控制果蔬采后病害的生物学技术

化学农药对环境和农产品的污染直接影响人类的健康,已成为当今公众所关注的主要问题之一。为了保证农产品的卫生和安全,世界各国都在探索能代替化学农药的防病新技术。生物防治是近年来被证明很有成效的新途径,它主要是利用微生物之间的拮抗作用,选择对农产品不造成危害的微生物来抑制引起采后腐烂的病原真菌的生长。生物防治的研究主要包括主要包括以下三方面：（１）选用有拮抗作用的微生物;（２）利用植物和动物产生的自然抗     

水果采后生物防治拮抗机理的研究进展

近20年来,人们在水果采后生物防治领域里取得了显著的成绩。目前已经分离获得了数百种对水果采后主要病害有明显拮抗效果的生物拮抗菌。很多拮抗菌经过了生产中试,有的已制成了生物药剂用于水果采后的商业化处理。有关拮抗菌的抑病机理研究也一直贯穿于采后生物防治的整个发展历程。本文在探讨了水果采后拮抗菌抑病机理的基础上,回顾了该领域的研究进展,并从拮抗菌与病原菌发生拮抗作用的4条主要途径入手,对该领域的研究成果及研究方法作一简要总结。     

水果采后生物防治拮抗机理的研究进展

近20年来,人们在水果采后生物防治领域里取得了显著的成绩。目前巳经分离获得了数百种对水果采后主要病害有明显拮抗效果的生物拮抗菌。很多拮抗菌经过生产中试,有的巳制成了生物药剂用于水果采后的商业化处理。有关拮抗菌的抑病机理研究也一直贯穿于采后生物防治的整个发展历程。本文在探讨了水果采后拮抗菌剂病机理的基础上,回顾了该领域的研究进展,并从拮抗菌与病原菌发生拮抗作用的4条主要途径入手,对该领域的研究成果及研究方法作一简要总结。     

芒果、香蕉采后病害生物防治的研究进展

芒果、香蕉采后主要病害为炭疽病、蒂腐病、冠腐病、黑腐病、黑星病.生物防治是当前芒果、香蕉采后病害控制的重要研究方向.概述了生物防治芒果、香蕉采后病害的方法,包括诱抗剂、植物提取物、拮抗微生物在芒果、香蕉采后病害防治上的研究与应用.     

嗜线虫致病杆菌抑制灰葡萄孢的效应

[背景] 灰葡萄孢（Botrytis cinerea）是引起葡萄采后病害的主要病原菌之一,严重影响葡萄的贮期和品质,给葡萄产业带来极大损失。利用拮抗微生物抑制采后病原菌生长已逐渐成为防治葡萄采后灰霉病的重要手段。[目的] 利用昆虫病原线虫共生细菌广谱高效的抑菌特性,从现有共生细菌资源中筛选对灰葡萄孢具有高拮抗作用的菌株,为葡萄采后灰霉病的抑制提供新的材料和研究方向。[方法] 通过平板对峙培养法和菌丝生长速率法分离筛选拮抗共生细菌,并对优选的高效拮抗共生细菌进行16S rRNA基因序列进化分析,采用扫描电镜观察其对灰葡萄孢菌丝生长的影响,利用损伤接种法对红地球葡萄防治效果进行验证。[结果] 初步分离筛选共获得9株拮抗菌,复筛与复测得到一株抑菌效果显著的共生细菌（命名为ALL）,经进化分析其为嗜线虫致病杆菌（Xenorhabdus nematophila）,其16S rRNA基因序列的Genbank登录号为MW488402,与菌株Xenorhabdus nematophi la NC116聚于同一分支,相似性达99.79%。扫描电镜观察该菌株导致灰葡萄孢菌丝扭曲变形、表面皱缩、失水塌陷,该菌株发酵（36 h）上清液浓度为1%时对灰葡萄孢菌丝抑制率达44.5%。在葡萄常温防效实验中,与对照组比较,ALL菌株发酵上清液对灰霉菌防治效果较好,3 d后防效为63.50%。[结论] 本研究应用昆虫病原线虫共生细菌生物防治葡萄贮期灰霉病,筛选出一株高效拮抗灰葡萄孢的昆虫病原线虫共生细菌,而且其上清液对灰葡萄孢具有良好的抑制效果,为生物防治贮期葡萄灰霉病提供了新的生物材料和相关研究基础。     

生物农药及其应用概况

由于化学农药污染严重 ,故作物保护从化学防治向生物防治转化是发展的趋势。生物农药是生物防治的重要组成部分 ,近年来世界各国都十分重视生物农药的研究和利用。生物农药是利用生物体本身或由生物体产生的生理活性物质作为杀病虫剂及除草剂 ,对特定的病虫草害产生作用的安全性高的新农药。目前全世界已注册的生物农药约有 6 0多种 ,年销售额为 2 5～ 3亿美元。因生物农药对病、虫、杂草且有专一性 ,对人畜较为安全 ,对生态无破坏性 ,并可弥补化学农药的某些缺陷 ,故其应用前景十分广阔。生物农药一般可分为直接利用生物体和利用源于生物…     

果蔬采后病害的生物防治(综述)

采用生物防治措施控制采后病害是当前果蔬采后保鲜的重要研究方向。概述了生物防治果蔬采后病害的方法,包括利用拮抗菌、诱导抗病性、天然植物产物以及抗病基因工程技术在果蔬病害防治上的研究与应用。     

猕猴桃采后真菌病害生物防治研究进展

猕猴桃果实易受多种病原真菌的侵染,采后易发生软腐病、灰霉病、青霉病等严重危害果实品质的真菌性病害。传统的有效防治方法主要为采前使用化学杀菌剂,但其易污染环境并可能危害人类健康。目前,已有一系列生物防治方法被研究并报道,这些方法可有效防控猕猴桃采后真菌病害：第一类为天然抑菌物质,包括植物提取物和其他天然物质;第二类为拮抗微生物,包括生防酵母、生防细菌、生防木霉,生防菌也能与物理及化学方法协同发挥作用。本文概述了各类生物防治方法在猕猴桃采后真菌病害绿色防控方面的研究进展及生防机理,并提出了目前存在的问题,最后展望了这一领域今后的研究方向。     

丛枝菌根真菌提高植物抗病性的作用机制*

近年来, 人们越来越重视丛枝菌根（AM）真菌对植物病原物的影响和提高植物抗病性的效应。当前建立在分子生物学、免疫学和组织化学技术上的基础研究, 可以从分子水平上深入了解AM真菌提高植物抗病性的作用机制。本文主要探讨AM真菌拮抗植物土传病原物、提高抗病性的可能机制和研究途径。1 AM真菌对植物土传病原物的拮抗作用自然条件下,绝大多数植物都能形成菌根。菌根围（Mycorrhizosphere）内的主要成员：根系、细菌、真菌、线虫等之间往往通过协同和/或拮抗作用达到动态平衡。其中植物—植物间、植物—微生物间、微生物—微生物间、…     

木霉和粘帚霉的生物防治研究进展

化学农药的大量使用,严重破坏农业生态系统,并对环境造成污染。而生物防治制剂可以克服这些问题,具有广阔的应用前景。目前已发现不少微生物具有生物防治作用。木霉（Trichoderma）和粘帚霉（Gliocladium）是其中一类可抑制土传植物病原菌的真菌,其作用机理主要是：抗菌、溶解、竞争、寄生和促进植物的生长[1].迄今为止,有关木霉和粘帚霉在生物防治方面的研究已开展近60年。早在1932年,Weindling观察到木素木霉（T.lignorum）和立枯丝核菌（Rhizoctoniasolani）同时培养时,木素木霉的菌丝缠绕着立枯丝核菌的菌丝,使其菌丝原生质凝…     

果蔬采后诱导抗病性

诱导抗病性是生物防治的途径之一 ,本文综述了诱导抗病性在果蔬采后病害防治中的研究进展 ,包括多种物理性、化学性和生物性激发子对许多采后果蔬抗病性的诱导以及诱导抗病性产生的机制 ,并分析它在果蔬防腐保鲜上的应用前景。     

果蔬采后诱导抗病性

诱导抗病性是生物防治的途径之一,本文综述了诱导抗病性在果蔬采后病害防治中的研究进展,包括多种物理性、化学性和生物性激发子对许多采后果蔬抗病性的诱导以及诱导抗病性产生的机制,并分析它在果蔬防腐保鲜上的应用前景。     

Biologically-based alternatives to synthetic fungicides for the control of postharvest diseases

Recently, biological control has been advanced as an alternative to synthetic fungicides and considerable success in laboratory and pilot scale tests has been realized utilizing antagonistic microorganisms to control postharvest diseases. Several antagonistic yeasts and bacteria have been isolated and shown to have a broad spectrum of activity against a number of postharvest pathogens on a variety of fruit. However, for biological control methods to emerge as an economically viable option, their consistency and efficacy in controlling postharvest decay needs to be enhanced to a level comparable to that of synthetic fungicides. This could be possible through an integrated strategy that exploits the additive and synergistic effects of different biological approaches. Received 06 February 1997/ Accepted in revised form 29 May 1997     

微生物源挥发性物质防治采后果蔬病害的研究进展

随着化学杀菌剂弊端的日益凸显,生物防治已逐渐成为采后果蔬病害控制的研究和开发热点。其中,很多微生物产生的多种挥发性物质(volatile organic compounds,VOCs),能显著抑制多种病原菌的生长繁殖,有效控制采后果蔬病害。由于微生物源VOCs具有有效、安全、环保、易降解和无残留等优点,越来越受到各国研究者的重视和青睐。本文综述了产生VOCs的微生物的多样性、微生物源VOCs的多样性、微生物源VOCs的抑菌活性、生防效果及其主要作用机制等方面的研究进展,以期为病原菌的绿色安全防治提供基础资料。     

Biocontrol of Postharvest Grey Mould on Tomato by Yeasts

The fungal pathogen Botrytis cinerea causes severe rots on tomato fruit during storage and shelf life. Biological control of postharvest diseases of fruit may be an effective alternative to chemical control. Yeasts are particularly suitable for postharvest use, proving to be highly effective in reducing the incidence of fungal pathogens. Yeast fungi isolated from the surface of solanaceous plants were evaluated for their activity in reducing the postharvest decay of tomato caused by B. cinerea. Of 300 isolates, 14 strains of Rhodotorula rubra and Candida pelliculosa were found to be strongly antagonistic to the pathogen in vitro and were selected for further storage experiment. The antagonists were evaluated for their effect on the biological control of postharvest grey mould. Artificially wounded fruits were treated by means of a novel technique: small sterile discs of filter paper imbibed separately in suspensions of each yeast and the pathogen were superposed onto each wound. After 1‐week, 11 isolates were significantly effective in reducing the diameter of lesions by more than 60% compared to the control treated with B. cinerea alone. Total protection was obtained with the strain 231 of R. rubra on fruits challenged with pathogen spores. To our knowledge, R. rubra and C. pelliculosa have not been described as biocontrol agents against grey mould caused by B. cinerea. Our data demonstrate that the application of antagonistic yeasts represents a promising and environmentally friendly alternative to fungicide treatments to control postharvest grey mould of tomato.     

Exploring the Citrus Sour Rot pathogen: biochemical aspects,virulence factors,and strategies for disease management - a review

Citriculture is an important economic activity worldwide and for decades, this sector has been responsible for creating job opportunities. Currently, Brazil is the largest orange producer in the world, which contributes to the country's economy. However, citrus production has been facing several issues that compromise the quality of the fruits. For instance, several postharvest diseases occur during storage and transportation, directly harming product marketing. Green mold, blue mold, and sour rot are considered the most common postharvest citrus diseases. Citrus sour rot is less common; however, the disease can lead to a significant loss in high rainfall seasons. The fungus Geotrichum candidum is the causal agent of sour rot and its chemical and biochemical infection strategies are still little explored in citrus fruits. Several conventional control methods, including the application of fungicides, aim to contain the disease proliferation, but most of the commercially available fungicides are not efficient against sour rot. For this reason, other strategies have been studied for disease control, such as chemicals (e. g. essential oils or other natural products), biological agents used as biocontrol, and physical strategies. Despite its importance, few reviews have focused on sour rot disease. Here, we summarize the biochemical aspects of G. candidum, as well as the metabolites produced by this phytopathogen, the known virulence factors, and advances for disease management.     

Inhibitory Effect of Selenium Against Penicillium expansum and Its Possible Mechanisms of Action

Some organic and inorganic salts could inhibit the growth of many pathogens. Selenium (Se), as an essential micronutrient, was effective in improving the plant resistance and antioxidant capacity at a low concentration. Penicillium expansum is one of the most important postharvest fungal pathogens, which can cause blue mold rot in various fruits and vegetables. In this study, the inhibitory effect of Se against P. expansum was evaluated. The result showed that Se strongly inhibited spore germination, germ tube elongation, and mycelial spread of P. expansum in the culture medium. The inhibitory effect was positively related to the concentration of Se used. Fluorescence microscopy observation of P. expansum conidia stained with propidium iodide (PI) indicated that the membrane integrity decreased to 37 % after the conidia were treated with Se (20 mg/l) for 9 h. With the use of an oxidant-sensitive probe 2,7-dichlorofluorescin (DCHF-DA), we found that Se at 15 mg/l could induce the generation of intracellular reactive oxygen species (ROS). Furthermore, methane dicarboxylic aldehyde (MDA) content, hydrogen peroxide (H₂O₂), and superoxide anion (O₂ ^?) production rate in P. expansum spores exposed to Se increased markedly. Compared with the control, the activities of superoxide dismutase (SOD) and the content of glutathione (GSH) were reduced, confirming that damage of Se to cellular oxygen-eliminating system is the main reason. These results suggest that Se might serve as a potential alternative to synthetic fungicides for the control of the postharvest disease of fruit and vegetables caused by P. expansum.     

Enhancement of biocontrol activity of yeasts by adding sodium bicarbonate or ammonium molybdate to control postharvest disease of jujube fruits

AIMS: To assess the potential of sodium bicarbonate and ammonium molybdate as additives in enhancing the biocontrol efficacy of Rhodotorula glutinis and Cryptococcus laurentii against blue mould in jujube fruits. METHODS AND RESULTS: Two yeasts at a concentration of 107 CFU ml-1, in combination with 238 mmol l-1 sodium bicarbonate or 15 mmol l-1 ammonium molybdate, showed a significant inhibition effect on blue mould of jujube fruits stored at 20 degrees C for 5 days. The colonizing ability of the yeasts in wounded sites was significantly decreased in the presence of ammonium molybdate. CONCLUSIONS: Combining R. glutinis or C. laurentii with sodium bicarbonate or ammonium molybdate provided a more effective control of postharvest disease than using the antagonistic yeasts or the chemicals alone. SIGNIFICANCE AND IMPACT OF THE STUDY: The addition of sodium bicarbonate or ammonium molybdate reduced the number of antagonists required to efficiently control disease of postharvest fruits, which could result in the reduction of costs.