皇帝蕉薄片外植体愈伤组织的诱导及植株再生

将皇帝蕉试管苗茎段徒手切成厚约1mm的薄片,经无菌的0.5%柠檬酸溶液处理片刻后,接入各种培养基中。结果表明:(1)适度的暗培养预处理有利于愈伤组织诱导,合适暗培养天数为4d;(2)诱导愈伤组织最佳培养基为:B5+2,4-D13.572μmol/L+IBA4.921μmol/L+NAA5.371μmol/L+KT13.94μmol/L+椰乳5%+PP3330.0001mg/L,愈伤组织诱导率为86.0%;(3)最佳愈伤组织分化芽培养基为:改良MS培养基+BA13.6831μmol/L+NAA0.537μmol/L,芽分化率达到87.0%;(4)诱导芽生根的最佳培养基是:1/2MS+IBA0.492μmol/L(或+NAA0.537μmol/L),生根率达到100%。     

离体培养条件下核桃器官发生和体细胞胚胎发生

采自幼树、成年树及成年树伐根萌条的嫩梢腋芽,在改良DKW培养基+6-BA1.0mg/L中可伸长生长;在加有6-BA1.0mg/L+IBA 0.01mg/L的继代培养基中,可保持腋芽的生长并形成不定芽。芽增殖率为每月600％左右。芽苗经5.0mg/L IBA处理7天,然后在含活性炭的无激素培养基中培养20天,有54％可生根成苗。5月中旬至6月上旬的幼胚,在改良DKW培养基+6-BA1.0 mg/L中,黑暗培养30天左右可产生体细胞胚,并可连续多代保持胚性分生能力。体胚在无激素的发芽培养基中黑暗培养7天左右可发芽成苗。胚性愈伤组织在悬浮振荡培养中可保持分生能力。     

Analysis of genetic variability in various tissue culture-derived lemon plant populations using RAPD and flow cytometry

Five populations of lemon plants [Citrus limon (L.) Burm] obtained from undeveloped ovules through different tissue culture procedures were examined for the presence of somaclonal and irradiation-induced genetic variation. Tested groups were: (1) nucellar seedlings; (2) organogenic, regenerated via adventitious buds from nucellar seedling internodes; (3) embryogenic population, regenerated from non-irradiated nucellar callus via somatic embryogenesis; (4) embryogenic population, regenerated from irradiated nucellar callus via somatic embryogenesis; and (5) protoplast-derived, regenerated via somatic embryogenesis. Genomic DNA samples from 360 plants (72 from each group) were screened for polymorphism among RAPD fingerprints amplified by 10 decamer primers. Among all tested plants, genetic variation was detected only within the group of plants recovered from irradiated embryogenic calli. Out of 72 plants from that group, three had RAPD fingerprints different from the rest of the population, and fourth plant was found to be cytochimeric, consisting of diploid and tetraploid cells as revealed by flow cytometry. In all other populations of regenerated plants, we did not come across any plants with changed ploidy level.     

Callus induction and plant regeneration from embryonic axes of Kosteletzkya virginica

Kosteletzkya virginica, a perennial dicot halophytic species of the Malvaceae, is native to American salt marsh. It was introduced into China as a potential species to improve coastal wetlands and to develop ecologically sound saline agriculture. K. virginica adapts excellently to the tidal-flat habitats in China's east coast, with multiple eco-benefits; in particular, its seed oil could be used to produce biodiesel. The purpose of this study was thus to develop a standardized protocol to induce a high frequency of callus and subsequent plantlet regeneration system for a K. virginica breeding program with the final objective of applying transgenic techniques to improve seed oil yield. The embryonic axes of K. virginica were used as explants for callus induction, shoot induction from the callus and then adventitious root induction from the shoots on nine culture media with different hormone combinations. The best results were achieved on the following media: (1) 93.94% callus induction on MS medium supplemented with 1.0 mg L⁻¹ indole-3-acetic acid (IAA), 0.3 mg L⁻¹ kinetin, 30 g L⁻¹ sucrose and 8 g L⁻¹ agar; (2) 65.83% shoot induction on 1/2MS medium supplemented with 0.1 mg L⁻¹ IAA, 0.5 mg L⁻¹ zeatin, 30 g L⁻¹ sucrose and 8 g L⁻¹ agar; (3) 96.67% rooting on MS medium containing 30 g L⁻¹ sucrose and 8 g L⁻¹ agar. The survival rate of plantlets by organogenic regeneration was 85% after being transplanted into potting soil in flowerpots and placed in the greenhouse. This experiment indicates that we established successful callus induction and plant regeneration protocols for K. virginica.     

In vitro shoot regeneration from immature seeds of Epimedium alpinum induced by thidiazuron and CPPU

In vitro propagation of Epimedium alpinum L. was carried out using immature seed explants. The effects of various concentrations of thidiazuron (TDZ) and 1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU), on the induction of organogenic callus, were evaluated. Organogenesis occurred most efficiently when explants were transiently exposed (48 h) to 20 μM CPPU or 80 μM TDZ followed by culture on hormone-free woody-plant medium (WPM). Organogenic callus consisting of white, compact clumps of tissue proliferated slowly on hormone-free WPM. To promote adventitious shoot induction, the effects of different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzyladenine (BA) were investigated. The highest per cent shoot regeneration, 66.7% of explants, and the maximum mean number of shoots, 2.6 per explant, were obtained on WPM containing 1.1 μM 2,4-D and 22 μM BA. Shoots were rooted on hormone-free WPM and well-developed plantlets were successfully transferred to soil.     

小麦抗赤霉病杂种的花培研究

利用MS培养基或N6培养基,添加适当的植物激素与有机成分,对非小偃血统的普通小麦抗赤霉病杂种材料进行组织培养,获得花粉植株。用花药作外植体进行离体培养,有愈伤组织形成,有些杂种材料花药诱导成愈伤组织的频率较高。因此,通过花药培养途经,以缩短杂种性状稳定的年限,加速小麦抗赤霉病高产品种的选育进程是可能的。     

桑离体再生过程中内源激素变化的研究

植物离体器官发生是一个受多种因素调节的过程。实验结果表明 :桑子叶在培养 16d内 ,脱落酸 (ABA)随培养时间的增加而浓度增大 ,吲哚乙酸 (IAA)在培养的第 6天和第 16天出现 2个峰 ,异戊烯基腺苷 (iPAs)在培养的第 6天出现高峰 ,之后随培养时间增长而降低 ;二氢玉米素核苷 (DHZRs)和玉米素核苷 (ZRs)在培养第 8天出现浓度峰 ,之后降低。内源激素的变化与桑离体器官的发生之间显示出密切的关系。实验还发现在添加硝酸银后 ,ABA、IAA、iPAs浓度降低 ,DHZRs和ZRs的浓度比对照有所提高。推测硝酸银在桑组织培养中 ,可能通过调节内源激素的含量与比例 ,影响形态发生。因此在桑离体培养中 ,可以通过添加硝酸银来控制离体器官发生 ,进而建立高效再生体系     

三种常用抗生素对苎麻种子发芽及子叶再生的影响

本研究测试了卡拉霉素、羧苄青霉素、头孢霉素对于3个不同基因型苎麻子叶再生的影响，还测试了卡拉霉素对于苎麻种子发芽及生长的影响，结果表明：苎麻子叶对于卡拉霉素有着较高的敏感性，20-25mg／L的卡拉霉素就能完全抑制苎麻子叶再生；羧苄青霉素能显著抑制苎麻子叶再生；浓度在500mg／L以下的头孢霉素对苎麻子叶再生没有明显影响。此外，苎麻种子对于卡拉霉素也较敏感，100mg／L卡拉霉素处理30d能使苎麻种子实生苗全部黄化（白化）死亡。     

大豆组织培养的研究进展

概述了大豆原生质体和单细胞的组织培养，以及外植体经器官发生和体细胞胚胎发生途径再生植株的研究进展，对不同再生途径进行了比较，并指出了大豆组织培养存在的主要问题和今后研究方向。     

不同外植体及激素对红茄器官形成的影响

 以红茄下胚轴、子叶、幼根和叶片为外植体,以MS附加不同浓度的激素和激素组合进行培养。结果:(1)不同类型外植体器官形成能力有较大差异,下胚轴分化出的幼芽最多,其次为子叶,再其次为根和叶片;胚轴不同部位,上部形成的芽多于中部和下部;幼叶形成的芽多于成熟叶。(2)不同类型的外植体,诱导产生芽的最佳激素不同,叶片和子叶在MS附加BA(2mg/L) 的培养基中诱导出最多的芽,而下胚轴和根以MS附加IAA(0.5mg/L)+BA(2.5mg/L) 的培养基效果最佳。