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1.
为了明确分离自火龙果黑斑病的病原种类、生物学特性及防治方法,对该病菌进行了种类鉴定、生物学特性研究以及室内药剂筛选。结果表明,引起该火龙果病害的病原菌为仙人掌平脐蠕孢[Bipolaris cactivora(Petrak)Alcorn]。该病菌菌丝生长最适温度是30 ℃,产孢最适温度20 ℃。菌丝生长最适pH为5,产孢最适pH8。光照对菌丝生长无显著影响,黑暗条件有利于产孢。菌丝生长最佳碳源是葡萄糖和D-果糖,产孢最佳碳源为甘露醇。菌丝生长和产孢的最佳氮源均为蛋白胨,菌丝致死温度为70 ℃,10 min。  相似文献   

2.
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   

3.
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   

4.
鉴定山竹蒂腐病的病菌,并对该病菌的生物学特性进行研究。根据病菌的培养性状、形态特征、寄主范围和致病性等特性,认为引起山竹蒂腐病的病原菌为可可球二孢菌(Botryodiplodia theobromae Pat.)。该菌菌丝生长的温度范围为10~40℃,最适为28~32℃;孢子萌发的温度范围为5~40℃,最适为28~32℃;在pH值3~11该菌均能生长,最适pH值为5~7;在全光照条件下,该菌菌丝生长最快;在供试碳源中,仅D-木糖不利于该菌菌丝生长,其它7种碳源对菌丝生长的影响无显著差异;在供试氮源中,牛肉  相似文献   

5.
对引起芒果果腐病的病原菌进行鉴定,并对该病原菌的生物学特性进行初步研究。结果表明:引起芒果果腐病的病原菌是芒果拟盘多毛孢[Pestalotiopsis mangiferae(Henn.)Steyaert],该菌菌丝生长最适温度为25~28 ℃,孢子萌发最适温度为32 ℃,致死温度为60 ℃,10 min;菌丝生长最适pH为4~5,而孢子萌发最适pH为4;最适碳源为甘露醇,而麦芽糖不利于菌丝生长;最适氮源为牛肉浸膏、蛋白胨,而尿素不利于该菌菌丝生长;该菌适合在暗光交替和黑暗中生长。  相似文献   

6.
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   

7.
芒果树回枯病病原菌鉴定及其生物学特性研究   总被引:1,自引:0,他引:1  
对芒果树回枯病病原菌进行鉴定,并对该病病原菌进行生物学特性测定。结果表明:引起芒果树回枯病的病原菌为可可球二孢菌(Botryodiplodia theobromae Pat.)。该菌菌丝最适生长温度为28~32 ℃,致死温度为60 ℃、10 min,最适pH值5~9;菌丝生长最佳碳源为蔗糖,木糖不适于该菌生长;最佳氮源是蛋白胨;全光照有利于该菌生长。  相似文献   

8.
层出镰孢菌Fusarium proliferatum是辽宁省玉米穗腐病致病镰孢菌之一。比较 4株层出镰孢菌的生物学特性、致病力、伏马毒素生物合成基因的表达量和产伏马毒素能力。结果表明,供试层出镰孢菌适宜生长温度为25℃~30℃, Fp-2、 Fp-3、 Fp-6最适温度为 25℃, Fp-7最适温度为 28℃。适宜 pH值为 5~8, Fp-2、 Fp-7的最适 pH值为 7; Fp-3耐碱性,最适 pH值为 8; Fp-6耐酸性,最适 pH值为 5。12 h光暗交替有利于菌丝生长,适宜生长培养基为PSA、 PDA。不同菌株对碳氮源的利用存在差异,适宜碳源为可溶性淀粉和蔗糖,适宜氮源为亚硝酸钠、天冬氨酸和脯氨酸。4株层出镰孢菌均能产生毒素,菌株间产毒能力差异显著,菌株Fp-7产伏马毒素B1能力最强,为77.65 mg/kg。菌株间产毒基因的相对表达量也存在差异,致病力无明显差异。  相似文献   

9.
水稻穗腐病病原分离、鉴定及生物学特性   总被引:3,自引:1,他引:2  
 水稻穗腐病(rice spikelet rot disease,RSRD)是近年上升较快的一种水稻穗部重要病害,影响水稻产量和稻米品质。从稻穗发病谷粒中,共分离到4种真菌,经形态学、生物学及分子生物学鉴定,分别为层出镰刀菌(Fusarium proliferatum)、澳大利亚平脐蠕孢菌(Bipolaris australiensis)、新月弯孢菌(Curvularia lunata)和细交链孢菌(Alternaria tenuis)。4种病原菌均能在温度4℃~40℃、pH 3~12条件下生长,最适的温度范围是25℃~30℃,不同菌最佳产孢的pH值差异较大。4种菌均能在供试的碳、氮源培养基上生长,不同的碳、氮源对各菌的菌丝生长和产孢的影响不同。穗腐病是由多种病原菌引起的水稻后期穗部褐变病害,病原菌具有多样性、复杂性和致病性分化的现象。  相似文献   

10.
刘文波  邬国良 《热带作物学报》2009,30(12):1835-1839
对橡胶树褐根病病原菌Phellinus noxius Corner生物学特性进行研究.结果表明,菌丝生长的最适温度为28℃,最适pH值为6~7,该菌可有效地利用部分碳源和氮源,碳源以D-果糖和酵母浸出液最好,氮源以L-天门冬酰胺最好.光照处理对菌丝的生长有明显影响,黑暗利于菌丝生长,光照和黑光有抑制作用.菌丝的致死温度为55℃,10 min.  相似文献   

11.
Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.  相似文献   

12.
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.
Health authorities worldwide have consistently recommended the regular consumption of marine fishes and seafood to preserve memory, sustain cognitive functions, and prevent neurodegenerative processes in humans. Shrimp, crabs, lobster, and salmon are of particular interest in the human diet due to their substantial provision of omega-3 fatty acids (n-3/PUFAs) and the antioxidant carotenoid astaxanthin (ASTA). However, the optimal ratio between these nutraceuticals in natural sources is apparently the key factor for maximum protection against most neuro-motor disorders. Therefore, we aimed here to investigate the effects of a long-term supplementation with (n-3)/PUFAs-rich fish oil, ASTA-rich algal biomass, the combination of them, or krill oil (a natural combination of both nutrients) on baseline redox balance and neuro-inflammation indexes in cerebellum and motor cortex of Wistar rats. Significant changes in redox metabolism were only observed upon ASTA supplementation, which reinforce its antioxidant properties with a putative mitochondrial-centered action in rat brain. Krill oil imposed mild astrocyte activation in motor cortex of Wistar rats, although no redox or inflammatory index was concomitantly altered. In summary, there is no experimental evidence that krill oil, fish oil, oralgal biomass (minor variation), drastically change the baseline oxidative conditions or the neuro-inflammatory scenario in neuromotor-associated rat brain regions.  相似文献   

15.
Wheat bran is a composite material made of several layers, such as pericarp, testa and aleurone. It could be fractionated into purified fractions, which might either be used as food ingredients, or serve as a starting material for extraction of bioactive compounds. The aim of this work was to evaluate the potential of using electrostatic separation as a way to obtain purified fractions from wheat bran. Ultrafine-ground bran obtained either by cryogenic grinding or by grinding at ambient temperature was used as starting material. The ultrafine bran was then charged by tribo-electrification and introduced in a chamber containing two high voltage electrodes, where bran particles were separated depending on their acquired charge, allowing positively and negatively charged fractions to be collected separately. The particle size distribution, microstructure and biochemical composition of the obtained fractions were studied. The charge of the particles was influenced by their biochemical composition: particles rich in highly branched and cross-linked arabinoxylans (pericarp) were separated from particles rich in β-glucan, ferulic acid and para-coumaric acid (aleurone cell walls). The testa and the intracellular compounds from aleurone were not highly charged, neither positively nor negatively. The most positively charged fraction represented 34% of the initial bran, and contained 62% of the ferulic acid present in the initial bran. The yield of the separation process was good (5.4% loss), and could be further increased.  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.
Pulque is made by fermenting the agave sap or aguamiel of Agave atrovirens with a whole array of microorganisms present in the environment including several lactic acid bacteria and yeasts such as Saccharomyces cerevisiae. Ascorbic acid was determined in pulque and aguamiel, respectively. Phytase activity in lees, liquid and freeze-dried pulque was assayed by measuring the appearance of phosphate from phytate by a colorimetric method likewise phosphate from phytate present in fresh corn tortilla was measured after in vitro incubation with pulque. Iron, zinc, calcium, magnesium and selenium contents were measured in pulque and corn tortilla as well as in nixtamalized corn flour (NCF), the latter is used to make instant tortilla, since corn provides most of the energy as well as most of the phytate in the Mexican rural diet. Pulque showed phytase activity but much less ascorbic acid and iron than previously reported; additionally, phytase in pulque hydrolyzed most of phytate’s corn tortilla. Lees, which is mostly made of pulque’s microbiota, significantly accumulated iron and zinc but no selenium. NCF was fortified with iron by the manufacturers but poorly blended. There were significant differences on selenium content between tortillas samples, apparently some soils in central Mexico are selenium deficient. Moderate pulque intake appears to increase the bioavailability of iron and zinc bound by phytate in corn.  相似文献   

18.
Summary Recurrent backcrosses (BC) were used to introduce nuclear factors ofS. tuberosum L. ssp.tuberosum into the cytoplasm of Andean potatoesS. tuberosum ssp.andigena (Juz. and Buk.) Hawkes andS. phureja Juz. and Buk. Each generation BC was produced in reciprocal directions to test the effect of cytoplasmic substitution on yield. This report analyses tuber number, tuber weight, and tuber length of BC2 and BC3 substitution into ssp.andigena cytoplasm and BC2 and BC2 substitutions intoS. phureja cytoplasm. Direction of cross had no consistent significant effect on yield components of ssp.andigena substitution lines. InS. phureja reciprocal progenies direction of cross was responsible for significant differences of some reciprocal sets. When there were significant differences the higher yield usually occurred when ssp.tuberosum was the pistillate parent, but in some progenies when ssp.tuberosum was the pistillate parent the yield was significantly lower than in the reciprocals. It is suggested that differences between reciprocals resulted from chromosomally encoded gene action, resulting from maternal and/or paternal effects, rather than cytoplasmic factors. Authorized for publication as paper No. 7494 in the Journal Series of The Pennsylvania Agriculture Experiment Station.  相似文献   

19.
Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.  相似文献   

20.
Résumé Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.
Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.

Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.
  相似文献   

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