【作者】 曹宇；

【导师】 曹子谊；

【作者基本信息】 山东师范大学 ， 发育生物学， 2010， 硕士

【摘要】 宽叶独行菜广泛分布于我国华北与西北地区,在国外亦分布于美国西部,新英格兰海岸,墨西哥、加拿大、澳大利亚等地。这种原产于欧洲东南部的杂草在许多栖息地具有极强的竞争力,特别是在河岸湿地地区。宽叶独行菜在不同的生态环境下具有广泛的适应力。国外的对它的研究主要集中在它的高度耐涝性,而在国内的分布显示它对干旱、盐、低温与高温生境有很强的适应能力。因此研究它对逆境的广谱适应机制具有重要的科学意义。本文利用采自我国青海荒漠地区干旱盐渍生境的宽叶独行菜种子,进行了耐盐耐旱的基础生理研究,并为建立遗传转化体系而进行了组织培养研究。本实验进行了盐胁迫下种子的萌发情况测定。实验结果表明,随着盐浓度的增加,种子的萌发率及发芽势呈不断下降的趋势,萌发活力指数也受到抑制。在相同盐浓度情况下,宽叶独行菜的种子萌发率和萌发活力指数远高于拟南芥。宽叶独行菜种子萌发阶段可耐受盐浓度范围为0-200mmol/L,而拟南芥种子萌发可耐受的盐浓度范围为0-100 mmol/L。在较高浓度的NaCl胁迫后宽叶独行菜仍然保持较高的种子萌发率和萌发活性,而拟南芥种子却几乎不能萌发。实验研究了不同浓度NaCl胁迫下宽叶独行菜的生理响应。结果表明,随着盐浓度的升高,干扰了植物体内的离子平衡,趋势是叶片中的Na+含量不断上升,而K+含量则不断下降,K+/Na+值逐渐降低。在盐胁迫处理之后,宽叶独行菜的叶片相对含水量下降,蒸腾速率和光合速率下降,叶片中叶绿素含量降低,叶片变黄,根系生长受到抑制等。实验还通过与盐芥和拟南芥相对比,结果显示,在盐胁迫处理下,宽叶独行菜表现出良好的耐盐性,拟南芥对盐胁迫最敏感,耐盐性最差。本实验以宽叶独行菜的种子、子叶作外植体,以附加30.0g/L蔗糖和7.0g/L琼脂的MS培养基为基本培养基。实验目的是希望发现一个宽叶独行菜的组织培养的优化体系。不同组合的生长调节剂(6-BA、2,4-D、NAA、ZT、IAA )被用来进行愈伤组织和不定芽的诱导。结果表明,激素对子叶切块愈伤组织诱导的影响是很明显的。2,4-D对于愈伤组织不定芽的诱导是必不可少的。在不添加2,4-D的培养基中,外植体的愈伤组织诱导率很低,并且需要诱导很长的时间。在添加2,4-D的培养基中,外植体愈伤组织的诱导率几乎达到了100%,但2,4-D浓度过大会导致愈伤组织变成黄色,这样很不利于芽的诱导,适宜的2,4-D浓度为0.5 mg/L。诱导不定芽再生的激素以BA1mg/L+NAA 0.25mg/L为宜。此外,NAA对生根有明显的促进作用。更多还原

【Abstract】 Lepidium latifolium L. is widely distributed in drought and saline soils of northern and northern-western China, it is also distributed in the western United States, coastal New England, Mexico, Canada and Australia, and in some contries it is treated as an invasive exotic weed. This weed is native to southeastern Europe and is extremely competitive in many habitats, especially in wetlands and riparian areas. Lepidium latifolium L. exhibits a wide range of ecological amplitude of adaptation to different environmental factors. Current researches about it are mainly focused on its flooding tolerance, and its habitats in China implies that it is vet adaptive to drought, salt, both low and high temperature. So, it may have important scientific significance to study is universal stress tolerance and the corresponding mechanism.In this paper, L. latifolia , which was collected from drought and salty soils of Qinghai desert area, is used as research materials, and foundmental physiological research on its salt and drought tolerance were carried out. In order to establish a transforming protocol, tissue culture and regeneration system is also optimized.This study was conducted to evaluate the effect of salinity on the germination. Based on the results of the experiment, germination tendency and germination percentage decreased with increased salt concentration, the germination vigour index was also inhibited. But in the same salt concentration, both germination rate and germination activity of Lepidium latifolium were much higher than that of Arabidopsis thaliana. L. latifolia can suffer salinity range of 0-200 mmol/L in germination period, and A. thaliana can only survive salinity range of 0-100 mmol/L. At higher concentrations of NaCl stress, L. latifolium remained high germination rate and germination activity, while almost no seed germination of Arabidopsis thaliana.The effects of different NaCl concentration on growth of seedling were investigated. The results showed that with the increasing salt concentration, the ionic balance in plants was disturbed.The trend is the Na+ content of leaves was increasing, while the K+ content of leaves was declining, K+/ Na+ was decreased.Under salt stress, the liquid water content of leaves was decreased, transpiration rate and photosynthetic rate were decreased, the chlorophyll content of leaves was also decreased and the leaves were yellowing. Compared with Thellungiella halophila and Arabidopsis thaliana. Lepidium latifolium showed high salt tolerance in the experiment.In this experiment, in vitro plantlet regeneration of Lepidium latifolium L.was investigated by using seeds and cotyledons as explants and MS medium supplemented with 30.0g / L sucrose and 7.0g / L agar as basal medium. The aim of this study was to develop an efficient tissue culture system for this species. The composition of plant growth regulators(6-BA, 2,4-D,NAA , ZT, IAA)was used for the callus induction and the shoot induction.The results show that the impact of hormone on callus induction from cotyledon is obvious. Inducing callus formation with 2,4-D was an absolute requirement for shoot regeneration to occur.Without added 2,4-D in the medium, explant callus induction rate is very low, and needed a very long time to induct. Adding 2,4-D in the medium, the explant callus induction rate was almost 100%, but the excessive concentration of 2,4-D leaded the callus became yellow, so it is not conducive to shoot induction, the suitable 2,4-D concentration was 0.5 mg/L. The best rate of shoot induction was BA1mg / L + NAA 0.25mg / L . In addition, NAA was significant for the root induction.更多还原