Fermentation, formulation and evaluation of PGPR Bacillus subtilis isolate as a bioagent for reducing occurrence of peanut soil-borne diseases

Four isolates of Bacillus subtilis coded,B4,B7,B8 and B10 were examined as biocontrol agents for their abilities and antagonistic effect on the in vitro growth of certain phytopathogenic fungi of peanut,Rhizoctonia solani and Sclerotium rolfsii.Bacillus subtilis isolate B4(GenBank accession no.EF150884)was the highly effective one for inhibiting the fungal mycelial growth.Batch fermentation of B.subtilis isolate B4 was carried out and the maximum biomass achieved was 4.53 g L-1 at 11 h.Bacillus subtilis isolate B4 was formulated and evaluated as a biofungicide to reduce peanut soil-borne diseases under greenhouse and field conditions at the side of Rizolex-T(fungicide)as standard.Treatments by formulated plant growth-promoting rhizobacteria(PGPR)B.subtilis B4 and Rizolex-T in a soil infested with R.solani,S.rolfsii and mixture of them were more effective in decreasing percentage of damping-off,root and pod rot disease incidence(%)in greenhouse and open field environment during the two seasons 2015 and 2016.Treatments by PGPR gave highly dry weight and number of healthy pods compared to control of fungi treatment which was nearby to dry weights of healthy pods achieved by treatments by Rizolex-T in a soil infested with S.rolfsii,R.solani and mixture of them.Formulated PGPR B.subtilis B4 gave higher increasing of yield percentage than treatment by Rizolex-T in the two evaluated seasons 2015 and 2016.It can conclude that the produced bioforumlated agent was more efficient as fungicide when compared with the other chemical synthesized fungicides,safe for human and the environment and economy.

Prevention and Control Technology of Potato Soil-borne Diseases

In recent years,potato soil-borne diseases have occurred severely.The investigation shows that potato Fusarium wilt greatly affects potato yield,leading to a yield reduction rate of 21.8%.Potato powdery scab shows very mild symptoms on potato tuber,basically with no symptoms in some plots,but shows obvious symptoms on the root system.A large number of nodules which are produced on one side of the root system seriously affect water and fertilizer absorption function of the potato root system.Potato tubers expand slowly,leading to small potato tuber,low yield and low commodity rate.The fungus can survive in soil for more than 10 years.Potato soil-borne diseases are harmful and are difficult to control.Susceptible plants can be detected by high definition chromatographic control method and pathogen detection.For prevention and control of potato soil-borne diseases,first of all,disease-resistant varieties should be chosen and virus-free potato seeds are used for sowing.Secondly,metham and dazomet can be used to treat soil in order to prevent and control potato soil-borne diseases.The results showed that the dead seedling rate treated by metham was reduced from 35%to 12.5%compared with the blank control,and the yield was increased by 44.09 kg/ha,with an increase rate of 18.2%.Compared with the blank control,the dead seedling rate treated by dazomet was decreased from 35%to 7.5%,and the yield was increased by 38.10 kg/ha,with an increase rate of 15.7%.The soil treatment received obvious yield increase effect.

Multiclass Cucumber Leaf Diseases Recognition Using Best Feature Selection

Agriculture is an important research area in the field of visual recognition by computers.Plant diseases affect the quality and yields of agriculture.Early-stage identification of crop disease decreases financial losses and positively impacts crop quality.The manual identification of crop diseases,which aremostly visible on leaves,is a very time-consuming and costly process.In this work,we propose a new framework for the recognition of cucumber leaf diseases.The proposed framework is based on deep learning and involves the fusion and selection of the best features.In the feature extraction phase,VGG(Visual Geometry Group)and Inception V3 deep learning models are considered and fine-tuned.Both fine-tuned models are trained using deep transfer learning.Features are extracted in the later step and fused using a parallel maximum fusion approach.In the later step,best features are selected usingWhale Optimization algorithm.The best-selected features are classified using supervised learning algorithms for the final classification process.The experimental process was conducted on a privately collected dataset that consists of five types of cucumber disease and achieved accuracy of 96.5%.A comparison with recent techniques shows the significance of the proposed method.

Screening of Two Biocontrol Strains of Bacillus subtilis against Ginseng Soil-borne Disease and Their Antifungal Activities

[ Objective] The paper was to obtain biocontrol strains with good control effects against ginseng soil-borne disease through screening. [ Method] Dilu- tion plate method and plate confrontation culture method were used to isolate and screen biocontrol bacteria from the rhizosphere soil of diseased ginseng. The strains were identified through morphology, physiological and biochemical characteristics and 16S rDNA. [ Result ] With Rhizoctonia solani, Fusarium oxysporum and Fu- sarium solani as the indicator strains, two biocontrol strains B59 and X1 with strong antagonistic effects were screened from the rhizosphere soil of diseased ginseng in Tieli farm of Heilongjiang Province, and they were identified to be Bacillus subtilis. The inhibition rates of two biocontrol strains against eight different fungi were all greater than 90%. The primary study indicated that B59 and X1 strains could secrete antifungal active substances. [ Conclusion] Two biocontrol Bacillus subti- lis strains 1359 and X1 all had strong antagonistic effect against ginseng soil-borne disease, which had certain potential for development and utilization.

Model for Cucumber Disease Images based on GMM

Based on the accurate analysis of cucumber disease images, the low level feature of images was effectively extracted, and Gaussian Mixture Model （GMM） for 8 common cucumber diseases was built. The parameters of GMM were estimated by the algorithm of expectation maximum （EM） to accurately charac- terize the feature distribution of 8 cucumber diseases, thus increased the correct identification of cucumber diseases and accurate grasping of damage conditions, and provided basis for achievement of real-time and accurate prediction of cucumber diseases.

Recognition of Greenhouse Cucumber Disease Based on Image Processing Technology

This paper mainly studies the disease of cucumber downy mildew, powdery mildew and anthracnose leaf image processing and recognition technologies. Application of median filtering method of filtering noise, leaf spot disease of cucumber leaf color range segmentation part extract color feature parameters of the lesion site, characteristic parameters of the shape;extraction texture parameters by using gray level co-occurrence matrix. Based on the shortest distance methods to identify diseases of images. The experimental result showed that the current method on disease recognition accuracy rates more than 96%.

Effects of Rivastigmine Combined with Reinhartdt and Sea Cucumber Capsule in Patients with Mild-to-Moderate Parkinson’s Disease Dementia: A Pilot Study

Many patients with Parkinson’s disease suffer cognitive impairment or dementia. Cholinesterase inhibitors (ChEIs) have positive effects on patients with Parkinson’s Disease Dementia (PDD). But it is only improve symptoms. There is no etiological cure for PDD. So, In order to achieve the best outcomes, the combination of ChEIs and other therapeutic strategies is needed to study.?In the present study, we investigate the efficacy and safety of rivastigmine combined with Reinhartdt and Sea Cucumber Capsule (RSC) in patients with mild-to-moderate PDD, and its effect on thyroid function.?There were 52 patients were randomly assigned to receive either rivastigmine (3 mg/ day) or rivastigmine plus RSC (2.7 g/day) treatment for 24 weeks. Efficacy was investigated by the change of the scores of Alzheimer’s Disease Assessment Scale cognitive subscale (ADAS-Cog), Activities of Daily Life (ADL) and Unified Parkinson’s Disease Rating Scale (UPDRS) part III (motor scale). Meanwhile, thyroid hormone levels were detected before and after 12 weeks, 24 weeks treatment in all patients. Results showed that?the patients treated with rivastigmine plus RSC showed more improvement in the cognition and the daily life activities compared to those treated with rivastigmine alone. Significant difference was present after being treated for 12 weeks or more. However, no group difference was found on UPDRS part III, thyroid hormone level change and the incidence of adverse events (11.1% vs 16.0%) between the two groups of treatment. Adverse effects were nausea and vomiting which were the main reasons for the dropout. The finding suggests that Rivastigmine plus RSC may improves the treatment effects in cognition and the ADL of the patients with mild-to-moderate PDD, compared with the rivastigmine treatment alone. However, no effect was observed on the motor symptoms and thyroid hormone levels. In addition, this joint treatment is safe.

Allelopathy of decomposed maize straw products on three soilborn diseases of wheat and the analysis by GC-MS

In northern China, the soil-born diseases of wheat have been getting more and more serious under a new farming system that returns maize straw to the field. In order to investigate the allelopathy of the decomposed maize straw products on three soil-born diseases of wheat, culture dish and pot experiments were conducted and the compounds in the products were identified by gas chromatography-mass spectrometry （GC-MS）. Culture dish experiments showed that the mycelial growth, sclerotia formation amount and total weight of Rhizoctonia cerealis were promoted at concentrations of 0.03, 0.06 and 0.12 g mL-1 and inhibited at concentration of 0.48 g mL-1 of the decomposed products. No significant effects were found of the product concentrations on average weight of the sclerotia. Mycelial growth of Gaeumannomyces graminis was promoted at almost all concentrations except the highest one. Mycelial growth and spore germination of Bipolaris sorokiniana were significantly inhibited by all concentrations of the decomposed products, with enhanced inhibition effects along with the increased concentrations. The length, number and dry weight of roots together with the root superoxide dismutase activity were promoted by the lowest concentration （0.03 g mL-1）, with a synthetic effect index of 0.012, and inhibited by other concentrations. The ion leakage of roots was increased and the root peroxidase activity of roots was lowered by all the treatments. Pot experiments revealed that occurrence of the sharp eyespot was reduced by 0.03 and 0.06 g mL-1 of decomposed products after irrigation. However, the incidence rates and disease indexes were significantly increased by 0.12, 0.24 and 0.48 g mL-1 of decomposed products. The results indicated that incidence rates and disease indexes of the take-all were significantly promoted after being irrigated with the decomposed products, while occurrences of the common rot didn＇t change, significantly. GC-MS results showed that the compounds of the decomposed products included organic acids, esters, hydrocarbons, amides and aldehydes, with the proportions 25.26, 24.01, 17.22, 14.39 and 7.73%, respectively. Further analysis investigated that the allelochemicals identified in straw decomposed products contained p-hydroxybenzoic acid （9.21%）, dibutyl phthalate （6.94%）, 3-phenyl-2-acrylic （5.06%）, 4-hydroxy-3,5-dimethoxybenzoic acid （2.26%）, hexanoic acid （1.73%）, 8-octadecenoic acid （1.06%）, 3-（4-hydroxy-3-methoxy-phenyl）-2-propenoic acid （1.04%）, 4-hydroxy-3-methoxy-benzoic acid （0.94%） and salicylic acid （0.94%）.

Progresses in the Mechanism of Resistance to Fusarium Wilt in Cucumber (Cucumis sativus L.)

Fusarium wilt caused by Fusarium oxysporum f.sp. cucumerinum （Owen） is one of the most devastating diseases in cucumber production worldwide. Recent progresses in the mechanism of resistance to Fusarium wilt in cucumber were reviewed in this paper, including pathogenic mechanism of Fusarium oxysporum, the resistance mechanism of cucumber, the heredity of resistance, and the location of resistance genes. Following works should be the location and cloning of resistance genes with molecular biologic methods.

设施黄瓜主要病害发生及综合防控

从病害发生特点、为害症状、侵染循环、流行因素及防控技术等方面对我国设施黄瓜主要病害发生情况及其综合防控技术进行总结、分析和展望,以期为黄瓜主要病害监测和防控技术研究提供参考。

外源水杨酸对黄瓜幼苗灰霉病防御酶活性的影响

为研究水杨酸(SA)对感染灰霉病黄瓜幼苗防御酶活性的影响,采用叶面喷施外源水杨酸(SA),测定SA对感染灰霉病黄瓜幼苗叶片中多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)、过氧化氢酶(CAT)、过氧化物酶(POD)和过氧化物歧化酶(SOD)5种防御酶活性的影响。结果表明:不同浓度SA对黄瓜幼苗抗灰霉病均有作用,能显著降低黄瓜幼苗的病情指数,其中以150 mg·L^(-1)的SA处理后的相对防效最高。叶面喷施150 mg·L^(-1)的SA后,随感染天数的增加PPO、PAL、CAT、POD、SOD 5种防御酶的活性均呈现出先上升后下降趋势,感染期间经SA处理后的5种防御酶的活性均高于未处理,其中PAL活性持续性较好。外源水杨酸能通过促进防御酶活性提高黄瓜幼苗抵抗灰霉病的伤害,浓度为150 mg·L^(-1)的SA处理抵抗作用最好。

不同药剂对黄瓜根结线虫病的防治效果研究

为有效防治黄瓜根结线虫病,保证黄瓜安全生产,本试验选择10.5%阿维·噻唑膦颗粒剂、0.5%阿维菌素颗粒剂和10%噻唑膦颗粒剂等药剂进行了黄瓜根结线虫病的田间药剂防治试验。结果表明,施药40 d,每667 m^(2)用10.5%阿维·噻唑膦颗粒剂1500~1800 g和10%噻唑膦颗粒剂1800 g较其他处理防治效果显著,防治效果达到77%以上,药剂的持效期长;试验期间观察各药剂处理区黄瓜的叶片颜色、株型等,均未见药害,亦未见药剂处理促进或抑制黄瓜生长的现象,说明各药剂在试验用量下对黄瓜生长安全。建议生产中交替使用阿维·噻唑膦复配制剂和噻唑膦单剂,不仅能够有效防治黄瓜根结线虫病,还可以延缓抗药性的产生和发展。

华南型黄瓜新品种中农脆绿1号的选育

中农脆绿1号是以雌性系171054为母本,以自交系17905为父本配制而成的华南型黄瓜一代杂种。该品种为雌性系,植株生长势强,分枝性较强,耐低温弱光性好。商品瓜圆筒形,瓜把短,刺瘤中等大小,无棱,白刺稀疏,瓜色花绿,平均瓜长17.0 cm,横径3.7 cm,心腔小,果肉淡绿色。高抗CMV,抗WMV、褐斑病,中抗白粉病、枯萎病,早熟,每667 m^(2)产量7 000~10 000 kg,适宜日光温室和春、秋大棚栽培。

海南黄瓜抗枯萎病嫁接砧木筛选研究

为筛选适宜海南冬春季节黄瓜抗枯萎病的嫁接砧木品种,对收集的21种砧木进行黄瓜枯萎病抗性鉴定,以易感砧木种质‘全福太郎’为对照,采用人工接种尖孢镰刀菌黄瓜专化型,鉴定各砧木的黄瓜枯萎病抗性。通过测定不同砧木的发病率、病情指数、根系活力、叶绿素相对含量、相对电导率、丙二醛含量等生理指标,结合新引进的病害严重程度指数曲线下面积(AUDRC)综合评价不同砧木对黄瓜枯萎病的抗性。结果表明,不同砧木对黄瓜枯萎病的抗性表现不同,病情指数评价指标表明,‘双力铁甲’‘金甲砧’‘创凡一号’为抗性砧木,‘金甲砧’AUDRC指标表现最好;生理指标中,根系活力表现较好为‘双力铁甲’‘金甲砧’‘创凡一号’;叶绿素含量较高的品种为‘金甲砧’‘创凡一号’‘日系冬之助’,显著高于对照组;相对电导率较低,为‘青根砧王’‘创凡一号’;丙二醛含量较低的为‘双力铁甲’‘金甲砧’‘创凡301’,显著低于其他砧木。依据病情指数、根系活力、SPAD、REC、MDA等生理指标,‘双力铁甲’‘金甲砧’‘创凡一号’为抗性砧木。研究表明,‘金甲砧’为21个砧木品种中综合抗黄瓜枯萎病最好的砧木。

唐山市刺参(Apostichopus japonicus)养殖情况和主要病害防治

刺参(Apostichopus japonicus)是唐山市重要的水产养殖品种,2022年养殖面积已超过5100 hm2,年产量超过7700 t。本文基于唐山地区多年的刺参苗种繁育和成参养殖的实践经验,总结了几种唐山地区常见的高温、细菌性疾病、霉菌病、寄生虫病的预防和治疗措施。

一种复配型生物种衣剂防治黄瓜苗期病害的研究

【目的】用多粘类芽胞杆菌(Paenibacillus polymyxa)P6与哌珀霉素(Peptaibols)复配制成一种生物种衣剂,防治黄瓜种子萌发及苗期猝倒病、根腐病和立枯病。【方法】(1)通过离体拮抗测试,筛选出对引起黄瓜猝倒病、根腐病和立枯病的病原菌(瓜果腐霉:Pythium aphanidermatum,茄腐镰刀菌:Fusarium solani,立枯丝核菌:Rhizoctonia solani)有较好拮抗活性的生防菌株和Peptaibols的使用浓度;(2)通过相容性测试,进一步筛选出能与生防菌株相容的哌珀霉素使用浓度;(3)通过生测试验,测定复配种衣剂对黄瓜种子萌发的影响,以及对猝倒病、根腐病和立枯病的防治效果。【结果】对瓜果腐霉,茄腐镰刀菌和立枯丝核菌的抑制率随哌珀霉素含量的增加而提高,当哌珀霉素的使用浓度在50 mg/L和200 mg/L时,对瓜果腐霉和茄腐镰刀菌的抑菌率分别达到100%;在200 mg/L时,对立枯丝核菌的抑菌率为69.00%;相容性测试结果显示,当哌珀霉素使用浓度为32.5 mg/L时,与多粘类芽胞杆菌的相容性好,且复配制成生物种衣剂,对瓜果腐霉,茄腐镰刀菌和立枯丝核菌的抑制率分别为90.8%,59.7%和90.6%,显著优于单独使用哌珀霉素或多粘类芽胞杆菌。生测试验结果显示,用含菌量为106 cfu/g的多粘类芽胞杆菌与浓度为32.5 mg/L的哌珀霉素复配裹种,防治黄瓜猝倒病、根腐病和立枯病,优于单独使用多粘类芽胞杆菌或哌珀霉素,防治效果分别为38.67%,57.00%,72.23%。【结论】P6具有广谱抑菌活性,与哌珀霉素复配有较好的生物相容性和稳定性,能较好地防治黄瓜苗期病害。

2种药剂复配对黄瓜根结线虫的防治效果研究

为了测定阿维菌素和氟吡菌酰胺复配的60%阿维·氟吡菌酰胺水分散粒剂的防治效果及最佳用药量,采用田间试验,设置不同剂量60%阿维·氟吡菌酰胺水分散粒剂、0.5%阿维菌素颗粒剂、41.7%氟吡菌酰胺悬浮剂和清水对照共6个处理,检测不同剂量药剂对黄瓜根结线虫病的防治效果和对黄瓜产量的影响。结果表明:60%阿维·氟吡菌酰胺水分散粒剂在黄瓜苗移栽缓苗后进行灌根1次,对黄瓜根结线虫病有较好的防效,施药后75 d防效为79.26%~82.66%,收获期防效为75.36%~78.47%,对黄瓜安全,且产量显著高于对照,有较高的增产率,推荐剂量为540.0~720.0 g.a.i./hm^(2)。

智能化诊断系统在温室黄瓜病虫害防治上的应用

在介绍智能化诊断系统的基础上,分析了智能化诊断在温室黄瓜病虫害识别、病虫害预测预报和病虫害防治决策中的应用。智能化诊断系统能显著提高病虫害防治效果,降低农药使用量,对保护生态环境和提高黄瓜产量具有重要意义。

基于VIGS技术干扰病毒RNA防控烟草黄瓜花叶病毒病

黄瓜花叶病毒(Cucumber mosaic virus,CMV)引起的花叶病是烟草上的重要病害。本试验通过病毒诱导基因沉默技术(virus induced gene silencing,VIGS)构建靶向沉默CMV-1a、CMV-2a、CMV-MP和CMV-CP的VIGS载体,测定基因沉默后CMV相对表达量、CMV病毒浓度和TRV相对表达量,并对VIGS载体对CMV的防治效果进行评价。结果表明,试验建立的VIGS载体能够有效导入烟株;沉默CMV-2a的处理CMV相对表达量最低,基因沉默效率最高,为46.25%;接种病毒30 d后CMV-2a处理的病毒浓度最低,仅为对照的72.8%,TRV载体的相对表达量显著高于其他处理;沉默CMV-2a的处理发病时间推迟,病情指数最低,防治效果最好。本研究建立的CMV-2a VIGS体系能够有效沉默外源侵入的CMV基因表达,抑制CMV在烟株内的传播,为防治烟草黄瓜花叶病毒病提供了新的思路与方法。

黄瓜枯萎病拮抗菌株的防病促生性能鉴定

【目的】有效防治设施黄瓜枯萎病,促进我国黄瓜产业的持续健康发展。【方法】通过对筛选得到的枯萎病拮抗菌株的促生性能进行鉴定,并开展黄瓜幼苗栽培试验,验证所试拮抗菌株对黄瓜幼苗枯萎病的防效。【结果】所试8株拮抗细菌均具一定的促生性能,菌株固氮酶活性、有机磷溶磷量和分泌IAA浓度范围分别为133.97~876.83 nmol(C2H4)/(h·mL)、14.14~20.08μg/mL、3.43~17.78μg/mL,其中促生性能较好的有抗生素溶杆菌42-3、唐菖蒲伯克霍尔德菌L1-3、少动鞘氨醇单胞菌L5-4和蜡样芽孢杆菌L3-1。栽培试验结果显示,唐菖蒲伯克霍尔德菌L1-3和少动鞘氨醇单胞菌L5-4对黄瓜幼苗枯萎病的防治效果最好,发病率仅为24.83%,防治效果分别为36.67%和42.67%。唐菖蒲伯克霍尔德菌L1-3对幼苗的促生效果更优,有助于黄瓜抗氧化酶活性提高。【结论】相较其他菌株,唐菖蒲伯克霍尔德菌L1-3对黄瓜幼苗枯萎病的防效更优,促生效果显著,可用于在实际生产中防治黄瓜枯萎病及其他土传病害,具有很大的研究价值。