小麦对小麦孢囊线虫抗病性研究进展

由小麦孢囊线虫引起的小麦孢囊线虫病发生分布范围广,防治困难,严重危害我国小麦生产.在我国危害小麦的孢囊线虫主要包括禾谷孢囊线虫(Heterodera avenae)和菲利普孢囊线虫(H.filipjevi).种植抗病小麦品种是防治小麦孢囊线虫病最经济有效的措施,近10年来,我国科学家制定了小麦孢囊线虫抗性评价标准,测试...     

Genetics of soybean-Heterodera glycines system

Genetics of resistance to soybean cyst nematode (SCN), Heterodera glycines Ichinohe is very complex. Crosses involving PI 437654, which is resistant to all races of cyst nematodes with other sources of resistance (Peking, PI 88788, and PI 90763) indicated that resistance to race 3 was controlled by four genes, two of which were dominant resistance genes and the other two were recessive resistance genes. For race 5, a four gene model with two recessive and two dominant resistance genes in epistasis has been proposed. For race 14, the results suggested a three gene model with one dominant and two recessive alleles. Several other plant introductions have been isolated which have different genes conditioning resistance. Most of the currently grown soybean varieties derived resistance from Peking and/or PI 88788. Resistance to SCN in these soybean varieties has broken down because of the emergence of several new races and populations of SCN. The use of PI 437654 or Hartwig and other plant introductions with different genes for resistance will broaden genetic diversity and stabilize yield.     

禾谷孢囊线虫(Heterodera avenae)的分子鉴定及抗性基因研究进展

禾谷孢囊线虫是温带禾谷类作物上的世界性重要病原线虫。本文回顾关于禾谷孢囊线虫的分子鉴定和亲缘分析等方面的研究,以及对国内外小麦品种抗性基因的筛选和应用等结果。根据上述方面的结果拟定更为合理的防治策略。     

植物抗线虫基因工程新途径及其在分子育种中的应用

 植物寄生线虫种类繁多、危害严重,给世界农业生产造成巨大经济损失。目前防治线虫通常采用轮作、杀线虫药剂、生物防治和应用抗性品种等措施,但存在一定局限性。随着植物与寄生线虫之间相互作用机制的深入研究以及分子遗传操作技术的逐渐成熟,利用基因工程技术构建环保、方便、有效的线虫防治策略逐渐成为研究热点。本文从植物抗线虫基因、抑制线虫的外源活性蛋白、特异表达启动子,以及RNAi介导的抗线虫基因工程策略等方面,简要概述了国内外近年来植物抗线虫基因工程新途径研究进展以及在分子抗病育种中的应用。     

新疆大豆孢囊线虫病的初步研究

大豆孢囊线虫病是威胁大豆生产的主要病害之一。随机调查了大豆孢囊线虫（Heterodera glycines Ichinohe）在新疆的分布;运用鉴别寄主法鉴定新疆大豆孢囊线虫的生理小种;室内盆栽法测定新疆主栽大豆品种对大豆孢囊线虫的抗病性。结果表明大豆孢囊线虫主要分布在新疆阿勒泰地区,为4 号生理小种,新疆主栽大豆品种均为高感品种,研究结果将为控制新疆地区大豆孢囊线虫的危害提供理论依据。     

山东省寄生烟草的孢囊线虫种类鉴定及种内群体间rDNA-ITS-RFLP分析

 在山东省5个植烟县/市采集烟草线虫土壤样本24份,其中10份土样中分离到孢囊线虫的孢囊,对之进行系统的形态学观测。孢囊阴门锥突出,双半膜孔,下桥和泡囊发达,阴门裂长（44.1±3.5） μm,阴门窗长（50.4±4.8） μm、宽（36.6±4.1） μm,下桥长（83.8±4.7） μm、宽（11.0±0.9） μm。利用大豆孢囊线虫特异性引物对分离到的孢囊线虫群体进行了分子鉴定。形态学和分子鉴定结果表明,山东省寄生烟草的孢囊线虫为大豆孢囊线虫Heterodera glycines Ichinohe,1952。对这10个孢囊线虫群体rDNA-ITS区进行了PCR扩增产物用7种限制性内切酶进行酶切和测序比对。发现,所有孢囊线虫群体均能扩增出一条大约1 000 bp大小的片段;用Alu Ⅰ、Bsh 1236 Ⅰ、Hae Ⅲ、Hha Ⅰ 、Mva Ⅰ 、Rsa Ⅰ酶切后,产生的酶切表型均相同;用Ava I酶切后,产生了2种酶切表型。所测孢囊线虫群体与GenBank收录的大豆孢囊线虫序列相似度高达99%以上。     

United States Department of Agriculture-Agricultural Research Service research on biological control of arthropods

During 1999-2001, ARS scientists published over 100 papers on more than 30 species of insect pest and 60 species of predator and parasitoid. These papers address issues crucial to the three strategies of biological control: conservation, augmentation and introduction. Conservation biological control includes both conserving extant populations of natural enemies by using relatively non-toxic pesticides and increasing the abundance of natural enemies in crops by providing or improving refuges for population growth and dispersal into crops. ARS scientists have been very active in determining the effects of pesticides on beneficial arthropods and in studying movement of natural enemies from refuges into crops. Augmentation involves repeated releases of natural enemies in the field, which can be inoculative or inundative. Inoculative releases are used to initiate self-propagating populations at times or in places where they would be slow to colonize. ARS scientists have studied augmentative biological control of a variety of pest insects. The targets are mostly pests in annual crops or other ephemeral habitats, where self-reproducing populations of natural enemies are not sufficiently abundant early enough to keep pest populations in check. ARS research in augmentative biological control centers on methods for rearing large numbers of healthy, effective natural enemies and for releasing them where and when they are needed at a cost less than the value of the reduction in damage to the crop. ARS scientists have researched various aspects of introductions of exotic biological control agents against a diversity of pest insects. The major issues in biological control introductions are accurate identification and adequate systematics of both natural enemies and target pests, exploration for natural enemies, predicting the success of candidates for introduction and the likelihood of non-target impacts, quarantine and rearing methods, and post-introduction evaluation of establishment, control and non-target impacts. ARS scientists have published research on several general issues in biological control. Among the most important are the mechanisms affecting mate- and host-finding and host specificity.     

Cereal diseases caused by <Emphasis Type="Italic">Fusarium graminearum</Emphasis>: from biology of the pathogen to oxidative burst-related host defense responses

Small grain cereals, such as wheat, barley and oats are considered among the most important food sources. Plant-parasitic nematodes play a considerable role in decreasing cereal yields. The three-major species of cereal cyst nematodes (CCN) Heterodera avenae, H. latipons, and H. filipjevi are distributed worldwide and cause considerable damage. This review provides information regarding the global distribution of these nematode species, yield loss due to CCN, their biology and pathogenic relation to plants, identification and control through agricultural practices, biological agents and resistance breeding. As morphological identification of CCN is difficult and time-consuming, several molecular techniques for the identification of these CCN species have been developed in recent years. The restrictions on the use of nematicides demand for resistance to CCN. Resistance genes in several lines are known and are used in numerous breeding programmes against CCN; pyramiding these resistance genes into high yielding cultivars that could become commercially available for farmers is progressing.     

为害地黄的大豆孢囊线虫的初步研究

 为害栽培地黄(Rehmannia glutinosa Llbosch.,f.hueichingensis Hsiao)的孢囊线虫,经形态和生物学特性的观察,以及在地黄与大豆间的交互接种试验,鉴定为大豆孢囊线虫(Heterodera glyines Ichinohe,1952)。本文报道了该线虫的主要形态、生物学特性及防治方法。该线虫在北京此区地黄上一年发生5-6代,平均土温24.5℃时完成一代约须27天;20.2℃时约须35天。干燥使孢囊中的卵和幼虫的生命力急剧下降。地黄根浸出液对幼虫孵化没有明显的刺激作用。轮作与抗病品种是防治该线虫的主要措施;D-D混剂处理土壤及热水处理繁殖材料也是有效的防治方法。该线虫除为害地黄外,尚可侵染高黄芩、黄花毛蕊花、比利牛斯金鱼草、小叶野决明和歪头菜等药用植物。     

小麦禾谷胞囊线虫病研究进展

从病原分布、分类、发生规律、为害症状及造成损失、致病型鉴定、防治方法几个方面介绍了国内、国外小麦禾谷胞囊线虫病研究的最新进展,并指出了其在我国主要麦区的发生呈逐年加重趋势。     

Expression of the Arabidopsis MCM Gene PROLIFERA During Root-Knot and Cyst Nematode Infection

ABSTRACT Expression of the Arabidopsis thaliana gene PROLIFERA (PRL) was examined during development of root-knot and cyst nematode feeding sites. These obligate plant parasites establish specialized feeding structures in roots that allow them to withdraw nutrients from the host. In the process of establishing feeding sites, nematodes alter cell cycle regulation. PRL is normally expressed specifically in dividing cells at all stages of plant development and was used here as a marker for cell division. PRL expression, reported from a PRL::GUS fusion protein, was detected in nematode feeding sites of both root-knot and cyst nematodes from the earliest stages of infection in both giant cells and syncytia. However, unlike other cell cycle genes, expression of PRL was detected only occasionally in cells surrounding the feeding sites. PRL::GUS activity persisted until late in the infection cycle, past the time when other cell cycle genes are expressed. These data indicate that some aspects of the PRL expression pattern during nematode infection differ from that of other cell cycle genes.     

贵州省大豆孢囊线虫的发生与分布

大豆孢囊线虫病是威胁大豆生产的重大病害之一。2015-2016年,采用随机取样的方法对贵州省大豆孢囊线虫的发生和分布情况进行了调查。调查范围包括贵阳、六盘水、安顺、毕节、黔西南和遵义等6个地区下辖的14个县(区),共采集土样287份。调查结果表明,贵州省大豆孢囊线虫的总检出率为28.2%,其中毕节地区的大方县和赫章县孢囊检出率最高,分别达到46.7%和45.0%,而在遵义市、贵阳市和黔西南州孢囊检出率为0。六盘水地区的水城县孢囊发生量最大,平均孢囊数为3.4个/200g土,最大孢囊数达到17个/200g土;安顺地区的镇宁和关岭县大豆孢囊线虫发生程度最轻,每200g土样平均孢囊数分别为0.3和0.2个,最大孢囊数仅为2个/200g土。分离的孢囊主要形态特征与大豆孢囊线虫一致,并且ITS序列与甘肃大豆孢囊线虫种群序列一致性达100%。根据形态学观察和ITS序列分析比对,将贵州省采集到的孢囊线虫鉴定为大豆孢囊线虫。本研究结果可为有效防控贵州省大豆孢囊线虫病提供依据。     

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%。     

大豆胞囊线虫侵染泡桐和豌豆的研究

 形态学观测和寄生性研究结果表明,发生于我国河南省兰考县泡桐(Pauloumia sp.)和内蒙古自治区凉城县豌豆(Pisum sativum)上的胞囊线虫均属于大豆胞囊线虫(Heterodera glyeines);上述两种植物上的胞囊线虫均可侵染大豆,在根部形成有卵雌虫。而兰考和凉城两地大豆上的胞囊线虫群体可分别在泡桐成豌豆上良好繁殖。以上结果证明,泡桐和豌豆为大豆胞囊线虫的两种新寄主植物,其中,泡桐为大豆胞襄线虫侵染多年生乔木植物的首例报道。     

淡紫拟青霉对大豆胞囊线虫卵及2龄幼虫的影响

研究了淡紫拟青霉M-14、IPC菌株对大豆胞囊线虫卵孵化及2龄幼虫活性的影响。结果表明,M-14滤液及其菌丝内溶物、IPC滤液、ZnCl_2溶液等不同处理间存在极显著差异(P<0.01)。代谢产物对卵生理活性的影响因试验菌株的不同而异,M-14菌株发酵滤液及其内容物对大豆胞囊线虫卵的孵化具有强烈的抑制作用,而IPC菌株的影响则较弱。大豆胞囊线虫2龄幼虫在M-14发酵滤液原液及1倍稀释液中均表现为麻痹僵直,线虫死亡率随时间的延长而增加,72h后幼虫死亡率分别达到96.8％和90.5％。将经M-14原液处理24h的幼虫置于清水中,仅有极少数能够恢复活性,证明M-14代谢产物具有很强的杀线虫活性。     

Current United States Department of Agriculture-Agricultural Research Service research on understanding agrochemical fate and transport to prevent and mitigate adverse environmental impacts

Environmentally and economically viable agriculture requires a variety of cultivation practices and pest management options as no one system will be appropriate for every situation. Agrochemicals are some of the many pest control tools used in an integrated approach to pest management. They are applied with the intent of maximizing efficacy while minimizing off-site movement; however, their judicious use demands a practical knowledge of their fate and effects in agricultural and natural ecosystems. Agrochemical distribution into environmental compartments is influenced by the physical and chemical properties of the agrochemical and environmental conditions, ie soil type and structure, and meteorological conditions. Agricultural Research Service (ARS) researchers working in the area of agrochemical fate have focused on accurately describing those processes that govern the transport, degradation and bioavailability of these chemicals under conditions reflecting actual agronomic practices. Results from ARS research concerning the environmental fate and effects of agrochemicals have led to the development of science-based management practices that will protect vulnerable areas of the ecosystem. The new challenge is to identify these vulnerable areas and the temporal and spatial variations prior to use of the chemical by predicting how it will behave in environmental matrices, and using that information, predict its transport and transformation within an air- or watershed. With the development of better predictive tools and GIS (Geographic Information System)-based modeling, the risks of agricultural management systems can be assessed at the watershed and basin levels, and management strategies can be identified that minimize negative environmental impacts.     

河北省大豆孢囊线虫分子鉴定及其分布

2003年,在河北省邯郸、邢台、石家庄、保定、秦皇岛、唐山、张家口等地采集大豆根际土壤样品65份,应用大豆孢囊线虫特异性引物对采集的孢囊线虫进行了分子鉴定,结果表明从邯郸的永年、磁县、峰峰,邢台的南和、广宗、清河,保定的南大园、西马池、望都、定州,石家庄的栾城、鹿泉、平山及石家庄市郊,秦皇岛的抚宁、昌黎,唐山的迁西、迁安、丰润的大豆和张家口的红云豆上采集的孢囊线虫的孢囊及其二龄幼虫均为大豆孢囊线虫;卢龙和滦县的样品中没有发现大豆孢囊线虫的孢囊及其二龄幼虫,且孢囊的检出率与二龄幼虫的检出率的趋势一致。     

United States Department of Agriculture-Agricultural Research Service research on pest biology: weeds

Over 125 permanent full-time scientists conduct research within the USDA Agricultural Research Service (ARS) on issues related to weeds. The research emphasis of most of these scientists involves ecology and management or biological control of weeds. Many scientists perform research on weed biology as components of their primary projects on weed control and integrated crop and soil management. Describing all ARS projects involved with weed biology is impossible, and consequently only research that falls within the following arbitrarily chosen topics is highlighted in this article: dormancy mechanisms; cell division; diversity of rangeland weeds; soil resources and rangeland weeds; poisonous rangeland plants; horticultural weeds; weed traits limiting chemical control; aquatic and semi-aquatic weeds; weed/transgenic wheat hybrids; seedbanks, seedling emergence and seedling populations; and weed seed production. Within these topics, and others not highlighted, the desire of ARS is that good information on weed biology currently translates or eventually will translate into practical advice for those who must manage weeds.     

植物根结线虫基因组学研究进展

根结线虫是世界农业生产中危害最大的植物病原之一,目前仍缺乏安全有效的防治措施。深入揭示寄生线虫与植物之间互作的分子机制,利用生物技术进行抗性育种被认为是最有前景的抗线虫策略。在根结线虫基因组学研究方面,目前已经构建了北方根结线虫AFLP遗传连锁图谱,南方根结线虫和北方根结线虫基因组测序也已完成;基因组的注释和比较基因组学分析,较全面地描述了根结线虫的遗传组成;以差异表达分析和比较基因组学为主的方法鉴定了大量的重要基因;以RNA干扰、植物转化和蛋白互作为主的根结线虫基因功能研究也取得了一些进展。本文就根结线虫基因组学研究予以综述,并进一步探讨其研究方向和可持续抗线虫新策略的发展前景。     

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。