铜胁迫对鸭跖草的生长及生理特性的影响

通过盆栽试验研究了不同浓度铜离子对鸭跖草的生长及生理特性的影响.处理用的铜离子浓度为20、50、100、200和400mg/L,以去离子水作对照组.研究结果表明,在5种不同浓度的铜离子浇灌下,鸭跖草均能正常生长.随着铜离子浓度的增加,与对照组相比,铜离子浇灌的鸭跖草植株在前期生长较快,后期生长减慢.在前期各处理组的平均株高增加量随着浓度的升高而增加.经过不同浓度的铜离子浇灌处理后,各处理组鸭跖草叶片的超氧化物歧化酶(SOD)活性及脯氨酸含量逐渐增加.方差分析结果表明,不同浓度的铜离子处理对SOD酶的活性及脯氨酸的含量均没有产生显著的影响.不论地上部分还是地下部分,各处理组的生物量都表现为随铜离子浓度的升高而降低.由此可见,在重金属铜离子的胁迫下,鸭跖草对铜具有较强的耐性.通过体内提高SOD酶及脯氨酸的含量等生理响应来增加抵抗重金属铜胁迫的毒害作用.     

湖南桂阳地区烟叶部分中微量元素含量分析

为深入研究近年来湖南桂阳地区烟叶内中微量元素含量的变化状况,分别于2005年、2007年从湖南省桂阳县的和平镇和桥市乡两个地区采集不同部位的烟叶样品,运用ICP测定方法对其部分中微量元素含量进行测定,并将桂阳地区烟叶与津巴布韦烟叶内中微量元素含量的进行对比分析,结果表明:与2005年相比,2007年桂阳地区烟叶中硼、铁、铜的含量明显降低,处于较低水平,锰的含量有所下降,但是仍在适宜范围,个别部位烟叶中镁和钙的含量略有下降,仍处于较低水平.与津巴布韦烟叶相比,桂阳地区烟叶中B,Fe,Cu的含量较低.建议桂阳地区应注意对烟叶的中微量元素的补充.     

天然橡胶微波干燥动力学模型研究

利用本课题组设计发明的微波干燥湿天然橡胶物料设备,对微生物凝固湿天然橡胶进行物料表面温度分别为358、373、388、403 K的微波干燥试验,干燥时间均为15 min,每4 s获取一组干燥过程相关数据,测试分析湿天然橡胶(微生物凝固)的微波干燥失水特性,并建立湿天然橡胶微波干燥动力学模型.结果表明,干燥温度越高,湿天然橡胶含水率下降越快;快速干燥阶段为物料干燥的主要失水阶段;湿天然橡胶微波干燥动力学模型可由多项式模型来表示.     

Antioxidant Properties of Isolated Isorhamnetin from the Sea Buckthorn Marc

In the present study, the process of separation and purification of isohamnetin from marc of sea buckthorn was obtained. The antioxidant properties of the pure isolated isorhamnetin were evaluated by the scavenging of the diphenylpicrylhydrazyl radical (DPPH), iron (III) to iron (II)—reducing, and iron-chelating assays. High purity isorhamnetin (92.1%) was obtained and the results of antioxidant assays showed that isorhamnetin performed significantly compared with ascorbic acid and BHT, and the linear correlations were good in these assays. In conclusion, isorhamnetin may have potential as a natural antioxidant to alternate synthetic substances as food additive with its antioxidant activity.     

The limiting irregularity of single wool fibers

Fiber irregularity affects fiber mechanical properties. This study has, for the first time, introduced the concept of limiting irregularity to single wool fibers. The limiting irregularity is the minimum variation in fiber cross sectional area that can be expected of a single wool fiber, assuming a random length-wise distribution of its constituent cortical cells. Cortical cells were extracted from merino wool fibers and their dimensions were measured from SEM images to calculate their cross sectional area variations both between cortical cells and within cortical cells, and to work out the average number of cortical cells in the cross section of wool fibers of a given diameter. Single wool fibers were also measured at 5 μm interval along length for fiber diameter variations. These variations were found to be larger than that based on fiber limiting irregularity.     

萝卜花药愈伤组织诱导及褐变因素初探

以萝卜为试材,研究了不同激素配比、供体基因型、光照与温度以及蔗糖浓度对花药愈伤组织诱导的影响,同时比较研究了花药愈伤组织褐变过程中几种抗氧化酶活性变化。结果如下：P403在2.0mg/L 2,4-D+1.0mg/L 6-BA+2.0mg/L KT的MS培养基中愈伤组织的诱导率最高,愈伤组织开始褐化的时间晚,抗氧化酶的活性较高;同时进行低温预处理、高温预培养和初期暗培养的协同效果较任何一种单独处理好;6%的蔗糖浓度有利于愈伤组织的诱导。     

Caffeoyl Glycoside对小鼠免疫细胞功能的影响

本实验室从胡黄连根茎分离到1,6-di-O-caffeoyl-β-D-glucopyranoside单体Caffeoyl Glycoside（CG）,体外试验测定其对小鼠免疫细胞功能的影响。通过MTT法检测CG对Balb／c小鼠脾淋巴细胞增殖,NK细胞对K562细胞杀伤活性的影响,以及小鼠腹腔巨噬细胞（PMφ）能量代谢水平;CG对PMφ吞噬中性红能力的影响。CG在一定剂量范围内单独或者协同非特异性丝裂原（ConA或LPS）作用均能够显著增强小鼠脾淋巴细胞、PMφ的增殖能力（P〈0．05或P〈0．01）,CG单独作用就能显著提高NK对K562细胞的杀伤活性（P〈0．05或P〈0．01）。CG在体外对小鼠主要免疫细胞的增值和功能方面具有显著的促进作用（P〈0．05或P〈0．01）。研究结果显示CG具有特异性与非特异性的免疫增强作用。     

长春地区鹿源性大肠杆菌的分离鉴定和耐药性分析

调查吉林省长春市周边地区（榆树、农安、九台、双阳和德惠）腹泻梅花鹿源大肠杆菌的血清型分布和耐药性。对梅花鹿源大肠杆菌进行分离、培养和生化反应鉴定;并对所得菌株进行玻片凝集法确定血清型;用平板扩散法或肉汤微量稀释法测定其对15种抗菌药物的敏感性;利用PCR方法检测9种耐药基因。共得到127株大肠杆菌,84株大肠杆菌属于36种不同的血清型,其中47株属于11种血清型,即O2,O7,O9,O21,O26,O87,O126,O128,O138,O142和O154;所得菌株对15种抗菌药物呈现不同程度的耐药性;耐药基因strB、strA、aadA、tetA和sul2在被检菌株中最为流行。菌株对磺胺类和四环素耐药性最严重, 而且大多数菌株呈多重耐药性;对阿莫西林、卡那霉素较为敏感。对临床用药有指导意义。     

河道生态修复的前沿领域

在广泛查阅国内外河道生态修复与功能重建相关资料的基础上,对生态河道的特征与前沿领域进行了总结与分析,并结合我国的实际情况,提出了河道生态修复的努力方向。       

Interaction between the eui gene and thermo-sensitive genic male sterility in rice

Panicle enclosure is a typical phenotype of almost all male-sterile rice lines. An elongated uppermost internode (eui) mutant exhibited notably rapid elongation of the uppermost internode at the heading stage; this is considered as a potential mechanism to eliminate panicle enclosure. We developed thermo-sensitive genic male-sterile (TGMS) eui mutants that were characterized by notably elongated uppermost internodes. The elongation of the uppermost internode in the TGMS eui mutant Changxuan 3S (CX) is mainly attributed to an increase in cell number and cell elongation, the latter being the more significant process. Temperature treatments revealed that the effects of temperature on panicle exsertion were similar to those on fertility and that the most temperature-sensitive stage coincides with the period from the formation of the pollen mother cell to meiosis during panicle initiation. These results indicate that elongation increases as temperature decreases and that the expression of the eui gene is more efficient at low temperatures than at high temperatures. In hybrid rice seed production using the TGMS eui mutant, the temperature range should be optimized at 24–28°C in order to preserve the development of completely male-sterile pollen and to eliminate panicle enclosure. Consequently, by using TGMS eui rice lines, gibberellin application can be avoided, thereby reducing the cost of hybrid seed production. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.