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为探讨外源NO缓解番茄幼苗次生盐渍伤害的光合生理机制,以秦丰保冠番茄幼苗为试材,在水培条件下,利用叶绿素荧光动力学技术研究喷施NO供体硝普钠(SNP)对80 mmol·L-1Ca(NO_3)_2胁迫下番茄幼苗PSII光化学效率、激发能分配和天线色素吸收光能利用的影响。结果表明,喷施SNP有效缓解了Ca(NO_3)_2胁迫对PSII的损伤,使第15天番茄幼苗叶片的PSII最大光化学效率(F_v/F_m)、天线转化效率(F_v'/F_m')、实际光化学效率(ΦPSII)、光化学荧光猝灭系数(q P)及吸收光能用于进行光化学反应(P)和非光化学耗散(Ex)的份额分别较胁迫处理显著提高了4.93%、39.31%、92.84%、39.00%、92.83%和10.33%;初始荧光(Fo)、非光化学荧光猝灭系数(NPQ)、双光系统间激发能分配不平衡偏离系数(β/α-1)和天线热耗散的份额(D)分别较胁迫处理显著降低了7.20%、13.22%、43.09%和24.70%。综上,外源NO能通过改善PSII光化学活性和增强PSII反应中心的非光化学耗散减轻Ca(NO_3)_2胁迫造成的光抑制,进而提高番茄幼苗的耐盐能力。本研究结果为利用外源NO缓解蔬菜设施生产的次生盐渍障碍提供了理论和技术依据。 相似文献
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水溶液及红壤提取液中镧的生物毒性研究 总被引:2,自引:0,他引:2
利用发光细菌法研究了水溶液及红壤提取液中镧的生物毒性。水溶液中镧有较高的生物毒性并随浓度的升高而增强 ,EC50 值为21.1mg·L-1。土壤提取液中的镧有一定的生物毒性 ,并随镧浓度的升高不断增强。随着培养时间的延长 ,土壤提取液中镧的生物毒性逐渐减小。镧在土壤中的生物毒性是直接的 相似文献
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Eduardo M Leaño Gilda D Lio-Po Lorena A Nadong Analyn C Tirado Resurreccion B Sadaba & Nicolas G Guanzon Jr 《Aquaculture Research》2005,36(16):1581-1587
This study was conducted to quantify and characterize the mycoflora associated with the ‘green water’ culture system of Penaeus monodon. Samples of water, tilapia gut and mucus, and shrimp hepatopancreas from three shrimp farms were collected during 15, 30, 45 and 60 days of culture (DOC). Results showed that high fungal loads were observed in tilapia gut (total: 117–1352 colony forming unit (CFU) 5 cm hind gut?1; yeasts: 0–136 CFU 5 cm hind gut?1) and mucus (total: 12–311 CFU (5 cm2)?1; yeasts: 0–88 CFU (5 cm2)?1), while minimal fungal populations were observed in water samples (total: 0–110CFU mL?1; yeasts: 0–5 CFU ml?1). Shrimp hepatopancreas harboured a very low number of filamentous fungi (0–27 CFU 0.1 g?1) and yeasts (0–7CFU 0.1 g?1) especially at 60 DOC. The filamentous fungal isolates were dominated by Penicillium and Aspergillus species, while the yeast populations were dominated by Rhodotorula and Saccharomyces species. The dominance of these fungi on tilapia mucus and gut and their presence in the rearing water might play an important role in the overall mechanisms involved in the control of luminous Vibrio in the ‘green water’ grow‐out culture of P. monodon. 相似文献
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Chen Zhonglin 《保鲜与加工》1989,(1)
According to the definition of luminous flux, and on the basisof the probability of fuzzy stechastic events in fuzzy mathematies, this paperstudies the fuzzy phenomena of the luminous flux increment obtained by thereciprocal reflection of light on indoor surfaces. This paper also suggests a newway to compute the transmission of luminous flux. 相似文献
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采用ATP发光法检测辐照对冷却猪、鸡肉ATP发光强度的影响,并对其他试验因素是否对样品ATP发光强度产生影响进行了分析。结果表明:ATP标准品的浓度与发光强度呈显著的正相关,ATP标准品发光强度与辐照剂量表现为显著的负相关;辐照冷却肉的细菌ATP发光强度随辐照剂量的变化趋势呈现为倒S形特征,其中6.0kGy辐照时发光强度最大,4.0、8.0kGy剂量辐照时强度最小;无菌水、灭菌样品未对ATP发光强度造成干扰,而未辐照大肠杆菌浓度与ATP发光强度之间呈显著线性正相关,相关系数达到0.9437。 相似文献
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Isolation and identification of Vibrio campbellii as a bacterial pathogen for luminous vibriosis of Litopenaeus vannamei 下载免费PDF全文
Outbreak of luminescent disease was reported from Litopenaeus vannamei shrimp farms in Zhangpu County, Southern China during May–July 2011. The clinical signs included fluorescent, less food consumption and high mortality. Bacteria were isolated from the infected shrimps. The pathogen, a luminescent bacterium named VH1 was identified as Vibrio campbellii based on MLSA analysis (16S rDNA, rpoD and toxR). The haemolysin (hly) gene specific in V. campbellii was detected in strain VH1. Pathogenicity test using immersion infection confirmed that strain VH1 was virulent to L. vannamei postlarvae and juveniles, and the LC50 value was 1.55 × 106 CFU mL?1 and 1.7 × 106 CFU mL?1 respectively. 相似文献
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简介农用运输车前照灯配光要求,以YJ160×100—1双联前照灯为例,重点介绍了农用运输车前照灯反射镜设计原理。 相似文献