【作者】 武俊英；

【导师】 刘景辉；

【作者基本信息】 内蒙古农业大学 ， 作物栽培学与耕作学， 2009， 博士

【摘要】 盐渍土壤的生物利用是提高土地利用率、改善生态环境行之有效的措施。燕麦在干旱、半干旱生态环境高度脆弱的地区具有广泛适应能力,是内蒙古的特色作物、绿色保健作物,对盐渍土改良具有很好的作用。本研究通过室内培养皿发芽法、防雨棚盆栽法进行,结合自然盐碱地田间试验法,从燕麦种子的耐盐性差异入手,研究了燕麦幼苗耐盐的生理生化特性,不同品种燕麦对盐胁迫的生长发育及生理生化差异,盐胁迫下营养因子、栽培和耕作措施对燕麦适应性和土壤盐分变化的影响,获得以下主要研究结果:1.盐胁迫对燕麦种子萌发和幼苗生长有明显的抑制作用,对幼苗生长的抑制强于萌发,对根系的抑制强于幼叶。在0.4%盐浓度胁迫下,对燕麦种子萌发和幼苗生长具有一定的促进作用;2.0%是燕麦幼苗生长的临界盐浓度;3.2%是燕麦种子萌发的临界盐浓度。鉴定燕麦耐盐性强弱的适宜盐浓度是1.2%,主要指标是发芽率、发芽指数、简易活力指数、单株干重。供试的36个燕麦品种可分为耐盐型、中度耐盐型和盐敏感型三类,类型间种子盐溶蛋白和α-淀粉酶活性等指标的差异显著。2.不同品种(系)燕麦对盐胁迫的生长发育及生理生化差异较大,随着盐胁迫的增强,对不同类型品种的形态抑制增强,叶片叶绿素含量降低;叶片相对质膜透性、丙二醛含量、游离脯氨酸含量、可溶性糖含量增加;茎叶中Na+含量增加,K+/Na+值下降。中度耐盐类型以上品种可耐0.32%盐胁迫,所有品种均不耐0.68%盐胁迫。皮燕麦与裸燕麦的耐盐差异不明显。3.盐胁迫对燕麦生长和生理特性有较大影响,0.2%含盐量对燕麦生长具有促进作用,燕麦生长可耐0.3%含盐量、出苗的致死盐浓度为1.0%、燕麦产量的极限盐浓度为0.7%;随着盐胁迫的加强,燕麦叶片叶绿素含量降低,光合速率下降,属于非气孔因素造成;盐胁迫下,燕麦幼苗叶片质膜透性增大、过氧化产物和渗透调节物质增加、保护酶活性增强。对盐分胁迫较敏感的渗透调节物质顺序是:游离脯氨酸>可溶性糖>可溶性蛋白、保护酶顺序是:CAT>POD>SOD;燕麦根系对离子吸收和运输具有选择性,SK+,Na+(运输)明显高于SK+,Na+(吸收)。燕麦是通过将Na+贮藏在茎中适应盐胁迫;可反映燕麦幼苗耐盐特性的主要生理生化指标为:相对电导率、丙二醛含量、可溶性糖含量、游离脯氨酸含量、CAT活性、叶绿素含量、Na+含量、Cl-含量、K+含量、K+/Na+值、叶面积、光合速率、产量。4.通过燕麦生长、质膜及K+、Na+含量的研究得出,营养因子氮、磷、钙剂不同调控处理能够促进燕麦植株的生长发育,减弱盐胁迫对细胞质膜的损伤,不同程度增加燕麦植株体内K+含量、减少Na+含量,增加K+/Na+值,增加燕麦产量。燕麦耐盐性最优营养调控组合是高氮(2.00g/盆)低磷(0.65g/盆)加钙(10g/盆)处理(T5),在各处理中,燕麦表现出较强的耐盐性,K+/Na+值和产量最高。5.翻耕、适宜播深、燕麦与其他作物混作、覆盖的栽培耕作措施可有效提高燕麦对盐碱地的适应能力,同时对耕层土壤可起到脱盐作用。通过形态指标、生理指标、K+/Na+值和选择性吸收及运输、产质量分析得出,不同措施的耐盐性表现为:混作>单作、翻耕>不翻耕、覆盖>不覆盖。燕麦与苜蓿混作是盐碱地较好的种植模式,干物质积累迅速、膜损伤较小、叶片叶绿素含量较高,保持了较高的光合性能,产量形成较高,其次是翻耕7㎝播深,不翻耕7㎝播种接近于常规3㎝播种。9㎝和11㎝播深出苗率小于15.0%,不宜在盐碱地采用,覆盖处理的适宜播深为5～7㎝。盐胁迫致使产质量降低的指标顺序是:籽粒产量>鲜草产量>干草产量>粗脂肪>粗纤维。中度耐盐品种内农大莜1号的产质量高于盐敏感品种大燕麦。因此,盐碱地上采用耐盐品种、与苜蓿混作、翻耕7㎝播深和覆盖方法种植,可提高燕麦对盐碱的适应性,降低土壤耕层含盐量。本研究可为盐渍土资源的利用、燕麦的耐盐育种和高产栽培提供理论基础。更多还原

【Abstract】 Saline soil biological utilization is the effective measure to enhance the utilization of land and improve ecological environment. Oat has extensive adaptabilities in arid and semiarid region of high vulnerable ecological environment, and it is the characteristic and green health care crop of Inner Mongolia and can reclaime saline soils. The study through the methods of indoor culture dish germination method, potted in canopy, combined with the natural saline field test method, analyzed on differences of oat seed salt tolerance and studied the physiological and biochemical characteristics of salt-tolerant on oat seedlings, such as oats growth and physiological differences under salt stress of different varieties, nutritional factors, cultivation and tillage measures affected soil salt changes and oats adaptabilities. The main details of the result were as follows:1. Seed germination and seedling growth of oat were inhibitted significantly by salt stress, and compared with oat seedling growth the inhibitory effect was much significant than seed germination, compared with root the inhibitory effect was much significant than seedling. Salt concentration 0.4% had significant synergistic effect on oat seed germination and seedling growth, and salt concentration 2.0% was the critical salt concentration of oat seedling growth, and salt concentration 3.2% was the critical salt concentration of oat seed germination. Salt concentration 1.2% can be used as the optimal salt concentration to identify the oat’s salt tolerance ability, and the main indexes were relative germination rate, germination index, relative simple activity index and total dry weight. The thirty-six varieties of oats can be divided into salt-tolerant, moderate salt-tolerant and non-tolerant types, and the salt-soluble protein andα-amylase activity of three types’seed were different significantly.2.Different varieties of oat growth and physiological characteristics were great difference under salt stress. With the strengthen of salt stress different varieties morphology inhibitory increased, total chlorophyll content decreased; leaves’plasma membrane, malondialdehyde content, praline content, soluble sugar content and Na+ content in stem increased, and K+/Na+ decreased. Moderate salt-tolerant variety can endure salt concentration 0.32%, and all varieties can not endure salt concentration 0.68%. Salt tolerance of Avena sativa and naked oat were not significant.3. Oat growth and physiological characteristics can be affected seriously under salt stress, even salt concentration 0.2% can enhance oat growth. Oat growth can endure salt concentration 0.3%, germination lethal salt concentration was 1.0%, grain yield limit salt concentration was 0.7%; With the strengthen of salt stress, oat leaf chlorophyll content decreased and photosynthetic rate decreased for non stomata factors; Oat seedling leaves’plasma membrane, per oxidation products, osmotic adjustment substances, and protective enzyme activities increased under salt stress. The Orders of protective effects on osmotic adjustment substances were praline >soluble sugar>soluble protein, and the orders of protective enzyme activities were CAT>POD>SOD; Ion absorption and transportation were choosed selectively by oat root, transportation of K+ and Na+ was significantly higher than absorption of K+ and Na+. In order to adapt to salt stress more Na+ was storied in the stems of oats; The main physiological and biochemical indexes which can response the oat seedlings’salt-tolerant traits were as follows, such as relative conductivity, malondialdehyde content, soluble sugar content, praline, CAT activity, chlorophyll content, Na+ content, Cl- content and K+ content, K+/ Na+ value, leaf area, photosynthetic rate and yield.4.Through the study of oat growth, plasma membrane, K+ content and Na+ content, it can be concluded that different regulatory effects of nutritional factors nitrogen, phosphorus and calcium can improve the growth of oat and decrease injure of plasma membrane with salt stress, different degrees increased K+ content and K+/Na+ ratio and yield and decreased Na+ content. The most ability optimal nutrition regulation of oat was the fifth treatment which is high nitrogen (2.00 g/pot) low phosphorus (0.65 g/pot) calcium (10 g/pot). In these treatments, oat had a relatively high tolerance to salt stress, and ratio K+/Na+ and yield were highest.5.Those measures plowing, suitable sowing depth, oat and other crops mixed cropping, cover cultivation can effectively improve the ability to adapt to saline soil and can fall desalination role. Through the analysis of morphological index, physiological indexes, K+/ Na+ value and the selective absorption and transportation, production quality, different treatments showed that mixed cropping>sole cropping, conventional tillage > no-tillage, cover> not covered. Oats and alfalfa mixed cropping was the better planting pattern in saline soil, its dry matter accumulated rapidly, membrane damage was low, leaf chlorophyll content was high, and kept the rapid photosynthetic performance and yield formation was high, next was conventional tillage 7cm, no-tillage 7cm was equal to the conventional tillage 3cm. Conventional tillage 9cm and 11cm emergence rate were less than 15.0%, they were not the suitable patens to plant on the saline soil, cover 5～7㎝ was better. The order of salt stress decreased the quality yield indexes were: hay yield > grain yield >grass yield > coarse fat >crude fiber. The quality yield of Moderate salt-tolerant variety Nei Nong Da You 1 was higher than non-tolerant variety Avena magna. Salt-tolerant variety, oat and alfalfa mixed cropping, conventional tillage 7 cm and cover measures can effectively improve the ability to adapt to saline soil and decrease salinity of cultivated horizon.The research supplied important theoretical basic in saline soil resource utilization, oat salt-tolerant cultivation and salt resistance breeding.更多还原