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1.
2012年10月,在海南省文昌市的椰子苗圃中,发现了一种新的叶斑病。显微观察表明,病原菌分生孢子稍弯曲,浅褐色,纺锤状或梭状,具有5~9个假隔膜、分生孢子梗多单生,直立或稍弯曲,表明其为平脐蠕孢属(Bipolari.sp)。ITS序列分析表明其和4株狗尾草平脐蠕孢的序列同源性(HE792936.1,JX462256,GUO73108.1,FJ606786.1)的同源性为99%。生物学特性研究结果表明:该菌菌丝适宜生长温度为20~30℃,菌丝生长和孢子最适萌发温度分别是25℃和30℃;最适p H值为4~11;玉米粉培养基(CAM)及马铃薯葡萄糖琼脂培养基(PDA)最适合菌丝生长,最佳碳源为蔗糖,甘油不适合菌丝生长;最佳氮源为蛋白胨,其次是磷酸氢二铵;完全光照有利于菌丝生长。菌丝及分生孢子的致死温度和时间分别是56℃,15 min。  相似文献   

2.
椰子茎泻血病菌生物学特性研究   总被引:1,自引:0,他引:1  
对椰子茎泻血病菌奇异长喙壳菌Ceratocystis paradoxa(Dade)Moreau[=Thie laviopsis paradoxa(De Seynes)V.Hohnel]xie331-4的生物学特性进行了研究。结果表明,马铃薯葡萄糖琼脂培养基(PDA)最适合该菌菌丝生长和产孢;以果糖为碳源最适合菌丝生长,以阿拉伯树胶粉为碳源最适合产孢;以磷酸氢二铵为氮源最适合菌丝生长,以蛋白胨为氮源最适合产孢;2%蛋白胨对孢子萌发有促进作用,2%葡萄糖、2%蔗糖对孢子萌发有抑制作用;25~35℃适合菌丝生长和产孢,25℃最适合孢子萌发,温度低于5℃或高于40℃孢子不能萌发;pH值4~11适合菌丝生长,pH为7产孢量最大,pH值为4孢子萌发率最高;光照对菌丝生长及孢子萌发无显著影响,但有利于产孢;分生孢子致死温度为52℃10min。  相似文献   

3.
巴西橡胶树棒孢霉落叶病病原菌的生物学特性   总被引:1,自引:2,他引:1  
研究多主棒孢菌(Corynespora cassiicola)的生物学特性,结果表明,菌丝生长的最适温度为28℃,最适pH为6~9,孢子萌发的最适温度为28~30℃。该菌能有效利用各种碳源和氮源,碳源以麦芽糖最好,氮源以蛋白胨最好。光照处理对菌丝生长速度影响不显著,交替光照有利于产孢。菌丝致死温度是60℃,15min;分生孢子的致死温度是55℃,5min。在PDA,PSA,Czapek等培养基上生长良好,但不能大量产孢,在保湿的卫生纸、玻璃片和橡胶离体叶片上,能大量产孢。  相似文献   

4.
茶轮斑病菌与灰斑病菌的特性比较及致病观察   总被引:2,自引:0,他引:2  
对Pestalotiopsis属的P.theae和P.guepinii菌侵染茶叶后的症状表现、菌落、形态特征和病菌生物学特性作比较观察。结果表明:发病初期二病症状差别不大,后期明显区分,轮斑病斑褐色具轮纹,着生明显凸起的黑点;灰斑病斑灰白,散生小黑点。前者菌落具轮纹,分生孢子附属丝2~4条;后者菌落波状隆起,分生孢子附属丝2~5条。2种菌孢子萌发适温25℃,萌发率分别为87.5%和86.1%。茶汁能促进孢子萌发和产孢。强光照对孢子萌发、菌丝生长及产孢皆有明显抑制作用。P.theae菌丝生长适温为26~28℃,P.guepinii菌则为24~25℃;以PDA培养基最适2者菌丝生长,PSA+200g/L茶叶煎汁培养基利于产孢。P.theae菌适宜pH值为6.0,P.guepinii菌则为7.5。用2种菌孢子茶汁悬液结合磨擦对新梢不同叶龄作涂抹接种。结果显示:伤口利于侵染,P.theae菌孢子可直接从芽、嫩叶侵入,也侵染损伤的成叶;P.guepinii菌孢子只能从损伤的芽、嫩叶和成叶侵染。  相似文献   

5.
研究南繁区棉花炭疽病菌的生物学特性为筛选其杀菌剂提供理论依据。从海南省南繁棉花区采集病样分离得到病原菌,对病原菌进行生物学特性研究。结果表明:棉花炭疽病菌(HNNC8)菌丝在PDA培养基上生长最好;菌丝生长和孢子萌发的最适温度分别为25和30℃;最适pH值分别为7~9和6~8;连续黑暗条件较适合菌丝生长;菌丝在以麦芽糖、阿拉伯糖为碳源的培养基上生长最好;在以蛋白胨为氮源培养基上生长最好;病菌分生孢子致死温度为 55℃水浴处理 5 min。温度过高或过低酸性环境都会影响菌丝生长和分生孢子的萌发,且不同的碳源、氮源亦会影响病菌菌丝的生长。  相似文献   

6.
2021年6月在甘肃省张掖市甘州区党寨镇自然感玉米鞘腐病的玉米植株中分离鉴定病原菌并观察分析病原菌的生物学特性。结果表明,该致病菌株(QF-1RC)形态学结构与拟轮枝镰孢菌(Fusarium verticillioides)一致。基于rDNA-ITS和微管蛋白序列分析发现,该病原菌与拟轮枝镰孢菌MN652651和FR997663的相似度达99%,结合形态学和与分子生物学的鉴定结果将其定为拟轮枝镰孢菌。生物学特性观察发现,菌丝生长最适温度为25℃,弱酸弱碱环境下均有利于菌丝生长,全光照环境条件下菌丝生长速率快,不同C、N源对菌丝生长和产孢量有一定的影响,D-纤维二糖培养基上菌丝生长相对受限,在海藻糖和D-半乳糖培养基上菌株产孢量较多,硫酸铵培养基上病原菌生长相对受限,乙酸铵培养基上菌株产孢量最多,硝酸钠培养基上菌株产孢量较少。  相似文献   

7.
油菜黑胫病菌(Leptosphaeria biglobosa)生物学特性研究   总被引:1,自引:0,他引:1  
为了解我国油菜黑胫病病原菌(Leptosphaeria biglobosa)的生物学特性,在实验室里研究了温度、pH值、光照、碳源及氮源等条件对该病菌营养生长及分生孢子产生的影响。结果表明:病原菌在5℃~35℃均可进行营养生长并产孢,最适生长和产孢温度为25℃;在pH4~10的范围内该菌均能生长并产孢,在pH7的条件下生长最快,产孢最多。光暗交替有利于菌丝生长和产孢,而持续光照不利于菌丝生长,尤其不利于产孢。最适的碳源、氮源分别是可溶性淀粉、牛肉膏。分生孢子的致死温度为52℃。  相似文献   

8.
鹤望兰叶斑病菌的鉴定及生物学特性   总被引:5,自引:0,他引:5  
鹤望兰(Srelizia regne)叶斑病菌鉴定为柯氏帚梗柱孢霉菌(Cylindroclalium collouniperdl colouni)。该病原菌的菌丝在不同培养基里生长情况不一致,其中以Richards培养基最佳。在5种培养基中Richards培养基和PCA培养基不产孢。菌丝生长的适宜温度为15~35℃,适宜pH是5.01~6.49,分生孢子萌发的适宜温度为25~30℃.病原菌分生孢子在碳源的利用上,D-葡萄糖、蔗糖、淀粉明显优于麦芽糖、D-果糖和乳糖∶;对氮源的利用以酵母浸膏、牛肉浸膏、硝酸铵明显优于蛋白陈、L-天冬氨酸和硫酸铵。  相似文献   

9.
木薯褐斑病病原鉴定及其生物学特性研究   总被引:1,自引:0,他引:1  
褐斑病是中国木薯生产中最为严重的叶部真菌性病害.采用多种分离方法,经致病性评价后获得该病的病原菌,形态观察和ITS序列分析结果表明其为亨宁氏钉孢(Passalora henningsii).比较光照、菌丝打断、紫外线和菌丝打断-紫外等方法的诱导产孢效果,结果表明:只有菌丝打断-紫外诱导法能够产生大量分生孢子,CME(麦芽木薯叶)培养基、28℃、pH6.0~7.0、紫外线连续诱导、25 mL/皿、14~21 d为产孢最适条件.对菌株CPHHN02的生物学特性研究表明,CA培养基、26~28℃、pH6.0、连续黑暗、碳氮源分别为D-葡萄糖、D-甘露醇、D-乳糖和胰蛋白胨为菌株最适培养条件.大型分生孢子的最适萌发温度为26℃,致死温度为60℃10 min.  相似文献   

10.
玉米穗腐病样本中温和镰孢菌的鉴定及其生物学特性   总被引:1,自引:0,他引:1  
孙华  李坡  郭宁  石洁  张家齐  张海剑 《玉米科学》2020,28(1):177-183,190
为明确引起玉米穗腐病的一种不常见镰孢菌病原菌及其生物学特性,对采集的镰孢菌穗腐病样本进行病原菌分离和纯化,并通过柯赫氏法则(Koch''s Rule)、形态学特征和分子生物学技术对菌株进行鉴定。结果表明,分离到的菌株ZBSF002为温和镰孢菌(Fusarium temperatum),是玉米穗腐病的致病菌。对其生物学特性研究表明,温和镰孢菌的最适碳源是可溶性淀粉,最适氮源是酵母浸粉,生长温度范围为10℃~35℃,最适温度为30℃。在pH值为4~11的培养基上均能生长和产孢,在pH值7~10培养基上菌丝生长较快且产孢量较大。光照对菌丝生长和产孢量影响不显著,菌株在光照、黑暗、交替光照3种培养条件下均能生长和产孢,连续光照条件下菌丝生长较快,且产孢量较大。病原菌菌丝和分生孢子致死温度为65℃、10 min。  相似文献   

11.
12.
Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.  相似文献   

13.
Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.  相似文献   

14.
15.
Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.  相似文献   

16.
Novel food and non-food uses for sorghum and millets   总被引:4,自引:3,他引:4  
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.  相似文献   

17.
Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X1 (also called RXact).  相似文献   

18.
The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.  相似文献   

19.
Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).  相似文献   

20.
The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O2•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O2•− scavenging, (IC50 = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC25 = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC50 = 863 µg/mL; elastase, IC50 = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O2•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.  相似文献   

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