Impact of long-term chemical fertilizer and organic amendment to Fusarium root rot of soybean

Soil suppressiveness to Fusarium root rot of soybean had been observed in a black soil field after a long-term fertilization with nitrogen(N)and phosphorus(P)fertilizer combined with pig manure as organic amendment(NPM),rather than that with only nitrogen and phosphorus fertilizer(NP)or no fertilizer(NF).To determine the microbial role on this suppressiveness,fungal and bacterial community characteristics in NPM,NP and NF treatments were investigated by q PCR and DGGE.Compared with the similar bacterial community characteristics among 3 treatments,fungal community,especially Fusarium population size and community composition in NPM treatment were different with those of NP and NF groups.Based on the isolation and pathogenicity test,pathogenic F.oxysporum,F.graminearum,F.verticillioide and F.lateritium absolutely dominated Fusarium community in NF and NP groups.Nonpathogenic F.avenaceum,F.equiseti,F.culmorum,F.redolens,F.solani and F.tricinctum dominated Fusarium community in NPM group.Isolation rate of pathogenic Fusarium in NPM reduced from 100%to 38%in NF.These results suggested that the dominance of soil non-pathogenic Fusarium population induced by organic amendment might play an important role on suppressing Fusarium root rot in the tested field.

Resistance Evaluation of Soybean Germplasm from Huanghuai Region to Phytophthora Root Rot

The aim of the study was to establish a set of differential strains and to identify soybean resistant genes to Phytophthora root rot and then to apply those strains for analysis of the resistant genes Rps1a,Rps1c,and Rps1k that soybean cultivars or lines may carry.Virulence formula of 125 Phytophthora sojae isolates were determined using the hypocotyls inoculation technique,the strains,which includ 6 isolates with different virulence formulas,were applied to identify the resistance of 55 soybean cultivars or lines and resistant genes were analyzed using the gene postulating procedure.Eighteen reaction types occurred in 55 cultivars or lines and results of gene postulation indicated that 2 cultivars or lines probably carried gene Rps1c and no cultivar may carry genes Rps1a or Rps1k.A few of soybean cultivars or lines from Huanghuai Region carry Rps genes Rps1a,Rps1c and Rps1k and tend to infect by P.sojae,so resistant cultivars or lines need to be bred and popularized actively.

Relationships between Microsclerotia Content and Hyperspectral Reflectance Data in Soybean Tissue Infected by Macrophomina phaseolina

Alternative methods are needed to assess the severity of charcoal rot disease [Macrophomina phaseolina (Tassi) Goid] in soybean [Glycine max (L.)] plant tissue. The objective of this study was to define the relationship between light reflectance properties and microsclerotia content of soybean stem and root tissue. Understanding that relationship could lead to using spectral reflectance data as a tool to assess the severity of charcoal rot disease in soybean plants, thus reducing human bias associated with qualitative analysis of soybean plant tissue and cost and time issues connected with quantitative analysis. Hyperspectral reflectance measurements (400-2490 nm) were obtained with a non-imaging spectroradiometer of non-diseased and charcoal rot diseased ground stem and root tissue samples of six soybean genotypes (“Clark”, “LD00-3309”, “LG03- 4561-14”, “LG03-4561-19”, “Saline”, and “Y227-1”). Relationships between the reflectance measurements and tissue microsclerotia content were evaluated with Spearman correlation (rs) analysis (p < 0.05). Moderate (rs = ±0.40 to ±0.59), strong (rs = ±0.60 to ±0.79), and very strong (rs = ±0.80 to ±1.00) negative and positive statistically significant (p < 0.05) monotonic relationships were observed between tissue spectral reflectance values and tissue microsclerotia content. Near-infrared and shortwave-infrared wavelengths had the best relationships with microsclerotia content in the ground tissue samples, with consistent results obtained with near-infrared wavelengths in that decreases in near-infrared spectral reflectance values were associated with increases in microsclerotia content in the stem and root tissue of the soybean plants. The findings of this study provided evidence that relationships exist between tissue spectral reflectance and tissue microsclerotia content of soybean plants, supporting spectral reflectance data as a means for assessing variation of microsclerotia content in soybean plants. Future research should focus on the modelling capabilities of the selected wavelengths and on the feasibility of using these wavelengths in machine learning algorithms to differentiate non-diseased from charcoal rot diseased tissue.

浅析黑龙江省大豆根腐病研究现状

大豆根腐病为大豆主要病害之一,具有发病范围广、卵孢子存活时间长、危害重等特点,严重制约黑龙江省大豆产业发展。为提高黑龙江省大豆根腐病防控技术水平,文章综述黑龙江省大豆根腐病致病菌种类及分布、发病症状及特点、抗病品种鉴定及防治措施,以期为黑龙江省大豆根腐病防治及研究提供理论依据,助力黑龙江省大豆产业振兴。

Conidia of one Fusarium solani isolate from a soybean-production field enable to be virulent to soybean and make soybean seedlings wilted

Fusarium is usually thought to cause soybean root rot,which results in a large quantity of annual yield loss in soybean production,by its secretions including Fusarium toxins and cell wall degrading enzymes,but not by the conidia themselves that do not underlie any virulence so far.Here we report that the conidia of one Fusarium solani isolate are able to be virulent to soybean and make soybean seedlings wilted alone.We isolated them from the wilted plants in a soybean-production field and molecularly identified 17 Fusarium isolates through phylogenetic analysis.Of them,except for one isolate that showed diversity of virulence to different soybeans(virulent to one soybean whereas avirulent to another soybean),the others were all virulent to the two tested soybeans:both conidia cultures and secretions could make soybean seedlings wilted at 5 days post infection,and their virulence had dosage effects that only conidia cultures of at least 5×10~6 conidia mL^(-1) could show virulence to soybean;however,the sole conidia of the F.solani isolate #4 also exhibited virulence to soybean and could make soybean seedlings wilted.Finally,we developed the specific cleaved amplified polymorphic sequences(CAPS)markers to easily differentiate Fusarium isolates.The isolate #4 in this work will likely be used to investigate the new mechanism of virulence of Fusarium to soybean.

Resistance identification of bivalent fungi-resistant genes transformed soybean to Phytophthora sojae

Soybean is one of the most important sources of edible oil and proteins in the world.However,it suffers from many kinds of fungal diseases which is a major limiting factor in soybean production.The fungal disease can be effectively controlled by breeding plant cultivars with genetic transformation.In this study,the resistance to Phytophthora sojae of five bivalent transgenic soybean lines was identified using the hypocotyls inoculation technique.The lines were the T,of the transgenic soybean which were transformed with kidney bean chitinase gene and barley ribosome inactivating protein gene,and were positive by Southern Blot analysis.The resistance difference was studied through comparing the death percentage of transgenic soybean with the control.The results showed that four lines were more resistant to P.sojae,whereas other one had no significant difference in comparison with the control.These transgenic soybean lines with enhanced resistance to P.sojae will be useful in soybean resistance breeding.

不同生物有机肥配施化肥对大豆植株生长、抗病及产量的影响

【目的】研究不同生物有机肥配施化肥对大豆植株性状、抗病性及产量和效益的影响。【方法】在大田条件下采用小区试验方法,设置常规施肥和不同生物有机肥配施化肥处理,研究大豆干物质、根瘤、抗病性及其产量变化。【结果】与常规施肥相比,不同生物有机肥配施化肥提高了苗期和盛花期大豆的地上部干物质、根干重和根瘤数,干物质提高幅度为5.31%~12.86%,根干重提高幅度为10.35%~20.24%,根瘤数提高幅度为12.34%~37.50%,差异均达到显著水平(P<0.05);不同生物有机肥配施化肥显著降低了苗期根腐病发病率和病情指数;显著提高大豆的株高、株荚数、株粒数及提高百粒重,提高大豆产量,2019~2020年产量提高幅度分别为7.25%~8.67%和6.50%~8.82%,与对照相比差异均达显著水平(P<0.05);与对照相比,不同生物有机肥配施化肥处理均提高了大豆的产值和效益值,效益值最高增加1 066.16元/hm^(2)。【结论】生物有机肥配施化肥能够促进大豆植株生长,降低病害,提高产量,提高经济效益。

我国大豆根腐病研究进展

随着大豆-玉米复合种植模式在全国推广,大豆病害的发生严重影响大豆的产量和品质。其中,由多种病原菌引起的大豆根腐病因其分布广、危害重、病原种类多、防治困难等特点,已成为制约大豆生产的主要障碍。文章对大豆根腐病危害现状、病害症状、病原菌种类、病害发生规律及防治的研究进展进行综述与展望,以期为生产上大豆根腐病防控提供理论依据。

中国大豆疫病的发生与防治

从病害发生情况、危害症状、病原侵染循环、流行因素和防控技术等方面对我国大豆疫病发生与防控的研究进展进行总结、分析和展望,以期为大豆重大病害监测与防控技术的深入研究提供参考。

哈茨木霉拌种对大豆生长及大豆根腐病的影响

为了明确哈茨木霉Th7拌种处理对大豆根腐病的防治及田间应用效果,为促进哈茨木霉拌种剂的推广应用奠定基础,于2020-2022年连续3年研究了Th7在大豆多年重茬地块应用对大豆根腐病的防治效果、大豆出苗率、生长情况和产量的影响。结果表明,Th7在大豆出苗后30 d对大豆根腐病的防治效果在37.51%~53.80%;在大豆出苗后60 d的防治效果在38.44%~43.28%;拌种处理大豆出苗率、单株荚数、单株粒数和百粒重均有提高;Th7拌种处理较不拌种处理产量提高3.27%~12.64%。说明,哈茨木霉Th7在提高大豆产量的同时,可以作为化学拌种剂的绿色替代产品用于大豆生产。

2021年黑龙江省疑似大豆猝死综合症的病原鉴定

大豆猝死综合症(Sudden Death Syndrome,简称SDS)是美洲大豆生产中严重发生的一种大豆根腐病,已知由茄腐镰孢菌复合种群分支2的4种镰孢菌所引起;该病在中国尚未有报道,但近年来部分大豆田块中发现疑似症状。为探明引起黑龙江省大豆疑似SDS茄腐镰孢菌的种类及致病性与药剂敏感性,于2021年从饶河、鹤岗、黑河和虎林等地采集58株疑似SDS大豆,分离根部和茎基部病原菌,进行形态学观察和基于EF1-α与RPB2的多靶标分子鉴定,以及致病性、杀菌剂敏感性与种衣剂防效测定。结果显示:分离到的31个茄腐镰孢菌菌株能够侵染大豆黄化苗下胚轴,导致大豆生长期根部腐烂,并引起叶片脉间褪绿、斑驳等类似于SDS的症状;这些菌株均属于茄腐镰孢菌复合种群分支3,分为两个类群,其菌落和分生孢子形态基本相似,但接种第一类群菌株后大豆植株的褐色病斑及上下扩展程度更明显;两个类群的8个代表菌株均对多菌灵、嘧菌酯、苯醚甲环唑、吡唑醚菌酯和咪鲜胺等杀菌剂表现敏感,6.25%精甲霜灵·咯菌腈悬浮种衣剂拌种可抑制病菌侵染。本研究为该类大豆病害的监测与防控提供了参考。

大豆根腐病生防链霉菌IRHB47的鉴定、生物学特性及防治效果

【目的】明确1株大豆根际细菌IRHB 47的分类地位及对根腐病的生防潜力,为根腐病防治提供理论依据。【方法】采用平板对峙培养、菌悬液浸种、盆栽接种试验检测IRHB47的抑菌效果、安全性、根腐病防效及环境适应性,通过菌落形态特征及16S rDNA序列分析鉴定其分类地位。【结果】菌株IRHB 47对尖孢镰孢菌Fusarium oxysporum、腐皮镰孢菌F.solani、藤仓镰孢菌F.fujikuroi等5种大豆根腐病致病菌的菌丝生长抑制率达51.04%~70.40%;对大豆白绢病菌Selerotium rolfsii、草莓灰霉病菌Botrytis cinerea、水稻稻瘟病菌Pyricularia oryzae等9种病原真菌拮抗作用显著。盆栽试验发现,IRHB 47菌悬液浸种预防处理和苗期灌根治疗处理均能够显著降低尖孢镰孢菌引起的大豆根腐病病情指数和植株死亡率。经16S rDNA序列分析,IRHB 47被鉴定为弗吉尼亚链霉菌Streptomyces virginiae,为革兰氏阳性菌。生物学特性检测表明,该菌株可在p H 5~10、6.25%LB培养基上生长,具有良好的耐酸碱性和低营养胁迫能力,且能够产生蛋白酶和酪蛋白酶以诱导大豆抗性。【结论】弗吉尼亚链霉菌IRHB 47菌株抑菌谱广,环境适应性强,能够有效缓解根腐病症状。

漯河地区大豆根腐病发生趋势及防治措施

近年来,随着漯河地区大豆种植面积增加,根腐病发病率呈逐年上升趋势,已成为影响该地区大豆生产的重要病害之一。文章对2017—2021年5年来漯河地区大豆根腐病的发生情况进行调查统计,并从选种、药剂拌种、病虫害防治及耕作模式方面提出根腐病防治措施,以期为当地大豆生产提供参考。

6株生防细菌对大豆根腐病防治效果初步评价

从大豆根际分离出的1500多株细菌中筛选出6株生防细菌,其在离体的条件下对大豆根腐病病原菌尖孢镰刀菌(Fusarium oxysporum )有很好的抑制作用,其中菌株18BRR2-2、18BRR9-1和3BRR16-2在离体的条件下也对茄腐镰刀菌(F. solani)、半裸镰刀菌(F. semitectum) 和立枯丝核菌(Rhizoctonia solani)有抑制作用,并且这6株生防细菌的发酵液可以抑制尖孢镰刀菌(F. oxysporum )的生长。通过温室盆栽和大田试验表明,这些生防菌对大豆根腐病有很好的防治效果,其中菌株18BRR2-2盆栽和大田的防效均最高,分别达到了45.9%和65.00%。而且这些生防菌也表现出对大豆明显的促生作用。认为18BRR2-2 号菌株有开发为防治大豆根腐病生防制剂的潜力。

新疆阿勒泰地区大豆镰刀菌根腐病病原鉴定及致病性测定

通过对2007和2008连续两年自新疆阿勒泰地区采集分离到的大量大豆镰刀菌根腐病分离物进行的种的鉴定,结果表明分离所得253个镰刀菌属菌株分属于5个种和1个变种,分别为尖孢镰刀菌、茄腐镰刀菌、禾谷镰刀菌、茄腐镰刀菌蓝色变种、燕麦镰刀菌和节状镰刀菌。各个种或变种所占的菌株比例分别为46.6%、24.1%、11.8%、9.8%、7.5%和0.8%。以黑河5号大豆品种为接种材料进行的致病性测定结果显示除节状镰刀菌无致病性外,其余4个种和1个变种对大豆有不同程度的致病性,其中尖孢镰刀菌为大豆镰刀菌根腐病病原菌中出现频率最大且致病性最强的优势致病种,茄腐镰刀菌次之。

复配生防菌株防治大豆根腐病的研究

大豆根腐病(Soybean root rot)是由多种病原真菌复合侵染所致的土传病害,其分布广、危害重,利用单一生防菌株防治困难。针对该问题将实验室筛选出的多个木霉菌生防菌株FMM35、FMM9、FMM5,毛壳菌CHZ1和生防细菌B7进行复配研究,通过测定生防菌的生长速度、产孢量、孢子萌发率及体外拮抗能力,探索复配可能性,并将适宜复配的生防菌组合进行盆栽防效试验。结果表明:不同生防菌之间生长速度、产孢量、孢子萌发率存在差异,综合分析其中组合C1(FMM9和FMM35)复配效果好,避免生防菌间拮抗作用,对大豆根腐病防治效果明显,并对大豆有促生作用,具有复配潜力可进一步研究。

福建省大豆根腐病病原菌的鉴定

为明确福建省大豆根腐病病原菌的种类及组成,于2007～2009年从漳州、厦门、龙岩等地大豆产区采集根腐病标样216份,从中分离到307株丝状病原真菌。根据其培养性状、形态学特征、代表性菌株的致病性测定及rDNA-ITS序列分析,将这些病原菌分为5种,分别为尖孢镰刀菌(Fusarium oxysporum,112株)、茄腐镰刀菌(Fusarium solani,74株)、大豆疫霉菌(Phytophthora sojae,79株)、立枯丝核菌(Rhizoctoniasolani,24株)和瓜果腐霉菌(Pythium aphanidermatum,18株)。致病性测定结果表明,5种病原菌的致病力存在明显差异,其中大豆疫霉菌、尖孢镰刀菌和茄腐镰刀菌的致病性较强,发病率分别为100%、97.8%和95.6%,立枯丝核菌、瓜果腐霉菌则相对较弱。

新疆大豆根腐病病原及防治技术初报

通过对大豆根腐病菌的分离、纯化培养和接菌试验,初步确定新疆大豆根腐病是由多种病原菌复合侵染所至,单一菌种的致病力小于复合菌种。药剂处理种子经室内、田间试验,多菌灵和福美双处理种子出苗情况良好,病情指数降低幅度明显,防病效果显著。

大豆根腐病生防细菌优势菌株的筛选、鉴定及生防效果验证

根腐病是影响大豆产量的主要病害之一,镰刀菌(Fusarium sp.)是引起我国大豆根腐病的主要病原菌。以致病尖孢镰刀菌为研究对象,通过平板对峙法从实验室保存的237株芽孢杆菌筛选到一株对该尖孢镰刀菌具有明显抑菌活性的芽孢杆菌8-32。对芽孢杆菌8-32经菌落、菌体形态,16S rRNA基因序列及生理生化性质鉴定,该菌株为枯草芽孢杆菌(Bacillus subtilis)。温室盆栽结果表明:该生防菌对大豆根腐病具有很好的防治效果,其病情指数减少32.08%。

大豆根腐病菌拮抗细菌筛选及抗生作用

从大豆根际土壤中分离纯化得到 388个细菌菌株 ,从中筛选对大豆根腐病病原尖孢镰刀菌 (Fusariumoxysporum )、茄腐镰刀菌 (Fusariumsolani)和立枯丝核菌 (Rhizoctoniasolani )有拮抗作用的菌株 ,采用无菌室内点接法初筛 ,抑菌带大于 2 0mm以上的有 12株 ,通过盆栽防效试验 ,进一步证明 12个菌株中有 6个菌株盆栽防治尖孢镰刀菌和立枯丝核菌达到 4 6 .0 % - 78.5 %。菌株与病原真菌共培养结果显示 ,菌株B2、B5 7、B85和B6 9使尖孢镰刀菌菌丝干重分别减少 5 1.2 7%、4 0 .78%、38.87%和 34.5 8% ;菌株B5 7使茄腐镰刀菌菌丝干重减少 71.4 8%。菌株分泌物对病原真菌的拮抗作用研究结果表明 ,B5 7的分泌物对尖孢镰刀菌抑制率最高 ,3d为 82 .1% ,6d为 90 .6 % ;其次是B16 ,3d为 5 8.8% ,6d为 5 1.1%。