏性紫色土遇水极易崩解是导致西南山区土壤侵蚀流失等水土灾害的重要原因,为揭示其崩解规律和机制,改善土体的崩解性,采用自制崩解测量仪对不同初始干密度、含水率及颗粒级配条件下的紫色土进行浸水崩解试验,并从非饱和有效应力角度分析了其崩解演化机制,在此基础上,通过扫描电镜（Scanning Electron Microscope,SEM）探讨利用微生物诱导碳酸钙沉积（Microbial Induced Calcite Precipitation,MICP）加固技术对紫色土崩解性的改善效果。结果表明：1）紫色土浸水崩解全过程包含排气吸水期、平衡期、崩解发展期、崩解残余期4个阶段;2）崩解率与平均崩解速率随初始干密度及含水率的增大而减小,且细颗粒含量越高,平均崩解速率越大;3）紫色土浸水后非饱和有效应力的衰减过程受初始饱和度的影响较大,平均崩解速率随初始饱和度的增大呈指数函数衰减;4）MICP加固土的崩解率和平均崩解速率相较于素土分别下降了73～97个百分点和84%～99%,固化沉积的碳酸钙晶体使土体结构中的微裂隙与大孔隙大幅减少,形成较为致密的孔隙结构,大幅增强了粒间胶结强度,使土体抗崩解性能明显提升。MICP技术可以作为西南山区紫色土水土灾害防治的有效措施。