大豆疫霉病研究进展

本文对大豆疫霉菌的检测和分离、生理小种和遗传多样性、抗性以及侵染和田间流行特点等方面的研究进展和取得的新成果进行了综述,从检疫、农业防治和化学防治等方面提出了该病的防治对策.     

大豆疫霉病的症状与分离技术

大豆疫霉病的症状与分离技术李宝英（黑龙江省农科院合江农科所佳木斯１５４００７）大豆疫霉病Ｐｈｙｔｏｐｈｔｈｏｒａｍｅｇａｓｐｅｒｍａｆ．ｓｐ．ｇｌｙｃｉｎｅａＫｕａｎ＆Ｅｒｗｉｎ也叫大豆疫霉根腐病，是一种分布较广、危害极其严重的土传性病害。产量损失一...     

大豆疫霉选择性分离技术研究

 由大豆疫霉(Phytophthora spiae)引起的大豆疫霉根腐和茎腐病广泛分布于世界大豆主产区。是大豆毁灭性病害之一。     

荔枝霜疫霉病的发生及防治

广西浦北地处桂南沿海，春夏荔枝开花至果实成熟阶段，雨日较多，雨量大，荔枝霜疫霉病病情扩展迅速。一些果园种植密度较大，回缩和间伐工作不到位，造成果园荫蔽，通风透光条件较差，一些果园偏施氮肥，致使植株营养生长过于旺盛，也极易诱发该病的发生流行。     

大豆疫霉根腐病在我国的发生及防治对策

由大豆疫霉根腐病菌Ｐｈｙｔｏｐｈｔｈｏｒａｓｏｊａｅ引起的大豆疫霉根腐和茎腐病１９４８年发现于美国印第安纳州,１９５１年俄亥俄州首次报道,此病目前已传播到世界各国大豆产区,是严重影响大豆生产的主要病害之一［１］。鉴于大豆疫霉菌的破坏性和毁灭性,１９８...     

蒙城大豆疫霉菌的鉴定及其生理小种

 在安徽省蒙城县对大豆疫霉根腐病的发生情况进行调查。应用选择性培养基对类似大豆疫霉根腐病症状的病株进行病原菌分离,在春大豆蒙城早熟青豆病株上分离到2株疫霉菌PMC1、PMC2和一些Fusarium spp.,在夏大豆上分离到的主要病原菌为Pythium spp.和Fusarium spp.,未分离到疫霉菌。根据疫霉菌分离物PMC1和PMC2形态和生理学特征以及对大豆的专化致病性,2个分离物被鉴定为大豆疫霉菌(Phytophthora sojae Kaufmann&Gerdemann)。应用国际通用鉴别寄主进行生理小种鉴定,PMC1和PMC2的毒力公式分别为1b,1d,3a,3c,5,7和1b,1d,4,5,为新的小种类型,定名为中国6号小种、中国7号小种(CNR-6和CNR-7)。这是首次报道大豆疫霉菌在我国淮北地区存在。     

陕西省猕猴桃疫霉病的病原鉴定

 作者于1997~1998年对陕西省主要猕猴桃产区病害的调查过程中,发现猕猴桃疫霉病在大多数果园有不同程度的发生,重病园发病率可达20%~30%,死亡率10%~20%,个别果园造成果树成片死亡。作者对病原菌的初步鉴定结果认为,陕西省猕猴桃疫霉病的病原菌主要为疫霉属的恶疫霉菌(Phytophthora cactorum (Leb.et Cohn) Schr.),该病害在国内尚未见报道。     

荔枝霜疫霉病发生规律及防治技术的试验研究

荔枝霜疫霉病（Peronophythora Litchi Chen et al）是荔枝一种主要病害,该病害可以为害荔枝的花和果,花期发病,造成大量的枯花,幼果期发病,引起落果,成熟期发病,引起果实腐烂。广东省廉江市是我国荔枝的主要产区之一,每年由于荔枝霜疫霉病的发生使荔枝产量受到较大的损失,一般发生年份产量损失达10％～15％,严重发生的年份产量损失达30％以上。为了做好本地区荔枝霜疫霉病的防治工作,使荔枝生产能健康发展,笔者2004～2007年对该地区荔枝霜疫霉病的发生规律及防治技术进行试验研究,初步掌握了该病害的发生规律及其防治技术,现总结如下。     

柑桔青霉病和绿霉病的发生与防治

柑桔青霉病和绿霉病的发生与防治叶德新（福建省德化县经济作物站３６２５００）许长敏（福建省德化县植保植检站３６２５００）柑桔青霉病（ＰｅｎｉｃｉｌｌｉｕｍｉｔａｌｉｃｕｍＷｅｈｍｅｒ）和绿霉病（ＰｅｎｉｃｉｌｌｉｕｍｄｉｇｉｔａｔｕｍＳａｃｃ）是柑桔果...     

张家港局检出大豆疫霉病

2005年1月,张家港局对一批来自美国的6万t大豆实施检疫时,抽取了样品和其中携带的土壤颗粒,经过PCR快速检测方法和传统的叶碟诱集法的两次相互验证检测,确认该批大豆中携带大豆疫霉病菌.现已对该批大豆进行了除害处理.     

几丁质酶活性与大豆抗疫霉根腐病的关系

测定了大豆不同抗性品种接种大豆疫霉菌后的几丁质酶活性的变化情况。结果表明：未接种的不同大豆品种中的几丁质酶活性无明显区别。大豆疫霉菌侵染后不同抗性的大豆品种的几丁质酶的含量和活性均有不同程度的提高。抗病品种酶活性上升的速度比感病品种快,酶的高活性维持的时间较长。抗病品种在接种后24 h酶活性达到峰值,中感和感病品种在接种后48 h达到峰值。说明大豆疫霉菌可诱导几丁质酶产生,大豆品种的抗病性与几丁质酶的活性呈正相关关系。酶学特性的研究结果表明,酶反应的最适温度为45 ℃,最适pH为5。该酶在45 ℃以下,pH在4~6时酶活性稳定,超过60 ℃,pH超过7时酶活性丧失较快。Mn2+、Zn2+、Ba2+、Fe3+、Ca2+对酶活性有激活作用,Al3+、Ag+、Fe2+、K+、Mg2+、Cu2+、Hg2+对酶活性有抑制作用。     

植物保护

球孢白僵菌混合粉剂是由     

大豆疫病的种子处理技术研究

本试验用不同浓度的瑞毒锰锌、杀毒矾和克露进行大豆种子处理试验，结果表明，５００ｐｐｍ瑞毒锰锌对大豆疫病具有很好的治疗作用，而用杀毒矾以种子重量０．４—０．５％的剂量闷种，能显著地抑制大豆疫霉菌的侵入     

大豆疫霉的土壤诱集检测

采用大豆叶碟诱集的方法研究了影响大豆疫霉ＰｈｙｔｏｐｈｔｈｏｒａｓｏｊａｅＫａｕｆｍａｎｎ＆Ｇｅｒｄｅｍａｎｎ土壤检测的因素。结果表明,自然感病的风干土壤加蒸馏水湿润至饱和或接近饱和状态,光照条件下预培养４～６天,加５～１０ｍｍ深的蒸馏水浸泡,然后加感病大豆品种的叶碟诱集６～２４小时,可以较稳定地检测到大豆疫霉。叶碟诱集后用蒸馏水培养或用选择性培养基培养的检测效果相似,但用蒸馏水培养便于检查检测结果。当诱集用离体叶碟采自含抗病基因的大豆品种的植株时,只有能克服该基因的大豆疫霉能被诱集和检测到。     

Management of phytophthora root rot in radiata pine seedlings

Chemical and biological agents were evaluated for their ability to suppress root rot, caused by Phytophthora cactorum , in field-grown radiata pine seedlings in New Zealand. Trials were conducted over two seasons in an area of a forest nursery with a natural infestation of P. cactorum , and a history of root rot. In each season, symptoms of root rot developed during April, one month after root pruning, when seedlings were approximately six months old. In trial one, root rot incidence by mid July 2007 was 9·1% in untreated plots and 8·4% in plots that had been treated with metalaxyl-M/mancozeb (14 kg ha⁻¹) at seedling emergence. Disease incidence was lowest (2·1%) in plots that received seven monthly applications of phosphorous acid (6·5 L ha⁻¹). Other treatments, including seed coating with thiram or Trichoderma spp., and foliar applications of methyl jasmonate, did not control disease. In trial two, effects of treatment timing relative to root pruning were investigated. By late June 2008, three months after root pruning, root rot incidence was 22·2% in the untreated plots. Phosphorous acid was the most effective treatment and almost completely suppressed disease (0·1% incidence) when applied fortnightly from February until May (seven applications). Metalaxyl-M/mancozeb (15 kg ha⁻¹) was not effective (21·4% incidence) when applied five months before root pruning. However, disease incidence was reduced when the chemical was applied one week after root pruning (14·9% incidence) and greater control was achieved (8·2% incidence) when the application rate was increased to 50 kg ha⁻¹.     

江苏口岸截获大豆疫霉菌的鉴定

采用叶碟诱捕法从江苏口岸进境的大豆所携带的土壤中,共分离了疫霉12株,选取6个菌株,对病原菌进行了形态特征、致病性、寄主范围鉴定。结果表明,形态观察为疫霉属真菌,接种大豆后可出现典型的大豆疫病症状,且人工接种只侵染大豆、豇豆和菜豆等少数豆科植物。采用大豆疫霉的特异性引物检测表明,所有12个菌株均能扩增出分子量为330bp的特异性条带。结合形态和致病性测定,这些病原菌鉴定为大豆疫霉(Phytophthorasojae)。     

Identities and pathogenicities of phytophthora spp. causing root rot of red raspberry

Phytophthora syringae, P. drechsleri, P. cactarutn, P. cambiuora and P. megasperma were isolated from the roots of red raspberry plants affected by severe root and crown rot with associated cane death. Phytophthora megasperma occurred most frequently and consisted of two types of isolates which differed in colony morphology, growth rates, and oogonial, oospore, sporangial and zoospore size, and pathogenicity to a range of plants. One type with large oospores was typical of P. megasperma var. megasperma , and was non-pathogenic to red raspberries, while the other with smaller oospores and which grew more slowly in culture than the first, was highly pathogenic, producing symptoms similar to those observed in the field. Highly pathogenic isolates from Germany and the USA were of this type.
All red and black raspberry cultivars tested were susceptible to the pathogenic type, although North American cultivars were generally less affected than British ones. Inoculated plants had reduced shoot and root weights, stem lesions and wilted and yellowed leaves. The blackberry × raspberry hybrid Tayberry and its blackberry parent were immune.
Phytophthora drechsleri, P. cactorum and P. cambivora produced small to moderate amounts of root rot on red raspberry, and P. cambivora also caused slight symptoms on shoots.     

The effect of three irrigation practices on phytophthora crown and root rot of apple trees under field conditions

The effect of microjet, drip, and two durations of sprinkler irrigation systems on phytophthora crown and root rot of apple trees was examined under field conditions. This eight year study indicates that crown and root rot caused byPhytophthora cactorum was most severe where young MM. 106 rootstock trees were watered by microjet irrigation for 2.3 h each day. There was no difference in infection byP. cactorum when trees were irrigated either by drip or sprinkler irrigation systems. The MM.106 apple rootstock trees watered by drip irrigation for 2.6 h each day were least affected by phytophthora crown and root rot.     

大豆疫霉菌部分生物学特性及其药剂筛选研究

采用大豆疫霉菌在不同条件下菌丝生长速度法研究了大豆疫霉菌的部分生物学特性,并应用杀菌剂室内生测、盆栽药剂防效对药效作了评价。研究结果表明,大豆疫霉菌营养生长的最适温度为25～30℃;最适pH为6;光暗交替有利于该菌营养体的生长,在Rye或CA培养基上生长最快。室内药效测定结果表明,烯酰吗啉EC₅₀为0.165 4μg/mL,抑菌效果最好,甲霜灵、甲霜灵.锰锌和氟吗啉.锰锌的EC_{50分别为0.261 00、.451 0和0.984 2μg/mL,效果次之。盆栽试验结果表明,几种药剂在活体条件下对大豆疫病的防治效果较好,并有较长持效期。}