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玉米灰斑病现已严重威胁中国北方玉米生产的可持续发展。本研究采用苗期鉴定、成株期鉴定、温室鉴定和田间鉴定等方法,利用玉米自交系和品种对玉米灰斑病菌致病性分化鉴定方法进行了研究。结果表明:玉米苗期和成株期均可用于玉米灰斑病的抗性鉴定,两者鉴定结果有一定的相似性,但利用成株期进行鉴定比较好,因为接种比较容易;利用自交系或品种均可进行抗性鉴定,从效果上看,利用自交系较好,因为利用成株期自交系鉴定法,不同自交系一菌株组合间病级差异较明显,变异系数为47.32%,能有效地区分不同菌株间致病性分化的程度,但是由于成株期品种鉴定法与成株期白交系鉴定法比较。变异系数差异很小,所以成株期品种鉴定法可以作为抗性鉴定的辅助方法。 相似文献
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绿色木霉TR-8菌株的生物学特性研究 总被引:1,自引:0,他引:1
绿色木霉菌TR-8是一株具有生防潜力的拮抗菌。研究发现TR-8菌株在PDA培养基、查彼培养基和基本培养基上均能较好生长,在基本培养基上生长最快,3种培养基对孢子产生影响不大。温度对菌丝生长和孢子产生影响显著,30℃时菌丝生长最快,25℃时产孢量最大。TR-8菌株在pH值2~10范围内均可生长,pH值5~6时菌丝生长最快,pH值为7时孢子产生量最大。光照处理对菌丝生长影响不明显,但可明显促进孢子产生。葡萄糖和麦芽糖为菌丝生长和产孢的最佳碳源。天冬酰胺是菌丝生长和孢子产生的最佳氮源。不同维生素对菌丝生长和孢子产生作用不同,烟酸对菌丝生长最有利。微量元素对菌丝生长有一定的促进作用,Mn有利于孢子产生。镰刀菌的菌丝提取物对TR-8的孢子产生具有促进作用。 相似文献
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对番茄煤霉病病原菌———番茄煤污尾孢霉(Cercospora fuligenaeRoldan)进行了生物学特性及杀菌剂抑菌效果测定研究。结果表明:病菌在不同培养基上菌丝生长速度存在明显差异,以燕麦片培养基、PSA培养基为最适,其次为PDA和果煎汁培养基;病菌菌丝生长温度范围5~35℃,最适为25℃;病菌菌丝体致死温度为55℃、10m in。病菌pH值在3~12范围均可生长,以pH值3~4为最适;光照对病菌菌丝生长影响较小。病菌在黑暗条件下较易产孢。病菌分生孢子萌发温度为10~40℃,最适为25℃,高温对孢子萌发有抑制作用;分生孢子在1%的木糖、果糖、葡萄糖中萌发较好,但在水滴中萌发率较低;pH值2~12范围均可萌发,pH值6为最适;病菌分生孢子致死温度为54℃、10m in。 相似文献
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用水杨酸、磷酸氢二钾、灰斑病菌波液和草酸作诱抗剂,研究了玉米对灰斑病的诱导抗病作用,同时测定了挑战接种前后的PAL酶活性的变化。结果表明:上述4种诱抗剂均有不同程度的诱导抗病性,其中水杨酸诱抗效果最好,病菌增减滤液和磷酸氢二钾次之,草酸诱抗效果最差。诱导后挑战接种,PAL酶活性变化都有增加,且酶活性曲线波形变化较大。 相似文献
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对我国高粱上发生的一种新病害-高粱靶斑病进行了初步的研究。结果表明:⑴引起靶斑病的病原菌为蜀黍生离蠕孢菌「Bipolaris sorghicola(Lefebvre&Shetwin)Shoem」;⑵病菌菌丝生长的适宜温度为25 ̄30℃,分生孢子萌发的适宜温度为20 ̄30℃;分生孢子萌发的适宜pH为3 ̄6;⑶该菌能利用多种碳源作为营养;以木糖、半乳糖、菊糖为佳,其次为蔗糖、麦芽糖等;利于病菌生长的培养基为玉米粉、燕麦片和白高粱煎汁培养基;⑷田间土壤表面残落的和堆积在村屯附近的高粱秸垛表面的病残叶上的病菌,是翌年田间病害发生的主要初侵染来源;⑸所鉴定的620份高粱不同品种资源中,对靶斑病的感病性存在明显差异,其中26份为免疫和高抗资源。 相似文献
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从辽宁省不同地区保护地采集番茄灰霉病菌。经单胞分离获得代表性菌株35株,彩菌丝生长速率法测定各菌株对嘧霉胺的敏感性。结果表明,番茄灰霉病菌已对嘧霉胺产生中等水平抗药性,抗性频率为22.9%。不同地区存在差异,嘧霉胺使用较多的锦州和瓦房店地区抗药性频率较高。在离体条件下,抗药性菌株具有良好的遗传稳定性,与敏感菌株相似适应能力。 相似文献
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玉米灰斑病是由玉蜀黍尾孢菌引起的,最早于1924年在美国亚历山大州和伊利诺斯州发现,该病现在美国普遍发生。1991年陈刚在辽宁发现该病,至今该病在辽宁、吉林、河北等地区均有发生。不同的学者采用不同的方法对玉米品系进行灰斑病抗性鉴定,其中常用的方法有病害发生率(DI)和病害严重度(DS)两种,两者相比各有优缺点。对玉米品系进行灰斑病抗性鉴定时,不仅要注意方法的选择,而且还要注意时间的选择和在整个玉米生长期内等级划分的次数。同时选择好一个适合鉴定的环境也是很关键的。国内外现已鉴定出一系列抗性品系,其中抗性品系主要存在于自交系中。玉为灰斑病的遗传属数量遗传,且主要受累加基因控制,并可以通过回交和轮回筛选转移。玉为灰斑病病原菌种群中致闰性存在差异。 相似文献
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分析了碱回收蒸发工段的工艺流程和控制要求,从硬件配置和软件设计等方面对碱回收蒸发工段进行了详细的叙述,同时采取软测量的方法测量黑液浓度,提出黑液浓度-压力串级控制方法;根据工艺要求设计出一种新型的DCS控制方法,它是由西门子公司的SIMATIC 400系列PLC连接ET200系列的分布式I/O系统及标准伺服控制系统组成的DP控制网络,通过相应的智能仪表及阀门对现场信号进行采集和控制;由此对碱回收蒸发工段实施集散控制的优化控制法案;工程实践表明,该系统在江苏甲乙粘胶公司生产线上投用,各种控制性指标能够很好地满足公司的要求。 相似文献
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Large‐area black/white bistable cholesteric liquid‐crystal display and the thermal‐addressing system
Po‐Wen Liu Chen‐Chu Tsai Wei‐Hsun Huang Chao‐Wen Chen Cheng‐Yi Wang Kuo‐Chang Lee 《Journal of the Society for Information Display》2010,18(12):1084-1089
Abstract— A 3‐m‐length black/white bistable cholesteric liquid‐crystal display was made by a roll‐to‐roll process and the display area is 25 × 300 cm. The black/white performance was made by black nano‐pigment and blended ChLC droplets with different wavelengths. It was written by a thermal‐addressing system, realizing high resolution and low cost. 相似文献
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由松材线虫(Bursaphelenchusxylophilus)引起的松树萎蔫病 ,是松树上的一种毁灭性病害 ,已在日本、美国、黑西哥、加拿大、韩国发生和流行。目前松材线虫的发生范围还在继续扩大。我国最早在1982年秋于南京紫金山的松林中发现该病 ,当年仅见枯树260株 ,现已查明在苏、浙、粤、皖、港、台均有分布 ,各地呈迅速扩展蔓延趋势。至1999年底该病在我国的发病面积已超过60万公顷 ,累计死树1600万株 ,直接经济损失1.28亿元。TomoyaKiyohare从日本松材线虫分布区内收集到37个线虫群… 相似文献
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Abstract— Cholesteric liquid crystals at zero field exhibit two optically contrasting stable states: planar texture and focal-conic texture. When a cholesteric liquid crystal is in the planar texture, the helical axis is perpendicular to the cell surface; the material Bragg-reflects colored light. When the liquid crystal is in the focal-conic texture, the helical axis is more or less parallel to the cell surface; the material is forward-scattering and has a black appearance if the back plate of the cell is painted black. We develop a cholesteric liquid-crystal/polymer composite in which a small amount of polymer is dispersed in the liquid crystal. The dispersed polymer changes the planar texture to a poly-domain structure, which has a white appearance but has little effect on the optical properties of the focal-conic texture. The result is a bistable black-white reflective display which is a good candidate for electronic-paper applications. 相似文献
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Abstract— Two measurement methods to characterize uniformity and the absolute cell gap of LCoS images will be reviewed. These are simple to use in a production environment and have allowed major improvements in manufacture to be achieved. For the purpose of this paper, the liquid‐crystal mode used is the 45° normally black mode. 相似文献
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Hin Yu Mak Vladimir G. Chigrinov Hoi‐Sing Kwok 《Journal of the Society for Information Display》2007,15(7):527-531
Abstract— Two configurations, (i) a double‐cell‐gap twisted nematic (DTN) liquid‐crystal display (LCD) and (ii) a single‐cell‐gap twisted‐nematic (TN) liquid‐crystal display (LCD) using a twisted LC retarder, were optimized for transflective liquid‐crystal displays. For the DTN configuration, both the single‐cell‐gap approach and the double‐cell‐gap approach were considered. The optimized configurations exhibit a high contrast ratio, wide viewing angles, and achromatic (black/white) switching in both the transmissive and reflective modes. They are easy to fabricate and also possess a perfect dark state. Both are suitable for high‐quality transflective TFT‐LCDs. 相似文献
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To reduce perceived motion blur on liquid crystal displays, typically various techniques such as overdrive, scanning backlight, black‐data insertion, black‐field insertion, and frame rate up‐conversion are widely employed by the liquid crystal display industry. These techniques aim to steepen the edge transitions by improving the dynamic behavior of the light modulation. However, depending on the implementation, this may result in the perception of irregularly shaped motion‐induced edge‐blur profiles. It is not yet fully understood how these irregularities in the steepened edge‐blur profiles contribute to the perceived sharpness of moving objects. To better understand the consequences of several motion‐blur reduction techniques, a perception experiment is designed to evaluate the perceived sharpness of typical motion‐induced edge‐blur profiles at several contrast levels. Relevant characteristics of these profiles are determined on the basis of the perception results by means of regression analysis. As a result, a sharpness metric with two parameters is established, where one parameter relates to the edge slope and the other to the overshoot/undershoot part of the motion‐induced edge‐blur profile. 相似文献
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Hin Yu Mak Xihua Li Peizhi Xu Tao Du Vladimir G. Chigrinov 《Journal of the Society for Information Display》2008,16(9):953-956
Abstract— A ferroelectric liquid‐crystal (FLC) display was optimized as a transflective liquid‐crystal display (LCD). In this configuration, the single‐cell‐gap approach was considered. The optimized configuration exhibits a high contrast ratio, wide viewing angles, and achromatic (black/white) switching in both the transmissive and reflective modes. Because no double‐cell‐gap structure, no subpixel separation, and no patterning polarizers and retarders are included in the configuration, the configuration is easy to fabricate and also possess a perfect dark state. This configuration is also suitable for bistable applications. 相似文献