小麦成熟胚无性系后代的性状表现

观察了来源于小麦成熟胚培养再生植株中R_2代无性系农艺性状的变异。结果表明;R_2无性系的株高、穗粒数、千粒重、抽穗期和穗长都发生了不同变异,每个农艺性状的变异频代率较高,并且穗系间也有变异,还对无性系的变异和利用进行了讨论。     

小麦幼穗耐盐细胞无性系及后代农艺性状变异

小麦幼穗耐盐细胞无性系及后代农艺性状变异裴翠娟方仁李洪杰郭北海（河北省农林科学院粮油作物所，石家庄０５００３１）朱至清（中国科学院植物研究所，北京１０００９３）ＶＡＲＩＡＴＩＯＮＯＦＳＡＬＴＴＯＬＥＲＡＮＣＥＳＯＭＡＣＬＯＮＥＳＤＥＲＩＶＥＤＦＲＯ...     

小麦幼胚培养再生植株第二代若干性状的变异*

再生植株第二代（R₂）各性状如F₂代一样均表现为介于双亲的连续变异,并有超亲遗传。各性状的变异幅度均大于F₂代,超出F₂变异范围的株率依性而有所不同,从1.64——65.3%。R₂代各性状的遗传力较F₂有较大的提高。这些都反映了经体细胞培养后诱导了变异,丰富了R₂的遗传基础。     

基因枪介导小麦成熟胚遗传转化的影响因素

小麦成熟胚作为转化受体可克服小麦幼胚存在的受季节和幼胚发育阶段限制的缺点。以湖北省小麦品种‘鄂麦12’和模式品种‘Bobwhite’为材料,成熟胚为转化受体,优化基因枪转化法的轰击压力、轰击距离、选择剂等因素,建立以小麦成熟胚为转化受体的高效转化系统。结果表明:小麦成熟胚作为转化受体时,适宜轰击压力和轰击距离组合是900 psi、6 cm;成熟胚对选择剂G418的敏感性强于幼胚,轰击后需要延长恢复时间,选择剂G418的适合浓度为20～40 mg/L。在以上优化条件下小麦成熟胚转化频率达0.3%～0.9%,已初步建立基因枪介导的小麦成熟胚遗传转化系统。     

小麦成熟胚高频植株再生系统的建立

在研究小麦成熟种子不同预处理时间、不同种类和浓度生长调节物质、分化培养基中是否添加CuSO4、不同外植体类型和不同放置方式对小麦成熟胚愈伤组织诱导和分化的基础上,建立了一套高效、可靠、重复性好的小麦成熟胚高频植株再生系统.以小麦成熟种子完整胚作为外植体的诱导频率为100%;除掉胚的原胚芽部位生长出的芽苗后,转分化的分化频率达到42.50%.     

小麦成熟胚愈伤组织诱导及分化研究

以2个小麦品种成熟胚为外植体进行离体培养,研究了不同预处理、不同2,4-D浓度及与KT组合、不同蔗糖浓度等因素对愈伤组织诱导及分化的影响。结果表明:4℃低温预处理可提高愈伤组织的出愈率及再生苗率,2个材料的出愈率及再生苗率均达到90%和30%以上;在不同预处理条件下,2,4-D浓度对出愈率及再生苗率的影响与基因型有关,2,4-D浓度为1~2 mg/L更有利于愈伤组织诱导及分化;附加KT能缓解高浓度2,4-D对再生苗率的抑制作用,而对于在1、2 mg/L 2,4-D的培养基中附加KT则不表现这种作用;蔗糖浓度则在30 g/L条件下更有利于愈伤组织诱导。因此通过4℃低温预处理,在MS基本培养基中附加1~2mg/L 2,4-D及30 g/L蔗糖亦可促进小麦成熟胚愈伤组织的诱导和分化。     

影响小麦成熟胚培养及植株再生因素的研究

对3个不同栽培品种小麦的成熟胚进行离体培养,研究影响小麦愈伤组织诱导和植株再生的一些因素。结果表明,东农7742的苗分化率明显高于龙麦9814和龙麦26;高浓度的玉米素可明显提高芽的分化率;附加低浓度NAA的1/2 MS培养基可有效促进生根。可见,基因型对小麦愈伤组织的分化有很大的影响,附加一定的外源激素有利于提高植株的再生频率。     

Somaclonal Variation in the Gliadin Patterns of Grains of Regenerated Wheat Plants

Maddock, S. E., Risiott, R., Parmar, S., Jones, M. G. K. andShewry, P. R. 1985. Somaclonal variation in the gliadin patternsof grains of regenerated wheat plants.—J. exp. Bot. 36:1976–1984. The banding patterns of the gliadin storageproteins of the grains of 590 regenerated plants from six wheatcultivars were examined by polyacrylamide gel electrophoresisusing lactate buffer. Variation additional to that present incontrol material was observed at a low frequency (1%). Two variantlines showed extensive changes in banding patterns which wereaccompanied by morphological variation of the plants. More limitedvariation in the form of an extra –gliadin band was observedin a third line. Differences in the seed gliadins were not foundin four lines which had shown stable phenotypic changes in heightin field trials. Key words: Wheat, somaclonal variation, gliadins, tissue culture, seed proteins     

诱发小麦成熟胚愈伤组织及其再生植株抗盐性变异的研究

本研究以普通小麦成熟胚为起始材料,以平阳霉素(PYM)和正定霉素(ZDM)为诱变剂。发现不同基因型对药物的敏感性不同,其中对药物敏感的在含盐筛选培养基上的存活率高。在诱导培养基内添加一定量的诱变剂可以产生耐盐变异。这种抗性愈伤组织转入与筛选培养基含盐量相同的分化培养基,比较容易产生耐盐再生植株。其M_1、M_2代较亲本系表现株高降低,穗长变短、籽粒饱满度也差;M_1代的结实率仅有5.5%,M_2代恢复到40.9%。利用M_1代和亲本系实生苗叶片,进行脯氨酸含量测定。发现耐盐变异株在无盐的Hoagland溶液中,游离脯氨酸的含量超过亲本系,对盐胁迫不敏感,其耐受力强于对照,具有一定的抗盐稳定性。     

菊苣体细胞再生植株的遗传稳定性分析

目的:研究菊苣再生植株的遗传稳定性.方法:以菊苣叶片为外植体,经第一代和第二代体细胞再生获得再生植株,分别对再生植株提取DNA,从12个引物中筛选了2个多态性好的引物,对第一代和第二代体细胞再生植株进行RAPD标记.结果:菊苣第一代体细胞无性系没有发生DNA多态性变异,第二代体细胞无性系在分子水平发生了1条DNA多态性变异.结论:RAPD分子标记方法可以鉴定菊苣组织培养过程中的遗传稳定性和遗传变异,为菊苣快繁和遗传转化奠定了基础.     

Studies on the Somaclonal Variation of Regenerated Plants from Protoplasts of Actinidia deliciosa

Protoplasts were isolated from leaf, petiole and stem segment-derived calli induced from one pistillate plant of Actinidia deliciosa line No. 26. Regenerated plantlets were obtained from protoplasts of leaf-derived and stem segment-derived calli, while only calli regenerated from protoplasts of petiole-derived calli. Seventy-six plants from protoplasts of leaf-derived calli and 21 plants from that of stem segment-derived calli survived after transplanting or grafting during 1987–1989. One staminate plant and two pistillate plants bloomed in May, 1991 and fruited soon afterwards. In all of those three plants regenerated from protoplasts of leafderived calli, sex differentiation occurred from somatic cells of Actinidia was verified. Somaclonal variation on leaf shape and plant morphology was obviously appeared. Chromosome number identified from 16 plants varied from 116 to 180.     

不定胚再生植株的染色体数目变异

本实验以甜瓜“小麦瓜”和“青皮绿肉”品种为试材,经不定胚诱导再生植株。分别调查了不同继代培养时间后形成再生植株的染色体数目,并将之与对照染色体数目相比较,发现通过诱导不定胚所得到的再生植株中存在着一定的变异,而且经过不同继代培养时间后,所得到的不定胚再生植株的变异程度不同,随着时间的增加,染色体数目的变异率从3.3%增加到30%,变异幅度也从2n=23~24增加到2n=13~48。从而得出结论：不定胚再生植株染色体数目变异程度随着培养时间的增加而增加;培养时间在1~2个月内所得到的不定胚再生植株的变异较少。此外,不定胚再生植株的染色体数目变异程度也因品种而异。 Abstract:Chromosomal number of different of somatic embryos regenerated plants were investigated in melon variety “xiaomaigua” and “Qingpilurou”.Certain variations of chromosomal number were found among the regenerated plants compared with normal sample,and range of variation covered from 2n=23～24 to 2n=13～48 with the increase of generation,the rate from 3.3% to 30%.The results indicated that degree of variation in chromosomal number of somatic embryos regenerated melon plants increased with the time of culture,and those cultured in one to two months had the least variation.It was also found that degree of chromosomal number variations varied with melon varieties.     

Somaclonal Variation in Chromosome Number and Nuclei Number of Regenerated Plants from Protoplasts of Actinidia eriantha

By counting the chromosome number of root tip cells in 18 regenerated plants derived from protoplasts of Actinidia eriantha Benth., the authors found 12 euploid plants and 6 mixoploid plants. Of the 12 euploid plants, 6 were diploid (2n = 2x = 58) and the other 6 were tetraploid (2n =4x = 116). The chromosome numbers of the mixoploid plants varied from 59 to 203. Mttltinueleate phenomenon was also observed in the interphase cells of 10 protoplast-derived plants. Cells with binuclei or trinuelei were common and cells having heptanuclei were also seen occassionally. Muhinucleate phenomenon did not occur in the control, i. e., the donor plant, where the chromosome number was 2n = 2x = 58.