京枣试管苗茎尖多倍体诱变研究

以京枣试管苗茎尖为试材,以秋水仙碱为诱变剂,通过在含不同浓度秋水仙碱的培养基中共培养来诱导京枣多倍体.结果表明:在含秋水仙碱30 mg/L的培养基中共培养30 d诱导率最高可达36.67％.通过染色体观察确定变异植株染色体数目为48条.对照植株染色体数目为24条.四倍体植株气孔长度为39.62 μm、宽度为22.06 μm、气孔密度为58.89个/mm2、活体叶绿素平均含量为11.71 spadr/mm2;分别为原二倍体植株的1.546、1.662、0.636、2.366倍.     

秋水仙素处理后‘无核丰’枣的减数分裂行为及2n花粉的形成

运用压片法对秋水仙素滴注处理后的‘无核丰’枣小孢子母细胞减数分裂行为及其与花蕾外部形态变化的相关性进行了研究,并测定了2n花粉的比例。结果表明:秋水仙素处理后枣小孢子母细胞第一次减数分裂正常;在减数分裂前期Ⅱ观察到胞质分裂异常现象;中期Ⅱ纺锤体主要有4种类型:平行型、垂直型、八字型和融合型,分别占27.31%、19.35%、45.27%和8.06%;四分体时期观察到二分体、三分体、四分体,分别占6.00%、43.04%、50.96%;定位异常纺锤体八字型与融合型分别与三分体、二分体呈正相关;秋水仙素处理后‘无核丰’枣2n花粉的形成受胞质分裂异常、纺锤体定位异常两种机制控制,因纺锤体定位异常而产生的2n花粉占2n花粉总数的96.97%,遗传上等同于FDR(第1次分裂重组)型配子,因胞质分裂异常产生的2n花粉在遗传上等同于SDR(第2次分裂重组)型配子;秋水仙素处理后‘无核丰’枣2n花粉绝大多数为FDR型,因而在枣有性多倍化中具有重要的利用价值。小孢子母细胞减数分裂进程与花蕾外部形态变化具有对应关系,花蕾直径达到1.34 mm时,小孢子母细胞开始进入减数分裂;达到1.68 mm时,小孢子母细胞进入四分体时期;超过1.92 mm时,减数分裂结束,且有大量花粉粒形成。2n花粉诱导最佳的秋水仙素滴注时期为细线期末期,即花蕾直径在1.34~1.42 mm时,诱导后‘无核丰’枣2n花粉发生比例为17.36%。     

不同处理条件对洋葱鳞茎表皮细胞骨架形态的影响

细胞骨架是活细胞的重要结构,研究细胞骨架的形态对于进一步研究其功能具有重要意义。本研究以洋葱为材料,对洋葱细胞骨架显微观察的关键条件进行了优化,设置了4个不同的1%TritonX-100抽提非骨架蛋白时间(10min、15min、25min、45min),同时分析了细胞环境温度(-20℃、4℃、20℃、50℃),Ca2+(0.05mol/L、0.10mol/L、0.15mol/L)处理及0.1%秋水仙素处理对洋葱细胞骨架形态观察效果的影响。结果表明:1%TritonX-100抽提非骨架蛋白25min观察效果较好;-20℃、50℃,Ca2+和秋水仙素处理均会影响洋葱鳞茎表皮的细胞骨架。     

部分菊属植物种间杂种难稔性及其克服

菊花(Dendranthema morifolium(Ramat.) Tzvel.)近缘种属植物中具有许多栽培菊花所缺乏的优良性状,如抗逆性、抗病虫性,通过远缘杂交结合幼胚拯救技术能有效克服菊属(Dendranthema (DC.)Des Moul.)种间障碍,进行菊花种质创新和品种改良[1].远缘杂交亲本由于缺少可识别遗传信息及染色体同源性差异,种间杂种可能具有难稔性[2].     

Improving androgenesis‐mediated doubled haploid production efficiency of FCV tobacco (Nicotiana tabacum L.) through in vitro colchicine application

Production of doubled haploid plants through androgenesis in flue‐cured Virginia (FCV) tobacco is a promising and convenient alternative to conventional selfing techniques for the generation of absolute homozygous lines. Here, we show a robust in vitro haploid and doubled haploid development protocol in FCV tobacco with major emphasis on improving the efficiency of chromosome doubling using in vitro colchicine treatment. We used five FCV tobacco hybrids for comparison of colchicine treatments. The anther culture response varied with developmental stages of the buds, and the highest response was observed in stage 2 buds. The effect of cold pretreatment was significant, and 4 days of pretreatment was optimum for gametic embryogenesis. Among the methods used for determining the ploidy status of plants, flow cytometry was found to be easy, fast and reliable for high‐throughput screening of haploids. Doubled haploids regeneration percentage varied from 6.77 to 11.95 in in vivo treatment, while the range of variation was 22.11% to 28.40% in in vitro colchicine treatment. We observed a pronounced increase in plant survival and the proportion of doubled haploid plants in in vitro treatment compared with the standard in vivo approach.     

非洲紫罗兰的核型分析

将低渗技术引入染色体压片法,首次对非洲紫罗兰(Saintpaulia ionantha)缟花品种"Sunray Trail"进行了核型分析,并摸索了适用于该试材的预处理方法,为与之有关的细胞学分类、分子育种、新品种培育及转基因的细胞学检测等方面提供了细胞学依据。结果表明,供试材料为4倍体品种,其核型公式为2n=4x=28=16 m+8 sm+4 T;核型类型属于2B型;核不对称系数为63.3%;最佳预处理方法为在4℃下用0.05%的秋水仙素处理根尖2 h。     

微管调节试剂对白菜型冬油菜萌动种子内源激素及抗寒基因表达的影响

以‘陇油7号’和‘天油4号’2个抗寒性不同的白菜型冬油菜为试验材料,通过添加400μmol·L^-1秋水仙碱(微管聚合抑制剂)和50μmol·L^-1紫杉醇(微管聚合促进剂)试剂后,在20℃和0℃下分别处理12 h和24 h,随后采用液相色谱质谱联用仪和荧光定量PCR测定萌动种子内源激素含量及抗寒基因表达量,研究微管调节试剂对白菜型冬油菜萌动种子内源激素和抗寒基因的影响。结果表明：与对照相比,添加秋水仙碱后,在0℃和20℃处理下‘陇油7号’和‘天油4号’ABA、IAA、GA₃、ZT含量明显降低;添加紫杉醇后,‘陇油7号’和‘天油4号’ABA、IAA、GA₃、ZT含量明显升高。添加秋水仙碱后,与0℃处理12 h相比,0℃处理24 h时,‘陇油7号’α-tubulin、β-tubulin、MKK2、ICE1、CBF1、BrAFP1的表达量增加,‘天油4号’α-tubulin、β-tubulin、CBF1表达量增加,但MKK2、ICE1、BrAFP1的表达量降低;与20℃处理12 h相比,20℃处理24 h时...     

扁茎黄芪离体快繁及多倍体诱导

以扁茎黄芪的干燥成熟种子为外植体,研究其离体快繁技术,并在无菌繁殖条件下探索了秋水仙碱溶液不同浓度和时间处理对扁茎黄芪的诱变效应。快繁研究结果显示,扁茎黄芪的发芽培养基为MS,继代增殖最适培养基为MS+6-BA3.0mg/L+NAA0.5mg/L,平均增殖系数达到4.5,平均苗高达3.5cm;生根最适培养基为1/2MS+NAA0.05mg/L,生根数为4～6条,生根率达到100%。采用浸泡法将扁茎黄芪的茎尖在0.1%,0.3%和0.5%不同秋水仙碱溶液浓度下分别处理1,2,3和4d,并对诱导处理后获得的再生植株进行染色体鉴定,得出以0.3%秋水仙碱溶液浸泡3d为诱导多倍体的最佳处理组合,诱导率达40%。     

Chromosome doubling and fertility study of Alstroemeria aurea × A. caryophyllaea

Self-pollinations of a diploid (2n = 2x = 16) interspecific hybrid Alstroemeria aurea × A. caryophyllaea, resulted in no seeds. Backcrosses of the hybrid with parent A. aurea did not produce any seeds. In an attempt to restore the hybrid fertility, an efficient in vitro procedure has been developed and applied effectively in the chromosome doubling of the diploid hybrid. Forty-one percent of the treated plants were proven to be truly tetraploid by chromosome counts and stomatal measurements after applying 0.2 to 0.6% colchicine for 6 to 24 hours. Over 87.5% of these colchicine-induced tetraploids were stable and retained their tetraploidy after one year of growth. The fertility of the hybrid was not restored although the pollen stainability was increased from 0 to 12% after chromosome doubling. Cytological studies on the pollen mother cells (PMCs) of the sterile diploid hybrids revealed abnormal meiotic behaviors. In addition, aneuploid chromosome numbers, ranging from 2n = 1 to 2n = 18, were observed in over 45% of the PMCs examined. PMCs of the colchicine-induced tetraploids showed that meiotic chromosome pairings were normal in most cases (1.59_I + 15.07_II + 0.05_III + 0.03IV). These results indicate that the sterility of this hybrid is not only caused by parental chromosome differences, but other complex fertility/sterility-regulating mechanisms are involved too. This revised version was published online in July 2006 with corrections to the Cover Date.     

苹果试管染色体组工程育种

用秋水仙０．４％和０．８％的浓度，诱变苹果７个二倍品种自然授粉的胚，通过试管培养，抑制胚芽成梢，促使染色体组突变的四倍体细胞分化不定芽，形成植株。经染色计数梢端切片，鉴定出一批同质的四倍体株系，部分植已栽植于果园。此项研究了简易可靠的诱变，有效地避免或减轻了浣诱变中嵌合体的干扰，为人工创造四倍种质，有计划地进行多倍体育种开辟了新途径。