20%噻森铜悬浮剂防治水稻白叶枯病田间试验

介绍了20%噻森铜悬浮剂对水稻白叶枯病的田间防效。田间试验表明,20%噻森铜悬浮剂对水稻白叶枯病具有良好的防效。在发病初期,使用20%噻森铜悬浮剂300～500倍液,连续用药3次,防效可达约80%。20%噻森铜悬浮剂是防治水稻白叶枯菌的良好药剂。     

新颖杀菌剂——噻森铜

噻森铜是浙江东风化工有限公司开发的防治植物真菌和细菌性病害的新颖杀菌剂,并已获取中国发明专利(专利号ZL00132657.0)。其可防治水稻细菌性条斑病、水稻白叶枯病、大白菜软腐病及番茄青枯病等20余种作物60多种病害,且其内吸性强,具有预防和治疗作用。     

TCCA防治水稻细菌性条斑病

水稻细菌性条斑病是国内植物检疫对象。近年来,该病已上升为中南地区水稻的主要病害。其对产量的影响较大,一般减产10～20%,严重影响了中南地区水稻生产的发展。1986年～1988年,我们利用TCCA(三氯异氰脲酸”、又名“强氯精”)进行了病种处理试验,取得了良好的防治效果。一、材料与方法1.药剂消毒效果测试1986年我们进行了室内病种消毒效果试验。供试药剂为85%TCCA(南宁化工厂)可湿性粉剂。试验设10个处理,分别为水 TCCA500倍(水浸12小时,再用TCCA500倍     

创制农药噻唑锌对水稻细菌性病害的田间药效

噻唑锌是噻二唑类有机锌杀菌剂,对水稻细菌性病害有较好的防治效果。两次药后14d调查结果表明,对水稻白叶枯病,20％噻唑锌SC225—375g a．i．／hm^2防治效果均极显著高于20％叶枯唑WP300g a．i．/hm^2的防治效果;对水稻细菌性条斑病,20％噻唑锌SC 300～375g a．i．／hm^2防治效果极显著高于20％叶枯唑WP 300g a．i．／hm^2的防治效果,225g a．i．／hm^2防治效果与20％叶枯唑WP 300g a．i．／hm^2的防治效果相当。生产上使用20％噻唑锌SC,推荐剂量为225-375g a．i．／hm^2,间隔7d左右,连续施药两次,对水稻白叶枯病、水稻细菌性条斑病均有较好的防治效果。     

新杀菌剂杀枯肽和叶枯宁防治水稻细菌性条斑病的效果

通过室内离体测定和盆栽稻株上的防病效果试验结果表明,新杀菌剂枯肽和叶枯宁两种药剂是防治水稻细菌性条斑颊的安全,高效药剂,在喷药接菌后１３天,５００ｐｐｍ浓度的防病效果为１００％,到２０天时杀枯肽还有４５．６５％的防病效果,喷药后观察对水稻安全无药害。同时指出离体测定的抑菌效果和稻株上的防病效果不一致,因此,筛选防治水稻细菌性条斑病的药效测定方法应以盆栽稻株测定为主。     

30%壬菌铜微乳剂防治水稻白叶枯病药效试验

[目的]验证30%壬菌铜微乳剂对水稻白叶枯病的田间应用效果,确定最佳使用量和使用方法,为大田推广提供理论依据。[方法]按照田间药效试验方法比较30%壬菌铜微乳剂3种处理和对照药剂的防治效果。[结果]30%壬菌铜微乳剂405 g a.i./hm2处理对水稻白叶枯病的防治效果可达84%以上,田间推荐用量337.5~405 g a.i./hm2。[结论]30%壬菌铜微乳剂在水稻白叶枯病田间防治上可以推广使用。     

10%溃枯宁防治水稻白叶枯病试验示范

宜良是云南省的水稻高产县,也是水稻白叶枯病常发重发区。,笔者于１９９４年和１９９８年对１０％溃枯宁可湿性粉剂进行了田间药效试验和示范,获得好的防效,结果如下：１　试验材料及方法１１　试验药剂１０％溃枯宁可湿性粉剂（主要成分：硫酸链霉素,河南新霸王化工有限公司）;２０％叶枯宁（川化０１８）可湿性粉剂（四川省化工研究院）１２　试验设计试验在本县南羊镇右所办事处左所村进行。１９９４年进行小区试验,试验设每６６７ｍ２用１０％溃枯宁１００、５０、３３．３ｇ和对照药剂２０％叶枯宁１００ｇ,空白对照,共五…     

靠山、施稻灵防治水稻细菌性病害

我市是水稻白叶枯病和水稻细菌性条斑病的常发地区 ,为了明确靠山、施稻灵对这二种病害的防治效果 ,1997年我们在晚稻上进行了药效试验 ,现将结果报道如下。1　材料与方法1.1　供试药剂56 %靠山水分散粒剂 (有效成分 :氧化亚铜 ,诺华农化 (中国 )有限公司生产 ) ,用量分别为 12 .5ｇ、16 .7ｇ、2 5.0 ｇ、33.3ｇ、50 .0 ｇ、10 0 .0ｇ/ 6 6 7ｍ2 。12 %施稻灵悬浮剂 (有效成分 :丙硫多菌灵 多菌灵 ,贵州道元科技公司研制 ) ,用量分别为 2 5.0 ｇ、33.3ｇ、50 .0ｇ、6 6 .7ｇ/ 6 6 7ｍ2 。2 5%叶青双可湿性粉剂 (浙江温州农药厂生产 ) ,用量…     

抗性诱导型杀菌剂噻酰菌胺(tiadinil)的开发沿革

噻酰菌胺系日本农药公司新开发的抗性诱导型新颖杀菌剂(图1)。从化学结构看,它兼具杂环和苯酰胺结构。其持效期长,在移栽当天于育苗箱使用后可维持80d以上的防治效果。同时,其亦可在水田使用,同样显示了良好的速效和持效性。此外,由于该药剂具有抗病激活的作用机理,故认为发生抗性的风险较低。除了水稻稻病外,此药对水稻白叶枯病、细菌性谷枯病等细菌病害均有效。     

Identification of a Chitooligosaccharide Mechanism against Bacterial Leaf Blight on Rice by In Vitro and In Silico Studies

This study focuses on a commercial plant elicitor based on chitooligosaccharides (BIG^®), which aids in rice plant growth and disease resistance to bacterial leaf blight (BLB). When the pathogen (Xoo) vigorously attacks rice that has suffered yield losses, it can cause damage in up to 20% of the plant. Furthermore, Xoo is a seed-borne pathogen that can survive in rice seeds for an extended period. In this study, when rice seeds were soaked and sprayed with BIG^®, there was a significant increase in shoot and root length, as well as plant biomass. Furthermore, BIG^®-treated rice plants showed a significant reduction in BLB severity of more than 33%. Synchrotron radiation-based Fourier transform infrared (SR-FTIR) analysis was used to characterize BIG^®’s mechanism in the chemical structure of rice leaves. The SR-FTIR results at 1650, 1735, and 1114 cm⁻¹ indicated changes in biochemical components such as pectins, lignins, proteins, and celluloses. These findings demonstrated that commercial BIG^® not only increased rice growth but also induced resistance to BLB. The drug’s target enzyme, Xoo 1075 from Xanthomonas oryzae (PDB ID: 5CY8), was analyzed for its interactions with polymer ingredients, specifically chitooligosaccharides, to gain molecular insights down to the atomic level. The results are intriguing, with a strong binding of the chitooligosaccharide polymer with the drug target, revealing 10 hydrogen bonds between the protein and polymer. Overall, the computational analysis supported the experimentally demonstrated strong binding of chitooligosaccharides to the drug target.     

Flavonone 3-hydroxylase Relieves Bacterial Leaf Blight Stress in Rice via Overaccumulation of Antioxidant Flavonoids and Induction of Defense Genes and Hormones

Efficient accumulation of flavonoids is important for increased tolerance to biotic stress. Although several plant defense mechanisms are known, the roles of many pathways, proteins, and secondary metabolites in stress tolerance are unknown. We generated a flavanone 3-hydroxylase (F3H) overexpressor rice line and inoculated Xanthomonas Oryzae pv. oryzae and compared the control and wildtype inoculated plants. In addition to promoting plant growth and developmental maintenance, the overexpression of F3H increased the accumulation of flavonoids and increased tolerance to bacterial leaf blight (BLB) stress. Moreover, leaf lesion length was higher in the infected wildtype plants compared with infected transgenics. Kaempferol and quercetin, which scavenge reactive oxygen species, overaccumulated in transgenic lines compared with wildtypes in response to pathogenic infection, detected by scanning electron microscopy and spectrophotometry. The induction of F3H altered the antioxidant system and reduced the levels of glutathione peroxidase activity and malondialdehyde (MDA) contents in the transgenic lines compared with the wildtypes. Downstream gene regulation analysis showed that the expression of F3H increased the regulation of flavonol synthase (FLS), dihydroflavonol 4-reductase (DFR), and slender rice mutant (SLR1) during BLB stress. The analysis of SA and JA signaling revealed an antagonistic interaction between both hormones and that F3H induction significantly promoted SA and inhibited JA accumulation in the transgenic lines. SA-dependent nonexpressor pathogenesis-related (NPR1) and Xa1 showed significant upregulation in the infected transgenic lines compared with the infected control and wildtype lines. Thus, the overexpression of F3H was essential for increasing BLB stress tolerance.     

Whole Genome Sequencing and Tn5-Insertion Mutagenesis of Pseudomonas taiwanensis CMS to Probe Its Antagonistic Activity Against Rice Bacterial Blight Disease

The Gram-negative bacterium Pseudomonas taiwanensis is a novel bacterium that uses shrimp shell waste as its sole sources of carbon and nitrogen. It is a versatile bacterium with potential for use in biological control, with activities including toxicity toward insects, fungi, and the rice pathogen Xanthomonas oryzae pv.oryzae (Xoo). In this study, the complete 5.08-Mb genome sequence of P. taiwanensis CMS was determined by a combination of NGS/Sanger sequencing and optical mapping. Comparison of optical maps of seven Pseudomonas species showed that P. taiwanensis is most closely related to P. putida KT 2400. We screened a total of 11,646 individual Tn5-transponson tagged strains to identify genes that are involved in the production and regulation of the iron-chelator pyoverdine in P. taiwanensis, which is a key anti-Xoo factor. Our results indicated that the two-component system (TCS) EnvZ/OmpR plays a positive regulatory role in the production of pyoverdine, whereas the sigma factor RpoS functions as a repressor. The knowledge of the molecular basis of the regulation of pyoverdine by P. taiwanensis provided herein will be useful for its development for use in biological control, including as an anti-Xoo agent.     

水稻叶鞘腐败病的药剂防治试验

１材料与方法1.1 供试药剂 Ａ．５０％多菌灵可湿性粉剂（国营江阴农药厂）; Ｂ.５０％雷多米尔可湿性粉剂（有效成分：甲霜灵,瑞士汽巴一嘉基有限公司）;Ｃ．６５％代森锌可湿性粉剂（成都市双流县农药厂）; Ｄ．高锰酸钾（哈尔滨市化工试剂厂）;Ｅ．５０％扑海因可湿性粉剂（有效成分：异菌脲,法国罗纳普朗克公司）;Ｆ．２５％施保克乳油（有效成分：咪鲜安,德国艾格福公司）;Ｇ．６４％恶霜锰锌可湿性粉剂（有效成分：恶霜灵、代森锰锌,浙江一帆农药厂）;Ｈ．３０％ＴＲＩＦＭＩＮＥ可湿性粉剂（有效成分：氟菌唑,日本曹达株式会…     

Quantitative Trait Loci Mapping for Bacterial Blight Resistance in Rice Using Bulked Segregant Analysis

Oryza meyeriana is highly resistant to rice bacterial blight (BB) and this resistance trait has been transferred to cultivated rice (O. sativa) using asymmetric somatic hybridization. However, no resistance genes have yet been cloned. In the present study, a progeny of the somatic hybridization with high BB resistance was crossed with a rice cultivar with high BB susceptibility to develop an F₂ population. Using bulked segregant analysis (BSA), 17 polymorphic markers that were linked to rice BB resistance were obtained through scanning a total of 186 simple sequence repeats (SSR) and sequence-tagged site (STS) markers, evenly distributed on 12 chromosomes. A genetic linkage map was then constructed based on the 17 linkage markers and the F₂ segregating population, which was followed by mapping for quantitative trait loci (QTLs) for BB resistance. Three QTLs were identified on chromosomes 1, 3 and 5, respectively, and the alleles of the resistant parent at any of the QTLs increased BB resistance. All of the three QTLs had a strong effect on resistance, explaining about 21.5%, 12.3% and 39.2% of the resistance variance, respectively. These QTLs were different from the loci of the BB resistance genes that have been identified in previous studies. The QTLs mapped in this work will facilitate the isolation of novel BB resistance genes and their utilization in rice resistance breeding.     

A Novel Allele Encoding 7-Hydroxymethyl Chlorophyll a Reductase Confers Bacterial Blight Resistance in Rice

Rice spotted leaf mutants are helpful to investigate programmed cell death (PCD) and defense response pathways in plants. Using a map-based cloning strategy, we characterized novel rice spotted leaf mutation spl^HM143 that encodes a 7-hydroxymethyl chlorophyll a reductase (OsHCAR). The wild-type (WT) allele could rescue the mutant phenotype, as evidenced by complementation analysis. OsHCAR was constitutively expressed at all rice tissues tested and its expression products localized to chloroplasts. The mutant exhibited PCD and leaf senescence with increased H₂O₂ (hydrogen peroxide) accumulation, increased of ROS (reactive oxygen species) scavenging enzymes activities and TUNEL (terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling) -positive nuclei, upregulation of PCD related genes, decreased chlorophyll (Chl) contents, downregulation of photosynthesis-related genes, and upregulation of senescence-associated genes. Besides, the mutant exhibited enhanced bacterial blight resistance with significant upregulation of defense response genes. Knockout lines of OsHCAR exhibited spotted leaf phenotype, cell death, leaf senescence, and showed increased resistance to the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo) coupled with upregulation of five pathogenesis-related marker genes. The overexpression of OsHCAR resulted in increased susceptibility to Xoo with decreased expression of pathogenesis-related marker genes. Altogether, our findings revealed that OsHCAR is involved in regulating cell death and defense response against bacterial blight pathogen in rice.     

Ac/Ds-Induced Receptor-like Kinase Genes Deletion Provides Broad-Spectrum Resistance to Bacterial Blight in Rice

Rice bacterial blight caused by Xanthomonas oryzae pv. oryzae (Xoo) seriously affects rice yield production. The discovery and application of broad-spectrum resistance genes are of great advance for disease resistance breeding. Previously, we identified that multiple receptor-like kinase (RLK) family gene deletions induced by the Ac/Ds system resulted in a lesion mimic symptom. In this study, the mutant #29 showed that this lesion mimic symptom was isolated. Further analysis identified that four RLK genes (RLK19-22) were deleted in the #29 mutant. The #29 mutant exhibited broad-spectrum resistance to Xoo and subsequent analyses identified that pathogenesis-related genes PR1a, PBZ1, and cellular H₂O₂ levels were significantly induced in the mutant compared to wild-type plants. A genetic analysis revealed that reconstruction of RLK20, RLK21, or RLK22 rescued the lesion mimic symptom of the #29 mutant, indicating that these three RLKs are responsible for broad-spectrum resistance in rice. Further yeast two hybrid and bimolecular fluorescence complementation assays demonstrated that RLK20 interacts with RBOHB, which is a ROS producer in plants. Compared to wild-type plants, the #29 mutant was more, while #29/RLK20 ox was less, susceptible to MV (methyl-viologen), an ROS inducer. Co-expression of RLK20 and RBOHB reduced RBOHB-promoted H₂O₂ accumulation in the cells. Taken together, our research indicated that the RLKs may inhibit RBOHB activity to negatively regulate rice resistance to Xoo. These results provide the theoretical basis and valuable information about the target genes necessary for the successful breeding of rice cultivars resistant to bacterial blight.     

防治水稻纹枯病的药剂筛选试验

为有效防治水稻纹枯病,对市售药剂进行了田间药剂筛选试验。结果表明:在水稻分蘖期与孕穗期2次施药情况下,240 g/L噻呋酰胺SC防效最好,在95%左右。325 g/L苯甲·嘧菌酯SC、75%肟菌·戊唑醇WG能有效防治水稻纹枯病,药效在80%以上。18.7%丙环·嘧菌酯SC需提高剂量再进行试验。300 g/L苯甲·丙环唑EC防效较差。所有药剂处理对水稻均安全。