锰胁迫对盐肤木种子萌发、幼苗生长及理化特性的影响

为揭示植物适应锰胁迫的生理机制,通过在不同Mn²⁺浓度(0、1、5、10、15、20 mmol/L)下开展盐肤木(Rhus chinensis)种子萌发以及幼苗生长实验,检测锰胁迫处理7、15、30 d后幼苗生理生化特性的变化。结果表明:(1)随着Mn²⁺浓度的升高,盐肤木种子发芽率变化不显著,在80.0%-81.6%之间,发芽势、发芽指数和活力指数则呈先升后降的趋势;其幼苗生物量也呈现先升后降的趋势;(2)随着Mn²⁺浓度的升高与胁迫时间的延长,盐肤木幼苗叶绿素a、叶绿素b含量均呈现先增加后降低的趋势,类胡萝卜素含量呈现下降的趋势;(3)胁迫7 d时,随着Mn²⁺浓度的升高,盐肤木幼苗超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性均显著上升;胁迫15、30 d时,高Mn²⁺浓度(15-20 mmol/L)下POD、CAT活性则均降低;(4)胁迫7 d时,随着Mn²⁺浓度的升高,可溶性糖、可溶性蛋白、游离脯氨酸含量升高;胁迫15、30 d时,在Mn²⁺浓度为20 mmol/L时可溶性蛋白与游离脯氨酸含量显著降低;(5)随着Mn²⁺浓度的升高与胁迫时间的延长,丙二醛(MDA)含量均升高。研究说明盐肤木具有较强的耐受锰胁迫能力,它可通过增强抗氧化酶活性、积累渗透调节物质含量来应对锰胁迫。     

A Preliminary Study on the Introduction and Cultivation

Some species and culltivars of Clematis L.were introduced and cultivated.They were divided into three groups according to the different flower branch growth position.Seed propagation on Cl.ranunculoides showed the vernalized seeds sowed in soil had the best germination rate up to 71 percent.     

Changes in Soybean Raceme and Petiole Anatomy Induced by 6-Benzylaminopurine

An enlargement of the peduncle and rachis of the terminal racemeand the petiole of the uppermost mainstem leaf was observedin soybean plants [Glycine max (L.) Merr.] treated with thecytokinin, 6-benzylaminopurine (BAP). Histological studies wereperformed to determine the timing and extent of anatomical changesaccompanying BAP treatment. Swelling of treated ‘Tracy-M’peduncles, rachises, and petioles was observed within 4–6d after treatment initiation. A significant increase in totalcross-sectional tissue area was observed at lower and intermediateinternodes of treated rachises after 11 d. Rachis enlargementwas due to increases in both cell size and cell number, particularlyof the vascular tissue. In treated petioles of IX93-100, procambialcells of vascular bundles were the first to respond to the BAPtreatment. These cells differentiated into a vascular cambiumwhich formed secondary xylem and phloem. Soybean, Glycine max (L.) Merr., anatomy, rachis, BAP.     

视觉系统中的性别差异

大脑性别差异一直是神经科学领域中的一个热门话题.以前的性别差异研究往往关注与高级认知相关的脑区结构和功能差异,而对低级感知觉系统中的性别差异没有足够的重视.近年来,越来越多的研究结果表明,男性和女性在视知觉功能上也存在着明显的差异.本文首先回顾和梳理了视觉系统中存在性别差异的行为学和神经生物学证据,然后对视觉系统中性别...     

以贵州梵净山国家级自然保护区为模式产地的维管植物物种模式标本研究

在对有关模式标本资料广泛查询的基础上，统计出以梵净山国家级自然保护区为模式产地的维管植物91种(含种下单位)，隶属于47科73属。除1种无采集人信息外，其余90种由31人或团队采集，这些标本保存于国内外21个研究机构。以该地为模式产地的物种中，19种以梵净山命名。原学名中有17个被归并，其中12个学名在种级水平发生了变化，5个学名在种下水平发生了变化。以该地为模式产地的物种中受威胁的共15种，包括极危(CR) 1种，濒危(EN) 6种，易危(VU) 8种。     

PERCEPTION OF FAT IN A MILK MODEL SYSTEM USING MULTIDIMENSIONAL SCALING

This study examined the contributions of stimulus fat content and flavor volatiles to the perception of fat in a milk model system. The model system was formulated by adding bland vegetable oil (0%, 5%, or 10% w/v) and natural cream flavor (0%, 0.5% or 1% w/v) to a skim milk base. Panelists judged pairs of samples for similarity on the basis of three attributes (fat content, mouthcoating and thickness) and the results were analyzed using a multidimensional scaling procedure. Two-dimensional solutions best represented the data. The stimulus spaces for fat content and mouthcoating were visually similar to each other and provided reasonable separation of the samples. Instrumental measures helped to define the underlying dimensions of the stimulus space for fat content. Dimension 1 related to texture and included the contributions of viscosity, and fat particle size and number distribution; dimension 2 related to flavor perception. The sample with a moderate fat content (5%) and the highest concentration of added cream flavor (1%) was perceived to be similar to the 10% fat samples with added flavor. Thus, the added flavor provided the sensation of higher fat content. These data suggest that flavor plays an important role in the preception of fat in dairy foods. A psychophysical model of fat perception in dairy foods is proposed which includes the contribution of viscosity, fat particle size and number distribution, and volatile flavor perceptions.     

益生菌联合口腔洁治对慢性萎缩性胃炎的疗效及安全性评价

目的对益生菌联合口腔洁治治疗慢性萎缩性胃炎的有效性、安全性进行评价。方法选择2015年12月到2018年2月我院收治的102例慢性萎缩性胃炎患者为研究对象,随机分为对照组(n=51)与观察组(n=51)。对照组患者采用益生菌治疗,观察组在对照组基础上予以口腔洁治进行治疗。对两组患者治疗的有效性、安全性进行比较。结果观察组患者总有效率(92.16%)高于对照组(68.63%),差异有统计学意义(χ~2=8.956,P=0.003)。治疗前,两组患者病理和症状评分差异无统计学意义(t=0.226、0.142,P=0.087、0.074)。治疗后,两组患者病理和症状评分均显著降低,且观察组患者病理评分(5.22±1.03)和症状评分(6.46±1.24)均低于对照组的病理评分(7.59±1.22)和症状评分(9.16±1.25),差异有统计学意义(t=10.600、10.951,P0.001)。观察组患者不良反应发生率(3.92%)低于对照组(31.37%),差异有统计学意义(χ~2=13.222,P0.001)。观察组患者无复发,对照组复发率为17.65%,差异有统计学意义(χ~2=9.871,P=0.001)。结论在慢性萎缩性胃炎治疗中应用益生菌联合口腔洁治具有显著效果,安全性较高,值得推广。     

超高产杂交水稻皮秒分辨荧光特性

采用时间分辨荧光光谱测试系统，研究了超高产杂交水稻(Oryza sativa L.)两优培九(P9)和对照汕优63(SH 63)类囊体膜的荧光光谱特性和时间特性。以脉宽为120ps，重复率为4MHz，波长为514nm的Ar^-激光分别激发P9和SH 63水稻类囊体膜荧光。通过对其超快荧光的时间特性和光谱特性比较研究发现：无论是在灌浆期还是在扬花期，P9水稻类囊体膜中光系统I激发能传递的速度比光系统Ⅱ的快；P9和SH 63两种水稻类囊体膜在灌浆期的激发能传递速度都比扬花期的快；两种水稻类囊体膜的光谱特性还给出，在从扬花期到灌浆期这一生长发育过程中，SH63水稻类囊体膜的色素成分和结合状态发生了变化，而P9却没有出现这种变化。