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魔芋软腐病与根腐病是魔芋上两大病害,在生产上造成损失占病害损失总量的４０%以上,有时成为主要发生的病害种类。二者症状既有相似且不易分开,防治上也有侧重点。一、症状及区分方法魔芋软腐病为细菌性病,主要危害魔芋块茎、茎秆及叶片,造成茎秆软腐、流汁、叶片黄化｜块茎腐烂。魔芋根腐病为真菌性病害,主要危害根部,造成根部腐烂,叶片黄化、萎蔫。２种病害的区分方法为:软腐病腐烂部位有臭味,茎秆容易倒伏,叶片及茎秆腐烂流汁,拔起植株及块茎,根部少有腐烂或根数量不减;根腐病无臭味,上部叶片变黄后茎秆不腐烂无流汁现象,根及块茎拔起观… 相似文献
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苯醚甲环唑在三七中的残留及其膳食风险评估 总被引：1，自引：0，他引：1
通过田间试验和气相色谱(GC-ECD)检测,研究了苯醚甲环唑在三七中的残留消解动态以 及三七茎叶对其的吸收、转运与分布特性。结果表明:苯醚甲环唑在三七植株中的半衰期为12.3~12.8 d;叶面施药后,其可被三七茎叶吸收并迅速向下传导至根部,且主要集中在须根中。苯醚甲环唑在三七不同部位之间的最终残留量存在差异,依次为花>须根>块根。于三七病害发病初期 (通常在三七开花前的营养生长期)施用苯醚甲环唑10%水分散粒剂,用量为有效成分67.5 g/hm2, 施药4次,间隔期为7 d,距最后1次施药后间隔28 d收获的三七块根中苯醚甲环唑的残留量RQ)仅为0.21%,处于安全水 平。建议在使用苯醚甲环唑10%水分散粒剂防治三七上的病害时,用药量为有效成分67.5 g/hm2, 最多施用3次,安全间隔期为28 d。 相似文献
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在中药材的栽培过程中 ,常因种种原因使药材的根茎叶等部位感染病害 ,如不及时防治 ,则会导致减产 ,影响药材的产量和品质 ,给药农造成不必要的损失。现就中药材栽培中常见病害及其防治措施介绍如下 :1 根腐病发病初期先由须根、支根变褐腐烂 ,逐渐向主根蔓延 ,最后导致全根腐烂 ,直至地上茎叶自下向上枯萎、全株枯死。该病常与地下线虫、根螨危害有关。另外 ,在土壤黏重 ,田间积水过多时发病严重。其中黄芩、丹参、板蓝根、黄芪、太子参、芍药和党参等中药材易感染此病。防治方法 :播前对土壤消毒 ,用杀虫药防治地下害虫 ,同时增施腐熟有… 相似文献
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小麦全蚀病、根腐病为根部主要病害,小麦纹枯病主要症状在茎部,由于连年重茬,此3种病害均日趋严重,且常混合发生。为了测定小麦根茎3种病害与损失率的关系,我们在1991年6月麦收期间进行了各自严重度调查及其减产损失率(以千粒重测定为主)的测定,现将方法与结果报道如下: 小麦3种病害田间危害分级标准见表1 相似文献
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小麦根腐病Ｂｉｐｏｌａｒｉｓｓｏｒｏｒｉｎｉａｎａ (Ｓａｃｃ .)Ｓｈｏｅｍ是近几年阜城县小麦发生的主要病害之一。 2 0 0 0年全县小麦种植面积 2 .4万ｈｍ2 ,此病发生 1 .3万ｈｍ2 ,病田率达 54% ,病田平均病株率达 61 % ,严重田块病株达1 0 0 %。小麦根腐病自苗期至成株期均可发病 ,能为害小麦植株的各个部位。苗期感病 ,芽鞘及根变褐腐烂 ,无效分蘖增多 ,丛生不长 ;成株期感病根冠或茎基部腐烂 ,引起茎基部折断而倒伏或形成“白穗” ,造成小麦减产。1 严重发生的原因根据调查分析 ,造成小麦根腐病严重发生的主要原因 ,一是小麦主栽… 相似文献
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我国小麦产区间病害发生与损失差异比较研究 总被引：1，自引：0，他引：1
为系统全面地掌握我国各产区小麦病害的发生情况,本文重点分析了我国小麦五大产区(华东麦区、华中麦区、华北麦区、西北麦区和西南麦区)小麦锈病、赤霉病、白粉病、纹枯病、黑穗病、根腐病和全蚀病的发生及防控情况。结果表明：我国小麦病害发生危害具有区域性特点,华东和华中麦区小麦纹枯病和赤霉病发病面积较大,且造成产量损失占比远超其余三大产区;华北麦区以白粉病发生最重;西北和西南麦区锈病和白粉病发生最重。我国小麦病害防治效果显著,华东和华中麦区赤霉病、纹枯病的年均挽回损失率均在80%以上;华北麦区年均挽回损失率最高的病害是白粉病(84.43%);西北和西南麦区对锈病年均挽回损失率分别为78.20%和85.26%;黑穗病、根腐病和全蚀病挽回损失率较低。 相似文献
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为有效防控太子参根腐病，本研究于2017年3月-2019年6月自福建省宁德市柘荣县太子参主产区采集具有典型根腐病症状的植株和块根病样，分离纯化获得病原菌，利用形态学特征、分子生物学特性及致病性测定对其进行鉴定；同时通过测定平板抑制率和扫描电镜观察分析6种杀菌剂对太子参根腐病病原菌菌丝生长的抑制效果。结果表明：太子参根腐病典型症状为苗期和生长期植株萎蔫、根部和茎基部褐变；块根表皮呈现开裂、组织褐变和干腐状。分离纯化后获得22株培养性状一致的菌株，结合菌株的形态学特征、EF-1α基因序列和特异性引物FOF1/FOR1检测，将该病原菌鉴定为尖孢镰刀菌Fusarium oxysporum。致病性测定结果表明其发病症状与田间表现一致，且符合科赫氏法则。经筛选6.6%嘧菌酯·1.1%咯菌腈·3.3%精甲霜灵悬浮种衣剂和25%吡唑醚菌酯乳油对该病原菌有良好的抑制效果，稀释至2 000倍液的抑制率分别为78.52%和75.36%；扫描电镜观察显示这2种杀菌剂处理组的菌丝体发育畸形、断裂、表面皱缩或消解，未见产孢细胞；而无菌水对照处理组的菌丝体生长正常，可见产孢细胞。表明筛选到的2种杀菌剂可用于防治由尖孢镰刀菌引起的太子参根腐病。 相似文献
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褐斑病(Marssoninamali)及斑点落叶病(Alternariaalternata,强毒株系)(简称两病)为铜川市苹果的主要病害,其为害程度及损失位居苹果病害首位,1999年、2000年、2002年在铜川地区大面积流行,3a受害面积均为2万hm2,造成苹果树提前落叶,树叶干枯死亡。10月上、中旬调查,落叶率50%～80%,平均病株率98%,病叶率84.2%,减产5%～30%,并且造成品质及等级下降。现以2002年为例分析其发生特点。1发生特点1)发病早且蔓延快。5月上旬,铜川市田间已见到零星病叶的发生和为害,5月底6月初,开始大面积扩展,发生面积占栽植面积的50%以上,病叶率6.7%,病指2.1;7月… 相似文献
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三七根腐病病原及复合侵染的研究 总被引：23，自引：1，他引：23
从三七根腐病不同发病期根部分离到假单胞杆菌Pseudomonas sp.、腐皮镰孢Fusarium solani、细链格孢Alternaria tenuis和小杆线虫Rhabditis elegans。活体接种假单胞杆菌的致病性最强,腐皮镰孢和细链格孢的致病性弱,小杆线虫无致病性。假单胞杆菌、腐皮镰孢和细链格孢混合接种的发病率都高于单独接种的发病率,尤以3种菌混合接种的发病率最高,含细菌的组合发病率高于不含细菌的发病率,说明细菌在侵染中起了主要作用。 相似文献
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Pseudomonas fluorescens CHA0 protects plants from damage caused by several soilborne fungi. In this work, immunofluorescence microscopy was used to investigate the colonization of tobacco roots by CHA0 and its physical relationship with the black root rot fungus Thielaviopsis basicola . The pseudomonad colonized the rhizoplane shortly after planting of tobacco seedlings in sterile soil microcosms, in which it had been introduced as soil inoculant. CHA0 was found between and inside cells in the epidermis and the cortex, as well as in the xylem vessels, within 4–7 days after planting of seedlings. The presence of CHA0 delayed the colonization of the interior of tobacco roots by T. basicola compared with the treatment in which only the fungus had been inoculated. Likewise, the pseudomonad reduced the extent of black root rot from 82% to 28%. However, CHA0 was seldom found in contact with the mycelium of T. basicola or in its vicinity, indicating that direct colonization of the mycelium of T. basicola by CHA0 was not required for protection of tobacco against black root rot. Overall, the results suggest that the interior of the root is a key site for implementation of the strain's biocontrol activity against soilborne plant-pathogenic fungi. 相似文献
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Contrasting canopy and fibrous root damage on Swingle citrumelo caused by ‘Candidatus Liberibacter asiaticus’ and Phytophthora nicotianae 
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下载免费PDF全文 Huanglongbing (HLB), associated with the phloem‐limited bacterium ‘Candidatus Liberibacter asiaticus’ (Las), is devastating trees in citrus orchards of Florida. Additionally, Phytophthora nicotianae, omnipresent in citrus soils, causes root rot that reduces water and nutrient uptake by fibrous roots. To investigate fibrous root damage and replacement and canopy size in relation to infection of fibrous roots by Las and P. nicotianae, rootstock seedlings of Swingle citrumelo (Citrus paradisi × Poncirus trifoliata) were inoculated with Las or P. nicotianae in two greenhouse pot trials. Phytophthora nicotianae caused root damage within 5 weeks post‐inoculation, which led to greater reduction of canopy size than for Las‐infected seedlings by the end of the experiment. Las increased accumulation of fibrous root biomass at 5 weeks post‐root trimming (wpt) in the 2014 trial and at 11 wpt in the 2015 trial. New root length was not consistently increased by Las. Reduced total leaf area of symptomless Las‐infected seedlings compared to noninoculated controls might be due to the combined effect of altered carbohydrate allocation between shoots and roots and altered leaf morphology. 相似文献
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Dong Yaojun Tang Binbin He Mimi Wang Lili Wu Kai Yang Sixia Liu Jianfeng Yang Hong Wang Changmei Yin Fang Zhang Wudi 《European journal of plant pathology / European Foundation for Plant Pathology》2022,163(1):143-153
European Journal of Plant Pathology - Sanqi ginseng Fusarium root rot caused by Fusarium oxysporum, is a serious soil-borne disease that threatens the sustainable development of the sanqi ginseng... 相似文献
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G.M.L.W. Kroes R.P. Baayen W. Lange 《European journal of plant pathology / European Foundation for Plant Pathology》1998,104(7):725-736
The histology of root rot of flax seedlings infected by Fusarium oxysporum f.sp. lini was studied using semi-thin sections of plastic-embedded roots. Within two days, the fungus colonised the root cap cell layers by intercellular and intracellular growth. Attempted intercellular penetration of root cap cells via the middle lamella induced the formation of appositions next to penetrating hyphae. Other cells next to invading hyphae collapsed, which was accompanied by swelling of the cells neighbouring the collapsing cells. Invasion of the root cap and growth towards the protodermis seemed retarded to some extent by the natural sloughing off of root cap cell layers. The protodermis and cortex were reached and penetrated in four days, which was followed by rapid and massive colonisation of the entire root tip. The protoxylem was reached in eight days. From eight to sixteen days after inoculation, the lower parts of the roots were colonised throughout and the cortical region was degraded. Colonised tissues were severely plasmolyzed. Heavily colonised roots were hollowed out, the only remaining tissues being the epidermis and exodermis outside, and remainders of the colonised xylem inside. Upward spread of root rot was restricted in the period studied to the first 10 mm from the root tip, the upper parts of the root and the hypocotyl being unaffected except for invasion through lateral roots infected at their respective tips. Mature roots with a well-developed epidermis and exodermis were not invaded from outside. Disease development was similar in partially resistant Hermes and susceptible Regina, except for rot development that was consistently slightly more extensive in the susceptible cultivar. Distinct extravascular resistance factors were not detected in Hermes, suggesting that extravascular resistance in flax to F. oxysporum f.sp. lini is of a quantitative nature. 相似文献
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Plum pox virus detection in dormant plum trees by PCR and ELISA 总被引：1，自引：0，他引：1
An immunocapture polymerase chain reaction (IC-PCR) protocol and ELISA were compared for their effectiveness in detecting plum pox virus (PPV) in dormant plum material. Although the IC-PCR was about one thousand times more sensitive than ELISA, PPV was detected by ELISA in 71–80% of bark samples collected in December, January and March 1996/97 from pot-grown rootstock trees inoculated with PPV the previous March, compared with 85–86% detection in the same samples by IC-PCR. In similar samples from one-year-old shoots taken from infected branches of orchard trees, 66–81% were positive by ELISA compared with 81–87% by IC-PCR. With bulked samples taken from the fibrous roots of the pot-grown trees, PPV was detected in 92–100% of samples by IC-PCR in winter compared with only 38–65% by ELISA. These results were confirmed in samples from the roots and shoots of the same trees in 1997/98. Three samples per shoot would have been sufficient to detect PPV by ELISA in 87 of the 88 infected shoots tested during the two winters. However, infected shoots are irregularly distributed in diseased trees and PCR assays of root samples offer the potential for improving the reliability of identifying trees infected with PPV. 相似文献
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为保证百菌清的安全使用，明确百菌清及其代谢物4-羟基百菌清在三七上的残留行为，2017年在云南三七主产区丘北、广南、弥勒和石林4地进行了百菌清在三七上的规范残留试验，建立了气相色谱 (GC-ECD) 测定三七中百菌清和超高效液相色谱-串联质谱 (UPLC-MS/MS) 测定4-羟基百菌清残留的分析方法。样品中百菌清用V (乙酸乙酯) : V (正己烷) = 2 : 8混合溶液提取，硅胶固相萃取柱净化，GC-ECD检测；4-羟基百菌清用乙腈提取，N-丙基乙二胺 (PSA) 分散固相萃取净化，UPLC-MS/MS检测，外标法定量。结果表明:百菌清在三七块根和须根中的添加回收率为93%~98%，相对标准偏差 (RSD) 为3%~6%，定量限 (LOQ) 为0.05 mg/kg；4-羟基百菌清在三七块根和须根中的添加回收率为75%~94%，RSD为3%~9%，LOQ为0.02 mg/kg。丘北和广南的消解动态试验结果显示:百菌清在三七植株上的半衰期为8.4~8.5 d，4-羟基百菌清为16.5~17.3 d；百菌清和4-羟基百菌清在三七地下部分根系中的消解不符合一级动力学反应模型，在施药后45 d内，百菌清呈波动性缓慢下降，4-羟基百菌清呈波动性缓慢上升的趋势。4地的最终残留试验结果表明:采用40%百菌清悬浮剂，分别按其有效成分2 400和3 600 g/hm2的剂量喷雾施药3~4次，每次施药间隔为7 d，于末次施药后21 d采样测定，三七块根中百菌清的残留量为<0.05~3.14 mg/kg，4-羟基百菌清为0.19~1.54 mg/kg；三七须根中百菌清的残留量为0.085~0.760 mg/kg，4-羟基百菌清为0.46~4.48 mg/kg。膳食摄入风险评估结果显示，百菌清的国家估算每日摄入量 (NEDI) 为0.967 mg，风险概率 (RQ%) 为76.8%，4-羟基百菌清的NEDI为0.012 mg，RQ%为2.4%，对一般人群健康不会产生不可接受的风险。 相似文献
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Sachiko Ikeda Tamotsu Hoshino Naoyuki Matsumoto Norio Kondo 《Journal of General Plant Pathology》2017,83(1):46-50
Typhula winter rot on overwintering carrots caused by Typhula variabilis is a newly confirmed disease, and no practical control measure is yet available. To develop a control method, here we researched the infection period of T. variabilis and the time that winter rot appeared on carrots. Using spore traps, we found that basidiospore rain occurred from September to November before snowfall in Memuro, Hokkaido. In addition, carrot leaves collected in autumn had already been infected by T. variabilis. These epidemiological investigations revealed that the pathogen releases basidiospores to infect carrot leaves before snow cover, resulting in root decay under snow. An effective control method was then developed to avoid direct contact of basidiospores of T. variabilis with plant tops by covering the plants with soil in autumn. Thus, the percentage of rotted roots was reduced to about half. 相似文献
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F. Moulin P. Lemanceau C. Alabouvette 《European journal of plant pathology / European Foundation for Plant Pathology》1994,100(1):3-17
Pythium spp. that cause damping-off of seedlings also can cause root rot of older plants and lead to yield reductions. This can be especially severe in soilless cultures where the fungus can spread easily with the nutrient solution. 39Pythium isolates obtained from discolored roots were assayed for their ability to cause damping-off on cucumber seedlings in sand-peat and for their pathogenicity in soilless culture of cucumber in rockwool or hydroponic solution. Isolates ofPythium aphanidermatum, P. irregulare, P. sylvaticum andP. ultimum were highly pathogenic in sand-peat, but onlyP. aphanidermatum strains were pathogenic in soilless conditions and led to root decay, plant death in rockwool culture and growth reduction in hydroponic culture. One strain ofP. aphanidermatum significantly reduced the yield of cucumber grown in rockwool under conditions similar to those of commercial cultures. 相似文献
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人参锈腐病菌潜伏侵染及其防治研究 总被引：9，自引：0，他引：9
试验表明,人参锈腐病菌[Cylindrocarpon destructans(Zinss) Scholten]具有潜伏侵染的特性。在1-5年生外观无病斑的参根内,是普遍带有潜伏的锈腐病菌,参根的带菌率和潜伏侵染点值,随根龄的增长而增高。3年生人参的根系中,主根对锈腐病菌的感染率最高。春季移栽3年生参根、盆栽鹿粪和50%禾穗胺600倍侵根,均对该病菌有一定的防治效果。 相似文献