半夏珠芽发育过程的形态学和解剖学研究

通过形态学观察和石蜡切片方法研究了半夏[Pinellia ternata(Thunb.)Breit.]的珠芽发育过程,结果显示:半夏珠芽着生于叶柄的下部,起始于幼嫩叶柄的腹面最外轮维管束外周薄壁细胞;恢复分裂的薄壁细胞分裂形成珠芽原基细胞团,在原基生长突破叶柄表皮后分化形成具有生长点的珠芽结构,发育中的珠芽无根分化;珠芽的生长被动地终止于叶片衰老(倒苗),无明显的成熟发育过程。研究表明,半夏的珠芽是不定芽性质的无性繁殖结构,但在发育过程上明显区别于其它植物的珠芽发育。     

Biological control of brown rot (Moniliana laxa Ehr.) on apricot (Prunus armeniaca L. cv. Hacıhaliloğlu) by Bacillus, Burkholdria, and Pseudomonas application under in vitro and in vivo conditions

In 2002 and 2003, a study was conducted to determine the effect of bacterial strains, Burkholdria OSU 7, Bacillus OSU 142, and Pseudomonas BA 8, on biological control of brown rot disease (Monilinia laxa Ehr.) on apricot cv. Hacıhaliloğlu in Malatya province of Turkey. Apricot orchard at full blooming stage was inoculated with conidial suspension (1 × 10⁶ spores/ml) of M. laxa Ehr. After inoculation, two apricot trees for each application were treated with each of the three biological control agents (Burkholdria gladii OSU 7, Bacillus subtilis OSU 142, and Pseudomonas putida BA 8) by spraying (1 × 10⁹ cfu/ml) on inoculated branches. Disease incidence was evaluated for untreated (control 1) and four different treatment groups including commercial disease management (control 2, positive control: 3% Bourdox in fall, 50% Cupper at pink flower, 30 g/100 l Corus at first blooming, and 300 g/100 l Captan at last blooming stage) and treatments including each of the three bacterial strains (OSU 7, OSU 142, and BA 8). The results showed that disease incidence for negative control (control 1) was 9.94, which was significantly higher than disease incidence for commercial application (2.57%) or bacterial treatments (2.82–5.00%) in the first year. In 2003, the lowest disease incidence observed in OSU 7 treatment (6.80%), while disease incidence rate for positive control and negative control were 9.45% and 28.46%, respectively. This result may suggest that OSU 7 has potential to be used as biopesticide for effective management of brown rot disease on apricot.     

半夏缓慢生长法保存及体细胞变异的ISSR检测

以添加了不同浓度的甘露醇、PP333和ABA的培养基对半夏试管苗进行缓慢生长法保存,并对保存材料再生后代的体细胞变异进行检测。结果显示,甘露醇、PP333和ABA均能有效抑制试管苗生长,且存活率高;最佳浓度分别为甘露醇2%～4%,PP3332.0mg·L-1,ABA 2.0～4.0mg·L-1。保存在添加了2%～4%甘露醇或2.0mg·L-1 PP333培养基上的植株未检测到变异,而保存在添加了2.0～4.0mg·L-1 ABA培养基上的植株检测到1条新增标记和1条缺失标记,位点变异率为1.7%,个体变异率为30%。研究表明,ABA不宜用于半夏试管苗的缓慢生长法保存,但有助于新突变体的产生,在种质创新上具有特殊意义。     

六角果鸢尾离体快繁技术体系的构建

为构建六角果鸢尾(Iris hexagona)的离体快繁体系,以其幼嫩根状茎为外植体,研究了培养基和植物生长调节剂对不定芽诱导、增殖和植株生根的影响。结果表明,根状茎用0.1%Hg Cl2消毒13 min的效果较佳;不定芽诱导最适培养基为MS+6-BA 1.5 mg L–1+NAA 0.5 mg L–1+蔗糖30 g L–1+琼脂7.5 g L–1,不定芽增殖的适宜培养基为MS+6-BA 0.5 mg L–1+NAA0.2 mg L–1+KT 0.3 mg L–1+蔗糖30 g L–1+琼脂7.5 g L–1;在MS+IBA 1.5 mg L–1+蔗糖30 g L–1+琼脂7.5 g L–1培养基上不定芽生根率可达100%;腐殖土和珍珠岩+泥炭土+蛭石(1∶2∶1)均可作为组培苗移栽的适宜基质,移栽成活率可达100%。     

单增李斯特菌胎盘感染的体内外模型研究进展

单核细胞增生李斯特氏菌（Listeria monocytogenes）是重要的食源性致病菌,能引发人类的李斯特菌病,是全球公共卫生问题之一。该菌易感染孕妇,引起胎儿和新生儿的侵袭性李斯特菌病,严重威胁母婴健康。因此,建立有效的单增李斯特菌感染胎盘体内外模型,解析和探究单增李斯特菌经胎盘感染机制,是预防和控制单增李斯特菌感染母婴的关键所在。本文综述了可用于研究单增李斯特菌母婴感染的体内外胎盘模型,总结和讨论了各类模型的优势和局限性;并着重分析了体外三维胎盘屏障模型在单增李斯特菌感染方面的研究进展和未来研究方向。以期为深入解析该菌经胎盘感染的途径、发病机制提供支持,并为预防和控制母婴李斯特菌病提供科学参考。     

多糖类益生元的筛选及凝结芽孢杆菌体外发酵特性北大核心

【目的】探究9种多糖对凝结芽孢杆菌(Bacillus coagulans)的增殖、产酶特性的影响。【方法】将凝结芽孢杆菌分别添加至菊粉多糖(inulin polysaccharide)、刺五加多糖(Eleutherococcus senticosus polysaccharide)、壳寡糖(chitosan oligosaccharide)、防风多糖(Saposhnikovia divaricata polysaccharide)、低聚木糖(xylo-oligosaccharide)、黄芪多糖(Astragalus polysaccharide)、甘露糖(D-mannose)、白术多糖(Atractylodes macrocephala Koidz polysaccharide)和玉屏风多糖(Yu Ping Feng polysaccharide)为唯一碳源的培养基中,通过菌株生长、酶活性及其体外厌氧发酵等作为指标,筛选出最优益生元。【结果】凝结芽孢杆菌能很好地利用防风多糖、黄芪多糖、白术多糖和玉屏风多糖;添加量为4%的防风多糖和白术多糖,pH差值差异最大,蛋白酶活性差异显著(P<0.05)。体外发酵乳酸活性和总蛋白酶活性均提高,4%白术多糖的乳酸和总蛋白酶活性差异显著(P<0.05);肠道内容物发酵液16S rRNA基因高通量测序结果表明,与对照组比较,添加黄芪多糖、防风多糖、甘露糖3种益生元发酵凝结芽孢杆菌显著降低了气单胞菌(Aeromonas)、α-变形菌(α-Proteobacteria)、链球菌(Streptococcus)、志贺氏杆菌属(Shigella)等致病菌的相对丰度,提高了乳杆菌(Lactobacillus)、厚壁菌门(Firmicutes)、乳酸乳球菌(Lactococcus lactis)、产酸杆菌(Acidobacteria)的相对丰度。【结论】凝结芽孢杆菌发酵4%白术多糖具有较好的产酶性能与益生特性,二者协同发酵添加至饲料中具有较好的发展潜力。     

睡菜离体快繁技术的研究

以睡菜的幼嫩茎段为外植体,接种到附加不同浓度激素配比(6-BA/NAA)的MS培养基,诱导睡菜愈伤组织、芽及根的生长。研究发现,外植体在1.0mg/L 6-BA+0.1mg/L NAA+MS的培养基上培养10d,可观察到浅绿色的愈伤组织。愈伤组织转接到4.0mg/L 6-BA+0.3mg/L NAA+MS培养基上2周左右可生成芽。对带芽的愈伤组织再进行诱导生根进而形成完整再生植株,最适根诱导培养基为0.3mg/L 6-BA+1.0mg/L NAA+MS培养基。该实验采用植物离体快繁技术成功建立了睡菜再生体系,为睡菜种苗规模化奠定了技术基础。     

狭叶薰衣草的离体培养及挥发性成分的分析

为建立新疆狭叶薰衣草(Lavandula angustifolia)的快速繁殖体系,以种子、茎、叶为外植体,对种子萌发、愈伤组织诱导、丛芽分化和生根的最适培养条件进行了研究;用水蒸气蒸馏法提取狭叶薰衣草挥发油,采用气相色谱-质谱法测定挥发油成分。结果表明,种子浸泡的适宜时间为6 h,切开种皮培养,出芽时间最少为6 d;诱导种子出芽的适宜培养基为MS+6-BA2 mg/L;以茎为外植体诱导愈伤组织效果较好,适宜培养基为MS+6-BA 2 mg/L+2,4-D 1 mg/L;诱导分化丛芽的适宜培养基为MS+6-BA 1 mg/L+NAA 0.5 mg/L;生根的适宜培养基为1/2MS+NAA 1 mg/L+6-BA 0.5 mg/L;盆栽薰衣草和无菌苗薰衣草的挥发油主要成分相差较大,离体培养的薰衣草的主要挥发性成分有叶绿醇、丁香油烃、氧化石竹烯等。     

黄芩苷对嗜水气单胞菌生物膜形成的影响及体内外的抑菌作用

[目的]探讨中药单体黄芩苷对嗜水气单胞菌在体内外生长及生物膜形成的影响.[方法]体外实验中,利用牛津杯法检测抑菌圈直径,结晶紫法检测生物膜的形成,通过泳动实验检测黄芩苷对嗜水气单胞菌运动性的影响,紫外吸收法检测细胞膜完整性,用透射电镜技术观察黄芩苷对细菌形态的影响.体内实验利用草鱼为对象检测黄芩苷对嗜水气单胞菌增殖的影...     

三叶半夏种质资源扩繁及保存研究*

目的:通过对三叶半夏扩繁和保存方法的研究,为三叶半夏种质资源的保育和开发利用提供技术支撑。方法: 首先,通过灭菌条件筛选、愈伤诱导及丛生芽诱导等进行扩繁条件探索;其次,通过设置不同基本培养基、蔗糖浓度、不同温度和光照强度等条件探索合适的种质保存条件;最后,探索了休眠块茎唤醒方式和丛生芽再诱导方法,为种质资源再扩繁提供基础。结果: 以叶柄为外植体,升汞灭菌12 min后,接种至添加2,4-D的培养基中可诱导疏松愈伤组织。外植体接种至MS+2.0 mg/L 6-BA+0.1 mg/L NAA+蔗糖30 g/L +琼脂6.0 g/L,pH 5.8中可进行丛生芽诱导。合适的种质保存基本培养基为MS和N6培养基;合适的蔗糖浓度为30 g/L,过低或过高均不利于种质保存;在丛生块茎诱导时需要提供足够的温度和光照,低温及避光条件不利于种质保存。待丛生芽自然倒苗休眠后可进行长达1~2年的离体保存。对休眠块茎进行唤醒诱导时可采用切割块茎后再接种的方式。萌发出来的叶柄直接进行丛生芽诱导增殖,而块茎则接种至MS+6-BA 1.0 mg/L+NAA 0.2 mg/L+蔗糖30 g/L+琼脂6.5 g/L,pH 5.8中进行再分化诱导丛生芽。诱导出来的丛生芽进行规模化扩繁或继续进行离体保存。结论: 通过对三叶半夏的种质扩繁,筛选合适的条件得到休眠丛生块茎,可对三叶半夏进行长时间的离体保存,而后唤醒和再次诱导的相关研究,为其种质资源保存、利用提供技术基础。     

Schistosoma mansoni: Schistosomicidal effect of mefloquine and primaquine in vitro

We investigated the effects of the anti-malarials mefloquine and primaquine against the juvenile and adult life stages of Schistosoma mansoniin vitro. Cercariae were incubated with 0.5 μg/ml, 1 μg/ml and 2 μg/ml mefloquine or primaquine and with 1 μg/ml praziquantel for 12 h. Schistosomula, pre-adults and adults were incubated with 0.5 μg/ml, 1 μg/ml and 2 μg/ml mefloquine or primaquine and with 1 μg/ml praziquantel for 7 days. The viability status was classified as viable, damaged or dead and was checked every 3 h for cercariae and every 12 h for schistosomula, pre-adults and adults. Both, mefloquine and primaquine show time and dose-dependent schistosomicidal effects on the four life stages of S. mansoni. The promising in vitro effects on all stages of the blood fluke S. mansoni warrants further evaluation of both anti-malarials and their derivatives for their prophylactic and therapeutic values in early and late schistosomiasis in field trials.     

造礁石珊瑚共生虫黄藻离体培养方法的优化

【目的】开发一种高效地从造礁石珊瑚中分离、培养共生虫黄藻的技术方法,为珊瑚共生虫黄藻藻种资源储备和生理功能研究积累基础。【方法】首先采用微孔滤网过滤法和密度梯度离心法从造礁石珊瑚组织中直接分离或富集共生虫黄藻细胞,然后用改良的L1培养基在96孔板上对所得细胞进行离体培养,最后进行单细胞分离、培养和(或)平板划线培养获得单克隆虫黄藻细胞系。对所得虫黄藻单克隆藻株进行聚合酶链式反应-限制性内切酶片段长度多态性(polymerase chainreaction-restrictionfragmentlengthpolymorphism,PCR-RFLP)分析,结合内转录间隔区2(internal transcribed spacer2,ITS2)和大亚基(large subunit,LSU)测序进行物种鉴定及系统发育分析。【结果】采用上述方法从涠洲岛的霜鹿角珊瑚(Acropora pruinose)和西沙群岛的丛生盔形珊瑚(Galaxea fascicularis)及柔枝鹿角珊瑚(Acropora tenuis)中分离、培养得到3个虫黄藻株系,编号分别为AP21C1、GF21D1和AT21A...     

滴水珠珠芽发育过程研究

珠芽是滴水珠(Pinellia cordata)的营养繁殖结构,为揭示滴水珠珠芽发育过程中的特征,该研究以野外采集材料进行盆栽观察试验,通过形态观察法和石蜡切片方法,探索滴水珠叶片和叶柄处珠芽发育过程中的形态学和解剖学结构特征。结果表明:滴水珠珠芽发育过程在形态上分为叶柄无现象时期、早期珠芽结构分化和珠芽膨大成熟时期三个时期;相应的解剖学发育时期为珠芽原基启动期和形成期、原基分化期和膨大成熟期四个阶段。叶片和叶柄珠芽起始细胞均由叶柄腹面表皮下层薄壁细胞组织脱分化形成,起始细胞不断分裂形成细胞团最后发育成珠芽原基;在原基分化期的特征是生长点形成,最终分化形成芽原基和鳞片叶;膨大成熟期的特征是珠芽结构不断生长,生长点侧生分化鳞片叶增多。叶片和叶柄处珠芽成熟脱落时期为灰色椭圆形结构,测得平均直径分别为(2.79±0.40)mm和(2.69±0.36)mm,外部有鳞片包裹,内部含大量营养物质。在环境适宜条件下,珠芽遇土萌发,萌发率达75%。这表明滴水珠珠芽与同属植物半夏珠芽发育过程差别不大,都是无性克隆营养繁殖体结构。     

Construction of a Tn5 derivative encoding bioluminescence and its introduction in Pseudomonas, Agrobacterium and Rhizobium

Summary A simple method based upon the use of a Tn5 derivative, Tn5-Lux, has been devised for the introduction and stable expression of the character of bioluminescence in a variety of gram-negative bacteria. In Tn5-Lux, the luxAB genes of Vibrio harveyi encoding luciferase are inserted on a SalI-BglII fragment between the kanamycin resistance (Km^r) gene and the right insertion sequence. The transposon derivative was placed on a transposition suicide vehicle by in situ recombination with the Tn5 suicide vector pGS9, to yield pDB30. Mating between Escherichia coli WA803 (pDB30) and a strain from our laboratory, Pseudomonas sp. RB100C, gave a Km^r transfer frequency of 10^-6 per recipient, a value 10 times lower than that obtained with the original suicide vehicle pGS9. Tn5-Lux was also introduced by insertion mutagenesis in other strains of gram-negative soil bacteria. The bioluminescence marker was expressed in the presence of n-decanal, and was monitored as chemiluminescence in a liquid scintillation counter. The recorded light intensities were fairly comparable among the strains, and ranged between 0.2 to 1.8x10⁶ cpm for a cell density of 10³ colony forming units/ml. Nodules initiated by bioluminescent strains of Rhizobium leguminosarum on two different hosts were compared for intensity of the bioluminescence they produced.     

无距虾脊兰花粉离体萌发及储藏条件的研究

以天目山野生无距虾脊兰的花粉为材料,采用离体萌发法研究了花粉的储藏性以及不同的培养基组分和培养条件对花粉萌发和花粉管生长的影响,并采用联苯胺-过氧化氢法测定了其柱头的可授性,以筛选无距虾脊兰花粉的培养方法以及储藏条件,为其种质资源保存等研究奠定基础。结果表明:(1)无距虾脊兰最适花粉液体培养基为200g·L-1蔗糖+50mg·L-1 H3BO3+40mg·L-1 Ca(NO3)2·4H2O,并且在pH 5.5~6.0、温度25℃恒温下培养48h,无距虾脊兰花粉萌发率(81.71%)和花粉管生长(247.42μm)最佳。(2)无距虾脊兰花粉在-80℃中低温干燥储藏360d后仍具有48.58%的萌发率。(3)无距虾脊兰的柱头在开花前5d内均具有可授性,花粉块在整个花期内均保持了28.96%~81.71%的生活力,但柱头可授性和花粉活力均随开花后时间的延长显著降低。     

肉苁蓉人工控制离体寄生关键技术研究

以梭梭无菌苗和肉苁蓉萌发种子为材料,对肉苁蓉离体寄生培养基质、离体寄生方式和离体寄生环境条件等进行了研究,以明确肉苁蓉的寄生特性,为肉苁蓉人工繁殖技术体系的建立与优化奠定基础。结果表明:玻璃纤维滤纸是肉苁蓉离体寄生适宜的培养基质;在黑暗、相对湿度80%、温度18℃～30℃的环境中,萌发的肉苁蓉种子与寄主梭梭寄生培养8d后开始建立寄生关系,寄生率达82%;而光照条件下,萌发的肉苁蓉种子与梭梭不能建立寄生关系。     

蒲公英糖蛋白体内外抗氧化作用研究

为了探讨蒲公英糖蛋白(TMGP)体内外抗氧化活性,采用H2O2、Fe2+、DPPH.和总抗氧化能力反应体系,检测蒲公英糖蛋白体外抗氧化活性,并与VC进行比较;同时建立D-半乳糖所致衰老小鼠模型,测定并比较TMGP组与模型组的血清、肝脏和脑内MDA含量和SOD、CAT、GSH-Px活性。结果显示:(1)随着TMGP浓度增加,其Fe2+、H2O2和DPPH.清除率均有所增加,当TMGP浓度为1.72mg/mL时,对H2O2、Fe2+清除率分别达到76.8%和55%,接近VC水平;当TMGP浓度为1.5mg/mL时,对DPPH.的清除率达到77%,也与VC水平相当,说明TMGP具有一定的体外总体抗氧化能力。(2)将TMGP按低、中、高剂量分别给小白鼠灌胃,可显著增强小鼠体内血清、肝脏、脑组织中SOD、CAT、GSH-Px活性,降低MDA含量,从而提高衰老小白鼠体内的抗氧化能力。研究表明,TMGP具有明显的体内外抗氧化作用。     

Schistosoma mansoni: Antischistosomal activity of the four optical isomers and the two racemates of mefloquine on schistosomula and adult worms in vitro and in vivo

Recent studies have shown that mefloquine (MQ) reveals interesting antischistosomal properties. We examined the antischistosomal activities of the erythro and threo isomers and racemates of MQ on newly transformed schistosomula (NTS) and adult Schistosoma mansoni in vitro and in mice harbouring adult S. mansoni. The in vitro effects in the presence and absence of haemin were monitored by means of microcalorimetry, scanning electron microscopy and phenotypic evaluation. Incubation of NTS with the erythro derivatives at concentrations of 3 μg/ml and above resulted in convulsions, granularity, decrease in heat flow, and death while NTS incubated with the threo derivatives were only affected at high concentrations (100 μg/ml). Extensive tegumental alterations, decrease in metabolic activity, viability, and death were observed when adult schistosomes had been exposed to 10 μg/ml of the erythro compounds. Moderate tegumental and viability changes but reduced heat production rates were observed with the threo derivatives at 10 μg/ml. In the presence of haemin, all MQ derivatives showed pronounced antischistosomal properties against adult S. mansoni in vitro. In vivo, MQ derivatives achieved statistically significant total and female worm burden reductions ranging between 65.4% and 100%. The highest total worm burden reductions of 93.4% and 90.2% were observed following treatment with the erythro and threo racemates, respectively. In conclusion, the optical isomers and racemates of MQ show only moderate stereoselectivity, in particular in vivo. Our results may enhance our understanding of the mechanism of action and therapeutic profile of MQ derivates on schistosomes.     

不同培养条件对勺叶茅膏菜试管苗矶松素含量的影响

为探讨培养条件对勺叶茅膏菜(Drosera spatulata)试管苗矶松素积累的影响,采用高效液相色谱(HPLC)法测定矶松素含量,对不同器官和不同培养条件下的勺叶茅膏菜试管苗矶松素含量变化进行研究。结果表明,勺叶茅膏菜试管苗根的矶松素含量显著高于叶片;光质和有机物含量对勺叶茅膏菜试管苗矶松素含量的影响不显著,但对试管苗的生长具有显著影响,最佳培养光质为白光,其次为红光和蓝光,最后为绿光;适当降低培养基中有机物含量可促进勺叶茅膏菜试管苗的生长发育;植物生长调节剂对矶松素积累的影响效应依次为6-BANAAKTGA3,而对试管苗生长的影响效应依次为6-BAGA3NAAKT。因此,勺叶茅膏菜试管苗的最佳培养条件为:以1/2MS为基本培养基,添加0~0.2 mg L–1 6-BA、0.2 mg L–1 NAA、0.5 mg L–1KT和0.1 mg L–1 GA3,于白光下培养。     

油莎豆快速繁殖体系的研究

为建立油莎豆(Cyperus esculentus)的快繁体系,以茎尖为外植体,MS为基本培养基,采用正交设计法研究了6-BA、KT和NAA组合对丛生芽增殖和生根的影响。结果表明,3种生长调节剂对油莎豆丛生芽增殖的影响为6-BA NAA KT,最佳生长调节剂组合为1.0 mg L~(-1) 6-BA+0.2 mg L~(-1) KT,培养4周的增殖系数为7.58。MS培养基为最优生根培养基,生根率可达88.10%,平均生根数为2.04条。这为高效繁育油莎豆优质种苗和种质资源优化奠定基础。