水葫芦象甲对水葫芦的生物防治效应

通过在室内塑箱释放专食性天敌昆虫——水葫芦象甲以控制水葫芦的研究。初步探明了水葫芦象甲不同释放密度对水葫芦植株生长的影响、控制效果以及适宜的水葫芦象甲释放密度,为水葫芦生物防除的推广应用提供了一定的理论基础。     

防除水葫芦高效除草剂筛选试验

对18种除草剂防除水葫芦的药效比较结果表明，水花生净1500倍液可有效控制水葫芦的发生，药后30d株死亡率超过90％，下沉率超过50％。药后40d死亡率超过97％，下沉率超过77％，并可兼治水花生。农达与草克星的药效虽略低于水花生净，但也能有效控制水葫芦的发生。     

水葫芦的生物防治

水葫芦是全世界公认的“十大”害草之一，危害严重。用物理和化学的方法防治该草难以得到持续的效果，且易造成二次污染，而生物防治是一种持久性、成本较低、环境友好型的治理方法。本文从水葫芦天敌、水葫芦病原菌和植物的化感作用等方面阐述了生物防治的现状及存在的问题，并就其前景进行了探讨。     

PM 9/8(1): Eichhornia crassipes

Specific scope

This standard describes the procedures for control of Eichhornia crassipes.

Specific approval and amendment

First approved in 2009–09.

     

利用水葫芦象甲和农达综合控制水葫芦

试验表明同时应用水葫芦象甲和农达控制水葫芦,可达到快速、持续的控制效果,但农达使用剂量应选择适当。药量４.５ｋｇ／ｈｍ^２的综防处理区中,由于农达的作用水葫芦植株在２０～５０ｄ内大部分死亡,水葫芦象甲亦很快死亡,象甲很难发挥有效的作用;药量为０.４５ｋｇ／ｈｍ^２的综防区中,水葫芦象甲和农达同时作用,对水葫芦的叶片数、繁殖量和生物量起到了明显的抑制作用,与单独施用同样药量的化防区和只释放象甲的生防区有显著差异,而且象甲保持了一定的种群密度;而药量为０.０４５ｋｇ／ｈｍ^２的综防区与只放象甲的生防区控制水葫芦的效果一样。     

Sexual reproduction of Eichhornia crassipes (Mart.) Solms in the Nile

In a study of some of the factors that are believed to affect fruit-setting in Eichhornia crassipes under Sudan conditions, the average number of flowers per inflorescence was twelve (range 4–26) while the average number of capsules per inflorescence was 1·5 (range 0–16). The problem of low fruit-setting was suggested to be basically due to the ecological factor of high temperature and low relative humidity. The flowers were preponderantly meso-stylic with the long and short-stylic ‘races’ absent or very rare. Recherches stir la biologic d'Eichhornia crassipes (Mart.) Solms dans le Nil Dans une étude sur quelques-uns des facteurs que l'on suppose actifs sur la mise à fruits de l’Eichhornia crassipes. dans les conditions du Soudan le nombre moyen de fleurs par inflorescence fut de 12 (s'étendent de 4 à 26), cependant que le nombre moyen de capsules par inflorescence fut de 1,5 (s'étendant de 0 à 16). Le probléme de la faible mise à fruit suggere qu'elle pourrait etre due a des facteurs écologiques: température élevée et faible humidity relative. Les fleurs étaient en majorité meso-stylées, les races à long style ou à style court étaient absentes ou tres rares. Generative Vermehrung von Eichhornia crassipes (Mart.) Solms. im Nil In einer Untersuchung über einige Faktoren, von denen angenommen wird, dass sie die Fruchtbildung von Eichhornia crassipes unter sudanesischen Bedingungen beeinflussen, war die durchschnittliche Anzahl von Blüten, 12 Blüten pro Inflorescenz (4–26), wáhrend die durchschnittliche Anzahl von Kapseln nur 1.5 Kapseln pro Inflorescenz war (0–16), Das Problem der geringen Fruchtausbildung wurde folgenden okologischen Faktoren zugeschrieben; hohe Temperatur und niedrige Luftfeuchtigkeit. Bei den Blüten wurden überwiegend Stempel miltlerer Länge gefunden, während die ‘Rassen’ kurzer und langer Stempel nicht oder nur sehr selten anzutreficn waren.     

Public awareness activities on Eichhornia crassipes in the Victoria Falls World Heritage Site,Livingstone, Zambia1

Invasive Alien Species (IAS) are a major threat to biodiversity and national economies worldwide. Public awareness and support is critical for the success of any interventions aimed at controlling and managing such invasions. Various communication tools have been identified for the implementation of public awareness programs. Assessment of public perceptions, attitudes and knowledge levels should be an integral part of any public awareness activities. This paper reports the communication actions undertaken in the Victoria Falls World Heritage Site by the Removing Barriers to Invasive Plant Management in Africa (RBIPMA) project during the year 2007. Several awareness meetings with various stakeholders were conducted during the year. A number of posters, leaflets, brochures and newsletters have been produced. Production of radio and television documentaries is currently ongoing. A pre‐knowledge survey was conducted to determine the baseline status as regards knowledge and awareness levels on IAS in the project area. A post‐knowledge survey will be conducted at a subsequent stage to assess the effectiveness of the project interventions on public awareness and knowledge levels. Recommendations for future action are also presented.     

黄浦江上游水源保护区不同河段水葫芦最佳治理对策

黄浦江对上海地区社会、环境和经济发展具有重要作用.但是,流域内点源和面源污染的日趋严重,造成了黄浦江水体的富营养化,为水葫芦的疯长创造了优越环境.水葫芦是一种全球性有害水生杂草,其繁殖能力极强,水葫芦的疯长给黄浦江水体带来了诸多的负效应.为抑制水葫芦的疯长,恢复水体功能,使水葫芦的生长保持在生态危害阈值以内,调查了黄浦江上游水源地保护区范围内的部分河段,观察水葫芦的污染现状及分布规律.根据水葫芦的污染现状及分布规律、不同治理对策(物理、化学、生物及综合对策)的优缺点,提出黄浦江上游水源保护区不同河段水葫芦的最佳治理对策,以期达到较高的生态效益和经济效益.     

Survey and Assessment of the Natural Enemies of Water Hyacinth,Eichhornia crassipes

Abstract

In northern Queensland, the addition of 2,4,5‐T butyl ester was found to be unnecessary to maintain the control of Echinochloa colona (L.) Link and Cyperus Iria L. In dry seeded rice when propanil rates were reduced below the registered rate of 4 kg a.i. ha^?1. Adequate weed control was obtained with 1.3 kg a.i. ha^?1 propanil alone. No adverse effects on rice yield were found with any of the propanil × 2,4,5‐T treatments. Low rates of propanil, 1.3 and 0.72 kg a.i. ha^?1, compared favourably with pre‐emergence treatments of thiobencarb, butachlor, oxyfluorfen and pretilachlor (plus a safener) when weed yields were low. Where water management was poor and Ischaemum rugosum Salisb. was the dominant weed, oxyfluorfen applied pre‐emergence at 0.96 kg a.i. ha^?1 produced a higher rice and a lower weed yield than the low rates of propanil. In three of the five experiments, weed growth was insufficient to depress rice yields significantly.     

外来恶性杂草——空心莲子草、水葫芦的分布调查及防控建议

从20世纪60年代起,尤其是对外改革开放以来,随着国际贸易交往,国外引种、人员交流的日益频繁,为外来影响农业的恶性杂草传入创造了便利条件,使其不断地向新地域扩散蔓延,繁殖生存为害。     

水葫芦象甲对外来杂草水葫芦的控制效果

外来植物水葫芦是目前我国南方危害最为严重的水生杂草。本文研究了野外释放从国外引进的专食性天敌昆虫控制水葫芦的效果。1996年8月在浙江温州面积为1372m^2、水葫芦覆盖率达100％的河道上释放1000头象甲，放虫2年后，水葫芦植株长势明显受到抑制，但仍有75％的水面被覆盖。防效仅为25％，3年后，发展迅速，效果十分显著，99％的水葫芦被清除。随着放虫区水葫芦数量和长势的减弱，象甲开始向四周扩散，首先扩散到紧邻放虫区面积为3000m^2的河道上，并在1999年4月将70％的水葫芦清除；同年12月发现，从放虫区沿河道向下游20km，均可发现象甲。     

Solid substrate for production of Alternaria alternata conidia: a potential mycoherbicide for the control of Eichhornia crassipes (water hyacinth)

Eichhornia crassipes (water hyacinth), a major aquatic weed in India, is one of the targets in a biological weed control research programme in India. A fungal pathogen, Alternaria alternata, is being evaluated as a biological control agent for this weed. The feasibility of solid substrate for the mass production of A. alternata has been examined. Conidia production and virulence of A. alternata were affected by temperature, light and incubation period. The highest number of conidia were produced on rice seed followed by wheat, sorghum, maize seeds and cornmeal at 20°C when exposed to near‐ultraviolet than on the other substrates, while the least conidia were observed on these substrates under light conditions. At 20°C, large numbers of virulent conidia were produced on rice seeds after 4 weeks of incubation under constant dark conditions. Henceforth, the use of rice seeds as a solid substrate for production of A. alternata could be a feasible method to produce conidia in a village co‐operative scenario in India.     

Herbicidal potential of allelochemicals from Lantana camara against Eichhornia crassipes and the alga Microcystis aeruginosa

In the field, the growth of the aquatic weed Eichhornia crassipes and the alga Microcystis aeruginosa may be inhibited by fallen leaves of Lantana camara. This study showed that extracts of L. camara leaves and their fractions reduced the biomass of E. crassipes and M. aeruginosa within 7 days under laboratory conditions. Two fractions with highly inhibitory activity from the extract were isolated and subsequently identified as the pentacyclic triterpenoids, lantadene A and lantadene B. Both compounds significantly inhibited E. crassipes and M. aeruginosa growth, even at a low concentration. At all concentrations tested, their inhibitory activities were much higher than that of salicylic acid, a putative allelochemical from L. camara. The results indicated that the predominant allelochemicals involved in L. camara against either E. crassipes or M. aeruginosa are not phenolic acids, but lantadene A and lantadene B. Field trials showed that released levels of lantadene A and lantadene B were significantly correlated with amounts and decomposition periods of L. camara leaves floated in water. The amount released from 5 kg L. camara leaves was over the inhibition threshold of both E. crassipes and M. aeruginosa and reached a maximum at days 15–20. This study suggested that allelochemicals of L. camara could potentially be used to improve the management of weeds and algae in aquatic systems.     

水葫芦花期不同部位的资源性化学成分分析与评价

分别采用减重、电感耦合等离子体-原子发射光谱法(ICP-AES)、凯氏定氮法和BCA试剂盒法、硝酸铝-分光光度法以及超高效液相-质谱联用HILIC-UPLC-TQ-MS/MS方法,对水葫芦花期不同部位水分和灰分、重金属、粗蛋白、总黄酮类、核苷类、氨基酸类成分的组成及含量进行分析评价。结果表明水葫芦花期须根、短缩茎、匍匐茎、叶柄、叶片、花序中水分含量分别为93.67%、96.34%、97.13%、96.65%、90.85%、96.03%,总灰分和酸不溶性灰分含量分别为25.83%、24.24%、26.32%、17.33%、18.64%、17.16%和6.83%、6.19%、7.36%、5.24%、4.97%、4.85%;砷、镉、铅含量之和分别为29.77、14.01、11.67、12.36、140.43、20.85 mg/kg;2种方法测得的粗蛋白含量分别为7.79%、7.17%、10.21%、8.29%、17.67%、18.23%,4.64%、3.95%、7.83%、5.14%、13.74%、14.02%;总黄酮类含量分别为2.81%、4.18%、3.38%、3.04%、8.29%、4.17%;总核苷类成分含量分别为0.46%、0.57%、0.64%、0.29%、1.04%、1.52%;总氨基酸类成分含量分别为0.21%、0.25%、0.55%、0.21%、1.44%、1.37%。水葫芦花期各部位均含有丰富的资源性化学成分,叶片和花序中粗蛋白、总黄酮类、核苷类、氨基酸类成分含量在各部位中最高,具有潜在的药用和营养保健价值。本研究结果可为水葫芦的资源化利用提供科学依据。     

Factors affecting dormancy and germination of seeds of Eichhornia crassipes (Mart.) Solms from the Nile

E. crassopes requires specific conditions for germination. The best laboratory germination was in clay soil, rich in organic matter, under less than 3 cm depth of water, in light. There are interactions with water depths, soil type, organic deposits, light and temperature. Storage conditions of seeds before germination affect the results. Wetting, drying and re-wetting gave quickest, and complete germination. After 2 years dry-storage, 78% of the seeds were still viable.     

A new record for the flora of Turkey: Eichhornia crassipes (Mart.) Solms (Pontederiaceae)

Eichhornia crassipes (Mart.) Solms (Pontederiaceae) is reported for the first time for the flora of Turkey. This invasive alien plant was observed in the Asi River (also called the Orontes River), which runs from Lebanon, through Syria to Turkey. The observation was made in the river near the border with Syria. This site is the in the district of Altinözü in the province of Hatay in the East Mediterranean region. Turkey is divided into grids for floral purposes by the book ‘Flora of Turkey’ and the plants described were collected in grid sector C6. The authors concluded that E. crassipes (water hyacinth) can establish and spread in Turkey.     

Random amplified polymorphic DNA markers reveal low genetic variation and a single dominant genotype in Eichhornia crassipes populations throughout China

Genetic variation within and between 34 populations of Eichhornia crassipes (water hyacinth) in China was surveyed using random amplified polymorphic DNA (RAPD) markers. A total of 1009 individuals were analysed, for which 12 RAPD primers amplified 69 reproducible bands, with 22 (32%) being polymorphic. The percentage of polymorphic loci (p) within a population ranged from 4.4% to 17.4%, and the mean Nei's gene diversity (H_e) was 0.046 ± 0.0145, indicating a low genetic diversity of E. crassipes in China. Each population contained at least four RAPD phenotypes (genotypes), and the same particular genotype was invariably dominant in all the populations sampled. The mean proportion of distinguishable genotypes was 0.29. Analysis of molecular variance revealed a large proportion of genetic variation (83.9%) residing within populations and a slightly larger proportion (88.1%) within localities, indicating a low genetic differentiation of E. crassipes populations, both locally and regionally. Human-mediated dispersal, vigorous clonal growth, and a generally low level of sexual reproduction were thought to be responsible for such a pattern of genetic structure.     

The environmental and socio‐economic impacts of Eichhornia crassipes in the Victoria Falls/Mosi‐oa‐Tunya World Heritage Site,Livingstone, Zambia1

The exotic water hyacinth (Eichhornia crassipes) has invaded the Maramba River, a tributary of the Zambezi River in the Victoria Falls World Heritage Site in Zambia presenting several negative environmental and economic impacts. The major impacts identified by recent studies are on the generation of hydro electric power, tourism development, native biodiversity, fish catches and human health. Other recorded impacts are reduced quality and quantity of water for domestic use, restricted navigation of waterways and the threat posed to vital infrastructure. This has led to the initiation of efforts to manage this infestation and address the resultant impacts. Methods proposed for control of water hyacinth in the Victoria Falls/Musi‐oa‐Tunya Pilot Site are an integration of mechanical and biological control measures. This paper discusses the impacts of water hyacinth invasion on the Maramba River and isolated clusters on the backwaters of the Zambezi. Two field surveys undertaken over the last three years and recent interviews with resource persons representing interested and affected institutions and local communities impacted by water hyacinth provide the basis for the data in this paper and the current intervention activities. The field surveys and questionnaires targeted government institutions involved in the management of the area and persons from the private sector engaged in tourism activities. Local peoples found in and around the project area were also interviewed. A pioneering effort is made to quantify the impacts and detail the costs arising from these impacts. Recommendations for the future control and management of E. crassipes are also made.     

Pistia stratiotes L. and Eichhornia crassipes (Mart.) Solms.: emerging invasive alien hydrophytes in Campania and Sardinia (Italy)

This article provides general information on the distribution and presence of invasive macrophytes in Italy and describes and discusses two hydrophyte invasion case studies: Eichhornia crassipes in Sardinia and Pistia stratiotes in Campania. The two invasions took place in the same period, but mechanical removal intervention started only in Sardinia, even if costly and unsuccessful in the long term. Two main pathways are responsible for the presence of these two species in Italy, i.e. introduction as ornamentals and investigation and use for phytoremediation. The drafting of a national strategy on biological invasions is a priority for Italy and several specific action plans for species and habitats, as in the case of inland waters, are required. Furthermore, there is the need for regulations in the trade sector of invasive plant species and to evaluate the possibilities for biological control for established aquatic alien invaders.