两种独行菜种子萌发及休眠的生理特性研究和SRAP体系建立

发布时间：2018-07-18 17:26

【摘要】：独行菜(Lepidium apetalum Wild.)和抱茎独行菜(Lepidium perfoliatum L.)是十字花科独行菜属近缘种植物,为新疆具有代表性的早春短命植物。本课题组前期研究发现二者萌发及幼苗生长阶段对低温的耐受性有明显差异,为进一步了解两种独行菜在种子休眠和萌发阶段的差异性,本研究对二者种子低温层积过程中生理生化特性进行了初步分析,并建立了适用于两种独行菜种子基因差异表达研究的序列相关扩增多态性分析体系(SRAP)。1比较了低温层积处理对两种独行菜种子萌发特性的影响,对层积过程中过氧化物酶(peroxidase,POD)、超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)活性的变化进行了测定。结果显示:抱茎独行菜种子萌发依赖低温层积,而层积处理仅提高了独行菜种子的萌发势;两种种子低温层积过程中相关酶活性均发生变化,但变化趋势不同。实验结果提示两种独行菜种子对低温层积处理具有不同的响应。此外,抱茎独行菜种子不同部位提取物处理白菜种子的萌发实验结果说明抱茎独行菜种子休眠机制可能与其种胚中存在萌发抑制物有关。2利用高效液相色谱测定了两种独行菜种子低温层积过程中赤霉素(GA)和脱落酸(ABA)含量的变化情况。结果显示,二者在层积过程中种子内源激素变化趋势相同:GA含量上升,ABA含量下降;抱茎独行菜种子层积处理前ABA浓度较高,独行菜种子层积处理前GA浓度较高,且独行菜种子在层积过程中激素变化幅度较大。结果提示GA和ABA在低温层积处理解除两种独行菜种子的休眠过程中可能具有重要作用。3研究了外源激素处理对两种独行菜种子休眠与萌发的影响。IAA、NAA可部分解除抱茎独行菜的种子休眠,对独行菜种子萌发则表现抑制作用。GA对两种种子均促进萌发,并且可完全解除抱茎独行菜种子的休眠。6-BA对解除抱茎独行菜种子休眠无作用,对独行菜种子萌发表现两重性。ABA严重抑制两种种子萌发。结果显示两种独性菜种子休眠释放过程对激素的响应各有异同。4为建立适合两种独行菜种子的cDNA-SRAP反应体系,分析了dNTPs、Mg2+、引物、cDNA模板、Taq DNA聚合酶的浓度对扩增结果的影响,并对扩增条件进行了优化。最终确定优化的cDNA-SRAP反应体系为:20μL体系中cDNA模板100 ng,Mg2+浓度1.75 mmol·L-1,dNTPs浓度0.275 mmol·L-1,引物浓度1.0μmol·L-1,Taq DNA聚合酶0.5 U。该体系扩增条带数目较多且较清晰,可用于后续低温层积处理下两种独行菜基因差异表达的研究。
[Abstract]:Lepidium apetalum Wild. And Lepidium perfoliatum L. It is a relative species of Cruciferae, which is a typical short-lived early spring plant in Xinjiang. The preliminary study of our group found that there were significant differences in the tolerance to low temperature between the two species during germination and seedling growth, in order to further understand the differences between the two species in seed dormancy and germination stage. In this study, the physiological and biochemical characteristics of the seeds during their low temperature stratification were preliminarily analyzed. A sequence-dependent amplified polymorphism analysis system (SRAP) was established for gene differential expression analysis of two species of single vegetable seeds. 1. The effects of low temperature stratification on seed germination characteristics were compared. The activities of peroxidase (POD), superoxide dismutase (superoxide) and catalase (cat) during stratification were determined. The results showed that the seed germination was dependent on low temperature stratification, but the seed germination potential was only increased by stratification, and the related enzyme activities of the two seeds changed during the low temperature stratification, but the change trend was different. The results showed that the two seeds had different responses to low temperature stratification. In addition, Germination of Chinese Cabbage Seeds treated with different extracts from Stem Seeds. 2. The dormancy mechanism of Chinese cabbage seeds may be related to the existence of germination inhibitors in their embryos. 2. Two kinds of seeds were determined by high performance liquid chromatography (HPLC). Changes of gibberellin (GA) and abscisic acid (ABA) contents during the low temperature stratification of the seeds. The results showed that the change trend of endogenous hormones in seeds was the same during stratification, the content of GA increased and the content of ABA decreased, while the concentration of ABA was higher before stratification and higher in GA before stratification. In addition, the changes of hormone in the seed of monopodium chinensis were larger during the stratification process. The results suggest that GA and ABA may play an important role in the dormancy process of the seeds of two species of single vegetable treated by low temperature stratification. 3. The effects of exogenous hormone treatment on the dormancy and germination of the seeds of the two species were studied. The seed dormancy of the single stem, On the other hand, GA promoted the germination of both seeds, and completely relieved the dormancy of the seeds. 6-BA had no effect on the dormancy of the seeds. The germination of the two seeds showed duality. ABA seriously inhibited the germination of the two kinds of seeds. The results showed that there were similarities and differences in the responses to hormones in the dormancy release process of the two species. 4. In order to establish a cDNA-SRAP reaction system suitable for the two kinds of seeds, the effects of the concentration of dNTPsMg2, primer cDNA template Taq DNA polymerase on the amplification results were analyzed. The amplification conditions were optimized. The optimized cDNA-SRAP reaction system was determined as follows: the concentration of 100ng / mg _ 2 and primer was 1.75 mmol / L ~ (-1), 0.275 mmol / L ~ (-1) and 1.0 渭 mol / L ~ (Taq) Taq DNA polymerase in 1: 20 渭 L / L system respectively. This system can be used to study the gene differential expression of two kinds of monopodium under the following low temperature stratification treatment because of the large number of amplified bands and the clarity of the amplified bands.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q945.3;Q943.2

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