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1 日光温室黄瓜霜霉病发生原因 1.1 温、湿度 黄瓜霜霉病的孢子囊在温度15～20 ℃,空气相对湿度高于83%时极易发生,且湿度越高产孢越多,叶面有水滴或水膜持续3 h以上孢子囊萌发和侵入.日均温15～24 ℃潜育期5 d;17～18 ℃4 d;20～25 ℃ 3 d. 相似文献
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黄瓜霜霉病的防治措施 总被引：5，自引：2，他引：3
霜霉病是大棚黄瓜的第一大病害,若防治不及时,5～7d就可能全田发生和病害流行.病害流行要具备三个因素:一是病原菌大量存在;二是种植的是感病品种;三是环境条件适合病害发生.黄瓜霜霉病的流行与温湿度有密切的关系,特别是湿度,孢子囊在温度5℃～30℃均可萌发,适温15℃～20℃,空气相对湿度高于83%才大量产生,且湿度越高孢子囊越多,叶面有水滴或水膜,持续3h以上孢子囊萌发侵入,若低于15℃或高于28℃,相对湿度60%时,不利于霜霉病的发生发展.黄瓜生产所需湿度为75%～80%,保护地日夜温差大,湿度高容易结露,加上结露时间超过2h,种植又是感病品种--密刺类.这是保护地霜霉病容易流行的主要原因. 相似文献
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温湿度对黄瓜霜霉病菌孢子囊存活的影响 总被引：1，自引：0，他引：1
以“鲁黄瓜3号”黄瓜为试材,研究了温湿度对其霜霉病菌孢子囊存活的影响.结果表明:温湿度对孢子囊的存活有显著的影响,随温度的升高孢子囊的存活率降低,恒温条件下10、15、20和25℃存活期为3～6 d;30℃为3 d;35℃时新鲜孢子囊存活期为1d.饱和相对湿度条件下的孢子囊存活率最高,并且与相对湿度75％和45％时孢子囊存活率存在明显差异. 相似文献
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樱桃黑色轮斑病的病原菌鉴定及其生物学研究 总被引：4，自引：0，他引：4
樱桃黑色轮斑病是甘肃省陇南地区樱桃盛果期树的重要病害。2000-2001年对该病害进行了病原鉴定,同时对病菌的生物学特性进行了观察。结果表明,该病害的病原为半知菌亚门真菌,链格孢属的樱桃链格孢(Alternaria cerasi);病原菌在5-35℃均能正常生长,而以25-35℃生长最好;病原菌在pH值为4.5-8.5培养基上生长最快;分生孢子萌发对温湿度的要求较高,孢子萌发的适宜温度为20-35℃,当温度低于5℃或高于45℃时分生孢子不能萌发;相对湿度在93％以上分生孢子才能较好地萌发,在水滴中萌发最好。病原菌对樱桃叶片的侵染受温度、湿度以及接种部位等条件的影响较大;在较高的温度、湿度下在叶片反面接种,发病最快。 相似文献
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研究人工控制光照对黄瓜霜霉病菌孢子囊存活率的影响。结果表明:在人工控制条件下,新鲜黄瓜双霉菌孢子囊经紫外光照4h便可失去萌发能力。阳光直接照射2h后,萌发率明显下降;照射4h后,50%的孢子囊失去活力;照射36h后,绝大部分孢子囊失去萌发能力。黑暗条件下,新鲜孢子囊在自然环境中放置5h萌发率开始下降,72h后绝大部分孢子囊完全失去萌发能力;漫射光有利于孢子囊的存活,经漫射光处理的孢子囊存活期长于黑暗条件下存活期。还表明1～2h的短时间光照能促进孢子囊成熟与萌发,从而提高孢子囊的萌发率。 相似文献
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对宁夏中部干旱带甜瓜“玉金香”采后主要病害的病原菌进行了生物学特性研究,探讨不同温度、pH、光照等条件对病原菌菌丝生长和分生孢子萌发的影响,以期掌握甜瓜采后主要病原菌的生物学特性,为甜瓜采后主要病害的防治提供理论依据.结果表明:粉红聚端孢霉菌(Trichothecium roseum)在10～35℃菌丝都能生长,孢子均能萌发.镰刀孢霉菌(Fusarium spp.)和链格孢霉菌(Alternaria alternata)在5～35℃菌丝都能生长,孢子均能萌发,最适生长温度和孢子萌发温度为25℃,其中在最适温度镰刀孢霉菌生长和孢子萌发的速度显著高于其它2种致病菌;粉红聚端孢霉在pH 4～10范围内都能生长,孢子萌发的适宜pH 4～8,最适pH为6,镰刀孢霉菌和链格孢霉菌在pH 3～10较宽的范围内均可生长,孢子萌发pH 2～10,最适宜生长的pH为7.光照条件对3种致病菌菌丝的扩展和孢子的萌发影响不明显. 相似文献
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采用常规组织分离法对采自山西省太谷县疑似镰孢刀菌引起的甜瓜果实新病害进行病原菌分离,根据柯赫氏法则明确其致病性。基于形态特征以及核糖体内转录间隔区(rDNA-ITS)、转录延伸因子(EF-1α)、组蛋白(Histone 3)和线粒体中核糖体小亚基(mtSSU)序列分析,鉴定该病原菌为变红镰刀菌(Fusarium incarnatum)。病原菌的生物学特性测定结果表明,菌丝生长和产孢最适培养基均为马铃薯蔗糖琼脂培养基(PSA);温度为20～35℃菌丝生长较快,20～25℃产孢量最大;羧甲基纤维素钠、淀粉和木糖等碳源适合菌丝生长,产孢的最佳碳源为乳糖;病原菌在多种氮源上均能较好生长,产孢的最佳氮源为酵母粉;pH为8时菌丝生长最快,不同pH处理的产孢量间差异不显著;病原菌在全光照和全黑暗条件下能较好生长,不同光照条件下产孢量差异不显著;菌丝致死温度为61℃(10min),分生孢子致死温度为56℃(10 min)。 相似文献
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【目的】明确杧果新病害露水斑病病原菌(Cladosporium cladosporioides)的生物学特性,以便为该病害的发生规律研究提供理论依据。【方法】测定了不同条件对病原菌菌丝生长、产孢量和孢子萌发的影响。【结果】菌丝在杧果葡萄糖琼胶培养基和PDA培养基上生长最佳,最适生长温度20℃,最适p H值7~8,光照对菌丝生长影响不明显,菌丝对有机碳源乳糖和有机氮源氨基乙酸利用最好,菌丝致死温度为50℃、10 min;产孢量以25℃、p H 6、光暗交替、麦芽糖为碳源、L-胱氨酸为氮源时最大;分生孢子萌发率以25℃、p H7、液态水、有机碳源阿拉伯糖、有机氮源L-天冬氨酸为最适条件,分生孢子致死温度50℃、10 min。【结论】杧果露水斑病菌喜好20~25℃、弱酸至弱碱、高湿、富含有机营养的环境。 相似文献
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The effects of combinations of salinity (no salt, 2000 p.p.m. or 4000 p.p.m. of CaCl2 and NaCl, 1:1) and water table (30 cm, 60 cm or 90 cm from the soil surface), on the vegetative growth and tolerance of ‘Golden Japanese’ plum and ‘Mit Ghamre’ and ‘Balady’ peaches were studied. The plants were grown in lysimeters. The growth of the trunk, total shoot length, the increase in shoot length per cm and the fresh weight of top, root and total plant were reduced with increasing salinity of the irrigation water. The effect was accentuated when the plants were maintained at high water table level. The salinity treatments resulted in the death of 43%, 73% and 76% of the plants in the plum, and the ‘Mit Ghamre’ and ‘Balady’ peaches, respectively, indicating that the plum is more tolerant to salinity than the peach. The plants of the salinity treatments showed various symptoms of salt injury, such as leaf burn, defoliation, shoot die-back and finally death. In the peaches, salt injury started to occur in the first growing-season, whereas the salt injury appeared in the plum in the second growing-season. The symptoms were more pronounced in the 4000 p.p.m. treatment than in the 2000 p.p.m. treatment and were more pronounced at the high water table level. The salinity level was the predominant factor and the effect of the water table on the vegetative growth diminished with increase in the salinity level of the irrigation water. 相似文献
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AIM：To establish a fast, accurate and economical technique for culturing mouse pulmonary arteriolar smooth muscle cells (PASMCs), and to explore the effects of hypoxia on the proliferation and apoptosis of the PASMCs. METHODS：In sterile condition, the pulmonary artery was isolated from the male BALB/c mice by digesting with collagenase I, and the cells were cultured in fetal bovine serum-coated flask. Centrifugal procedure was not used during the cell passage. The cell morphology was observed under an inverted phase-contrast microscope. α-Smooth muscle actin was identified by immunocytochemistry and immunofluorescence. The effects of hypoxia on the proliferation and apoptosis of the PASMCs were detected by CCK-8 assay and TUNEL assay. RESULTS：PASMCs were identified by the methods of immunocytochemistry, immunofluorescence staining and observation of morphology. Unlike the rat PASMCs with typical subcultured peak-vally pattern, the mouse PASMCs showed a lot different without a peak-vally pattern. The cells could be subcultured after 5 d to 7 d and there was 3 to 5 generations depending on the activity of the cells. CCK-8 assay demonstrated that the A values of PASMCs exposed to hypoxia increased after 24 h (P＜0.05) as compared with normoxia. TUNEL result showed that the apoptotic index of the PASMCs in hypoxia decreased after 24 h (P<0.05). CONCLUSION：This technique for obtaining cultured mouse PASMCs is simple, fast, accurate and economical. The digestion time is easy to control. Hypoxia promotes the proliferation and inhibits the apoptosis of PASMCs. 相似文献
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小檗碱和壳聚糖抗蔬菜病原真菌活性测定及复合膜制备 总被引：2，自引：0，他引：2
研究了小檗碱和壳聚糖对几种常见蔬菜病原真菌的抑制活性,以及以小檗碱和壳聚糖为主料制备复合膜的方法,并测定了该膜的药物释放效果。试验表明:低浓度(0.234 mg/mL)小檗碱即可抑制辣椒炭疽病菌(Vermicularia capsici)等5种蔬菜病原真菌的生长。20 mg/mL浓度壳聚糖对番茄灰霉病菌(Botrytis cinerea)的抑制率高达65%,而对其余4种果蔬病原真菌也有一定的抑制作用。为了集成这2种天然化合物的优点,制备了小檗碱-壳聚糖复合膜,该膜具有缓释功能,在模拟外部环境(磷酸缓冲液,pH 6.8)条件下,20 d小檗碱累计释放率接近25%,提示其在果蔬贮藏抗菌中的应用价值。 相似文献
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钾肥在小白菜和萝卜上的施用效果 总被引：6，自引：0，他引：6
采用盆栽试验方法研究了施用钾肥对小白菜、萝卜生长发育、产量、品质及钾素含量的影响。结果表明 ,施用钾肥对小白菜和水萝卜的株高、叶片数无显著的影响 ,但可提高水萝卜块根的产量 ,提高幅度为 31.0 4 %～ 97.93%。施用钾肥可提高小白菜和萝卜的蛋白质和VC含量 ,降低硝酸盐含量 ,增加植株的钾素含量 相似文献
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Fresh onion seeds desiccated to 6.0% seed moisture content (SMC) were stored in various packaging materials under different storage conditions. Seeds packed in aluminum-laminated pouches beside those stored with silica gel at 25 °C maintained satisfactory germinability and vigour after 12 months. Desiccated seeds stored in moisture impervious containers produced more vigourous seedlings. Germination potential of onion seeds increased with reduced SMC besides storage in moisture impervious packets along with desiccants as physiological and biochemical attributes are regulated. Seed viability and vigour decreased with accelerated ageing due to increased lipid peroxidation, decreased activities of several free radical and peroxide scavenging enzymes. Electrical conductance of seed leachates also increased with ageing. Thus, adoption of appropriate storage temperature and moisture control techniques would significantly affect onion seed quality, which was due to minimum accumulation of free peroxide radicals and enhanced activity of free radical scavenging enzymes. 相似文献