绿优谷对混合盐碱胁迫的生理响应

【作者】 张强；

【导师】 石德成；

【作者基本信息】 东北师范大学 ， 植物学， 2004， 硕士

【摘要】 据统计，全世界约有100 多个国家57 亿亩土地受盐碱化影响，而我国的盐碱地约占全国耕地面积的25%。土壤中盐份过多会危害大多数植物的正常生长，尤其对耐盐性较低的农作物危害更大。随着人口的日益增长，耕地面积不断减少与人口增长的矛盾越来越突出，研究植物在盐碱胁迫下的生理生化变化，开发新的抗盐品种具有重要意义。本实验以C4植物绿优谷幼苗为研究对象，将NaCl、Na2SO4、NaHCO3及Na2CO3按不同比例混合并对苗龄四周的绿优谷幼苗进行混合盐碱胁迫处理。混合盐碱胁迫处理液覆盖了总盐度50—150mmol/L，pH7.12—11.03范围的各种盐碱生态条件。测定绿优谷幼苗存活率等十几项胁变指标，并用数学方法分析盐度、pH等胁迫因素与诸项胁变指标间的相互关系。结果表明：①各胁变值标值随混合盐碱胁迫的增强产生规律性变化，具体来说，存活率、相对生长率、相对含水量、叶绿素含量随之下降；丙二醛、脯氨酸含量随之上升；超氧化物歧化酶活性先升后降，过氧化酶活性呈上升趋势。②混合盐碱胁迫中的盐度和碱度（pH）间具有协同效应，即高盐度与高pH加合后对绿优谷幼苗的危害作用明显大于各因素的单独作用。③由地上部分含水量及SOD活性变化可得，绿优谷幼苗在受较低水平的混合盐碱胁迫时具有一定的适应性。混合盐碱胁迫对作物的伤害不同于NaCl等单纯盐或碱的胁迫，并且从盐分组成上也更符合天然盐碱地的实际情况，因此本项研究结果除了具有理论价值外还可为盐碱地的科学治理提供理论依据。更多还原

【Abstract】 [Abstract] According to approximate estimate, there is 1000 million hectare land which is affected by alkali-saline in more than 100 countries of the world, and that the area of alkali-saline land is 25 percent of the total area of plantation in our country. Superabundance of salinity in the soil imperils the growth of the mass of plants, especially does more harm to croppers which have lower tolerance to salinity. As the rapid increase in population, there are more inconsistencies between the decrease in arable area and the rapid increase in population. So there is the important significance in researching into physiological and biochemical changes of the plants in alkali-saline environment and in exploiting new salt tolerant varieties. Seedlings of millet (Setaria italica (L.) Beauv.) were stressed with 20 kinds of mixed salt which were composed of NaCl, Na2SO4, NaHCO3 and Na2CO3 at various proportions and were different in salinity and alkalinity each other (the range of total salt concentration 50-150mmol/L and pH 7.12-11.03). Ten strain indexes, such as survival rate, were determined. The relationships between the all stress acting factors and each strain index were statistically analyzed.The results showed as follows. ① All the strain indexes were changed regularly with the increasing strength of mixed salt-alkaline stress. Survival rate, relative growth rate, water content, chlorophyll content decreased; proline content，saccharose content, soluble sugar content and MDA content increased; superoxide dismutase activity increased first then decreased, peroxidase activity increased; ② There was a combined effect of salinity and alkalinity in mixed salt-alkaline stress, and this effect was more great than either simple saline stress or alkaline stress.③ According to the changes of water content, surperoxide dismutase activity and peroxidase activity, seedlings of millet showed some adaptability to lower stress of salinity and alkalinity. <WP=6>Mixed salt-alkaline stress was different from simple saline stress, such as NaCl stress, or simple alkaline stress in damaging to crops .The composition of mixed salt-alkaline was more close to natural salt-alkaline soil, so that this research can contribute to improve the salt-alkaline soil.更多还原