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为筛选对猕猴桃黑斑病和白纹羽病具有良好防效的生防菌,选用前期获得的1种生防菌和市售的6种生防菌剂对其病原链格孢菌Alternaria alternata与褐座坚壳菌Rosellinia necatrix进行室内抑菌试验。结果表明,7种生防菌对上述两种病菌的抑菌效果较一致,抑菌效果最好的为生防菌株西姆芽孢杆菌JY-1,荧光假单胞杆菌、枯草芽孢杆菌、巨大芽孢杆菌和蜡质芽孢杆菌4种生防菌剂也都具有较好的抑菌效果,而解淀粉芽孢杆菌和哈茨木霉的抑菌效果则较差。可选用上述4种防效较好的生防菌剂对猕猴桃黑斑病和白纹羽病进行生物防治,并对JY-1菌株进行开发利用。 相似文献
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从紫花苜蓿根际土中分离出2株芽孢杆菌(Bacillus spp.)菌株CYY-6和CYY-42,并评价了其对尖孢镰刀菌(Fusarium oxysporum)的抑制作用,及其对由尖孢镰刀菌引起的苜蓿根腐病的防治效果。经过形态观察、16S rDNA序列分析和生理生化鉴定,确定菌株CYY-6为地衣芽孢杆菌(Bacillus licheniformis),CYY-42为短短芽孢杆菌(Brevibacillus brevis)。同时检测发现这2株芽孢杆菌均能不同程度地合成嗜铁素。在平板对峙实验中,2株菌株均能对尖孢镰刀菌产生拮抗作用,并产生抑菌带,抑菌率分别为49.3%和56.3%。且其发酵液可以致使尖孢镰刀菌菌丝及孢子生长异常,出现菌丝扭曲、断裂、破碎,孢子数量明显减少等现象。在盆栽实验中,2株菌株对由尖孢镰刀菌引起的紫花苜蓿根腐病的相对防效分别为57.55%和64.03%,在紫花苜蓿根腐病防治方面具有较好的应用潜力。 相似文献
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香蕉枯萎病是毁灭性土传病害，引入生物防治技术可有效降低目前化学杀菌剂的用量，保护生态环境和人类健康。通过平板抑菌试验，研究了2株香蕉枯萎病生防芽孢杆菌C10-1和A5-6对尖孢镰刀菌古巴专化型(Fusarium oxyporum f. sp. cubense)的平板抑制效果以及对化学杀菌剂的适应性，在此基础上，将生防芽胞杆菌与杀菌剂复配，进一步研究其对枯萎病菌的室内抑制效果。结果表明，C10-1菌株对病原菌的抑制效果和对杀菌剂的适应性均优于A5-6菌株，与0.1mg/L咪鲜胺复配后，其抑菌效果显著增强，可达94.96%。 相似文献
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本研究采用平板对峙法从健康燕麦根际筛选能够拮抗燕麦根腐病致病菌(禾谷镰刀菌)的菌株,同时,将早期研究获得的生防菌株纳入筛选范围。采用透明圈法测定菌株产蛋白酶、纤维素酶、淀粉酶以及产铁载体的能力,对菌株进行复筛,并将产酶能力优良的菌株进行定量测定;利用酸沉淀法进行脂肽类物质粗提并验证其抑菌能力,对生防特性优良的菌株进行16S rRNA分析鉴定。结果表明,共得到4株综合特性优良的菌株,抑菌率均达到65%以上;铁载体活性34.33%～59.57%、蛋白酶活性36.88～70.12 U·mL-1、纤维素酶活性7.68～22.28 U·mL-1、淀粉酶活性80.56～167.26 U·mL-1;菌株分泌的脂肽类物质对病原菌抑菌率最高为68%。通过16S rRNA鉴定,4株菌分别为枯草芽孢杆菌、贝莱斯芽孢杆菌、萎缩芽孢杆菌和皮尔瑞俄类芽孢杆菌。本研究筛选的4株生防细菌均可分泌多种抑制菌物质,具有进一步开发为生物杀菌剂的潜力。 相似文献
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芽孢杆菌(Bacillus)能产生多种抑制真菌的物质,对植物病原真菌具有良好的抑制效果,已成功应用于包括桑树真菌类病害在内的多种植物真菌类病害的生物防治.本文综述了近几年国内外有关生防芽孢杆菌抑菌物质的研究进展,包括生防芽孢杆菌抑真菌物质的种类、抑菌作用机制及其在桑树和其他植物真菌病害生物防治中的研究与应用现状,同时对生防芽孢杆菌在桑椹菌核病防治方面的应用前景进行了展望,以期为未来研发和应用新型生防菌剂防治桑树真菌病害提供参考. 相似文献
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《蚕业科学》2015,(5)
桑椹菌核病是由桑椹核地杖菌(Scleromitrula shiraiana)等病原真菌引起的果桑毁灭性病害。寻获对桑椹菌核病病原菌有拮抗作用的桑树内生菌,可以达到通过安全、长效的生物防治方法控制病害的目的。以生产上对桑椹菌核病抵抗力较强的桑树品种川7637为材料,采用组织分离法从其健康植株的茎中分离获得一株对桑椹核地杖菌具有显著拮抗作用,且对桑树组培苗有促生作用的内生细菌7PJ-16菌株。基于7PJ-16菌株的形态、生理生化特性及16S rDNA系统发育分析结果,将其鉴定为特基拉芽孢杆菌(Bacillus tequilensis),命名为Bacillus tequilensis 7PJ-16。抑菌谱测试结果表明B.tequilensis 7PJ-16菌株96 h发酵滤液对10种植物病原真菌具有不同程度的抑制作用,其中对桑椹核地杖菌的抑菌率高达100%,且发酵滤液的热稳定性强。对B.tequilensis 7PJ-16菌株培养特性的初步研究表明,该菌株的最适生长温度为25℃,培养96~120 h的发酵滤液对桑椹核地杖菌的抑菌率可达100%。田间防效试验的初步结果显示,在桑树花期喷施5次B.tequilensis 7PJ-16菌株的发酵上清液,其病果率仅为1.83%,较清水对照处理组降低18.66个百分点。综上研究表明,筛选获得的桑树内生细菌B.tequilensis7PJ-16菌株对桑椹核地杖菌有较强的拮抗作用,是开发桑椹菌核病生防制剂较为理想的候选菌株 相似文献
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枯草芽孢杆菌(Bacillus subtilis)对桑炭疽病菌的抑制作用 总被引：5，自引：0，他引：5
以枯草芽孢杆菌(Bacillus subtilis)菌株BS-LX04为材料,测定其对桑炭疽病病原菌(Colletotrichum m orifoli-um)的抑制作用。结果表明BS-LX04对桑炭疸病病原菌的菌丝生长和分生孢子萌发具有较强的拮抗作用:能够使菌丝生长受阻且产生畸形;能够抑制分生孢子的萌发,培养24 h检查孢子萌发抑制率为73.22%;能够推迟分生孢子的萌发时间,并导致萌发孢子的芽管和菌丝畸形而不能继续生长。BS-LX04发酵培养滤液中可粗提到对菌丝生长和分生孢子萌发具有抑制作用的粉状物质,随着菌株培养时间的延长,粗提物对桑炭疽病菌菌丝生长和孢子萌发的抑制率也逐渐升高,即抗菌物质产生逐渐增多,培养48 h是适宜的发酵时间。菌株在28℃培养,获得的抗菌物质粗提物的抑菌率和孢子萌发抑制率均最高,28℃为菌株最适发酵温度。 相似文献
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文章综述枯草芽孢杆菌在体内、体外的抑菌性能，旨在保障枯草芽孢杆菌的饲用效果，重点总结3方面：其一，枯草芽孢杆菌抑菌性能评估方法；其二，枯草芽孢杆菌的体外抑菌作用（牛津杯法体外抑菌试验评估）；其三，饲用枯草芽孢杆菌对畜禽肠道菌群的调控效果（体内抑菌试验评估）。体外试验文献显示，枯草芽孢杆菌对肠道有害菌和饲料源有害菌的抑菌报道较多，对肠道有益菌和其他商业益生菌的抑制研究很少，且不同菌株的抑菌性能差异较大，这与饲用枯草芽孢杆菌对畜禽肠道有益菌及个别有害菌调控出现差异化结果相符。文章建议完善枯草芽孢杆菌体外抑菌评估的体系，这有助于筛选安全的菌株及高效地研制单一和复合饲用枯草芽孢杆菌制剂。 相似文献
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3株分离自高寒草甸根际芽孢杆菌的分子鉴定及其生物活性 总被引：1，自引：0，他引：1
为青海省退化草地植被恢复、提高地上生物量筛选优良的生防芽孢杆菌菌源,采用16SrDNA及gyrB基因序列分析法,鉴定分离自青海省黄南州高寒草甸高山嵩草(Kobresia pygmaea)根围的3株芽孢杆菌菌株;平板对峙试验检测菌株拮抗病原真菌活性;菌悬液(细胞浓度为106 cfu·mL-1)浸种以检测菌株对植物催芽及促生效果;CMC、Gram染色法及DNS法检测菌株降解纤维素活性,并扩增菌株降解纤维素酶编码基因。结果表明,菌株HNC3被鉴定为短小芽孢杆菌(Bacillus pumilus),菌株HNC8、HNC11被鉴定为苏云金芽孢杆菌(Bacillus thuringiensis);3株菌株对小麦赤霉病菌(Fusarium graminearum)、瓜类枯萎病菌(Fusarium oxysporum)具有明显的拮抗活性(抑菌圈平均直径均≥11mm);3株菌株对小麦(Triticum aestivum)种子具有明显的催芽及促生效果;小麦种子经菌株HNC3菌悬液处理后,芽长、根长增加率分别达55%、80%;菌株HNC3降解纤维素酶活高达367.51U·mL-1,并在该菌株中扩增到地衣聚糖酶(Lichenase,blg1S)、甘露糖苷酶(mannosidase,ManSig)、木聚糖酶(xylanase,xynD、xynB)4个纤维素酶编码基因。分离自青藏高原高寒草甸根围的3株芽孢杆菌兼具拮抗、催芽、促生及降解纤维素活性,在高原草地植被恢复、生态农牧业中具有一定的研究及应用潜力。 相似文献
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根腐病是苜蓿（Medicago sativa）生产中的重要限制性病害,应用生物技术对其进行防治对环境友好型可持续农业具有重要意义。本研究从不同地区苜蓿根际土壤中分离得到的95株真菌中筛选出了2株对根腐病病原菌抑菌率较高的菌株,经鉴定,2株拮抗真菌ZY56和GY37分别为哈茨木霉（Trichoderma harzianum）和康宁木霉（Trichoderma koningii）。对2株菌株的拮抗能力及盆栽防效的测定结果表明：2株菌株对4种镰刀菌（Fusarium spp.）均有较好的抑制效果,其7 d抑菌率在54.9%~75.3%之间,其中ZY56对尖孢镰刀菌（F.oxysporum）和半裸镰刀菌（F.semitectum）的抑菌率较高,而GY37对燕麦镰刀菌（F.avenaceum）和腐皮镰刀菌（F.solani）的抑菌效果更好;ZY56对盆栽苜蓿根腐病的防效显著高于多菌灵,达到66.4%,且促进生根效果明显,GY37也具有良好的防治效果,防效为55.1%。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献