高浓度细胞分裂素诱导棉花悬浮细胞程序性死亡

棉花悬浮细胞经高浓度细胞分裂素（2mg／L KT或4mg／L KT）处理后第4天大量死亡，培养物呈褐黑色；抽提总DNA，进行琼脂糖胶电泳，结果表明：2mg／L KT和4mg／L KT两处理中有明显的大小为140～180bp及其倍增量片段的DNA“梯”。进行PI和FDA染色显微观察可以看到：2mg／L KT处理中大部分细胞的细胞核较小，核质浓缩，呈棒形或弯月形；胞质浓缩，出现了不对称的质壁分离，且丧失了FDA染色活性。这些结果表明，由高浓度细胞分裂素处理引起的棉花悬浮细胞大规模死亡是一种细胞程序性死亡（PCD）。不同的生理状态（UCSA和BAE）和不同生长时期（指数增长期和静止期）的棉花悬浮细胞对高浓度细胞分裂素的诱导反应存在差异。     

Effect of Synthetic Cytokinin Application on Pod Setting of Individual Florets within Raceme in Soybean

Abstract

The application of synthetic cytokinin (6-benzylaminopurine, BA) to racemes of soybean genotype IX93-100 at 7 days after anthesis (DAA) enhanced pod-set percentage of the florets at the 5th position and above (numbered from the base on rachis). The endogenous cytokinin (trans-zeatin riboside) content of individual florets was measured at the 1, 3, 5, 7th position every 3 days after anthesis. Cytokinin was detected only from the florets at 9 DAA, and the content was higher in the more proximal florets while it became negligible in the 7th floret. These results suggest that an increase in the amount of cytokinin in individual florets might enhance the pod setting of the florets positioned at the middle or distal part within the raceme.     

生长素和细胞分裂素对平邑甜茶组培苗PAs和NO含量的影响

 以平邑甜茶继代组培苗为试材，研究了NAA、IBA、ZT和6-BA作用下组培苗的生长、内源多胺（PAs）和一氧化氮（NO）含量的变化。结果表明，在MS培养基中添加0.02 ~ 1.00 mg·L^-1的NAA或IBA后，外植体鲜样质量增加率和蛋白质含量以及多胺含量和一氧化氮含量均明显增加，其中浓度在0.10 ~ 0.50 mg·L^-1 时增加最高；同样浓度下，NAA处理的外植体鲜样质量增加率和腐胺含量高于IBA。在0.08 ~ 4.00 mg·L^-1范围内，随着ZT或6-BA浓度的升高，外植体鲜样质量增加率、可溶性蛋白含量、多胺含量和一氧化氮含量均逐渐升高；同样浓度下，6-BA处理的外植体鲜样质量增率和腐胺含量高于ZT。生长素和细胞分裂素促进组培苗生长与促进内源PAs和NO的生成相伴随，组培苗生长动态与内源多胺和一氧化氮含量的变化趋势一致。     

红花萱草的花茎花蕾组织快繁技术的研究

取红花萱草的花蕾、花茎外植体,在MS培养基上用不同浓度的细胞分裂素BA和生长素NAA进行培养。结果表明:花茎的分化率比花蕾高,而最适合的培养基配方是:MS+BA 0.5 mg/L+NAA 0.1 mg/L+蔗糖30 g/L+琼脂8 g/L。可诱导分化出愈伤组织,继代培养愈伤组织增埴的同时可获得健壮的再生植株。最适的生根培养基为:MS+NAA 0.3 mg/L+活性碳0.3 g/L+蔗糖30 g/L+琼脂8 g/L。     

Spontaneous induction of tetraploidy in hop using adventitious shoot regeneration method

In the process of breeding triploid hop cultivars, diploid varieties need to be raised to the tetraploid level. Existing methods are predominantly based on treatment of the apices with antimitotic substances, in vivo or in vitro , resulting in a reported maximum of 26% tetraploids and a large proportion (over 60%) of mixoploids. This study was set-up to test whether an adventitious shoot regeneration protocol can be used as an alternative. In the first part of the experiments, regeneration media and a choice of explants (internodes, petioles and leaf discs) were optimized using three hop cultivars with putatively low, medium or high adventitious shoot regeneration capacity. On an optimized induction medium supplemented with 6 mg/l N ⁶-(2-isopentenyl) adenine (2iP), a regeneration rate up to 17.7% was obtained from cultured internodes, even of the most recalcitrant 'Aurora', while the regeneration rate of the most responsive 'Tettnanger' was 56.9%. Flow cytometric analysis of ploidy level revealed a high frequency of tetraploid induction, the highest (58.6%) being in 'Savinjski golding'. In 616 regenerants of all three cultivars, 30.4% were found to be tetraploid, the others were diploid. Cytokinin content was found to be of minor importance in tetraploid induction. The high frequency of spontaneous tetraploid induction and, in particular, the complete absence of mixoploids makes this protocol an alternative to the currently established methods of chromosome doubling based on the use of antimitotic substances. The occurrence of a high proportion of tetraploid adventitious regenerants in hop is discussed in view of certain other biotechnological applications.     

Callus Induction of Aloe vera L var chinensis (Haw) Berg

Studies were given to the induction and growth of callus of Aloe vera L.var.chinensis(Haw.) Berg when the young stem was applied as explant.MS was taken as basic medium,added with various concentrations of auxins(IAA,IBA,NAA and 2,4-D),cytokinins(6-BA,KT and Zeatin) and the different combinations of these plant growth regulators.Results showed that the callus is barely induced by cytokinin alone,and the callus induction rates have significant difference when different concentrations of auxin and different combinations of auxin with cytokinin are used on the MS medium.In order to inhibit callus browning during culturing,various concentrations of vitamin C or active carbon are added into four combinations of auxin and cytokinin respectively,which can induce callus most effectively.The result showsd that vitamin C can alleviate callus browning more effectively than the active carbon.The most efficient medium for induction and growth of callus of Aloe vera L.var.chinensis(Haw.) Berg was MS+2.0 mg/L 6-BA+0.5 mg/L 2,4-D+10 mg/ L vitamin C,with which the callus induction rate can reach to 91.4% and callus grow vigorously.     

细胞分裂素促进白杨派树种插穗生根作用的研究

用细胞分裂素(Cyt)配合生长素(Aux)处理银白杨、毛白杨和山杨插穗的试验表明,增加Cyt有促进愈伤组织发育和不定根形成的作用。与Aux处理相比,Aux+Cxt处理可使愈伤组织生根时间从50d缩短至30d左右。在人工气候室条件下,山杨扦插生根率达85％。     

冬季修剪对苹果新根细胞分裂素含量的影响研究

本试验以盆载３年生新红星／海棠为试材，应用高效液相色谱分析方法，研究了冬季修剪对苹果新根内源细胞分裂素含量的影响。新根中玉米素核苷（ＺＲ）、玉米素（Ｚ）的含量，缓放植株高于短截植株；但ＺＲ／Ｚ的比值，缓放植株低于短截植株。     

植物激素对高山红景天试管苗愈伤组织诱导的影响

以高山红景天试管苗的叶片和茎为外植体研究不同植物激素配比对愈伤组织诱导的影响，结果表明：在4种生长素（2，4-D，NAA，IAA，IBA）和3种细胞分裂素（6～BA，ZT，KT）的配合中，NAA和6-BA组合的培养基对高山红景天愈伤组织诱导的效果最佳；试管苗茎的愈伤组织诱导率高于叶片．     

杂交水稻再生芽萌发生长与植株内源细胞分裂素含量变化的关系

采用植物激素ELISA方法，研究了杂交水稻各器官内源细胞分裂素（iPA)的变化及其与再生芽萌发生长的关系。结果表明，头季稻齐穗后5－19d稻株叶和叶鞘中内源激素iPA的含量较低，再生芽生长缓慢或处于休眠状态；齐穗19d以后，内源激素iPA含量增加，再生芽萌发、伸长的速度也相应加快。前期（齐穗后19d)下部节位茎中iPA含量高于上部节位，低位芽长于高位芽；后期（齐穗后33d）上部节位茎、芽的iPA含量高于下部节位，上位芽生长速度则快于下位芽，可见，再生芽萌发生长与内源激素iPA变化关系密切。