【作者】 孙志伟；

【导师】 李霞； 蔡庆生；

【作者基本信息】 南京农业大学 ， 植物学， 2009， 硕士

【摘要】 水稻是世界上最重要的作物之一。随着水稻育种研究的两次绿色革命,水稻的群体光能利用率和光合效率都得到了提高,使水稻产量有了显著提高。但是在水稻育种中仍然存在着很多问题,如：抗性差、适应性不强等,这就极大地限制了水稻良种的推广。目前水稻对于单一环境胁迫的响应和适应的研究已经有很多的报道,并且一些研究结果在水稻适应性育种中起到了重要的指导作用,但是对多种环境适应性的联合筛选研究尚不多,而且已报道研究都是对于单一环境条件的离体条件下的研究结果,与可直接应用于大田条件下大量水稻材料的适应性筛选还有相当的距离。本文通过不同水稻材料对高、低光强、干旱、以及不同氮素水平的批量筛选,发现水稻材料在不同的环境条件下叶绿素、叶色以及根茎比等生长及生理指标对于其环境适应能力以及抗性有着很好的指示作用,具体表现如下：1、高、低光强筛选及可靠指标的确定：叶绿素含量下降程度与光氧化程度呈现负相关性,光氧化级别与叶绿素含量下降程度的相关系数为-0.609(p=0.000),Fv/Fm的下降程度与光氧化级别的相关系数为-0.282,均呈极显著负相关；大田叶绿素含量与人工遮阴处理前后干物质下降量的相关系数为-0.329,也存在着显著的正相关2、干旱筛选：按照不同萎蔫程度将水稻材料耐受干旱能力分为四级：1级为全株萎蔫,2级为叶片萎蔫,3级为叶片1/2萎蔫,4级为生长良好。同时按照复水后恢复情况将水稻的生长状况也分成4级：1级为全株死亡,2级为只有茎存活,3级为小于1/2叶面枯萎,4为生长良好。通过对大田条件下开花后生长的水稻材料叶片的SOD、POD、CAT活性以及MDA含量的测定发现大田条件下其各相关生理指标分型不明显。可见,水稻对干旱的响应是个复杂的过程,特别对于耐旱能力中等的材料,不同生育期的生长和生理指标有交叉,需要进一步的生理研究加以阐明。3、不同氮素浓度的筛选：通过对大量水稻材料的不同氮浓度处理(57.2mg/L114.3mg/L、228.6mg/L, NH4NO3),通过对根茎比、干物质重进行相关性和聚类分析将水稻材料分为6类。在6类中每个选取5个材料进行N-free处理,并在处理前后分别测定了SPAD、NRA.可溶蛋白含量及Rubisco含量等生理指标,结果显示不同环境氮浓度前期处理影响水稻在N-free处理下的响应,同时水稻的SPAD值与Rubisco含量和可溶蛋白含量有显著的相关性。总体而言,虽然不同的环境条件对水稻的影响是不同的,但是其对水稻生长和生理的影响有类似的表现,虽然没有筛选出对各种逆境都有明显广适性的水稻材料,但其中叶片的叶绿素含量、Fv/Fm以及Rubisco含量等指标可作为水稻对高低光强、干旱以及不同氮素适应性筛选的重要指标。本研究对不同水稻组合对不同逆境适应性的筛选有一定的参考意义。更多还原

【Abstract】 With the twice green revolution of rice breeding which is the most important crop of the world, the production of rice has been improved notability by the enhancement of group utility rate of luminous energy and photosynthetic efficiency. But there are still many problems in rice breeding, such as:lack of resistance, weakness of adaptability, etc. It’s a restriction for the extending of improved variety of rice seed. In one hand, there are lots of reports about researches of the tolerance and adaptability to different environment and some of the reports have been used in rice breeding, but the researches aren’t useful in wild condition because they were taken in vitro. In another hand, there are less of the researches about tolerance and adaptability to total environment and the index about these researches. We found that the content of chlorophyll, leaf color(SPAD) and the ratio of root/shoot had a good prescription to tolerance and adaptability to total environment of rice by the selection of different of rice materials under different light, water and nitrogen condition in this research. The main results as follow:1. The index of selection of high and low light:there was a significant positive correlation with the degrees of photoinhibition between the decreases content of chlorophyll, Fv/Fm and the degrees of photoinhibition, the correlation coefficient of the decreases content of chlorophyll and the degrees of photoinhibition is-0.609(=0.000), the correlation coefficient of the decreases Fv/Fm and the degrees of photoinhibition is-0.282; there was a correlation(-0.329) between either the content of chlorophyll in the field condition or the changes of them and the decrease of dry weight after shading treatment, so the content of chlorophyll can be used as a parameter of shading and high light sensitivity.2. The selection of drought stress:the germination rate of rice has evident differentiation when treated with drought stress. In comparison with the germination rate of dry rice, we can make certain that the rice which germination rate exceeded 50% and grow well in both drought and wet conditions were high-anti-drought rice. By relativity analysis, R/S ratio in germination period was also a good screening index that has some relativity with germination rate. By clustering analysis, we could classify the different rice into six degrees on anti-drought ability.3. The selection under different nitrogen concentration:by different nitrogen concentration (57.2mg/L、114.3mg/L、228.6mg/L, NH4NO3) and N-free treated to hybrid rice materials, R/S ratio, dry weight were measured at the end of different nitrogen concentration treatment, after correlation and cluster analysis, the rice materials were clustered to 6 series according the different adaptability to nitrogen, then 5 of each series were chosen treated with N-free(no N in the solution) in order to illustrate the different response to N starvation of rice which is grown under different N concentration. SPAD, NRA, the content of Rubisco and protein were measured before and after N-free treatment. The results showed NRA, the content of Rubisco and protein showed that different environment N concentration can change the response of rice to N-free treatment:lower N concentration can enhance the adaptability of rice to N starvation and there were a significant correlation ship between SPAD either the content of Rubisco or protein.In conclusion, rice is influenced by environment at different way, but there are something similar in response in its growth and physiological change. In this research, we did not find a metarial, but all the content of chlorophyll, SPAD, Fv/Fm and the content of Rubisco can be used as index to the response of rice to high/low light, dry stress and nitrogen stress in rice wild condition breeding.更多还原