大豆不同轮作系统主要植物线虫季节动态

为从线虫生态角度评价土壤健康状况和大豆轮作系统的合理性及预测大豆根部病害发生与为害,利用浅盘法收集大豆不同轮作系统下苗期、花期和结荚期土壤线虫,研究大豆不同生育期土壤总体线虫和重要属植物线虫群体动态.取大豆连作14年、小麦-玉米-大豆轮作、麦豆麦豆迎茬、米豆米豆迎茬和休闲区0～20 cm土壤.结果表明:土壤中胞囊线虫密度为迎茬(米豆、麦豆)轮作连作休闲;从大豆苗期、花期至结荚期,各轮作系统胞囊线虫密度逐渐递增,麦豆迎茬和轮作土壤中总体线虫密度呈递增趋势,各轮作系统苗期和花期土壤总体线虫差异显著;3个时期,轮作土壤中总体线虫密度分别最大,而休闲土壤中螺旋-盘旋-拟盘旋线虫为优势种群.     

大豆连作孢囊线虫病的发生与防治

大豆孢囊线虫病严重影响大豆产量。连作地块土壤中，孢囊线虫数量迅速增长，大豆产量递减。实行非寄主作曲轮作。土壤中孢囊绒虫数量锐减，大豆产量回升。5％甲拌磷颗粒剂，3％呋喃丹颗粒剂，35％多、克、福种衣剂可有效地控制、杀灭连作大豆田土壤中的绝大部分孢囊线虫。是连作大豆生产中孢囊线虫防治的有效途径。     

大豆生育条件与孢囊线虫密度关系(节译)︶

大豆生育条件与孢囊线虫密度关系︵节译由于大豆连作，大豆孢囊线虫害加重，为减轻受害，作为一般的农业技术措施，把非寄主作物编入轮作体系。查文献得到：在大豆孢囊线虫密度高的土地种植大豆时，大豆根系受到线虫寄生而不能充分发育，根系细弱，分布范围也狭小。施用氮...     

大豆连、轮作土壤微生物生态分布与大豆孢囊线虫群体动态的研究

连作与轮作大生各生育期土壤微生物生态分布和大豆孢囊线虫群体动态的研究结果表明,无论上壤微生物总数或大豆根表微生物总数的动态变化,均以细菌数量占绝对优势,其次是放线菌。真菌最少。根表微生物总数大于土壤微生物总数的几十倍到100多倍。大豆各生育期微生物总数以开花期为最多,其次是成熟期.再次是分枝期。根瘤密度和大豆孢囊密度以成熟期为最大,其次是开花期,分枝期最小。微生物总数和根瘤密度,轮作区高于连作区。孢囊密度则相反,连作区高于轮作区。值得注意的是,真菌数量动态变化与孢囊密度动态变化是一致的.其次序是分枝期<开花期<成熟期。这种吻合可能有着内在的联系,有待进一步研究。     

不同茬口种植的大豆品种根渗出物对大豆孢囊线虫卵孵化的影响

取北方5种作物轮作茬口和休闲土壤种植不同大豆品种,出苗后22d制备植株的根渗出物观察对大豆孢囊线虫(SCN)卵孵化的影响.试验结果表明,同一品种在不同茬口土壤种植后获得的根渗出物对SCN卵孵化率不同,抗线3号在不同的茬口条件下根渗出物对SCN卵孵化率差异很大,豆麦米轮作、米豆米迎茬和豆麦豆迎茬条件下对SCN卵孵化具有促进作用,但在麦豆麦迎茬、连作12a大豆和休闲条件下根渗出物对SCN卵孵化具有抑制作用.合丰25只在连作12a大豆条件下对SCN卵孵化具有促进作用,而在豆麦米轮作、麦豆麦迎茬、米豆米迎茬和豆麦豆迎茬条件下均表现为对SCN卵孵化的抑制作用,在休闲条件下与对照差别不大.抗线4号在6个茬口中没有明显的促进或抑制作用,基本与对照差别不大.     

麦类作物线虫病的研究现状及对策

本文阐述了麦类作物主要线虫病及其有关症状、发生规律等新的研究进展。研究指出小麦粒瘿线虫对寄主有特异性识别作用.侵染后寄主的新陈代谢受到干扰。粒瘿线虫、燕麦孢囊、根结、根腐等线虫.可与细菌、真菌造成复合侵染加重为害。它们大都存在生理分化现象,轮作与抗病育种时应予以注意。穿刺巴氏芽孢杆菌、厚垣孢轮枝菌、嗜雌线疫霉菌对燕麦孢囊和根结线虫的雌虫和卵有一定生防作用.可进一步研究应用。     

作物轮作系统对大豆胞囊线虫二龄幼虫寄生真菌的影响

采用蔗糖梯度离心法和传统真菌鉴定技术,研究定位试验条件下长期连作、麦豆迎茬、米豆迎茬和麦米豆轮作不同轮作方式下大豆胞囊线虫二龄幼虫虫口密度和寄生真菌情况.结果表明:连作大豆田土壤中大豆胞囊线虫二龄幼虫寄生真菌只有明尼苏达被毛孢(Hirsutella minnesotensis),其它轮作方式中,寄生真菌有2种即洛斯里被...     

大豆胞囊线虫主要寄生真菌对大豆耕作系统的响应

大豆长期连作以后,随着土壤中大豆胞囊线虫的增多,胞囊线虫天敌也在不断积累,逐步形成大豆胞囊线虫抑制性土壤。真菌作为主要因子,在抑制性土壤中发挥重要作用。为探讨大豆长期连作对大豆胞囊线虫寄生真菌的影响,以大豆22年定位试验区为研究对象,分离和鉴定了22年大豆连作、3年大豆连作和22年大豆轮作(小麦-玉米-大豆)土壤和土壤中大豆胞囊线虫不同虫态寄生真菌。结果表明:大豆经过22年连作后,厚垣轮枝菌(Verticillium chlamydosporia)和淡紫拟青霉(Paecilomyces lilacinus)分离数量高于3年连作和22年轮作,其中厚垣轮枝菌的数量最高,每克土中含有1.5×104株,胞囊、卵和J2上分别分离到14,18和8株,显著高于3年连作和轮作。研究结果证明了大豆经过长期连作后,土壤中积累了大豆胞囊线虫寄生真菌,而厚垣轮枝菌可能是抑制性土壤中的主要寄生真菌。     

春大豆长期连作对土壤线虫群落结构和食物网的影响

以土壤线虫为指示生物,研究了大豆不同耕作系统土壤线虫群落结构、生态指数和食物网指数的变化特征,以期明确大豆长期连作对土壤生物多样性和土壤食物网结构的影响。结果表明:大豆轮作土壤线虫属最丰富,大豆长期连作25年后土壤线虫属水平种类最少。大豆轮作和大豆短期连作3年土壤线虫群落组成Jaccard相似性最高(0.81),大豆轮作和大豆长期连作25年Jaccard相似性最低(0.66)。大豆短期连作3年土壤中植物寄生线虫的数量最高,显著高于大豆轮作和大豆长期连作25年。食真菌线虫在大豆长期连作25年土壤中较丰富,显著高于大豆轮作和大豆短期连作3年。大豆长期连作25年植物寄生线虫成熟度指数(PPI)高于大豆短期连作3年和大豆轮作。土壤线虫的通路指数(CI)在3个处理中均小于50,土壤腐蚀食物网的降解以细菌降解通路为主。大豆短期连作3年处理位于富集指数(EI)和结构指数(SI)食物网特征图的A象限,大豆轮作和长期连作25年位于食物网特征图的B象限。结果表明,大豆长期连作改变了土壤线虫的群落结构,降低了属的多样性,食物网结构向成熟稳定的方向恢复。     

长期轮作和连作对土壤中 大豆胞囊线虫数量的影响

在白浆土设计长期轮作和连作试验区,采取麦麦豆油玉豆6区轮作和麦玉豆连作, 18a内连续调查土壤 中大豆胞囊线虫( SCN)的胞囊数量,观察轮作或连作对土壤中SCN胞囊数量的影响。试验结果表明,长期轮作使 土壤中胞囊数量有减少的趋势,各茬口间胞囊数量变化幅度减小,轮作12a后土壤中胞囊数量达到动态平衡;大豆 连作的前2a土壤中胞囊数量急速增加,以后缓慢增加, 7a后有下降趋势, 14a后土壤中的胞囊数量在较高水平上趋 于平衡;小麦或玉米连作前3a土壤中的胞囊数量呈快速下降, 4a后缓慢减少, 14a后土壤中胞囊数量极少。     

Cereal cyst nematode effects on wheat water use,and on root and shoot growth

Wheat (Triticum aestivum L.) is grown in many arid regions using fallow management whereby no crop is grown in alternate cropping seasons. Although fallowing is important in increasing the availability of water and nitrogen to crops in many environments, experiments in Israel revealed that water carryover from the fallow season for wheat production was rare. This paper examines the possibility that improved water use, and improved root and shoot growth, result from soil sanitation of cereal cyst nematode (CCN, Heterodera avenae Woll.) in the fallow season. Pot experiments in controlled environments revealed a dramatic, negative effect of various populations of CCN on wheat root growth. The decrease in root growth was associated with decreased shoot growth and decreased rates of transpiration. Mechanical pruning of roots mimicked the effects of CCN infestation indicating that root pruning is probably the primary damage of CCN. In the field, dry weight yields of wheat were maintained even in continuous wheat management when a soil biocide was used to control CCN. It is proposed that the success of the fallow management is based on the fact that CCN cysts hatch in wet soil during rainy periods of the fallow year but fail to produce a new generation of cysts because no host plants are present.     

Model analysis of a straw mulch system for continuous wheat in an arid climate

Wheat (Triticum aestivum L.) production in some dryland regions is severely limited by the cereal cyst nematode (Heterodera avenae Woll.). Conventional fallow management during a wet period has been shown to allow hatching of the cysts during the fallow season and thereby sanitize the soil for the subsequent wheat crop. Recently a straw mulch (SM) management has been introduced into a long-term experiment in the Negev region of Israel. This management ameliorated the nematode damage and allowed continuous wheat production. Only three seasons of successful experimentation exist with the SM system so questions remain about its performance over seasons with differing weather conditions. A simple, mechanistic, wheat model was extended to simulate wheat development and growth when the crop is grown on nematode-infested soils. Incorporating statements describing inhibition of rooting depth as a result of nematode activity resulted in good agreement between simulations and 16 seasons of yield observations on continuous wheat. The effect of SM was simulated simply by decreasing soil evaporation and this resulted in higher levels of soil water and decreased nematode inhibition of rooting. Good agreement was obtained between the three seasons of experimental data and simulations of the SM system, with predicted grain yield within 10% of observations. Over 16 seasons, simulations of the SM system indicated substantial grain yield increases over continuous wheat in all but the highest-yielding season. Simulations in 14 seasons with conventional fallow management revealed that annual yields of SM were equivalent to biennial yields of the fallow system, resulting in a predicted doubling of wheat production for this dryland region of the Negev.     

禾谷孢囊线虫初始密度对其繁殖及小麦生长和产量的影响

为明确土壤中禾谷孢囊线虫(Heterodera avenae)初始密度(Pi)与小麦生长和产量的关系,在2011-2013年的两个冬小麦生育周期里,通过网室盆栽试验,分析了土壤禾谷孢囊线虫初始密度对其繁殖及小麦生长和产量的影响。结果表明,禾谷孢囊线虫的繁殖系数(Rf)随Pi的增加而减少,当Pi为0.5个卵·mL-1土时,Rf达到8.7;当Pi为64个卵·mL-1土时,Rf仅为2.8。小麦株高、茎叶干重、根干重及产量均与Pi呈显著负相关。当Pi≥8个卵·mL-1土时,小麦植株生长受到抑制,产量显著下降,因此田间禾谷孢囊线虫的初始密度高于该值时,应当采取有效措施进行防治。     

Effect of crop rotation,cultivar and nematicide on growth and yield of potato (Solanum tuberosum L.) in short rotations on a marine clay soil

Summary The effects of cropping frequency on the yield of potato and on the development of soil-borne diseases was studied from 1979 to 1985 in a crop rotation experiment on a marine clay soil. Tuber yield decreased markedly with increasing cropping frequency. The yield of cv. Hertha was reduced by 27% in continuous cropping and by 15% in a wheat/potato or sugar beet/potato rotation, when compared with the rotation wheat/sugar beet/oats/potato. However, a pot experiment showed that yield depression in continuous cropping depended on the cultivar used. Crop growth declined in the second part of the growing season, and senescence accelerated as the cropping frequency increased.Verticillium dahliae was the most important yield-reducing factor. Root infection by this fungus was stimulated by the root-lesion nematodePratylenchus neglectus.     

普通小麦品种中育6号对两种禾谷孢囊线虫的抗性遗传分析

为了解小麦品种中育6号对菲利普孢囊线虫(Heterodera ilipjevi)焦作博爱群体和燕麦孢囊线虫(H.avenae)郑州荥阳群体的抗性遗传特点,在前期对该品种对两种禾谷孢囊线虫群体抗性鉴定的基础上,采用主基因+多基因混合遗传模型分析方法,分析了温麦19×中育6号杂交组合F2代群体抗性分离状况.结果表明,中育6号对两种禾谷孢囊线虫的抗性表现均为数量性状遗传,且由一对主基因控制.其对H.avenae郑州荥阳群体的抗性存在负向部分显性,是显性基因和加性基因共同作用的结果,且以加性效应为主,抗性主基因遗传率为59.35％;对H.filipjevi焦作博爱群体的抗性表现为负向完全显性效应,主基因遗传率为38.12％.     

Causes of differences in growth pattern,yield and quality of potatoes (Solanum tuberosum L.) in short rotations on sandy soil as affected by crop rotation,cultivar and application of granular nematicides

Summary A crop rotation experiment was carried out on a light sandy soil in 1979–1986 to study the effects of the frequency of potato cropping on yield, quality and on the occurrence of soil-borne pathogens other than potato cyst nematodes. Tuber yield decreased markedly with increasing cropping frequency, but also depended on what crops were grown in rotation with potato. Growth during the early part of the season, as well as the length of the growing period, were reduced in short rotations. The fungiVerticillium dahliae andRhizoctonia solani, and root-knot nematodes (Meloidogyne spp.) were the most important yield reducing pathogens. The effects of rotation depended on the cultivar used. The percentage of mis-shapen tubers increased with increasing cropping frequency and after application of granular nematicides, but the incidence of common scab (Streptomyces scabies) was not affected.     

甘南农牧过渡区燕麦田孢囊线虫的发生与分布

为明确孢囊线虫在高寒、高海拔区的发生与分布情况,2015年8月,采用Z字型取样法,对甘南农牧过渡区10个乡镇燕麦田的80份根际土样进行了孢囊线虫调查。80份土样中孢囊线虫平均检出率为87.5%,夏河县的达菱乡、达麦乡、唐嘎尔乡与那吾乡,卓尼县杓哇乡及临潭县冶力关镇土样的检出率均达100%;夏河县王格尔塘镇最低,为60%。海拔高度不同,孢囊线虫的分布不同,在海拔2 501~2 800m的区域土样中,孢囊线虫检出率最高,为100%,在海拔3 101~3 500m区域检出率最低,为58.3%。燕麦田间孢囊线虫密度平均为3.7个·100g~(-1)土,其中卓尼县杓哇乡的密度最高,为14.4个·100g~(-1)土,夏河县王格尔塘镇和临潭县冶力关镇的最低,为1.1个·100g~(-1)土。通过形态学特征鉴定,此区的孢囊线虫为燕麦孢囊线虫(Heterodera avenae)。     

黑土区不同抗性大豆品种与大豆胞囊线虫群体动态关系

大豆胞囊线虫(Heterodera glycines Ichnohe,简称SCN)病是一种大豆最严重的病害之一,应用抗病品种和轮作是控制该病最经济有效的方法.上个世纪80年代以来我国也相继育成了一些抗大豆胞囊线虫病品种,为了探讨不同抗性品种与大豆胞囊线虫群体动态关系和抗性品种的抗性机制,在黑土区的中国科学院海伦农业生态试验站的长期定位区,取我国大豆主产区常见的小麦--玉米--大豆轮作、玉米--大豆--玉米--大豆迎茬、小麦--大豆--小麦--大豆迎茬和大豆连作13年4种轮作方式,以在我国大豆主产区育成的抗大豆胞囊线虫3号生理小种的抗线4号和非抗病品种黑农35为材料,研究了不同抗性品种大豆在不同轮作系统中根内不同龄期线虫和根面雌虫发育动态.结果表明,不同大豆品种根内二龄幼虫(J2)数量存在着差异,在大豆连作13年、豆米豆和豆麦豆茬口上种植的抗线4号根内J2数量高于黑农35;在大豆连作13年、轮作、米豆米豆迎茬和麦豆麦豆迎茬4个茬口中抗线4号根内三龄幼虫(J3)、四龄幼虫(J4)数量和根面雌虫数量明显低于黑农35.由此推断抗线4号对大豆胞囊线虫3号生理小种的抗性机制可能是抗线虫发育,而不是抗线虫侵入.     

部分国内外小麦种质资源对燕麦孢囊线虫的抗病性

燕麦孢囊线虫是小麦生产上的重要病原线虫。为筛选抗燕麦孢囊线虫的小麦种质资源,采用室内接种方法测试了104个国外小麦品种（系）和37个国内小麦品种对燕麦孢囊线虫的抗病性,并利用不同抗性评价标准在自然病田对37个国内小麦品种的抗病性进行了评价。室内接种试验表明,104份国外小麦品种（系）中有高抗品种（系）14个,中抗品种（系）12个,中感品种（系）27个,其他均属高感,37个国内参试品种均属感病品种。自然病田鉴定结果表明,采用不同的评价标准对37个国内品种的评价结果具有较大差异。依据Andersen等的评价标准,37个小麦品种中有7个品种表现感病,30个品种表现抗病,与室内接种测试结果差异较大;依据Ireholm的标准,仅良星66表现抗病,其他品种均表现感病,与室内测试结果接近;依据Soriano等的标准,37个品种均表现感病,与室内测试结果相同。建议在筛选抗孢囊线虫小麦资源时首先采用Andersen等的标准进行初筛,然后利用Soriano等的标准进行田间评价。