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Maninder Kaur Yogesh Vikal Harleen Kaur Lalit Pal Kirandeep Kaur Jasbir Singh Chawla 《Journal of Phytopathology》2019,167(10):591-600
Southern leaf blight (SLB) caused by the fungus Cochliobolus heterostrophus (Drechs.) Drechs. is a major foliar disease of maize worldwide. Our objectives were to identify quantitative trait loci (QTL) for resistance to SLB and flowering traits in recombinant inbred line (RIL) population derived from the cross of inbred lines LM5 (resistant) and CM140 (susceptible). A set of 207 RILs were phenotyped for resistance to SLB at three time intervals for two consecutive years. Four putative QTL for SLB resistance were detected on chromosomes 3, 8 and 9 that accounted for 54% of the total phenotypic variation. Days to silking and anthesis–silking interval (ASI) QTL were located on chromosomes 6, 7 and 9. A comparison of the obtained results with the published SLB resistance QTL studies suggested that the detected bins 9.03/02 and 8.03/8.02 are the hot spots for SLB resistance whereas novel QTL were identified in bins 3.08 and 8.01/8.04. The linked markers are being utilized for marker‐assisted mobilization of QTL conferring resistance to SLB in elite maize backgrounds. Fine mapping of identified QTL will facilitate identification of candidate genes underlying SLB resistance. 相似文献
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目的:波前像差引导的准分子激光角膜消融是屈光手术的新方法,研究人眼波前像差的测量原理、方法、表示、人眼波前像差准分子激光矫正的原理,以此理论用于准分子激光人眼像差矫正系统。方法:采用理论研究、计算机模拟、实验室实验等手段。分析人眼像差的概念和产生的原因,用数学的Zern ike多项式来表示像差,理论上定量分析Zern ike多项式表示的波前像差与角膜切削深度的关系,研究准分子激光切削角膜的机理,研究准分子激光进行矫正人眼像差的原理框图。结果:通过计算机模拟和实验室实验,用准分子激光矫正低阶和高阶像差是可行的。结论:用波前像差来引导屈光手术,使人眼的视力能够达到20/10上,并能避免当前PRK、LASIK屈光手术前后像差增大而引起的对视觉质量的影响。 相似文献
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穴位激光照射的剂量和机理初探 总被引:4,自引:0,他引:4
穴位激光照射疗法是一种通过低强度激光束直接照射穴位的治疗方法,具有针灸作用。阐述了激光照射机体穴位在临床应用的本质,并对其使用的光剂量和作用机理做了初步讨论和分析。 相似文献
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本文旨在建立基于高效体积排阻色谱(high-performance size-exclusion chromatography,HPSEC)偶联多角度激光散射仪(multi-angle laser light scattering,MALLS)的猪圆环病毒2型(porcine circovirus type 2,PCV2)疫苗抗原检测方法。以纯化的PCV2灭活病毒及病毒样颗粒(virus-like particles,VLP)为参照,对4家生产企业的2种PCV2灭活病毒疫苗(a、b)及VLP疫苗(c、d)破乳后进行HPSEC-MALLS检测及分子量分析;结合PCV2抗原检测卡、Western blotting和透射电子显微镜(transmission electron microscope,TEM),鉴定了特征色谱峰;考察了方法的重复性和检测线性。结果表明,两家企业生产的PCV2灭活病毒疫苗破乳液水相经HPSEC分离,在保留时间约13.3 min处出现抗原特征峰;MALLS计算该色谱峰分子量分别为2.61×106(±4.34%) Da和2.40×106(±2.51%) Da。两种VLP疫苗也在13.3 min处出现抗原特征峰,分子量分别为2.09×106(±2.94%) Da和2.88×106(±11.85%) Da,接近PCV2的理论分子量;同时在保留时间约11.4 min处也出现色谱峰,经检测分子量为4.37×106(±0.42%) Da,TEM表征显示为VLP二聚体。取疫苗d和PCV2 VLP纯品进行重复检测,抗原色谱峰面积的RSD(n=3)均小于1.5%,重复性好;将PCV2 VLP纯品梯度稀释检测,VLP及其多聚体的色谱峰面积与浓度均呈良好的线性关系,R2分别为0.999及0.997,能够满足定量及多聚体含量分析。该方法有望成为一种准确、高效的PCV2疫苗的体外评价方法,用于质量评价与提升。 相似文献
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This review is intended to draw attention to the importance of the culture media composition on the health of the embryos, fetuses, newborns, and adults derived from assisted reproductive technologies (ART). Although current research and industry trends are to use chemically defined media because of their suitability for manufacturing, commercialization, and regulatory purposes, compelling evidence indicates that those media fail to adequately account for the biological demands of early embryogenesis. Here, we list the main undesirable consequences of the ART described in the literature and results we and others have obtained over the past decade exploring an alternative and more natural way to support embryo growth in vitro: inclusion of endogenous reproductive fluids as additives in the ART culture media for pigs, cows, and humans. This review systematically assesses the pros and cons of using reproductive fluid additives, as well as the requirements to implement this approach in the future. 相似文献
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H Spring M F Trendelenburg M Montag 《Biology of the cell / under the auspices of the European Cell Biology Organization》1988,64(3):371-374
The complex spatial DNA distribution in the mammalian interphase nucleus was investigated in Feulgen stained thick sections through mouse trophoblast giant nuclei after Lowicryl embedding. DNA-fluorescence was visualized using confocal laser scanning microscopy. Our results show that the spatial arrangement of major interphase chromatin areas can be precisely documented, including the distribution of small intra-nucleolar chromatin zones. 相似文献
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Use of oxygenates in gasoline in the United States may increase atmospheric levels of aldehydes. To assist in health assessments of inhalation exposure to aldehydes, we studied glutathione (GSH) depletion by low-molecular-weight n-alkanals and 2-alkenals, ubiquitous air pollutants, in adult rat lung (ARL) cells by laser cytometry. For each homologous series, the effective aldehyde concentration that depleted GSH by 50% (EC50) in ARL cells correlates with published values for the median lethal dose of the chemicals and with Hammett/Taft electronic parameters, * for n-alkanals and p* for 2-alkenals. n-Alkanals (EC50, 110–400 mmol/L) were 1000 times less effective in depleting GSH than were 2-alkenals (EC50, 2–180 mol/L), of which acrolein was the most potent. Ability of the 2-alkenals to deplete GSH follows the second-order rate constant for adduct formation. Ability of n-alkanals to deplete GSH follows chain length. Within a homologous series of low-molecular-weight aldehydes, structure–activity relationships are useful for predicting the toxicity of the aldehydes in vitro and in vivo. 相似文献