大豆种质资源对大豆孢囊线虫的抗性评价

 大豆孢囊线虫(Heterodera glycines Ichinohe,SCN)是大豆(Glycine max (L.) Merrill)生产中的毁灭性害虫,种植抗性品种是控制其危害、减少产量损失的最佳途径。本研究通过温室盆栽实验评价了300份大豆种质对大豆孢囊线虫3号和4号生理小种的抗性。分别筛选到高抗和中抗3号生理小种的大豆种质27份和21份;高抗和中抗4号生理小种的大豆种质11份和9份。在所有供试材料中有10份材料同时对大豆孢囊线虫3号和4号生理小种表现高抗。线虫侵染实验表明,抗性材料对大豆孢囊线虫的发育有阻碍作用,并能显著降低最终形成的孢囊数。     

一种值得关注的大豆病害——大豆红冠腐病

大豆红冠腐病是一种为害大豆生产的重要病害,该病害的典型症状是大豆叶片变黄萎蔫,植株枯萎,根系变黑腐烂,茎基部及根系表面产生大量红橙色小点,是病原菌的子囊壳。其致病菌为寄生柱枝孢菌（Cylindrocladiumparasiticum）,有性阶段为冬青丽赤壳菌（Calonectriailicicola）。本文对大豆红冠腐病及其致病菌的文献进行了简要的综述。     

模拟转基因大豆混杂在常规大豆中的空间分布格局研究

在室内把同种常规栽培大豆染色后与非染色大豆按照1∶20、1∶40、1∶60、1∶80比例模拟混合后,随机取样,统计染色大豆的分布和数量。之后采用方差均值比、Morisita指数检验、卡方测验3种格局分布类型检验方法,对经过模拟收获、运输、储藏过程的4种比例混合后的染色大豆进行分布格局分析。结果表明,在高比例情况下,染色大豆呈聚集分布;中比例和低比例下,分布格局呈现随机分布。该研究结果对转基因大豆混杂在常规大豆中的田间抽样检测技术制定有一定参考价值。     

Identification of a second Asian soybean rust resistance gene in Hyuuga soybean

ABSTRACT Asian soybean rust (ASR) is an economically significant disease caused by the fungus Phakopsora pachyrhizi. The soybean genes Rpp3 and Rpp?(Hyuuga) confer resistance to specific isolates of the pathogen. Both genes map to chromosome 6 (Gm06) (linkage group [LG] C2). We recently identified 12 additional soybean accessions that harbor ASR resistance mapping to Gm06, within 5 centimorgans of Rpp3 and Rpp?(Hyuuga). To further characterize genotypes with resistance on Gm06, we used a set of eight P. pachyrhizi isolates collected from geographically diverse areas to inoculate plants and evaluate them for differential phenotypic responses. Three isolates elicited different responses from soybean accessions PI 462312 (Ankur) (Rpp3) and PI 506764 (Hyuuga) (Rpp?[Hyuuga]). In all, 11 of the new accessions yielded responses identical to either PI 462312 or Hyuuga and 1 of the new accessions, PI 417089B (Kuro daizu), differed from all others. Additional screening of Hyuuga-derived recombinant inbred lines indicated that Hyuuga carries two resistance genes, one at the Rpp3 locus on Gm06 and a second, unlinked ASR resistance gene mapping to Gm03 (LG-N) near Rpp5. These findings reveal a natural case of gene pyramiding for ASR resistance in Hyuuga and underscore the importance of utilizing multiple isolates of P. pachyrhizi when screening for ASR resistance.     

Differential necrotic lesion formation in soybean cultivars in response to soybean mosaic virus

In this study, we examined the necrosis phenotype on leaves of two cultivars of soybean (ZheA8901 and Nannong1138-2) that show varying level of resistance to soybean mosaic virus (SMV). The necrotic symptoms seen on inoculated and systemic leaves of soybean cultivar ZheA8901 were reminiscent of programmed cell death (PCD). The cell death phenotypes were evaluated using the TUNEL method, quantification of hydrogen peroxide (H₂O₂) and salicylic acid, callose production, as well as by monitoring expression of defence genes GmPR-1 and GmNPR1. Our results show that SMV inoculation induced PCD on ZheA8901 is associated with rapid increase in H₂O₂, increased SA and callose accumulation and higher defence gene expression.     

转基因耐草甘膦大豆对豆田节肢动物群落多样性的影响

在田间试验条件下,采用直接观察法,通过对多样性指数、优势集中性指数、均匀性指数、物种数的分析比较,研究转基因耐草甘膦大豆对豆田节肢动物群落多样性的影响。结果显示,大豆生长期转基因耐草甘膦大豆和受体的节肢动物多样性指数、均匀性指数、物种数均显著低于当地常规品种,优势集中性指数显著高于当地常规品种,但转基因抗草甘膦大豆与对照受体间各指标无显著性差异,说明转基因耐草甘膦大豆对豆田节肢动物群落无明显影响。     

Quantification of within-field spread of soybean mosaic virus in soybean using strain-specific monoclonal antibodies

ABSTRACT Strain-specific monoclonal antibodies were used to follow the temporal increase and spatial spread of soybean mosaic virus (SMV) strain G-5 released from a point source. The use of strain-specific monoclonal antibodies allowed discrimination of within-field temporal and spatial spread of SMV strain G-5 from non-G-5 SMV isolates that originated from exogenous field sources. SMV isolates originating from exogenous sources have potential to alter the temporal and spatial pattern of within-field virus spread, which could potentially affect the choice of models used to quantify within-field pathogen spread. Analysis of SMV epidemics in field-plot experiments indicated that the logistic model was the most appropriate model to describe and compare the temporal spread of SMV among years. On the basis of ordinary runs analyses, within-field spread of SMV strain G-5 was random in 1991 and 1994, but was mostly aggregated in 1992 and 1993. Non-G-5 SMV isolates arising from exogenous sources displayed a random spatial pattern over time. This is the first study in which pathogen incidence (detection of SMV using strain-specific monoclonal antibodies) as opposed to disease incidence (based on symptoms) was employed to monitor and model SMV spread in time and space.     

Chloroaniline peroxidation by soybean peroxidases

4-chloroaniline was oxidized by soya cell-wall peroxidases in the presence of hydrogen peroxide. The main product, an orange compound with a maximal absorbance at 455 nm, was probably 4, 4′-dichloroazobenzene. The optimum pH of the reaction was 4. Michaelis constants, determined as described by Dalziel, were 21 mM for 4-chloroaniline and 94 μM for hydrogen peroxide. Syringaldazine was an uncompetitive inhibitor of 4-chloroaniline peroxidation (K_i =46 μM) and modified the progress of the reaction with the appearance of a lag period. By contrast, 4-chloroaniline was a non-competitive inhibitor of syringaldazine peroxidation with a K_i value of 21 mM_x at pH 7.5. Therefore, these two inhibiting effects were compatible with the presence of two binding sites for two different hydrogen donors. Both sites were linked by allosteric interactions. The inferences on chloroaniline binding are discussed.     

大豆重迎茬减产的病虫害等原因及解决办法探讨

大豆重迎茬减产严重。调查分析其主要原因是重迎茬的病虫害加重、土壤营养失调等。据此,试验提出了减轻重迎茬为害的技术措施。     

控制大豆孢囊线虫生物种农剂的研制及沈阳田间小区防效的初步试验

以“辽豆15”为材料,采用田间小区试验,探讨了自行研制的生物种衣剂对大豆孢囊线虫数量的影响。试验结果表明：2007年在沈阳汪家的试验中,处理4（复配菌株F1024,B482,A4+微量元素组合3+助剂）对大豆根外孢囊的抑制率达65.66%,与对照有显著差异。2008年对处理4进行了精细的试验设计,并在2个不同地点布置试验,结果处理5（复配菌株F1024,B482,A4+元素组合+助剂）在汪家和康平2个试验点的根外孢囊数量及根内线虫数量都与对照差异达到显著水平,2个试验点的根外孢囊抑制率分别为 62.13%和46.45%,根内线虫抑制率分别为62.50%和81.78%。     

Soil suppressiveness against the disease complex of the soybean cyst nematode and sudden death syndrome of soybean

The ecology of the complex of soybean cyst nematode (SCN) and sudden death syndrome (SDS) of soybean was investigated under soybean monoculture in two field experiments from 2003 to 2007. Initially, susceptible soybean 'Spencer' was planted while inoculating Fusarium virguliforme into nonfumigated or preseason-fumigated plots (methyl bromide, MB, at 450 kg/ha), and SCN and SDS were monitored. In one field, SCN population densities declined in nonfumigated but increased in fumigated plots. After years of limited SDS in 2003 and 2004, SDS developed later in nonfumigated than fumigated plots. In 2006 in the greenhouse, nondisturbed or disturbed soil cores (10-cm diameter, 30-cm depth) from field plots received two two-level factors: (i) nonfumigated or fumigated (1,070 kg/ha MB); and (ii) noninoculated or inoculated with 9,000 second-stage juveniles of SCN. At harvest, nonfumigated cores from nonfumigated plots had fewer nematodes and less SDS regardless of disturbance or inoculation than the corresponding fumigated cores and any cores from fumigated plots. In the second field, SCN became detectable after 2003 during the monoculture in nonfumigated plots and lagged in fumigated plots; both treatments had low levels of SDS. Exploiting the suppressiveness of the first field could allow for biological control of SDS and SCN in soybean production.     

大豆玉米间作和同穴混播对大豆病虫发生的综合效应研究

１９９３～１９９５年进行了大豆玉米间作和同穴混播对大豆病虫发生的综合效应研究。结果表明,间作和同穴混播豆田的病虫发生危害轻于纯作豆田,与纯作比较,间作田和同穴混播田主要害虫降低率分别在１１．４％～８１．４％和２０．９％～７６．０％之间;其病害降低率分别为７０．０％～１００％和５６．７％～１００％。间作只有豆天蛾和蛴螬可达防治指标,同穴混播田仅豆天蛾达防治指标。由于间作和同穴混播田提高了生物多样性,增强了自然生态控害功能。捕食性天敌,瓢虫分别较纯作增加８４．０％和８６．５％,草蛉增加５８．９％和８０．６％,蜘蛛增加４１．３％和５２．３％;寄生性天敌显著增加,蚜茧蜂对蚜虫寄生率增加２３．９％和２９．９％,赤眼蜂对豆天蛾卵寄生率增加１３．０％和２０．０％,银纹夜蛾幼虫被寄生率增加１８．７％和２５．３％。这２种种植方式产生的经济效益较纯作田增加３２．９％和３３．７％。     

Systemic properties of myclobutanil in soybean plants, affecting control of Asian soybean rust (Phakopsora pachyrhizi)

BACKGROUND: The demethylation inhibitor (DMI) fungicide myclobutanil can be an effective component of spray programmes designed to control the highly destructive plant pathogen Phakopsora pachyrhizi Syd. & P. Syd., causal agent of Asian soybean rust. Myclobutanil is known from previous studies in grapevines to be xylem mobile. This study investigates the mobility profile of myclobutanil in soybean as an important component of its effective field performance. RESULTS: Over a 12 day period under greenhouse conditions, a constant uptake of myclobutanil from leaflet surfaces into the leaflet tissue was observed. Once in the leaflet, myclobutanil was seen to redistribute throughout the tissue, although no movement out of leaflets occurred owing to a lack of phloem mobility. The ability of myclobutanil to redistribute over distance within the soybean plant was revealed when visualizing movement of the compound to foliage above the point of application on the plant stem. An efficacy bioassay demonstrated that the systemic properties of myclobutanil allow control of disease at a point remote from the initial site of compound application. CONCLUSION: It is suggested that the high degree of xylem systemicity displayed by myclobutanil in soybean foliage is a contributory factor towards its commercial effectiveness for control of Asian soybean rust. Copyright © 2008 Society of Chemical Industry     

淡紫拟青霉发酵滤液对大豆胞囊线虫趋化性的影响

 实验室条件下,研究了大豆胞囊线虫幼虫对大豆根和根浸出液的趋化性以及淡紫拟青霉代谢产物对其趋化性的影响。结果表明,大豆胞囊线虫二龄幼虫(J₂)对大豆根存在着一定的趋化性,而淡紫拟青霉发酵滤液对J₂存在明显的驱避性。在根浸出液、真菌滤液及其混合液剂处理下,大豆胞囊线虫J₂在WA平板上靠近处理液的0~1cm区间中分布率存在极显著差异(P <0.0 1),而加样时间(液剂与线虫同时放置或提前2 4h处理)对其分布率没有显著影响。大豆幼根蘸取滤液后对线虫J₂在该区间的分布与不经处理的幼根差异显著(P <0.0 5),证明淡紫拟青霉发酵滤液可以明显地降低线虫与大豆根的亲和力,并强烈抑制线虫对大豆根的侵染。     

抗、感大豆品种对尖镰孢根腐病菌侵染及毒素的反应

为了进一步明确大豆抗感品种对根腐尖镰孢的抗病机制,通过透射电镜和形态观察分析了尖镰孢(M38)侵染及产生的毒素对抗感大豆品种的影响。研究表明大豆幼苗胚根经粗毒素处理后,抗病品种‘东农56’幼苗胚根生长没有显著差别,但显著抑制了感病品种‘黑农53’胚根的伸长和侧根的生长;尖镰孢毒素高浓度和低浓度(V粗毒素∶V无菌水=1∶0和1∶15)对抗感品种的致萎能力无显著差异,高浓度处理平均萎蔫指数为100,低浓度处理为17.9~18.1左右;但中等浓度(V粗毒素∶V无菌水=1∶1,1∶5,1∶10)对于感病品种的致萎作用更大;同时,发现尖镰孢侵染感病大豆品种根内侵染量要明显多于抗病品种,且感病品种组织中菌丝的直径明显大于抗病品种,都出现很明显的质壁分离和细胞壁加厚的现象。     

美国大豆中镰刀菌的分离鉴定

为加强对美国输华大豆真菌病害的监测力度,降低外来生物入侵风险,本文通过对美国进境大豆病菌分离,共得到32个菌株,并对其中3株镰刀菌进行了形态学和分子生物学鉴定,确认了它们分别是尖孢镰刀菌(Fusarium oxysporum)、木贼镰刀菌(F.equiseti)和拟枝孢镰刀菌(F.sporotrichioides)。本研究从32个分离菌株中得到的3株镰刀菌分属于不同种,不仅证实了美国大豆中镰刀菌的多样性,也可为港口的植物检疫工作提供借鉴。     

大豆炭疽病菌Colletotrichum chlorophyti的鉴定

从进口的乌拉圭大豆的残留茎秆上分离到一种新的大豆炭疽病菌,根据菌落形态、分生孢子形态、ITS序列及ACT序列特征以及对大豆的致病性,将其鉴定为Colletotrichum chlorophyti,这是我国口岸首次截获该菌。     

大豆锈病研究现状与进展

大豆锈病近年在东南亚、南美洲发展迅速,对大豆生产威胁越来越大,尤其2004年11月登陆美国大陆,更引起大豆研究者、大豆生产国和进口国的极大关注。本文介绍了近年国际上大豆锈病的研究进展,主要包括大豆锈病的发现、地理分布、病原、症状、寄主范围、病原菌生理分化和防治技术研究等。     

美国大豆中链格孢的分离鉴定研究

本文通过对美国进境大豆病害分离,共得到36个菌株,并对其中5株链格孢菌进行了形态学和分子生物学鉴定(其中2株),确认了它们分别是细极链格孢(Alternaria tenuissima(Kunze)Wiltshire)、樱桃链格孢(Alternaria cerasiPotebnia)、苘麻链格孢(Alternaria abutilonis(Speg.)Schwarze)、百日菊链格孢(Al-ternaria zinniaeH.Pape)、落葵链格孢(Alternaria basellaeT.Y.Zhang)。本研究证实了美国大豆中链格孢菌的多样性,不仅充实了正在构建的大豆病害数据库和菌种资源库,也可为港口的植物检疫工作提供借鉴。     

防治大豆孢囊线虫的生防放线菌初步筛选

大豆孢囊线虫是我国大豆主产区的主要病害之一,已造成严重产量损失,而且防治困难,目前人们试图利用生物防治来控制线虫病害,以达到农业可持续发展的目的。本试验采用稀释分离法,从东北和华北等地区采集土样分离获得400株放线菌,通过筛选获得6株对大豆孢囊线虫有强烈抑制作用的菌株,分别是C49、C44、C25-3、C58、H-2和H-4。其中C49和C44菌株的菌悬液对大豆孢囊线虫J2有较强的杀死作用,C25-3、H-2、C49、H-4和C44菌株的发酵液代谢物对大豆孢囊线虫孢囊孵化和J2活性均有不同程度的抑制作用。C49菌悬液处理48h后大豆孢囊线虫J2的校正死亡率达到77.78%;C25-3发酵液4×稀释浓度下,处理24 h后J2校正死亡率达到94.84%;C49、C25-3、C58对孢囊的孵化相对抑制率分别达89.50%、89.50%、88.80%,均与对照差异显著。