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1.
红毛丹炭疽病菌生物学特性研究   总被引:2,自引:0,他引:2  
对红毛丹炭疽病病菌进行分离,鉴定病原菌为胶孢炭疽菌[Colletotrichum gloeosporioides(Penz.)Sacc.]。研究培养基、温度、湿度、pH值、光照、营养对红毛丹炭疽病菌生长和孢子萌发的影响。结果表明,该菌菌丝在PDA、CA和CZ培养基上生长较好,10~35℃下均能生长,适宜生长温度为25~28℃,分生孢子萌发的最适温度为28℃;病原菌在pH3~11都能生长,pH5~8生长较好,菌丝生长及孢子萌发最佳pH值为7;分生孢子在饱和湿度中萌发快,相对湿度低于99%时不能萌发;光照对病原菌的生长有明显的促进作用,病原菌的致死温度为:55℃,10min;PDA培养基中加入不同的糖对病原菌生长有明显的促进作用,以鼠李糖、果糖、半乳糖、麦芽糖、甘露糖和木糖最好;PDA培养基中添加2%的不同的无机氮源对病原菌的生长有明显的促进作用。  相似文献   

2.
芒果可可球二孢蒂腐病菌生物学培养特性   总被引:3,自引:1,他引:2  
对芒果可可球二孢蒂腐病菌(Botryodiplodia theobromae Pat.)的生物学培养特性进行了研究.结果表明:菌丝生长最适温度30℃;孢子萌发最适温度30℃;菌丝生长最适pH值5~6,孢子萌发最适pH值7~10;菌丝生长的最佳碳源是棉子糖、葡萄糖,最佳氮源是牛肉浸膏、蛋白胨:光照及振荡培养对菌丝生长无显著影响;菌丝的致死温度为60℃,30 min或65℃,10 min,孢子的致死温度50℃,15min.  相似文献   

3.
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   

4.
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   

5.
对广西三七灰霉病的典型病斑进行分离培养、致病性检测,通过形态学观察并结合r DNA-ITS序列分析鉴定病原菌;通过室内及田间试验研究了温湿度对菌丝生长、孢子萌发的影响,以及病害的病程和病斑显症率,并对不同立地条件、不同生长年限三七灰霉病的发生规律进行调查;最后采用菌丝生长速率法研究了15种杀菌剂对病原菌的抑制作用。结果表明,三七灰霉病病原菌为灰葡萄孢菌(Botrytis cinerea);菌丝生长、孢子形成及萌发的最适温度为20℃,孢子萌发需要高湿度,低于100%湿度不萌发;不同季节、不同生长年限三七的病程为5~13 d,病斑在田间的持续显症期为6 d;三七灰霉病在三七生长期都能发生,10~11月份为发生高峰期,其中不同立地条件下的发病严重度顺序为旱地坡地林下,不同生长年限下的顺序为3年生三七2年生三七1年生三七;咯菌腈、嘧菌环胺与嘧菌酯、氟硅唑对病原菌的菌丝生长抑制率达100%。  相似文献   

6.
玉米瘤黑粉病菌生物学特性研究   总被引:1,自引:0,他引:1  
对影响玉蜀黍黑粉菌冬孢子萌发和双核菌丝生长的生物学特性进行研究。结果表明,冬孢子萌发最适温度为30℃,pH为3,碳源为蔗糖、麦芽糖和葡萄糖,氮源为半胱氨酸、天冬氨酸和甘氨酸;双核菌丝生长的最适温度为30℃,pH为8,碳源为葡萄糖和蔗糖,氮源为天冬氨酸、半胱氨酸和甘氨酸。光照条件对冬孢子萌发和菌丝生长的影响不显著。  相似文献   

7.
火龙果镰刀菌果腐病病原菌鉴定及生物学特性研究   总被引:2,自引:0,他引:2  
采用形态学特征观察、rDNA-ITS序列、EF-1α序列比对和系统发育树分析的方法对引起火龙果镰刀菌果腐病病原菌进行鉴定,并初步研究其生物学特性。结果表明:引起火龙果镰刀菌果腐病是单隔镰刀菌(Fusarium dimerum Penzig in Saccardo),这是该菌引起火龙果果腐病在国内的首次报道。该菌菌丝生长的适宜温度25~35℃,最适温度30℃,适宜产孢温度25~35℃,最适产孢温度30~35℃,致死温度75℃(10 min);适宜pH5~9,最适pH7,最适产孢pH4;连续光照、D-果糖为碳源、牛肉膏和蛋白胨为氮源时最有利于该菌菌丝生长;完全黑暗、D-半乳糖为碳源、尿素为氮源时最有利于该菌产孢。综合分析认为,该菌耐高温,光照充足、弱酸和富含有机营养的环境有利于该菌的生长和繁殖。  相似文献   

8.
在海南省儋州市的三药槟榔(Areca triandra Roxb)苗圃中发现一种为害严重的叶斑病。根据该病的病原菌形态特征以及ITS序列分析,鉴定该病原为克卢亚拟盘多毛孢菌[Pestalotiopsis clusiae(GriffonMaubl)]。病原生物学特性分析发现,该病原菌菌丝生长的适宜温度为28℃,pH为6.5,适宜的碳源为D-麦芽糖和D-葡萄糖,适宜氮源为硝酸钾和硝酸钠;光暗交替有利于菌丝生长及产孢;孢子萌发的适宜温度为30℃,pH为5.5,孢子致死温度为50℃,10 min。采用含毒介质法对4种药剂进行室内敏感性测定,发现该病原菌菌丝生长对50%多菌灵(WP)敏感性最高,50%异菌脲次之。  相似文献   

9.
橡胶树炭疽菌生物学和侵染特征研究   总被引:8,自引:0,他引:8  
橡胶树炭疽病是危害我国橡胶树的一种重要叶部病害,致病菌为胶抱炭疽菌。对其生物学特性研究结果表明,在28 ℃下,有利于菌丝体生长、产孢和孢子萌发 。最适合菌丝体生长的pH值为6。黑暗下有利于孢子萌发和菌丝体生长,但产孢则不如在光照条件下。在100 %相对湿度下孢子萌发率最高。在葡萄糖、橡胶叶汁和琼脂胶等营养液中, 孢子萌发率高于清水对照。对其侵染特征研究结果表明,主要侵染源为受害嫩梢和半枯死枝条,寄主范围广泛。病菌可从伤口、气孔和表皮3种途径入侵,风雨是传播媒介。潜育期一般3~6d,条件最适宜时潜育期为1~ 2d。田间气温21~24℃、相对湿度大于95%时,病菌产孢多,侵人迅速,病斑扩展快  相似文献   

10.
研究结果表明,墨西哥食用仙人掌嫩茎外植体在室温25℃±2℃,光照强度1500~2 000lx、光照时间12h条件下,茎萌发最适培养基为MS+6-BA 1.5mg/L+NAA 1.0mg/L,茎增殖最适培养基为MS+6-BA 1.5mg/L+NAA 0.5mg/L,茎生根最适培养基为1/2MS+NAA1.0mg/L。外植体茎萌发初始阶段先经暗培养约7d后转入光照培养有利于茎萌发和生长,茎萌发时间提早,可提高茎萌发率且茎生长健壮。   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.
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   

17.
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   

18.
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   

19.
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   

20.
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   

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