963 resultados para 2,4-DICHLOROPHENOXYACETIC ACID 2,4-D


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含脲酶抑制剂的肥料作为缓/控释肥料在提高养分利用率和减少环境污染方面明显优于普通化学肥料,已成为世界肥料研究和应用的热点。大量实验显示,NBPT和PPD提高尿素或硝铵尿素(UAN)的利用率很有潜力。NBPT,N-丁基硫代磷酰三胺,是目前最有效的脲酶抑制剂之一。本论文借助高效液相色谱仪对NBPT在我国不同气候带五种土壤中的降解及在土壤环境中影响其降解因子进行了研究,并摸索了色谱条件:在流动相为甲醇+去离子水50+50(V:V),流速为0.3 mlmin-1时,紫外检测器,检测波长为195 nm时,回收率达到82.8%~101%。变异系数为1.1%~4.85%。相关系数为r=0.9994,回归方程为y=43266.6x-1124.51。结果表明:NBPT在偏酸的江西红壤和湖北黄壤中降解较快,半衰期为4.8~5.2 d,而在辽宁棕壤和江苏黄棕壤中降解较慢,半衰期为7.2~7.6 d;在吉林黑土中降解半衰期为8.2 d。 在未灭菌的土壤中,NBPT的半衰期为4.8~7.6 d,远远小于在灭菌土壤中22.4 d的半衰期;NBPT在偏酸的江西红壤和江苏黄壤中降解较快,半衰期为4.8~5.2 d,而在棕壤和黄棕壤中降解较慢,半衰期为7.2~7.6 d;随着环境温度增高(2O℃上升至3O℃),NBPT降解速度略有提升(半衰期由7.6 d缩短至6.5 d);NBPT在黑暗条件下降解半衰期为4.5 d,而在光照条件下的半衰期为5.9 d。可见,几种试验因子对土壤中NBPT的降解均有不同程度的影响。其中土壤微生物是影响NBPT降解的主要因素,有利于土壤中微生物生长的环境因素,如偏酸的土壤、较高的环境温度,对土壤中NBPT的降解有促进作用,而葡萄糖则可能因为增加了土壤颗粒的团聚性,增加了土壤对NBPT的吸附而抑制了NBPT的降解。

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随着工业化和城市化的迅速发展,高浓度CO2和高浓度O3对植物影响的研究受到了广泛的重视,但二者交互作用对城市树木的生理及碳氧平衡的影响尚不清楚。银杏(Ginkgo biloba)、油松(Pinus tabulaeformis)是沈阳市城市森林的两种重要树种,对大气环境变化的响应具有代表性。本文采用开顶箱法研究了在高浓度CO2(700 μmol•mol-1)、O3(80 nmol•mol-1)及其复合作用条件下城市银杏、油松生长、光合、蒸腾以及呼吸作用的日动态、季节动态变化,揭示了银杏、油松光合对高浓度CO2、O3的适应机制及其本身环境效应的变化规律,为研究城市森林对全球变化的响应与反馈提供了重要基础。 得出的主要结果如下: 1. 短期(0-30 d)高浓度CO2处理提高了银杏、油松叶片/针叶细胞间CO2浓度、羧化效率和表观量子效率,从而提高了银杏、油松的净光合速率。 2. 一个生长季(100 d)高浓度CO2处理促进了银杏、油松叶片/针叶的生长,提高了细胞渗透调节物质含量,增强了银杏、油松抵御逆境胁迫的潜能。银杏、油松日变化曲线趋向单峰曲线,缓解了中午的光抑制现象;固碳释氧量提高了近1倍,有助于减缓全球变化的速度。 银杏、油松的气孔导度和羧化效率的降低是发生光合适应的重要原因。 3. 高浓度O3处理可导致两树种的生理伤害,银杏叶片表现为褐斑型伤害,油松则为水锈型,叶片生长受到抑制。同时两树种可溶性蛋白、可溶性糖含量降低,电导率升高。 两树种叶绿素含量降低,净光合速率下降。银杏光合速率的降低前期表现为气孔限制,后期转为非气孔限制为主。油松光合速率下降则是两种限制因素共同作用的结果,难分主次,表明油松的气孔调节能力弱于银杏,更易受到O3的伤害。造成实验处理后期银杏、油松光合速率下降的非气孔因素是表观量子效率和羧化效率的降低。 高浓度O3处理使银杏、油松的光抑制现象加强,固碳释氧、降温增湿能力降低,且油松降低幅度大于银杏。 4. 高浓度CO2和O3复合处理提高了银杏油松的叶绿素含量,减轻了高浓度O3对叶片/针叶的伤害,促进了叶的生长。 与对照相比,复合处理提高了银杏、油松的净光合速率,降低了气孔导度和蒸腾速率,从而使水分利用效率和含水量得到提高。表观量子效率和羧化效率的提高是光合速率大幅度上升的重要因素;呼吸速率的提高则是后期光合速率增幅减小的重要原因。复合处理前期CO2主要是通过气孔调节来缓解O3对树木的伤害,高浓度CO2处理对光合作用的促进作用大于高浓度O3处理的抑制作用。 高浓度CO2和O3复合处理的银杏、油松的光呼吸速率、可溶性蛋白、可溶性糖的含量增加,电导率降低,提高了银杏、油松的抗逆性,这是高浓度CO2缓解O3胁迫对树木伤害的一个原因。复合处理同样缓解了银杏、油松光抑制现象,提高了固碳释氧量,但银杏降温增湿能力降低。

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N_2O 是影响全球气候变化的重要温室气体,其源汇估算是深入了解人类活动对环境变化的基础。目前 N_2O 源汇的估算仍有不确实性。大气 N_2O 主要来自生物排放。植物本身作为 N_2O 排放源的发现为 N_2O 源的估算开辟了新的研究领域,为提高 N_2O 源汇估算的精确度提供了可能。植物排放 N_2O 的研究己日益引起科学家的重视。本文采用田间栽种和室内培养实验相结合的研究方法,对植物 N_2O 排放与光照的关系,及相关生物化学过程进行了系统的研究。通过对大豆及叶菜类蔬菜的观测实验,进一步证实了植物释放 N_2O 这一重要植物生物生态现象的存在;对影响植物释放 N_2O 的重要环境因子-光照对 N_2O 排放通量的影响进行了深入的探讨;研究了植物体 N 代谢过程中涉及N_2O 产生过程的硝酸盐还原作用、亚硝酸盐还原作用和植物 N_2O 释放通量之间的关系。部分揭示了植物释放 N_2O 的机理,为植物释放 N_2O 及光调节机理模型的建立提供了必要的实验和理论依据。主要实验结果如下:1)通过对不同光照条件下,不同 N 素营养供给水平大豆N_2O 释放通量 叶片内的硝酸盐、亚硝酸含量的测定,结合使用硝酸盐同化(或异化)还原作用的抑制剂(如 CH_4 或 C_2H_2),对不同培养条件下大豆的 N_2O 释放进行了测定,进一步证明了光照对大豆释放 N_2O的影响,即强光照下大豆 N_2O 的释放较少,弱光照下大豆 N_2O 的释放较多。验证乙炔对大豆植物转化 N_2O 的抑制作用。硝酸盐培养同铵盐培养相比,在不同光照条件下,大豆苗 N_2O 释放明显增加,并有较高硝酸盐积累,光照强度的降低也能导致 NO_3~- 的积累,硝酸盐培养的大豆体内 NO_2~- 含量高于铵盐培养。2)用封闭式箱法和乙炔抑制技术,通过对 200 和 40 μmol·m~(-2)·s~(-1) 光照条件下不同苗龄大豆植株 N_2O 释放通量和叶片硝酸盐还原酶活性及硝酸盐和亚硝酸盐含量的同步测定,研究了不同光照对苗期大豆 N_2O 释放和硝酸盐还原酶活性的影响。首次揭示,在强光照条件下苗期大豆叶片硝酸还原酶活性呈现“V”形变化,在此期间 N_2O 释放通量逐渐增加,两者变化趋势不呈现相关性;在弱光照条件下,同一时期大豆体内硝酸盐还原酶活性与强光照条件下相比较低,而 N_2O 释放通量较高,也呈现逐渐增加趋势,硝酸还原酶活性和 N_2O 释放通量显著相关。强光照条件下大豆叶片硝酸还原酶活性和大豆叶片硝酸盐含量显著相关。两种光照处理下,亚硝酸盐含量均较低。3)利用 3 种不同光照条件处理,对苗期大豆亚硝酸盐还原酶提取液的活性进行了观测,同时结合三种不同处理亚硝酸盐还原酶提取液的 N_2O 释放通量测定,发现不同光照条件对 30-55 天大豆亚硝酸还原酶活性没有明显的影响,三种不同处理酶提取液 N_2O 释放或吸收呈现不同变化,发育时期和亚硝酸还原酶活性对酶提取液 N_2O 释放通量起主要作用;还原剂和三种亚硝酸盐还原提取液 N_2O 释放没有明显相关性。4)通过对除草剂 2,4-D 和溴苯腈处理的大豆 N_2O 释放的观测,首次发现 2,4-D 和溴苯腈处理的大豆 N_2O 释放通量分别是 14.1 和 19.7 ng N_2O g~(-1) fw h~(-1)。2,4-D 和溴苯腈处理的大豆中 N_2O~--N 含量为 8 μmol·m~(-2)·s~(-1),是对照的 5 倍;除草剂处理的大豆体内 NO_3~--N 与对照相比,没有显著差别,因此推断 NO_3~--N 吸收过程中代谢积累的 NO_2--N 导致所观测的 N_2O 释放,N_2O 有可能是植物代谢过程中 NO_2~--N 植物代谢物反应或是 NO_2~--N 降解的副产物。5)通过对强弱两种光照条件下,高硝酸盐含量叶菜类蔬菜小白菜、菠菜和芹菜的 N_2O 释放的吸收随时间变化的观测,结合叶片中硝酸根、亚硝酸根含量的测定,发现光照强度对菠菜、芹菜、小白菜 N_2O 释放和吸收有影响,总体上表现为弱光照下三种植物 N_2O 释放量较高,强光下很少释放或表现为吸收。在 120 min 的观测中,三种植物释放和吸收曲线没有呈现明显的规则变化。喷洒除草剂 2. 4-D 增加芹菜在黑暗条件下 N_2O 的释放。强光照射与弱光相比三种植物的硝酸根含量均略低,而亚硝酸含量没有明显的差异。6)结合实验结果探讨了植物释放 N_2O 的三种机理:1)N_2O 是逆境条件下植物不正常代谢化学反应的产物的可能;2)植物将土壤中产生 N_2O 传输到大气中;3)N_2O 可能作为植物体硝酸还原代谢产物而被植物释放。综合后三种可能提出了在各种环境因子作用下植物释放 N_2O 的模型,认为植物N_2O 的释放可能是后两种途径共同作用的结果,硝酸盐代谢过程中相关酶的还原起主要作用,随环境条件的不同,三种释放途径的作用强度可能发生改变。

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以PCR技术从金黄色葡萄球菌基因组DNA中首次克隆编码成熟SECZ蛋白的全基因sec2。该基因共717bp,编码239个氨基酸,Genbank Accession number:AY450554。构建了SEC2的表达载体pET-28a-sec2,并在大肠杆菌BL21(DE3)中高效表达可溶性rSEC2蛋白。经亲和层析纯化,其纯度在95%以上,平均回收量为每升培养物40mg。纯化的rSEcZ保持了与野生型相当的生物学活性。以限制性核酸内切酶连接技术分别将两个抗人表皮生长因子受体HER-2单链抗体基因通过DNA Linker与sec2融合,构建融合基因b-l-sec2和ml小sec2,并以两种方式表达纯化。以pET-32a表达载体在E,coliAD494(DE3)中以氨基端融合大肠杆菌硫氧还蛋白(TrxA)形式高效表达融合蛋白TRX-B-L-SEC2和TRX-ML-L-SEC2,经亲和层析纯化,并以肠激酶切割得到成熟融合免疫毒素B-L-SEC2和ML-L-SEC2,其纯度在95%以上,平均回收量为每升培养物smg;以构建的新型表达载体pASK-75-EX在E.coliBL21(ED3)中以不溶性包涵体形式表达融合免疫毒素蛋白,经变性、纯化和复性后得到具有生物学活性的融合免疫毒素,其纯度在95%以上,平均回收量为每升培养物30mg。以两种方式制备的融合免疫毒素都保持了SECZ蛋白的免疫原性,都能有效刺激人外周血单个核细胞的增殖,并且都显示出在体外与HER-2过表达的乳腺癌细胞SK-Br-3特异性结合能力,具有显著的靶向性抑瘤作用。用PcR方法扩增了编码TrxA蛋白的基因trxA并克隆至表达载体pET-28a启动子上游,构建了一种在单质粒中利用两个相同的启动子游离共表达硫氧还蛋白与目的蛋白的表达载体。利用该载体可使TrxA与外源蛋白在大肠杆菌BL21(DE3)中以非融合形式高效共表达。共表达的TrxA可明显促进外源蛋白单链抗体ML3.9(scFv-ML)、3一轻基苯甲酸-6-单加氧酶(3HBA)的可溶性表达;并明显减少肠毒素C2(SEC2)、结核杆菌螺旋酶A亚基(GYRA)的包涵体表达。

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从Vc“二步发酵法”生产用菌[系一株氧化葡萄糖杆菌(小菌)和一株巨大芽孢杆菌(大菌)的混合菌株]的无细胞抽提液中分离纯化了 2-酮基-L-古龙酸还原酶(KGR),测得其分子量为90,000道尔顿;对其动力学性质的研究表明它是一个典型的米-孟氏酶,它对2-KLG作用的K_m为3.42*10~(-3)Mol,最适作用pH和最适作用温度分别为6.5和30℃;其温度敏感程度中等,受40℃温度作用时开始失活,45℃温度作用则立即失活。该酶为混合菌株中小菌的酶。研究了发酵过程中KGR活性和比活的变化情况,发现在发酵开始进行时其活性和比活呈增长趋势,进行一段时间(12小时)之后则保持恒定不变,其变化趋势和发酵液中小菌的浓度变化呈同步关系;它的生物合成不受2-KLG和L-山梨糖的诱导,系小菌的组成酶。

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三面压缩式高超声速进气道在侧压式进气道的基础上加入顶面压缩,理论上具有的更短的压缩距离,从而有利于超声速飞行器的整体设计。该进气道不同于传统的顶压式进气道和侧压式进气道,由于其压缩激波在竖直和水平方向都存在,因此出现三维空间的激波相交和反射,造成流场复杂度大大增加,而其也直接影响了进气道设计构型与波系的相对位置关系及进气道性能。\newline 三面压缩进气道由于顶板与侧板两个方向压缩,在顶板与侧板相交线附近区域,激波并不是简单的二维平面激波结构。顶压激波和侧压激波相交后,在波型上产生了明显的变化。在角区的激波相干后的波系结构:顶板激波与侧壁激波相交后,都变得不再连续,即在相互"穿越"的过程中发生了"断裂",出现了过渡的桥波2。然而对该相干结构的认识目前也仅限于此,其流动的特征,对进气道性能的影响以及如何规划三面压缩进气道设计构型都还需要深入的探索。忽略激波边界层干扰,专注于激波相干现象本身,对于这种三维激波相干结构开展了无黏数值分析研究,探索了其关键影响因素,理论分析了其相干特征。\newline 本文分析认为角区波系可分成$A$,$B$,$C$,$D$,$E$5个部分,$A$为未经激波压缩的区域;$B$为只经过顶压激波3压缩的区域:$C$为只经过侧压激波1压缩的区域;$D$为经过顶压激波3和侧压激波1共同压缩的区域;$E$为过桥波2压缩的区域。对于顶压激波来说,$B$区域的气体与$D$区域的气体参数并不相同,因为$D$区域的气体还经过了侧压激波的压缩,因此在相同的气流转角下,$D$区域的顶板激波角大于$B$区域的顶板激波角,所以顶压激波在穿越侧压激波后发生了"断裂",7的位置高于3的位置;同理,侧压激波穿越顶压激波后,4的位置也会向对称面移动,侧压激波也发生"断裂"。基于以上物理模型,应用二维激波关系,探索性给出的三维激波相干位置的无黏近似计算方法。\newline 数值研究进一步发现相干结构产生的桥波区域为低总压区,对进气道总压恢复系数不利。

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本文介绍了薯蓣植物中所含甾体皂甙和甾体皂甙元的化学研究概括。阐述了该属植物皂甙和甙元的结构特点,简要介绍了提取分离及结构鉴定的新方法,并把从此属植物中分离得到的甾体皂甙和甾体皂甙元的来源,理化常数及13C-NMR的化学位移值以表格形式列出。本文的实验部分是从四川产黄山药根茎的乙醇提取物中分离得到六种甾体皂甙,其中三个为E—试剂正反应成分,用化学方法及IR、FDMS、13CNMR、1HNMR、DEPT等技术鉴定了他们的结构,都是薯蓣皂甙元的皂甙。The chemical study in steroid saponins and sapogenins from Dioscorea family is reviewed. Their stuctures are discussed, and the newer techniques used in their isolation and structural elucidation are briefly introduced. A compilation of the saponins and sapogenins from dioscorea family along with their available physical data, source and 13CNMR chemical shifts is included. The experimental paper is that six steroidal saponins were isolated from rhizomes of Dioscorea panthaica Prain et burkill from Sichuan province. Of these saponins the three are positive to Ehrlich reagent. With the aid of IR, FDMS, and NMR spectrometric analyses, their chemical structures have been elucidated as: 3-O-[α-L-rhamnopyranosyl(1→4)]-[β-D-glucopyranosyl]-diosgenin,3-O-[α-L-rhamnopyranosyl(1→2)]-[β-D-glucopyranosyl]-diosgenin; 3-O-[α-L-rhamnopyranosyl(1→2)]-[β-D-glucopyranosyl]-26-O-[β-D-glucopyranosyl]-diosgenin,3-O-[α-L-rhamnopy-ranosyl(1→2)]-[α-L-rhamnopyranosyl(1→4)]-β-D-glucopyranosyl-26-O-[β-D-glucopyranosyl]-diosgenin,3-O-[α-L-rhamnopyranosyl(1→2)]-[β-D-glucopyranosyl(1→3)]-β-D-glucopyranosyl-26-O-[β-D-glucopyranosyl]-diosgenin

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本学位论文首先报道了为解决低极性化合物的电喷雾质谱(ESI-MS)分析难题而建立的一种衍生化分析方法;然后从色谱-质谱联用分析、分离纯化和结构鉴定等方面分别报道了几种中藏药材的活性成分研究。论文由下述六章组成: 第一章报道了盐酸羟胺衍生化方法在电喷雾质谱 (ESI-MS) 分析中的应用。该方法利用盐酸羟胺和羰基成肟的快速反应,建立了针对三萜酮等含酮或醛羰基低极性化合物的ESI-MS 信号增强技术。此方法不仅可应用于增强羰基化合物的ESI-MS 质谱信号,还可检测化合物中羰基的个数以及辨别涉及羰基官能团的同分异构体。此外,通过简单的氧化反应,还可将该方法拓展到三萜醇、甾醇等含羟基的低极性化合物,增强它们的ESI-MS 信号。对比已报道的相关ESI-MS 增强质谱信号的衍生化方法,此方法有经济、实用、快速和简便的显著特点。 第二章是关于野生羌活及其栽培品种化学成分的色谱-质谱联用分析。对不同产地野生羌活生长过程中活性成分的动态变化、野生羌活不同形态部位和人工栽培羌活中的活性成分含量进行了HPLC 定量分析。结果表明主要活性成分羌活醇和异欧前胡素都随生长期存在规律性变化,羌活不同形态部位中的活性成分含量也有明显不同。这些实验结果有些较好地印证了传统中医的用药理论,有些也对羌活的传统使用方法提出了新的建议。 第三章介绍了几种传统中藏药材的色谱-质谱联用及串联质谱分析。通过GC-MS 方法,从藏药材长花党参挥发油中共分离鉴定出45 个化合物;利用HPLC方法测定了该藏药材中的主要化学成分——木犀草素的含量(0.7%);利用串联质谱技术,对西番莲和射干中的主要成分进行了快速鉴定,从西番莲中鉴定了4个黄酮碳苷;从不同产地的射干和川射干中鉴定了8 个主要异黄酮成分,其中包括一个未见报道的化合物。 第四章的内容为藏药材石莲叶点地梅的活性成分研究。从植物石莲叶点地梅(Androsace integra (Maxim.) Hand.-Mazz.) 乙醇提取物的正丁醇萃取部分共分离和鉴定了6 个化合物,利用MS 和NMR 等现代波谱学技术阐明了它们的结构:其中包括4 个三萜类化合物:分别是androsacin (1)、 ardisiacrispin A (2) 、saxifragifolin A (3) 和20(29)-lupen-3-one (4);一个神经酰胺:4-羟基-Δ8,9(Z)-鞘氨醇-2'-羟基正二十四碳酸酰胺(5);一个甾体类化合物:胡萝卜苷(6)。化合物1为新的13,28-epoxy-oleanane 型三萜皂苷,在其结构表征的过程中,采用LC-MS 进行糖分析,获得了值得推广的好结果。通过活性筛选发现化合物1~3 对HepG2肝癌细胞表现出不同程度的抑制活性,其中化合物2 活性最好,其IG50 为1.65μg/mL。 第五章是关于一些传统中藏药材的农药活性筛选。利用Syngenta 公司的活性筛选平台对68 种传统中藏药材醇提物进行了抗菌和除草的生物源农药活性筛选。结果表明所筛选的68 种植物提取物中,共有14 种样品表现出明显的除草/杀虫活性,其中水母雪莲花、松萝和茯神木等植物提取物还具有多种生物活性。活性成分还有待进一步追踪分离、纯化和结构鉴定。 第六章为文献综述,概述了羌活药材的研究进展。对羌活属及药用羌活植物从分类学、本草学、品质评价、人工栽培、化学成分及药理作用等方面进行了文献归纳和总结。 In this dissertation, an electrospray ionization mass spectrometry (ESI-MS) signal enhancement method, as well as the work of bioactive components study, HPLC-MS/MS application, bioassay screening, chromatograph separation and structure identification of the metabolites in several medicinal herbs have been reported. First chapter expounded a rapid, simple ESI-MS sensitivity enhancement method for detecting carbonyl groups in natural products has been developed by using hydroxylamine hydrochloride (NH2OH·HCl) as a derivatization reagent. We use the oxime formed during the derivatization reactions and its Beckmann rearrangement intermediates as a means of detecting the carbonyl groups originally present in these triterpenoids. In comparison with other derivatization methods in the literature, this method is simple, specific and can be used to detect carbonyl groups in triterpenoids which have low polarity and are poorly or non-ionizable. Moreover, it can also be used to detect hydroxyl groups by using the Dess-Martin periodinane (DMP) to convert primary and secondary hydroxyls into carbonyl groups. Chapter 2 reported an HPLC-MS method for analyzing the main bioactive compounds in both wild and cultured Notopterygium incisum. The results indicated that the main bioactive compounds varied through different seasons regularly, and in different commercial parts of this herb the content of these compounds also differed from each other. The quantitative analysis results showed that in the traditional commercial parts, the content of main chemical constitutes in Silkworm Notopterygium, Bamboo Notopterygium and Irregular-nodal Notopterygium are higher than that in Striped Notopterygium. This result is tally with the traditionally concept that the quality of Notopterygium, Bamboo Notopterygium and Irregular-nodal Notopterygium are better than that of Striped Notopterygium, which means that the quality of rhizomes is better than main roots. The chemical constituents of cultured N. incisum is reported for the first time in this dissertation and the analysis results showed some growth curves of chemical constituents in this plant, but still left some questions unanswered. Chapter 3 discussed the GC/LC-MS analysis of the traditional Chinese medicines Codonopsis thalictrifolis, Passiflora incarnate, Belamcanda chinensis and Passiflora incarnate. The main constituent, luteolin was isolated and identified from the traditional Tibet medicine of C. thalictrifolis. The quantitative analysis by HPLC has revealed that the content of luteolin in this herb is 0.7%. GC-MS was employed to analyzed chemical constituents of the essential oil from the flower of C. thalictrifolis. More than 60 peaks were detected and 45 of them were identified by comparing their spectra with that of the standards in the database and literatures. ESI-MS/MS was used to analyze the n-butanol extract of Passiflora incarnate. Based on the information of pseudo molecular ions and fragment ions of the glycosides, four major flavone-C-glycosides have been detected and identified as 7-methoxyluteolin-6-C-β-D-glucopyranoside, vitexin, swertisin and orientin. The isoflavone compounds in theextracts of three samples of B. chinensis collected in Gansu, Sichuan and Hunan, and the extract of Iris tectorum collected in Sichuan were analyzed by using TOF-HRMS and IT-MS. From the extracts of these herbs, a new isoflavone, identified as 5’,5,6,7-tetrahydroxy-3’4’-dimethoxyl isoflavon, and 7 known ones have been identified by analyzing the fragmentation patterns and their molecular formulas given by HRMS and the tandem mass spectrometry acquired by IT-MS. Chapter 4 elucidated the isolation and identification of a new triterpene saponin, androsacin (1), along with five known compounds (2-6) were isolated from the whole plants of Androsace integra (Maxim.) Hand.-Mazz., an herb used in traditional Chinese and Tibetan medicine. The chemical structure of the new compound was established as 3β-O-{β-D-glucopyranosyl-(1→4)-O-β-D-xylopyranosyl-(1→2)-O-β-D-glucopyranosyl-(1→4)-[O-β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranosyl}-16α-hydroxy-13β,28-epoxy-olean-30-al by analyzing its MS, 1D- and 2D-NMR spectra. Compound 2 was cytotoxic toward HepG2 cancer cell with the GI50 value of 1.65 μg/mL. Chapter 5 described the biogenic pesticide activity screening of 68 traditional Chinese and Tibetan medicine extractions. The intention of this study is to explore bioactive natural compounds from these traditional medicinal herbs for biogenic insecticides use. Based on Syngenta’s bioassay, 14 extractions of these traditional medicines showed pesticide activities, and some of them had multi-activities on antibacterial and insecticidal. Chapter 6 is a review on the chemical and bioactivity research progress of Notopterygium incisum and N. forbesii.

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角蟾科(Megophryidae)是以角蟾属(Megophrys Kuhl and Van Hasselt, 1822)为模式属而建立的,隶于无尾目(Anura),变凹型亚目(Anomocoela)。角蟾科包括2 亚科11 属142 种,分布于东洋界,从巴基斯坦、中国西部向东直到菲律宾和苏达群岛;中国有9 属75 种分布于华中和华南地区。角蟾科被认为是原始的两栖动物之一,其分类学、系统学、生态学、动物地理学的研究均深受中外科学家的瞩目。近年来,通过形态学、古生物学、细胞学、生态学、支序系统学的研究,角蟾科的分类与系统学研究取得了较大进展。与成体形态和分子系统学研究结果相比较,蝌蚪的研究存在更多的问题和挑战,尚需深入研究:(1)角蟾科蝌蚪的形态多样性分析;(2)角蟾科的系统发育关系与蝌蚪的演化,以及口漏斗的起源;(3)角蟾科蝌蚪表型分化与栖息环境和觅食行为的适应演化。针对上述问题,本文对角蟾科9 属30 种蝌蚪的形态特征,包括外部宏观形态和口器外部结构特征、口器内部显微结构、唇齿和角质颌的亚显微结构作了深入细致、多层次的比较研究;通过12s rRNA 和cytochrome b 基因构建最大简约树,采用贝叶斯系统发育进行分析,蝌蚪型的演化采用祖先性状的重建方法分析;得到如下结论:1)初步将角蟾科蝌蚪分为4 种类型;并且建立了2 种新的角蟾科蝌蚪类型。A 型:拟髭蟾型蝌蚪,该型蝌蚪包括拟髭蟾属、髭蟾属、齿蟾属和齿突蟾属的物种;B 型:新类型,掌突蟾型蝌蚪,该型蝌蚪在本文中包括掌突蟾属、小臂蟾属的物种;C 型:新类型,短腿蟾型蝌蚪,一种特化类型,该型蝌蚪在本文中仅包括短腿蟾属的物种;D 型:角蟾型蝌蚪,该型蝌蚪在本文中包括无耳蟾属、小口拟角蟾属和异角蟾属的物种。2)对角蟾科的分类进行了修订:(1)支持角蟾科两个亚科的分类系统;(2)角蟾亚科包括拟角蟾属、异角蟾属、无耳蟾属和短腿蟾属;该亚科形态差异小,系统学关系比较复杂,暂不作族级分类的再划分;(3)拟髭蟾亚科分为2 个族:拟髭蟾族,该族物种具有类型A 的蝌蚪,包括4 个属:拟髭蟾属、髭蟾属、齿蟾属、齿突蟾属;掌突蟾族,该族物种具有类型B 的蝌蚪,包括2 个属:掌突蟾属和小臂蟾属。3)结合分子系统进化关系探讨了4 种蝌蚪类型的演化。(1)角蟾科蝌蚪的最近共同祖先来自于一类具有拟髭蟾型蝌蚪性状的蝌蚪;(2)掌突蟾型蝌蚪和角蟾亚科的蝌蚪是由具有拟髭蟾型蝌蚪性状的祖先蝌蚪分别演化而来;(3)短腿蟾型蝌蚪是角蟾型蝌蚪的一种特化类型;(4)外群蝌蚪具有与拟髭蟾型蝌蚪相似的性状,进一步印证了类拟髭蟾型蝌蚪是角蟾科蝌蚪的最近共同祖先的假说;(5)具有口漏斗的蝌蚪类型是由不具口漏斗的蝌蚪类型演化而来,在角蟾科中口漏斗是一种衍生性状。4)分析了角蟾科四种蝌蚪类型与栖息环境的适应演化。(1)角蟾科蝌蚪的口部和体形的变化反映了该科蝌蚪由缓流向类似静水生境的回水凼的渐变式适应,角蟾科蝌蚪的形态显示了多方面的适应变化;(2)随着蝌蚪类型由A 向D的演化,当水速较大时,拟髭蟾型的蝌蚪营流水攀吸型生活方式;当水速递减时,掌突蟾型蝌蚪营流水附着型生活方式;当水速进一步递减时,具有较小口漏斗的短腿蟾型蝌蚪和具有大漏斗的角蟾型蝌蚪营流水浮泳型生活。角蟾科蝌蚪对于水流递减的适应演化说明蝌蚪的生态学适应是具有进化意义的;(3)蝌蚪口器内部结构的分化揭示了蝌蚪和食性的适应关系,蝌蚪以口部的唇齿与角质颌刮取或吞吸水中的物质,然后,通过口乳突有选择地过滤进入口腔中食物。拟髭蟾亚科蝌蚪的唇齿多而窄,唇齿间距宽,颌鞘粗而稀,反映了其植食性为主的特点;它们的舌前乳突一般为指状,在口腔入口处所占面积小,其机械过滤的作用很多被唇齿和角质颌分担了;而角蟾亚科的蝌蚪,其角质颌弱,其舌前乳突一般为匙状,几乎填满了口腔入口处,因此舌前乳突起了主要的机械过滤作用。The family Megophryidae is the largest and most diverse families inArchaeobatrachia, and most of its species occur in India, Pakistan, and eastward intoChina, Southeast Asia, Borneo and the Philippines to the Sunda Islands. Currently thefamily includes 142 species have been grouped into two subfamilies, Megophryinaeand Leptobrachiinae. The mountains of central and southern China are rich in speciesof Megophryidae, 75 species belong to 9 genera and two subfamilies.The family was supposed to be ideal materials of studies in many fields of biology,such as taxonomy, evolution, systematics, ecology, and biogeography. Recently, therehave a great development in taxonomy and systematics of megophryids throughstudied by morphology, paleontology, cytology, ecology, and cladistics. However,larvae of megophryids were generally unknown, although the tadpoles might be veryimportant for above studies.In this paper, we examined the evolutionary scenario of the tadpoles’ morphologyin the context of a phylogenetic framework. Our objectives are (1) to evaluate thedivergence of larval body shape and oral discs in the family Megophryidae, (2) toexplore the evolutionary trends of the larvae in megophryidae, and test if thefunnel-shaped oral disc is apomorphic, and (3) to explore the relationship of the larvalstructure, diet and microhabitat.We examined larval morphology of 30 megophryid species, the larval body shape,oral discs, the buccopharyngeal cavity, and jaw sheaths and denticles of the Chinesemegophryid frogs were re-examined. We constructed a phylogeny of the species on thebasis of published mitochondrial cytochrome b and 16S rRNA gene segments usingpartitioned Bayesian analyses. Furthermore, hypothetical changes of larval morphologywere inferred using parsimony principle on the phylogeny. The results showed that:1) Four tadpole types in Megophryidae. The larval morphological charactersseries in Chinese megophryids fall into four general categories according to the bodyshape and oral discs: (A) Leptobrachiini type, species from genera Leptobrachium,Oreolalax, Scutiger and, Vibrissaphora share this type of tadpoles. (B) Leptolalax type,species of genus Leptolalax have this type of tadpoles. (C) Brachytarsophrys type,species of the genus Brachytarsophrys have this type of tadpoles. (D) Megophryinitype, species of the genera Atympanophrys, Ophryophryne, and Xenophrys share this type of tadpoles. Of which B and C are two novel types.2)Taxonomic implications. The present study leads us to reconsider the generalclassification of tribes attributed to members of Megophryidae. More specifically,concerning the phylogenetic relationships and the two novel tadpole types describedherein, we propose a provisional taxonomy for the family but suggest that further taxasampling of other megophryids be performed to confirm this taxonomic change. TheMegophryidae is composed of two subfamilies (Leptobrachiinae and Megophryinae).The Leptobrachiinae was recogonized the two tribes: (1) tribe Leptobrachiini sensuDubois, corresponding to the tadpole of type A, including four genera, i.e.,Leptobrachium, Oreolalax, Scutiger and, Vibrissaphora; (2) tribe Leptolalaxini,corresponding to the tadpole of novel type B, including two genera, i.e., Leptolalaxand Leptobrachella. However, the relationships among the genera of Megophryinaewere largely unresolved, they recognized no monophyletic groups above the generalevel. A more thorough sampling will likely foster a better taxonomic solution.3) The larval evolutionary scenario in Megophryidae.Type A is characteristicof normal-mouthed with multiple tooth rows, representing the tadpole type of theMRCA of Chinese megophryids. Type B is characteristic of normal-mouthed withreduced tooth rows, prolonging labium, and integumetary glands. Type C ischaracteristic of no labial teeth and smaller umbeliform oral disc. Type D ischaracteristic of no labial teeth, enlarged umbeliform oral disc, representing the tadpoleof the MRCA of subfamily Megophryinae. A previous hypothesis, referring tofunnel-shaped oral discs as an apomorphy, is supported.4) The larval adaptation to habitats in Megophryidae. Tadpoles generallyadhere to substrates using their mouths, and the microhabitat that the tadpoles occupyreflects the degree of adhesion and oral complexity. The morphological changes inmegophryid tadpoles virtually allow a progressive adaptation to a changing habitatfrom faster water to slower water. Within the tadpoles of Type A to type D, the TOTbecomes smaller and smaller, and the oral disc orientates from anteroventral toumbelliform upturned, and eye position orientates from dorsal to lateral, and the trunkis more and more depressed and tail becomes relatively longer and slender. Within therunning water, the normal-mouthed with multiple tooth rows of Leptobrachiini tadpoles are correlated with lotic-suctorial, benthic feeders with anteroventral oraldisc and the largest body. With the water’s velocity decreasing, the lotic-adherentfeeders of Leptolalax tadpoles have tube-shaped labium with reduced tooth rows andintegumetary glands. And then, the smaller umbeliform in Brachytarsophrys tadpolesand the enlarged umbeliform oral disc in the Megophryini tadpoles are inhabitmicrohabitats of non-flowing backwaters of rivers, indicative of adaptive traits oflotic-neustonic surface feeders. The scheme of megophryid tadpoles andmicrohabitats provided the first clear evidence which congruent with the hypothesis ofAltig and Johnston (1989). The ecological divergence plays a general role in thedivergence and evolution of megophrid larvae. There is a definite correlation amongthe buccopharyngeal cavity, diet and feeding mechanisms, the tadpole graze orswallow the food particles, then through papillae which like a sieve and sort out foodparticles to the oesophagus. The tadpole of Leptobrachiinae possess multiple toothrows, wide intertooth distance as well as thick and sparse jaw sheath, these tadpolesinhabit bottom of the streams and graze on epiphyton or major detritus of organicmatter on the substrates, their prelingual papillae like single finger, the mechanicalpurpose of papillae served share in by tooth and jaw. The tadpoles of Megophryinaeoccur near the water surface of small streams and are the filter feeder, their dietincludes plankton and organic debris floating on the water surface, those tadpolepossess weak jaw, their prelingual papillae like spoon, the mechanical purpose ofpapillae served mostly for sieve.

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鞑靼荞麦是我国特有的农业产品,具有抗寒耐旱特性和较高的营养保健功能。荞麦的开花习性及遗传特点导致其人工杂交授粉难以成功,这成为荞麦杂交育种难以获得突破的重要原因。因此利用转基因技术导入有益基因有可能成为荞麦遗传改良的新途径,而再生及转化体系的建立是开展转基因研究的基础。 本文研究了苗龄、外植体、几种激素配比对鞑靼荞麦(Fagopyrum tataricum Gaertn.)离体培养的影响,初步建立了鞑靼荞麦离体再生体系。结果表明,鞑靼荞麦离体再生的最佳取材时间为苗龄6-8d;诱导愈伤组织的最适培养基为MS+2.0 mg/L 2,4-D+1.5 mg/L 6-BA,子叶诱愈率达75%左右,下胚轴的可高达86.62%;愈伤组织分化的最适培养基为MS 0.1mg/L IAA+2.0mg/L 6-BA+1.0 mg/L KT+0.5mg/L TDZ,下胚轴的分化率可达9.52%。下胚轴的诱愈率与分化率均高于子叶,更适于离体再生培养。培养基中加入AgNO3后,能有效降低褐化率。生根最适培养基为含有0.5mg/L NAA的1/2MS培养基,生根率在50%左右。TDZ在诱导鞑靼荞麦的愈伤组织分化出芽的过程中起到明显的促进作用,可提高分化率约20%。 在上述研究基础上,本文还对鞑靼荞麦的遗传转化体系进行了探索性研究。分别利用根癌农杆菌(Agrobacterium tumefaciens)介导法和微粒轰击法(基因枪法)对黑水苦荞下胚轴进行遗传转化。 在农杆菌介导的方法中,携带有质粒pCAMBIA2301的农杆菌菌株EHA105用于转化。载体质粒pCAMBIA2301包含有gus和npt-II 基因, 并受35s启动子驱动。研究结果表明,在侵染方式选择上,浸泡方式比吸打方式更有效,根癌农杆菌侵染的较适浓度为OD600=0.5,共培养3天,恢复培养7天,能检测到gus基因的表达。 基因枪法使用质粒pBI121,同样包含有gus和npt-II基因, 并受CaMV35s 启动子驱动。轰击距离为9cm较合适,甘露醇前处理在本研究中未表现出明显优势。 两种转化方法比较,基因枪法比农杆菌介导法更快速有效。 本研究为进一步的遗传操作研究打下基础。 Tartary buckwheat (Fagopyrum tataricum Gaertn.), the traditional and unique agricultural product of China, is a kind of crop with strong drought and cold tolerance, abundant nutrition and high medical value. Artificial hybridization is hard in buckwheat because of its flowering habits and genetic characteristics, which leads to no breakthrough in tartary buckwheat breeding. However, biotechnological approaches, especially genetic transformation for the direct introduction of good genes into tartary buckwheat for quality improvement, hold great promise. In this study, we established tartary buckwheat regeneration system in vitro. It is the foundation for genetic manipulation of this crop. The effects of seedling age, hypocotyl and cotyledon as explants, and proportions of several growth regulators were tested in tissue culture of tartary buckwheat for establishing its in vitro regeneration system. The results showed that the best seedling age for callus induction was 6 to 8 days. On the MS medium containing 2.0mg/L 2, 4-D and 1.5mg/L 6-BA, the induction rate of callus from hypocotyls was up to 86.62%, while from cotyledons was about 75%. The suitable shooting medium was the MS medium+0.1mg/L IAA+2.0mg/L 6-BA+1.0 mg/L KT+0.5mg/L TDZ, and the shooting rate from hypocotyls was 9.52%. The callus induction and shooting rates were higher from hypocotyls than from cotyledons. Browning reduced when the medium mixed with AgNO3. Half strength MS supplemented with 0.5mg/L NAA was the best for rooting, the rate was around 50% after 30 days culture. TDZ can accelerate the shoot differentiation distinctively, and it could improve the shooting rate nearly 20%. On the base of above, the explorative research of the genetic transformation in tartary buckwheat was done. In the study, hypocotyls from Heishui tartary buckwheat were transformed by Agrobacterium-mediated method and microprojectile bombardment method (gene-gun), comparatively. In Agrobacterium-mediated method, a disarmed Agrobacterium tumefaciens strain EHA105 harboring plasmid pCAMBIA2301 was used. The vector pCAMBIA2301 contains gus and npt-II genes, driven by CaMV35s promoter. The results showed that the appropriate concentration of Agrobacterium tumefaciens for infecting was OD600=0.5, and co-culture time was 3d. Seven days later after coculture, GUS expression could be tested. In particle bombardment transformation, plasmid pBI121 was used. pBI121 also contains gus and npt-II genes, driven by 35s promoter. Hypocotyls pretreated with mannitol, no effect was observed, and the suitable distance of bombardment is 9cm. Comparing with Agrobacterium-mediated method, gene-gun method is more convenient and effective. All above results could be a basic work for further study in tartary buckwheat transformation.

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同源四倍体水稻(2N=4X=48,AAAA)是由二倍体水稻(2N=2X=24,AA)通过秋水仙素诱导染色体加倍后得到的新品系,具有优良的抗病性以及较高的蛋白质含量。因此,在四倍体水平上挖掘水稻的增产潜力成为水稻育种的新手段。同源四倍体水稻具有很强的遗传可塑性和很弱的遗传保守性,利用其作为水稻远缘杂交的桥梁,从野生物种中不断地引进有益的基因,这将有助于杂交水稻的多代利用和固定水稻的杂种优势。但是迄今为止,还没有关于同源四倍体水稻遗传多样性,遗传背景的报道。目前世界关于同源四倍体水稻的研究主要集中在中国,主要研究方向为培育、筛选结实正常的亲本材料,配置和筛选结实率正常或接近正常的组合。经过几十年研究,虽然在材料构建,细胞学研究等方面取得了较大进展,但同样由于结实率低的瓶颈问题未解决,而使多倍体水稻育种未能取得实质性进展。而近年来一些关于同源四倍体水稻低结实率机理的细胞学研究也由于缺乏统计学数据而缺乏说明性。本文用SSR标记,对选取的36个结实率正常同源四倍体水稻三系亲本和14个来源二倍体亲本,分析他们的遗传差异和群体遗传结构。本文还利用我们培育的高、低结实率的同源四倍体水稻恢复系、优良保持系和杂种F1及二倍体对照为材料,进行系统深入的细胞遗传学研究,进一步探讨同源四倍体水稻有性传递后代的发育过程,探索分裂期染色体行为特征与遗传性状稳定性的关系,为进一步选育多倍体水稻品种并将其应用于生产提供理论依据。同源四倍体水稻突变株D4063-1直链淀粉含量比来源二倍体明恢63下降一半,即其直链淀粉含量为5.23%,为研究其直链淀粉含量下降的原因,本文还根据普通水稻Wx基因设计引物,扩增测序获得了D4063-1Wx基因的全序列,与已报道Wx基因进行比对分析,并根据D4063-1和籼稻、粳稻的序列差异并根据D4063-1在该片段上的特征序列位点设计了用于识别D4063-1的寡核苷酸片段,为快速、准确的鉴别低直链淀粉的D4063-1创造了条件。 SSR标记具有基因组分布广泛、数量丰富、多态性高、容易检测、共显性、结果稳定可靠、实验重现性好、操作简单、经济、易于高通量分析等许多优点,被认为是用于遗传多样性、品种鉴定、物种的系统发育、亲缘关系及起源等研究的非常有效的分子标记。本研究选取了中国科学院成都生物所培育的同源四倍体和二倍体水稻亲本,并用36个微卫星标记进行了遗传差异和种群遗传结构分析。在50个品系中,我们观察到较高水平的多态性,每基因等位基因数(Ae)分布于2至6之间(平均值3.028),多态性信息含量(PIC)分布于0.04至0.76之间(平均值0.366);期望杂合度(He)分布于0.04至0.76之间(平均值0.370),Shannon指数(I)分布于0.098至1.613之间(平均值0.649)。同源四倍体品系的等位基因数,期望杂合性和Shannon指数都比二倍体品系高。在供试50个品系中,较多材料均发现Rare基因,根据SSR多态性指数我们构建了同源四倍体和二倍体水稻的核心指纹库。F-统计值表明遗传差异主要存在于同源四倍体品系中(Fst=0.066)。聚类分析结果表明50个品系可以分为4个组。I组包括所有的同源四倍体和二倍体籼稻保持系,以及一个同源四倍体籼稻雄性不育系及其来源二倍体。II组仅包括IR来源的品系。III组比II组和IV组更复杂,包括同源四倍体和二倍体籼稻恢复系品系。IV组包括同源四倍体和二倍体粳稻品系。此外,由于等位基因及配子的遗传差异,同源四倍体与二倍体品系中存在单位点和双位点的遗传差异。分析结果表明,二倍体和四倍体水稻基因库的不同,其中遗传变异可以区分四倍体与二倍体水稻。同源四倍体水稻具有长期而独立的遗传性,我们能够选育并得到与二倍体亲本相比有特殊优良农艺性状的品系。 本研究以高结实率的同源四倍体水稻恢复系DTP-4、D明恢63及优良保持系D46B为材料进行农艺性状及细胞遗传学比较研究。DTP-4、D明恢63及保持系D46B的的染色体组成均为2N=4X=48,花粉母细胞具有较为理想的减数分裂行为,配对染色体的比率在99%以上,这与理论染色体组构成相符。DTP-4和D明恢63PMC减数分裂各个时期单价体和三价体的比例都非常低,而在MI, PMC观察到较多的二价体和四价体且四价体多以环状形式出现,其最大频率的染色体构型分别为12II 6IV和10II 7IV。恢复系DTP-4和D明恢63在MI四价体频率分别为2.00/PMC和2.26/PMC,而保持系D46B在MI四价体频率为6.00/PMC,极显著地高于恢复系品系,表明保持系D46B具有更好的染色体配对性质;AI保持系D46B的染色体滞后频率为10.62%,远低于恢复系材料DTP-4和D明恢63的19.44%和23.14%,接近二倍体对照明恢63的7.30%水平;TI保持系D46B具有比恢复系更低频率的微核数。而在TII,D46B的正常四分小孢子比率不但高于恢复系品系甚至高于二倍体对照。对高低结实率的同源四倍体水稻恢复系和杂种F1代的花粉育性,结实率和细胞遗传学行为进行了比较研究。DTP-4, D明恢63, D46A´DTP-4和D46A´D明恢63的花粉育性和结实率比D什香和D46A´D什香显著提高。减数分裂分析的结果表明,DTP-4,D明恢63,D什香,D46A´DTP-4,D46A´D明恢63和D46A´D什香其减数分裂染色体构型分别为:0.05I +19.96 II (9.89棒状+10.07环状) +0.01III + 2.20 IV, 0.11I +19.17 II (8.90 棒状+10.37 环状) +0.09III + 2.26 IV + 0.01 VI, 1.33I +9.46 II (4.50 棒状+4.96 环状) +0.44III + 6.02 IV + 0.09VI + 0.09 VIII, 0.02I +14.36 II (6.44 棒状+7.91 环状) +0.01III + 4.80IV + 0.01VIII, 0.06 I +17.67 II (11.01 棒状+6.67 环状) +0.06 III + 3.10 IV + 0.01 VI and 1.11 I +11.31 II (5.80 棒状+5.51 环状) +0.41 III + 5.63 IV+0.03VI+0.03VIII。在同源四倍体水稻恢复系和杂种F1代材料中,最常见的染色体构型为16II +4IV和12II +6IV。在减数分裂过程中,结实率较高的材料染色体异常现象较少而结实率较低的材料染色体异常现象较严重。在杂种F1代中,二价体的比例要低于其相应的恢复系亲本,同样的,单价体,三价体和多价体的比例相比其恢复系亲本也偏低。然而,在减数分裂MI,杂种F1代中四价体的比例要显著高于其恢复系亲本。在中期I,每细胞单价体的比例和花粉育性呈现出极高的负相关(-0.996),当单价体数目升高时,花粉育性下降。其次是每细胞三价体的比例(-0.987),之后则是每细胞多价体的比例与花粉育性的负相关(-0.948)。但是统计分析表明,二价体和四价体的比例对花粉育性和结实率没有显著影响。这一结果表明出了花粉育性和细胞减数分裂行为的相关性,同源四倍体的减数分裂行为为筛选高结实率的同源四倍体种系提供了理论依据。 突变体是遗传学研究的基本材料。利用突变体克隆水稻基因,并进而研究基因的生物学功能是水稻功能基因组学的重要研究内容。本课题组在多年的四倍体水稻育种研究中已获得多个低直链淀粉含量突变体,其中一些突变体在直链淀粉含量下降的同时,胚乳外观也发生了显著改变,呈半透明或不透明。同源四倍体水稻突变株D4063-1直链淀粉含量比来源二倍体明恢63下降一半,即其直链淀粉含量为5.23%。为研究其直链淀粉含量下降的原因,我们根据普通水稻Wx基因设计引物,扩增测序获得了D4063-1Wx基因的全序列,与已报道Wx基因进行比对分析;同源四倍体水稻D4063-1Wx基因最显著变化为在外显子序列中发生了碱基缺失,导致移码突变,在第9外显子终止密码子提前出现。D4063-1Wx基因碱基位点的变化还导致了其序列上的酶切位点的变化,对常用限制性内切酶位点分析分析结果表明同源四倍体水稻相对于籼稻和粳稻多了2个sph1酶切位点,相对于粳稻减少了6个Acc1,增加了4个Xba1,1个Xho1,1个Pst1和1个Sal1酶切位点。聚类分析表明D4063-1Wx基因序列与籼稻亲源关系较近,由此推测D4063-1Wx基因来源于籼稻的Wxa基因型。另外,根据D4063-1Wx基因的碱基差异,我们推测D4063-1Wx基因外显子碱基变化导致的RNA加工障碍是其直链淀粉降低的主要原因,并可能与其米饭较软等品质相关。本文还根据D4063-1和籼稻、粳稻的序列差异并根据D4063-1在该片段上的特征序列位点设计了用于识别D4063-1的寡核苷酸片段,并作为PCR反应的引物命名为AUT4063-1,将该引物与我们设计的扩增普通籼稻、粳稻的Wx基因引物F5配合使用建立了识别D4063-1的显性和共显性两种检测方式的分子标记,为快速、准确的鉴别低直链淀粉的D4063-1创造了条件。 研究同源四倍体水稻基因组的遗传差异,探索同源四倍体水稻的遗传规律,研究分裂期染色体行为特征与遗传性状稳定性的关系,旨在揭示四倍体水稻中同源染色体配对能力的遗传差异,为进一步选育多倍体水稻品种并将其应用于生产提供理论依据。 Autotetraploid rice (2N=4X=48, AAAA) is a new germplasm developed from diploid rice (2N=2X=24, AA) through chromosomes doubling with colchicines and is an excellent resource for desirable resistance genes to the pathogens and high protein content. Therefore, heterosis utilization on polyploidy is becoming a new strategy in rice breeding. At present, the main research on autotetraploid rice centralizes in China. Breeding effort has been made to improve autotetraploid rice genetically, however, the progresses are limited due to higher degree of divergence between hybrid sterility and polygenic nature. But to date, almost nothing is reported about the genetic diversity, original and genetic background of autotetraploid rice. Despite several reports on cytological analysis of the mechanisms of low seed set in autotetraploid rice still the results are inconclusive due to lack the statistical evaluation. Therefore, the study on the mechanisms of low seed set in autotetraploid is a priority for rice breeding. Microsatellites or simple sequence repeats (SSRs) are the widely used marker for estimating genetic diversity in many species, including wild, weedy, and cultivated rice. In our research, genetic diversity and population genetic structure of autotetraploid and diploid populations collected from Chengdu Institute of Biology, Chinese Academy of Sciences were studied based on 36 microsatellite loci. For the total of 50 varieties, a moderate to high level of genetic diversity was observed at population levels with the number of alleles per locus (Ae) ranging from 2 to 6 (mean 3.028) and PIC ranging from 0.04 to 0.76 (mean 0.366). The expected heterozygosity (He) varied from 0.04 to 0.76 with the mean of 0.370 and Shannon’s index (I) ranging from 0.098 to 1.613 (mean 0.649). The autotetraploid populations showed a slightly higher level of effective alleles, the expected heterozygosity and Shannon’s index than that of diploid populations. Rare alleles were observed at most of the SSR loci in one or more of the 50 accessions and core fingerprint database of the autotetraploid and diploid rice was constructed. The F-statistics showed that genetic variability mainly existed among autotetraploid populations rather than among diploid populations (Fst=0.066). Cluster analysis of the 50 accessions showed four major groups. Group I contained all of the autotetraploid and diploid indica maintainer lines and a autotetraploid and its original diploid indica male sterile lines. Groups II contained only original of IR accessions. Group III was more diverse than either group II or IV and comprised of both autotetraploid and diploid indica restoring lines. Group IV included japonica cluster of the autotetraploid and diploid rices. Furthermore, genetic differences at the single-locus and two-locus levels, as well as components due to allelic and gametic differentiation, were revealed between autotetraploid and diploid varieties. This analysis indicated that the gene pools of diploid and autotetraploid rice are somewhat dissimilar, which made a variation that distinguishes autotetraploid from diploid rices. Using this variation, we can breed new autotetraploid varieties with some new important agricultural characters but the diploid rice has not. Cytogenetic characteristics in restorer lines DTP-4, DMinghui63 and maintainer line D46B of autotetraploid rices were studied. DTP-4, DMinghui63 and D46B showed the advantage of high seed set and biological yield. The meiotic chromosome behavior was slightly irregular in DTP-4, DMinghui63 and D46B. We observed less univalent, trivalent and multivalent at MI, but more bivalent and quadrivalent were observed. The most frequent chromosome configurations were 12II 6IVand 10II 7IV in restorer and maintainer lines, respectively. The quadrivalent frequency of DTP-4 and Dminghui63 at metaphase(MI) was respectively 2.00/PMC and 2.26/PMC. However that frequency of D46B was 6.00/PMC, which was greatly significantly higher than DTP-4 and Dminghui63. That indicates the maintainer D46B has better chromosome pairing capability in metaphase (MI). The frequency of lagging chromosomes of the maintainer D46B at anaphaseI (AI) was 10.62%, which was significantly lower than that of DTP-4(19.44%) and Dminghui63(23.14%) and nearly reaching the level of diploid CK(7.30%). In telophaseI (TI) maintainer D46B showed lower frequency of microkernel at TI and lower frequency of abnormal spores at telophaseII(TII). We also studied pollen fertility, seed set and cytogenetic characteristics of restorer lines and F1 hybrids of autotetraploid rice. DTP-4, DMinghui63, D46A´DTP-4 and D46A´DMinghui63 showed significantly higher pollen fertility and seed set than DShixiang and D46A´DShixiang. Pairing configurations in PMC of DTP-4, DMinghui63, DShixiang, D46A´DTP-4, D46A´DMinghui63 and D46A´DShixiang were 0.05 I+19.96 II (9.89 rod+10.07 ring)+0.01 III+2.20 IV, 0.11 I+19.17 II (8.90 rod+10.37 ring)+0.09 III+2.26 IV+0.01 VI, 1.33 I+9.46 II (4.50 rod+4.96 ring)+0.44 III+6.02 IV+0.09 VI+0.09 VIII, 0.02 I+14.36 II (6.44 rod+7.91 ring)+0.01 III+4.80 IV+0.01V III, 0.06 I+17.67 II (11.01 rod+6.67 ring)+0.06 III+3.10 IV+0.01 VI and 1.11 I+11.31 II (5.80 rod+5.51 ring)+0.41 III+5.63 IV+0.03 VI+0.03 VIII, respectively. Configuration 16 II+4 IV and 12 II+6 IV occurred in the highest frequency among the autotetraploid restorers and hybrids. Meiotic chromosome behaviors were less abnormal in the tetraploids with high seed set than those with low seed set. The hybrids had fewer frequencies of bivalents, univalents, trivalents and multivalents than the restorers, but higher frequency of quatrivalents than the restorers at MI. The frequency of univalents at M1 had the most impact on pollen fertility and seed set, i.e., pollen fertility decreased with the increase of univalents. The secondary impact factors were trivalents and multivalents, and bivalents and quatrivalents had no effect on pollen fertility and seed set. The correlative relationship between pollen fertility and cytogenetic behaviors could be utilized to improve seed set in autotetraploidy breeding. The amylose content of autotetraploid indica mutant Rice D4063-1 dropped by half than diploid Minghui 63, that is, its amylose content of 5.23%.The whole sequence of Waxy gene of D4063-1 is amplified and sequenced. And the discrepancy of bases is found comparing to the reported Waxy gene. The Waxy gene of autotetraploid Rice D4063-1 had a base deletion in exon sequence, which resulted frameshift mutation in exon 9 and termination codon occur early. The mutation of Wx also led to the change of some common restriction endonuclease sites. Results showed compared to indica and japonica, D4063-1 had two adding sph1 sites. Compared to japonica, D4063-1 had six decreasing Acc1, a adding Xho1, Pst1 and Sal1 restriction sites. Phylogeny analysis shows that the DNA sequence of Waxy gene of D4063-1 is closer to Indica, and we suppose that the Waxy gene of D4063-1 is origin from genotype Wxa. In addition, according to the base differences of Wx in D4063-1, we deduce that RNA processing obstacle led by base change of intron is the main cause to low the amylose content, and related to phenotype of its soft rice. Based on analysis of fragments of D4063-1, indica and japonica and according to the special point of the three species, primers as markers-AUT4063-I were designed for distinguishing the D4063-1 from other rice. Combining with primer pair F5, dominant and codominant ways were established for discriminating them., rapid and correct identification of D4063-1 from other rice could be done. The genetic analysis is important to ensure the original of autotetraploid rice, for maintaining the “distinctiveness” of autotetraploid varieties, and to differentiate between the various genetic background of autotetraploid rice. The autotetraploid breeding will benefit from detailed analysis of genetic diversity in the germplasm collections. Further investigation on mechanisms of meiotic stability should benefit polyploid breeding. These findings demonstrated opportunity to improve meiotic abnormalities as well as grain fertilities in autotetraploid rice.

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水稻是重要的粮食作物,其产量的增加和品质的改良都是关系国计民生的大事。就我国现阶段的国情而言,水稻产量在现有水平上稳步提升仍是未来十几年甚至几十年农业生产最重要的目标之一。尽管根据“超级杂交水稻育种”的战略设想和水稻育种实践,通过不断地改进育种技术可望在更高的产量水平上进行水稻杂种优势利用,在稻属植物内还具有很大的产量潜力可以挖掘。然而,仅仅从现有的种质基础出发,要更大幅度提高水稻单产,实现“超级杂交稻”的目标也存在一些困难:现有的推广品种是二倍体,尽管种类众多,但是其基因组的来源相对单一;同时,水稻基因组DNA含量也是作物中最少的,基因组内寻求开发潜力有一定困难;水稻作为C3植物,光合利用效率不高也是制约水稻产量提高的因素之一。因此,寻求常规手段以外的技术突破或者方法创新,是实现“超级杂交稻”的目标的迫切需求。本研究利用秋水仙素能抑制细胞分裂中纺锤丝的收缩、使细胞染色体加倍的作用,对水稻幼穗诱导的愈伤组织细胞进行加倍,并分化出再生植株;创制出水稻同源四倍体新的种质材料,在此基础上选育水稻同源四倍体雄性不育三系材料,并实现水稻同源四倍体的三系配套,开展水稻同源四倍体杂种优势利用和四倍体杂交水稻选育研究,建立水稻同源四倍体杂种优势利用的新技术体系。这不仅有助于倍性水平杂种优势的开拓和利用,同时也将为我国新世纪“超级稻”育种研究开辟一条新的技术途径。 水稻幼穗诱导愈伤组织并分化成苗是一项成熟、简单的组织培养技术。本研究以普通二倍体水稻亲本为材料,用秋水仙素进行水稻的多倍体化诱导,创制同源四倍体水稻三系亲本材料并对其进行鉴定。多倍体化以秋水仙素诱导的愈伤组织培养为基础,研究不同秋水仙素浓度梯度和愈伤组织诱导培养基组合对诱导四倍体植株的影响。结果表明在MS+2,4 D 1.0mg/L+ KT0.2mg/L+ IAA0.2mg/L 和500mg/L的秋水仙素处理下,水稻愈伤组织染色体加倍(有最高的效率)效果较好,平均加倍频率可达25.26%,其中,材料CDR22和IR26诱导较易成功,加倍频率分别达到75%和26.5%;相对材料94109 1.3%加倍频率和冈46B 10.8%加倍频率,诱导率差异极显著。 对水稻四倍体材料进行了形态学鉴定结果表明,与二倍体水稻对照相比其株高、穗长、花粉育性等主要农艺性状,确定四倍体材料在穗长和千粒重两方面极显著提高,种子的长度和宽度也显著增长。对花粉育性鉴定,确认水稻四倍体不育系材料仍为不育,保持系材料自交和杂交可育,恢复系材料自交和杂交可育。对四倍体材料进行细胞形态、染色体数目等方面进行细胞学鉴定,经核型分析表明水稻四倍体材料具有48条染色体,是二倍体水稻的两倍。水稻四倍体材料根尖分生组织细胞与二倍体的根尖分生组织细胞相比,细胞体积、细胞核和核仁显著增大。四倍体三系材料在细胞有丝分裂中期均可规则排列在赤道板,并能均等地移向两极;后期观察中没有发现染色体分离滞后现象,分裂末期细胞能够形成大小相对均一的子细胞。水稻同源四倍体三系材料细胞分裂未见异常,植株生长发育正常。 从1996年至2006年,针对结实率、有效分蘖、着粒数和穗长等主要农艺性状,通过系谱选育的方法,对培育的同源四倍体水稻亲本材料进行了连续选择和改良,取得较好成效。表现为结实率的改良效果极佳,所有改良材料的平均结实率均呈上升趋势,如D237(29.70%→72.70%)、DTB(19.55%→53.21%)等。有效分蘖总体呈现上升趋势,但在不同的年份,如1998和2002存在较大的负向波动。部分材料改良效果明显,如D19B(5.87→13.50)、D什香 (7.00→12.00)等;同时一些材料如DTB和D明恢63虽然总体略有提高,但在不同的年份波动很大,因此存在较大改良阻力,原因还有待进一步研究。着粒数的改良上升趋势比较显著,除保持系的DTB之外,其余材料的平均着粒数有显著提高。穗长的改良阻力较大,虽然不同材料总体上有所提高,但效果并不显著,并且不同年份有较大负向波动(2001)。此外还对株高、剑叶长等性状也进行了选择,但效果不显著,原因有待进一步提高。同源四倍体材料产量相关性状遗传改良幅度不一致,保持系和恢复系间的遗传改良效果也存在差异。这为同源四倍体水稻的进一步利用打下了良好的基础。 籼稻和粳稻亚种间杂交及杂种优势利用的主要障碍就是其低的结实率。而同源四倍体杂交水稻的研究为提高杂交水稻的杂种优势利用创造了新的途径。本研究通过随机区组设计方案,挑选性状优良的二倍体水稻材料,包括雄性不育系,保持系和恢复系进行秋水仙素诱导加倍,从而获得同源四倍体水稻对应的三系材料。利用选育的优良水稻同源四倍体三系材料,配制7个杂交组合,杂交F1代与其恢复系亲本进行比较,用于计算超亲优势(HB);而杂交F1代与生产上大面积推广的二倍体杂交品种汕优63进行比较,用于计算杂种优势。结果显示,同源四倍体杂交水稻的超亲优势表现为:每株有效穗变化幅度为1.4%至105.9%,总粒数为0.5%至74.3%,每穗实粒数为17.6%至255.7%,结实率为9.6%至130.4%。这些农艺性状的改良使得这7个杂种F1的理论产量的超亲优势高达64.8%至672.7%。小区试验中四倍体杂交水稻组合T461A/T4002和T461A/T4193分别比二倍体对照汕优63提高46.3%和38.3%以上,除一个品种以外所有品种产量均接近或高于汕优63的产量。同源四倍体水稻强大的杂种优势表明,亚种间杂交育性低的问题可通过四倍体化及强化选择来解决。此外,同源四倍体杂交水稻器官的巨大性也是其产量提高的有利因素,水稻同源四倍体三系杂种优势利用研究具有一定的理论价值和商业生产潜力。 Rice is one of the major food crops, the improvement of the production and quality of it is an important thing related to the people's livelihood. On China's current national conditions, steadily increase of the rice yield based on the current level is still one of the most important goals in the next decade or even decades of agricultural production. According to the "super hybrid rice breeding" the strategic and rice breeding practice, improvement of the use of hybrid rice heterosis through continuous improvements in breeding technology is expected to get a higher level of rice yield, there are also a great yield potential can be exploited. However, there are also some difficulties to increase rice yield obviously and implement the goal of "super hybrid rice" based on the existing germplasm: Rice varieties in promotion are diploid, although there are many varieties, but their genome are from a comparatively single source; Meanwhile, the rice genome DNA are the least among the crops, it is difficult to exploit the development potential within the genome; Rice as C3 plants, photosynthetic efficiency is not high, it is one of the factors constraint rice yield. Therefore, seeking technological breakthroughs or innovative methods different from conventional means is the urgent needs to reach the target of "super hybrid rice". Using colchicine inhibit spindle contraction during cell division, double the cell chromosome, we induced callus cells from rice panicle to be doubled, and differentiated regeneration; we created a new autotetraploid rice germplasm material, and on that basis we bred male sterility three line autotetraploid rice materials, and the achieved the three line rice autotetraploid matchmaking, researched in autotetraploid rice heterosis usage and tetraploid hybrid rice breeding, constituted a new technology system of autotetraploid hybrid rice heterosis utilization. This not only helps the tetraploid rice heterosis exploration and use, but also inaugurates a new technical means for China in the new century "super rice" breeding research. We chose ordinary diploid rice as materials, using colchicine to induce the polyploidization, created the autotetraploid rice three-line materials and identified them. The polyploidization was based on the colchicine-induced callus tissue culture, and we experimented different colchicine concentrations and culture mediums to induce tetraploid plants, confirmed that the optimal concentration for inducement was 500 mg/L, the average induce rate was 25.26 %. Among all the materials, CDR22 and IR26 had higher induced rate; in contrary, 94109 and GANG46B had lower induced rate, the difference was significant. Autotetraploid materials was identified of both morphological and cytological, compared plant height, length of pollen sterility, and other major agronomic traits with a diploid rice as the control plant, identified that the autotetraploid materials had very significant advantages in ear length and thousand-grain weight, as well as the size of the seeds. Cytology identification included observation of the cell morphology, the number of chromosomes, and karyotype analysis on the autotetraploid materials confirmed that their chromosome number was 48, twice of the diploid rice. Mitoses in the three lines were common: chromosomes arrayed normally in metaphase and separated balanced into the two poles, chromosome moved without lagging in anaphase and daughter cells normally formed in telophase except one. It has been proved that tetraploid rice has normal meiosis as their diploid relatives, which usually including series of sub-phases as interphase, prophase I (five sub-phases), prophase II, metaphase I, II, anaphase I, II and telophase I, II. However, abnormal phenomena, such as formation of tetravalent, trivalent and univalent, chromosome lagging and so on, which would finally block meiosis. Configurations of chromosome in metaphaseⅠwere versatile in structure and form accept the bivalent. That condition varied in different strain, suggesting more complex paring configurations and more versatile genetic characters in tetraploid rice. All these abnormalities in meiosis contributed to low fertility of gamete and might consequently resulted in low seed setting. Successive selection and improvement on seed set, productive tiller per plant, total grains per panicle, panicle length and so on had been carried out from 1996 to 2006. The raise of seed sets was significant in both restorers and maintainers. Seed sets of some strains were improved more significantly than others, for example D237(29.70%→72.70%)、DTB(19.55%→53.21%)and et al.. Productive tiller per plant was improved to some extant. The tendency of improvement was rising on the whole but changed in some years such as 1998 and 2002. Part of the stains increased greatly, such as D19B(5.87→13.50)、Dshixiang (7.00→12.00) and so on, but some strains including DTB and Dminghui63 only increased little and decreased in some years by unknown reason. Total grains per panicle increased significantly and all strains except DTB increased. Improvement of panicle length termed to be hard. Different strains showed different capacities for improvement and floating existed in different years for example 2001. It has been proved that other agronomical traits including plant length, flag leaf length and so on could be improved but not significantly by selection also. In a word, agronomical traits could be raised by successive selection that is prerequisite for further utility of autotetraploid rice. Poor fertility is the main barrier for utilizing heterosis between the two rice (Oryza stiva L.) sub-species, indica and japonica. Recently, the development of autotetraploid hybrids (2n=4x=48) has been suggested as a new method for increasing heterosis in hybrid rice. Using standard experimental protocols, the elite diploid rice male sterile, maintainer, and restorer lines were colchine-doubled and autotetraploid counterparts were obtained. Seven resulting hybrids were analyzed for heterobeltiosis (HB), where the F1 was compared to the male parent, and the degree of heterosis, where the F1 was compared to the diploid commercial hybrid, Shanyou 63. The HB among the autotetraploid hybrids ranged from 1.4 to 105.9% for the productive panicles per plant, 0.5 to 74.3% for total kernels per panicle, 17.6 to 255.7% for filled kernels per panicle, and 9.6 to 130.4% for seed set. Improvements in these yield components resulted in the HB for kernel yield ranging from 64.8 to 672.7% among the seven hybrids. Hybrids T461A/T4002 and T461A/T4193 yielded 46.3 and 38.3% more, respectively than Shanyou 63, and all other hybrids but one yielded the same or more than Shanyou 63. The high heterosis for yield suggests that hybrid sterility between two rice sub-species may be overcome by using tetraploid lines followed by intensive selection. Also, the gigantic features of the autotetraploid hybrids may establish a plant structure able to support the higher yield.

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绞股蓝(Gynostemma pentaphyllum)系葫芦科绞股蓝属植物,药用价值广泛,但其野生资源日趋减少,绞股蓝主要药效成分为绞股 蓝皂甙。利用组织和细胞培养生产绞股蓝皂甙是合理开发利用和保护绞股蓝资源的可能途径之一。本文对绞股蓝组织培养中培养基 的蔗糖和激素的组成以及各种胁迫条件:渗透压、重金属离子、真菌诱导物等对皂苷产量的影响进行了初步研究。其中,渗透压、 重金属离子、真菌诱导物对绞股蓝愈伤组织皂甙产量的影响尚未见报道。1. 蔗糖对绞股蓝愈伤组织之生长影响显著,2,4-D对绞股 蓝愈伤组织皂甙含量、产量影响显著。增加蔗糖用量,减少2,4-D的用量可提高皂甙产量。2. Mn++ 用量的提高抑制绞股蓝愈伤组 织的生长,但可促进皂甙含量、产量的提高。Mn++用量提高至MS培养基的20-30倍时可使皂甙产量增加近一倍,而提高Cu++浓度的 作用不明显。3. 甘露醇用量增加抑制绞股蓝愈伤组织的生长,但可使皂甙含量、产量提高。0.680mol·l-1甘露醇可使皂甙产量提 高83%,而Nacl较大抑制愈伤组织的生长并使皂甙产量降低。4. 米曲霉粗提物对绞股蓝愈伤组织生长先略微促进,然后抑制,而根 霉粗提物则使愈伤组织生长受抑制;两者对皂甙含量、产量的作用相似:在较低浓度范围内升高,然后下降。米曲霉粗提物可提高 产量一倍,根霉粗提物可提高42%。这些结果为高产细胞系的筛选和生长、生产培养条件的优化积累了资料。在综述部分,对植物 细胞培养中组织和器官分化、细胞结构变化、生化水平的变化与次生物合成和积累的关系作了讨论。Gynostemma pentaphyllum blongs to Gynostemma, Cucurbitaccae. It has a wide medical use, but its wild resource is threatened by people's excessive use. Its effective medical components are gypenosides. For reasonable use and protect its resource, it is a possible way to product gypenosides by plant tissue and cell culture. This paper has a primary study on the components of sucrose and hormones and a variety of stress conditions: osmostic pressure, heavy metal ion, fungal elicitors in the medium for the calli culture. The effects of osmostic pressure, heavy metal ion and fungal elicitors on the calli of Gynostemma pentaphyllum have not been reported. 1. Sucrose had a significant effect on the growth of the calli, 2,4 D had notable effects on the gypenosides content and production of the calli. Increased the concentration of sucrose and decreased the concentration of 2,4 D improved the production of gypenosides. 2. Increased the concentration of Mn++ inhibited the growth of the calli, but improved the content and production of gypenosides. The optimum concentration was 20-30 times as MS medium which improved the production 100%. Increased the concentration of Cu++ had not a notable effect. 3. Increased the concentration of mannitol inhibited the growth of the calli, but improved the content and production of gypenosides. The optimum concentration was 0.680mol·l-1 which improved the production 83%. Nacl apparently inhibited the growth of the calli and decreased the production of gypenosides. 4. The crude preparation of Aspergillus oryzae inhibited the growth of the calli that in low concentration. The crude praparation of Rhizopus formosensis inhibited the growth of the calli throughout. Their effects on the content and production of gypenosides are alike, but the former is higher than the latter. On the optimum concentration, each crude preparation improved the production 100% (Aspergillus oryzae), 42%(Rhizopus formosensis). These results has accumulated some informantion on the select of high yield cell strains and choose the best culture conditons for the growth and gypenosides product of the calli. In the review, it is discussed that the differentiation on tissue-organal, cellular and biochemical levels related to the synthesis and accumulation of secondary metabolites in plant culuture.

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水华暴发是一个世界性的问题,近年来在发展中国家显得尤其严重。水华暴发给环境和公众健康带来巨大灾难,一些蓝藻产生的毒素可以造成鱼类、鸟禽和家畜的死亡,而臭名昭著的微囊藻产生的微囊藻毒素更是有强烈致癌效应。因此,寻找控制水华藻类的有效方法非常迫切。在利用物理和化学方法处理不甚理想的情况下,利用溶藻细菌控藻成为一个新的研究方向。溶藻细菌一般直接从富营养化水体中分离,杀藻活力对有害蓝藻具有较强的选择性而不危害其它生物,尤其适合在水华发生初期使用,可以在短时间内达到阻止藻类增殖的效果。本研究富集分离到一个高效溶解铜绿微囊藻的溶藻菌群,对其溶藻效应和溶藻机制进行了探索研究。 1溶藻菌群的富集筛选及其溶微囊藻效果 富集筛选得到一个有明显抑藻效果的菌群,它对铜绿微囊藻有显著溶藻效果。与对照组相比,加入富集的溶藻菌后,第4 d开始出现溶藻现象,6~8 d出现明显的溶藻效果,8 d后测得叶绿素去除率在85%以上。 2 溶藻菌群的作用范围及溶藻特性 富集分离到的溶藻菌群对铜绿微囊藻和念珠藻有显著溶藻作用,对水华微囊藻和其它几株受试微囊藻没有明显溶藻效应。该溶藻菌群不仅可以在液体中溶解铜绿微囊藻,生长在固体平板上的藻苔也有一定的溶藻效应,生成溶藻空斑。保证快速溶藻的最大稀释度可以达到1/100, 000。 3 环境因子对菌群溶藻效力的影响 试验发现,不同的pH、温度、和光照条件下,溶藻菌群溶藻效力明显不同,且不同种类的氮源对其溶藻作用也有一定影响。这些条件对该菌群溶藻作用的影响,在相当的程度上可能取决于它们对藻和细菌两者的生长状况的影响综合。 4 溶藻菌群的溶藻作用机理 溶藻菌液过滤除菌和煮沸灭菌处理后溶藻液,未见明显的溶藻效果,只有原液具有很好的溶藻效果。因此可初步确定,蓝藻细胞的溶解可能是由溶藻菌直接接触藻细胞产生的作用效果。显微镜观察发现,细菌在溶藻的过程中频繁地接触藻细胞并侵入藻细胞,破坏进而裂解杀死藻细胞。这也进一步说明了此溶藻菌是通过直接方式杀藻。 5 溶藻菌群的菌群结构解析 分离有溶藻效果的纯菌的多次尝试都没有成功。结合DGGE和16S rDNA文库综合分析发现:Rubritepida菌,假单胞菌和鞘氨醇单胞菌是存在于铜绿微囊藻中的三种伴生细菌。加入富集的溶藻菌群后,菌群结构发生明显的变化,Rubritepida菌、假单胞菌消失,混合菌群则包含未培养黄杆菌,鞘氨醇单胞菌和噬氢菌,其中黄杆菌是优势菌群,并且细菌种群结构的变化与藻细胞消亡之间有显著的相关性。通过菌种的分离鉴定与DGGE和16S rDNA文库的测序结果比较,一些未培养菌可能在溶藻过程中起重要调控作用。 6 溶藻细菌控藻应用基础 (1) 扩大规模的模拟水华实验进一步确定了细菌对微囊藻的强烈溶解作用。 (2) 铜绿微囊藻(Microcystis aeruginosa 905, zc)、微囊藻(Microcystis spp., zd)和溶藻菌群共培养试验表明,zc可以抑制zd生长,而溶藻菌群可以溶zc。 本研究是第一次报道混合菌群的溶藻效应。该溶藻菌群对带有藻际细菌的铜绿微囊藻具有高效的溶藻效力,表明它对自然界中存在的带菌铜绿微囊藻和其它一些蓝藻的生消具有一定的控制作用。对进一步研究菌藻关系与生态学作用,以及对富营养化湖泊和水库水体中蓝藻暴发的防控,该菌群具有一定的应用潜力。 Cyanobacterial blooms break out frequently all over the world, especially in developing countries. Blooms create enormous disasters to public health and to the environment. Some cyanobacterial blooms produce extremely toxic substances that have killed fish, domestic animals and birds. It has been well known that microcystins, a hepatoxin produced by Microcystis, can promote tumors in humans. So it is very important to find an effective method for controlling the growth of the bloom-forming algae. Measures for controlling such kind of algae include physical, chemic and biologic means, but the former two may damage the aquatic environment and require high-energy inputs. The alternative approach for the elimination of nuisance algae involves the application of algicidal bacteria. The algicidal bacteria, which are nontoxic to other organisms and most of which are isolated from the eutrophic lake in situ, may be potential microbial algaecides. In the initial stages of the water blooms, they are able to restrain the biomass or multiplication of the bloom-forming algae in a short time. In order to use algicidal bacteria to suppress blooms of M. aeruginosa, we isolated a bacterial culture capable of lysing the noxious cyanobacteria M. aeruginosa. In this paper we described some properties of the bacterial culture and its growth-inhibiting or algicidal effects on the growth of M. aeruginosa, and investigated its algicidal mechanisms. 1 Enrichment of a microbial culture that lyses Microcystis aeruginosa A mixed bacterial culture was isolated from a hypereutrophic pond and showed significant algicidal activity against the noxious Microcystis aeruginosa. Algae lysis would be seen obviously 4 days later when the algae culture was killed and became yellow contrast to no-addition controls, and chlorophyll a (chl-a) reduction went beyond 85% 8 days later. 2 The host range and some other algicidal feature of the mixed algicidal culture. Microcystis aeruginosa, Nostoc sp., were susceptible to the mixed algicidal culture, while the lytic effects of this mixed culture on Microcystis flos-aquae and some other tested Microcystis were feeble.The algicidal culture can not only lyse M. aeruginosa in liquid media, but aslo lyse M. aeruginosa lawns on soft agar plates and form plaques. The maximun dilution of the mixed culture required for rapid Microcystis lysis is 1/100, 000. 3 Influences of environmental factors such as pH, temperature, illumination, and the nitrogen source on the lytic activity of the mixed bacterial culture on Microcystis aeruginosa. In our investigations, it was shown that the lytic activity of the mixed bacterial culture on Microcystis aeruginosa was straightly correlated with pH, temperature, illumination, as well as the nitrogen source in the medium. The impacts of these environmental factors on the algicidal activity of the mixed bacterial culture, to a certain extent, may depend on both the algal and the bacterial growth rates under the tested environmental conditions. 4 The mechanisms of algal cell lysis by the algicidal bacteria Death was detected when the mixed bacterial culture was added to the algal culture, but not when only the culture filtrate or autoclaved bacterial culture was added. This indicates that the mixed bacterial culture did not release extracellular products inhibitory to Microcystis aeruginosa. In addition, under the microscope, we observed frequent contacts btween bacteria and algae cells, and some bacteria can even penetrate into target algal cells and destroyed them. These results may suggest that the bacterium kill the alga by direct contact. 5 Molecular Characterization of the algicidal bacterial culture Attempts for isolation of pure bacterium or bacteria from the enrichment culture responsible for Microcystis lysis have so far been failed. Based on PCR-DGGE (denaturing gradient gel electrophoresis) and 16S rDNA clone library analysis, Rubritepida sp., Pseudomonas sp. and Sphingomonas sp., as accompanying bacteria, were existed in M. aeruginosa. The bacterial community in M. aeruginosa showed significant change after adding the enrichment culture, where uncultured Flavorbacterium sp., Sphingomonas sp. and Hydrogenophaga sp. were observed, and the uncultured Flavorbacterium sp. became a dominant species. The obvious correlation can be seen between change of bacterial population and extinction of M. aeruginosa. Compared identification of pure bacterium with sequencing of DGGE bands and the clone distribution of the clone libraries, it was inferred that some uncultured bacteria were probably play an important role in controlling the growth and abundance of M. aeruginosa. This report is the first example of a mixed bacterial culture with the ability to lyse M. aeruginosa. 6 Further study for algae control by applications of algicidal bacteria (1) Algae lysis would be seen obviously 6 days later when the algae culture was killed and became yellow contrast to no-addition controls, and chlorophyll a (chl-a) was reducted to a low level 20 days later in the simulated water bloom experiments. (2) The growth of Microcystis sp. (zd) was restrained by Microcystis aeruginosa 905 (zc) when they were co-cultured together, and zc was lysed by the algicidal bacterial culture. This report is the first example of a mixed bacterial culture with the ability to lyse M. aeruginosa, and its algicidal activity remained high against non-axenic tested M. aeruginosa, suggesting that bacteria in the natural environment could play a role in controlling the growth and abundance of M. aeruginosa and other cyanobacteria. Such bacteria could also potentially be used as agents to prevent the mass development of cyanobacteria in eutrophic lakes and reservoirs.