高加索三叶草与白三叶杂交后代对氮和钾的反应及固氮性研究

发布时间：2018-06-21 07:06

  本文选题：根瘤菌 + F_1代株系　； 参考：《内蒙古农业大学》2017年硕士论文

【摘要】：内蒙古大兴安岭林区分布有逸生型白三叶种群。这个白三叶种群具有优良的环境适应性和固氮能力,已经作为父本材料与高加索三叶草杂交,形成大量杂交后代株系。为了提纯白三叶根瘤菌用于对研究材料进行接种,观察杂种F1代接种根瘤菌后的固氮性,同时试验观察氮钾元素对F1代株系生长的影响,本试验首先对白三叶根瘤菌培养条件(培养基初始pH值、培养温度和摇床转速)进行了筛选,提纯了根瘤菌。根瘤菌培养条件采用单因素和双因素设计,3次重复;氮钾元素处理采用双因素设计,3次重复,分别对F1代株系及亲本进行不同施氮和施钾水平处理,观察不同氮钾水平处理下对植株的生理指标与根系的影响;对F1代株系及2种亲本进行根瘤菌接种试验,将发芽后的种子移栽至灭菌后的蛭石中,分别进行不接种根瘤菌、接种根瘤菌激活和接种根瘤菌不激活3种处理,3次重复,观察3种处理对植株根系及干重的影响,并用元素分析仪测定植株的含氮量,测定是否具有固氮能力。结果表明:1.在单因素处理条件下,白三叶根瘤菌的理想培养条件是培养基初始pH值为7.0,培养温度为25℃,摇床转速为180r/min。在双因素处理条件下,当温度和初始pH值为自变量时,温度为25℃、pH值为7.0时,适宜根瘤菌生长;在转速与初始pH值为自变量时,转速为160r/min、pH值为7.0时,适宜根瘤菌生长;当转速与温度为自变量时,转速和温度分别为160r/min和25℃时,适合根瘤菌生长。2.在不同氮钾元素处理下,植株的生理指标和根系指标会随着施氮量与施钾量的增加先增加后降低,在氮钾元素处理下,植株表现为氮为主要影响因素,亲本对氮钾元素的反应更为强烈。3.随着接种根瘤菌,白三叶根系及干重指标明显升高;在接种根瘤菌处理下,F1代株系及高加索三叶草仍表现为固氮性缺失,白三叶在接种根瘤菌后固氮性增强。
[Abstract]:In Daxingan Mountains, Inner Mongolia, there is an ectogenetic white clover population. This white clover population has excellent environmental adaptability and nitrogen fixation ability and has been used as a male parent to cross with Caucasian clover to form a large number of hybrid progeny lines. In order to purify white clover rhizobia for inoculation, the nitrogen-fixation of F1 hybrids was observed, and the effects of nitrogen and potassium on the growth of F1 strains were also observed. In this experiment, the culture conditions (initial pH value of culture medium, culture temperature and shaking table speed) were screened and the rhizobia were purified. The culture conditions of rhizobia were designed three times by single factor and two factors, and the treatments of nitrogen and potassium were used to treat F1 strains and their parents with different levels of nitrogen and potassium respectively. The effects of different nitrogen and potassium levels on plant physiological index and root system were observed, and rhizobia inoculation test was carried out on F1 strain and two parents. The germinated seeds were transplanted into sterilized vermiculite and inoculated with rhizobia respectively. The effects of three treatments on the root system and dry weight of the plants were observed. The nitrogen content of the plants was determined by elemental analyzer and the ability of nitrogen fixation was determined. The result shows that 1: 1. Under the condition of single factor treatment, the ideal culture conditions for rhizobia were as follows: the initial pH value of culture medium was 7.0, the culture temperature was 25 鈩，

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