农杆菌介导的玉米自交系愈伤组织转化条件的优化

采用农杆菌介导法,将外源基因导入玉米骨干自交系掖515和掖502胚性愈伤组织并再生玉米植株。在农杆菌浸染玉米胚性愈伤组织过程中,采取真空渗入、部分酶解和超声波处理,可以显著提高转化率。农杆菌浸染玉米胚性愈伤组织时,在50kPa下真空渗入5min,掖515和掖502胚性愈伤组织的转化率分别从6.3％和4.5％提高到8．7％和7．8％。愈伤组织在农杆菌浸染前,以0．2％离析酶酶解10min,掖515和掖502胚性愈伤组织的转化率分别提高到8.3％和8．9％。在农杆菌浸染时,以功率100W超声波处理90-120s,掖515和掖502胚性愈伤组织的转化率最高可达9．1％和9．4％。     

兔眼越桔幼苗胚轴、子叶诱导再生植株

植物名称:兔眼越桔(Vaccinium ashei)材料类别:无菌苗胚轴、子叶。无菌苗培养:种子用70％酒精浸泡1分钟后,转移到10％的漂白精片过滤液中灭菌15分钟,再用无菌水冲洗三次,接种于0.5％琼脂上,培养温度为25～28℃,光强为2,000lx,每日光照16小时。培养3～4周后幼苗高约2～3cm,子叶绿色。于无菌条件下取子叶、胚轴(5～7mm)作为外植体进行诱导培养。     

一种鉴定金花茶人工杂交F_1代杂种苗的简易方法

本试验选用了两个以金花茶作父本的人工杂交组合F_1代实生苗,经根尖体细胞染色体观察鉴定四倍体杂种。一、云南野山茶(Camellia pitardii var.yunnanica六倍体)×金花茶(C.Chrysantha二倍体)。结果为:所获56株子叶和下胚轴为红色的F_1代杂种苗中,有55株(98.2％)是真正的四倍体杂种(X~2=0.0128,D.f.=1,0.95>p>0.90);所获50株子叶和下胚轴为黄白色的杂种苗中,有13株(26％)为真正四倍体杂种(X~2=27.38,D.f.=13,0.02>p>0.01)。二、云南山茶花(C.reticulata六倍体)×金花茶。结果为:在78株子叶和下胚轴为红色的杂交苗中,有77株(98.7％)为真正四倍体杂种(X~2=0.0128,D.f.=1,0.95>p>0.90);而在78株子叶及下胚轴为黄白色的杂种苗中,只有21株(26.9％)是真正四倍体杂种(X~2=41.65,D.f.=24,0.02>p>0.01) 在多数杂种实生苗中的这种红色素,是因种子直感现象而发生的父本金花茶的一种遗传性状。金花茶的另一特征——多子叶现象(3枚以上),则在一些F_1代杂种苗或杂种种子中表现得不明显。因此,利用F_1代杂种苗子叶和下胚轴所具有的红色特征,在杂种种子萌发期用来鉴别以金花茶为亲本的F_1代杂种的真伪,是一种简便、快速的、有发展前途的方法。     

菘蓝子叶和下胚轴的离体培养

植物名称:菘蓝(Isatis indigotica)。材料类别:子叶和下胚轴切段。培养条件:诱导分化与生长培养基为MS KT2mg/L(单位下同) NAA0.2;诱导生根培养基为B_5 NAA1 IAA1。培养温度25±2℃,每天光照10h,光照度为20001x。生长与分化情况:外植体培养7d后,切口处开始形成少量白色愈伤组织,10d后子叶切块开始分化出绿色的小芽;15d后下胚轴上也开始分化不定芽。20d后统计芽的诱导率为:子叶69.6％,下胚     

大别山五针松子叶和下胚轴离体培养成苗

植物名称:大别山五针松(Pinus dabeshanensis) 材料类别:子叶和下胚轴。种子冷水浸种24小时,剥去种壳,经0.1％升汞(8分钟)和70％酒精(0.5分钟)表面灭菌后,用无菌水冲洗5遍,接种到MS培养基上发芽。2周后,根长至0.5～1cm,剥去胚乳,切取子叶和下胚轴培养。培养条件:基本培养基为改良的MS(MS无机成分中NH_4NO_3浓度减低到1/4,KNO_3为1/2;有机成分改为VitB_1 0.4mg/L、甘氨酸2mg/L)和     

种子萌发出苗过程中胚轴的伸长和胚根的发展

在讲种子的萌发时,对胚各部分的发展变化,曾听到过如下的解释:胚轴发育成植物的主茎,胚根发展成植物的根系.这样说是否确切呢?下面谈谈与此有关的问题. 一株植物的主茎是否完全由胚轴发育而成的问题,了解了胚轴伸长的情况,就很容易得到答案.大家知道,双子叶植物种子胚中的胚轴以子叶为界可区分为两部分:子叶以下与胚根连接的部分叫下胚轴,从子叶着生位置以上至第一真叶着生处之间的部分叫上胚轴.单子叶植物常见的禾本科种子胚的胚轴则可区分为下胚轴(子叶即盾状体着生处以下与胚根连接的部分)、中胚轴(盾状体着生处以上至胚芽鞘着     

马铃薯实生苗子叶及下胚轴原生质体培养研究

用马铃薯普通栽培种（Ｓｏｌａｎｕｍ ｔｕｂｅｒｏｓｕｍ Ｌ．）３ 个品系的实生苗刚展开的子叶及下胚轴游离和培养原生质体。实验结果表明,子叶及下胚轴原生质体的分裂频率显著地高于经多次继代繁殖的试管苗顶部幼嫩叶片和茎尖的原生质体;在强连续光照下培养的实生苗,其原生质体的产量和质量都显著地高于弱光下培养的;在完全黑暗下培养的黄化实生苗不能游离出完整的原生质体;酶解前对子叶及下胚轴切段在酶液中进行真空渗透处理能显著地提高原生质体的产量,但此种处理对试管苗叶片无明显效果;下胚轴原生质体的产量显著地高于子叶,但在原生质体的质量方面,这两种组织间无明显的差异     

白皮松后期胚发育的研究

白皮松成熟胚的显著特点是苗端发达,胚苗端的H／D(高度与直径)比率平均为0.83, 有时达0.96,为松柏类植物所罕见。它的苗端可分为四个细胞区：顶端原始细胞、中央母细 胞、周缘组织和肋状分生组织区。在肋状分生组织与下胚轴的髓之间,有一过渡组织区。 从成熟胚的结构来看,松科成熟胚基本上可以分为3种类型：1．子叶特别发达,但下胚轴短; 2．下胚轴与根冠近等长; 3．下胚轴比较发达,白皮松就是这种类型。     

荞麦组织培养及高频植株再生体系的建立

通过对荞麦(Fagopyrum esculentum Moench)不同外植体、不同激素配比的比较研究,建立了荞麦离体培养高效植株再生体系。荞麦子叶切段在含2．0 mg/L 2,4-D和1．0 mg/L 6-BA的MS培养基上愈伤组织诱导率为89．6％,而下胚轴切段在含2．0 mg/L 2,4-D和1．0-2．0 mg/L 6-BA MS培养基上愈伤组织诱导率高达100％。在2．0 mg／L 6-BA、0．1 mg,L IAA和1 mg／L KT的MS培养基上通过愈伤组织间接分化或外植体直接分化形成不定芽。来自子叶和下胚轴的愈伤组织的分化率分别为42．5％和73．6％,下胚轴的分化率明显高于子叶。将生长状态良好的不定芽转至含1．0 mg/L IBA和0．5mg/L NAA的1/2 MS培养基上生根,生根率达到100％。再生植株移栽到盆土中,成活率达91．6％,并且生长状态和特征均表现正常。     

莲种子的极端高温耐性与抗氧化酶活性的变化

莲（Nelumbo nucifera Gaertn．）种子是一种长寿命和耐极端高温的种子．莲和玉米（Zeamays L．）种子的含水量分别为0．103和0．129gH20／g干重,随着在100℃处理时间的延长,种子的含水量、萌发率和由存活种子产生的幼苗鲜重逐渐降低．100℃处理15min时,玉米种子的萌发率为零;但莲种子被处理24h时,其萌发率仍然为13．5％．50％的玉米和莲种子被100℃处理致死的时间（T50）分别为6min和14．5h．随着100℃处理时间的延长,莲胚轴的相对电解质渗漏明显增加,总叶绿素含量显著下降,当在100℃处理时间短于12h时,莲下胚轴的亚细胞结构保持完整;当处理时间长于12h时,细胞逐渐发生质壁分离、内质网变得不清晰、核和核仁降解、大多数线粒体膨胀、脂质颗粒在细胞边界积累,最后细胞器和质膜降解．此外,莲胚轴和子叶的丙二醛（MDA）含量在100℃处理的0～12h内下降,然后增加：玉米胚和胚乳的MDA含量在100℃处理的5～10min内增加,然后有所下降．莲胚轴和子叶的超氧物歧化酶（SOD）、谷胱甘肽还原酶（GR）和胚轴的过氧化氢酶（CAT）活性在100℃处理初期增加,然后下降;而莲胚轴和子叶的抗坏血酸过氧化物酶（APX）、脱氢抗坏血酸还原酶（DHAR）和子叶的CAT活性随100℃处理时间的延长而逐渐下降．玉米胚和胚乳中的SOD,DHAR以及胚的GR活性在100℃处理初期增加,然后下降;玉米胚和胚乳中的APX,CAT和胚乳的GR活性随100℃处理时间的延长迅速下降,与种子萌发率下降的趋势相同,莲胚轴和子叶的SOD,APX,CAT,GR和DHAR活性下降缓慢,而在玉米胚和胚乳中这些酶的活性则迅速降低。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Time of detection of recessive genes: effects of system of mating and number of examined individuals

Summary Anthers were cultured from two sets of seven lines of hexaploid wheat (Triticum aestivum L.) with different cytoplasms, the euplasmic nucleus donors, Siete Cerros 66 and Penjamo 62, as well as their six alloplasmic lines derived from wild relative species of the genera Triticum and Aegilops. Significant cytoplasmic and nuclear effects but no cytoplasmic-nuclear interaction were found for embryogenic anther response, with the best performance of Penjamo 62 in Ae. kotschyi cytoplasm. Plant regeneration was not affected significantly by the cytoplasmic background of the lines cultured. The possible genetic implications of the observed cytoplasmic and nuclear influences on the in vitro haploid induction of wheat are discussed.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.