【作者】 闫志利；

【导师】 牛俊义；

【作者基本信息】 甘肃农业大学 ， 作物栽培学与耕作学， 2009， 博士

【摘要】 土壤水分是限制干旱地区农业生产与作物布局的主要生态因子,揭示作物对水分胁迫的响应机制及复水效应,对选育作物新品种、建立节水高产栽培技术具有重要意义。本试验于2008年3～8月在甘肃农业大学农学院实验基地进行,采用盆栽土培人工控水法,模拟水分胁迫和复水生境,设定了水分胁迫及复水时期、水分胁迫程度及历时(持续时间)等处理,通过测定水分胁迫及复水条件下豌豆生长形态及相关生理、生化指标,系统研究了豌豆对土壤水分胁迫的响应和复水效应。1.水分胁迫导致豌豆植株外部形态发生变化,并存在滞后效应。复水可产生补偿效应。各生育时期水分胁迫均导致株高降低,分枝数减少,主茎、主根变细,叶面积减小,主、侧根伸长,侧根数增加,随水分胁迫程度加重和胁迫历时延长变化量增大。苗期水分胁迫对豌豆外部形态的影响最大,花期次之,灌浆期最小;复水对水分胁迫引起的豌豆植株外部形态变化产生补偿效应,苗期补偿效果最好,花期次之,灌浆期最差。复水在一定程度上减弱了水分胁迫对主、侧根伸长及侧根数的促进作用。2.水分胁迫导致豌豆冠层干重降低、根部干重增大、根冠比提高,并存在滞后效应。复水能有效促进根冠协调生长。水分胁迫没有改变根、冠干物质积累的总趋势,但导致豌豆侧根数增多、侧根总长增加、根系生长量加大,株高降低、分枝数减少、主茎变细、叶面积减小、冠层干重降低。复水对苗期轻度胁迫处理根冠比可产生超补偿效应,对花期轻度胁迫5d处理根冠比可产生等量补偿效应,对苗期、花期重度胁迫处理和灌浆期各胁迫处理根冠比产生等量补偿效应,集中体现在促进了根冠的协调生长。3.水分胁迫导致豌豆根系活力降低,离体叶片保水力及叶绿素含量发生变化,根系总吸收面积、活跃吸收面积和活跃吸收面积率均降低,影响了根瘤的生长。复水可产生补偿效应。在水分胁迫下,豌豆各生育时期根系活力降低,随着水分胁迫强度加重降幅增大。苗期复水可产生超补偿效应,花期和灌浆期可产生等量补偿效应;重度水分胁迫引起离体叶片保水力发生显著变化,复水可产生等量补偿效应;苗期和花期豌豆在水分胁迫下叶绿素含量均增加,叶绿素a含量和叶绿素b含量的变化幅度不同。灌浆期水分胁迫导致叶绿素a含量和叶绿素b含量以及叶绿素总量降低,复水产生等量补偿效应或超补偿效应;水分胁迫导致各生育时期豌豆根系总吸收面积和活跃吸收面积、活跃吸收面积率降低,复水可产生部分补偿效应;水分胁迫导致豌豆根瘤个数下降,苗期和花期最大根瘤直径增大,灌浆期最大根瘤直径缩小,复水促进了根瘤的生长。4.水分胁迫均导致豌豆叶片ABA、IAA含量增加,ZT、GA含量降低,各种内源激素比例发生变化,复水可产生补偿效应。水分胁迫对豌豆各种内源激素含量的影响存在滞后效应,复水的补偿效应因豌豆的生育时期、水分胁迫强度和历时不同而不同。复水5d对部分内源激素含量产生部分补偿效应,复水10d时可产生等量补偿效应。复水对水分胁迫引起的各种内源激素比例变化产生部分补偿效应。5.水分胁迫影响了豌豆保护酶活性、膜脂过氧化程度和抗氧化能力,复水对各种保护酶活性可产生补偿作用。水分胁迫导致苗期和灌浆期豌豆叶片SOD活性降低、CAT、POD活性提高,随水分胁迫程度加重和胁迫历时延长变化量加大。水分胁迫存在滞后效应。复水对各种保护酶活性均产生补偿效应。水分胁迫导致豌豆叶片过氧化产物MDA含量和叶片质膜透性增加,随水分胁迫程度加重和胁迫历时延长增幅加大。复水5d可产生补偿作用,有效地改善了抗氧化能力。6.水分胁迫导致豌豆细胞可溶性蛋白含量减少、脯氨酸和可溶性糖含量增加,并存在滞后效应,复水可产生补偿效应。各生育时期水分胁迫均导致豌豆叶片可溶性蛋白含量呈现较大变化,复水产生等量补偿效应;水分胁迫均导致各生育时期豌豆叶片脯氨酸含量增加,苗期和灌浆期水分胁迫后复水5d时仍保持增加趋势,复水10d时产生补偿效应。花期轻度胁迫10d和重度胁迫处理复水后先显现超补偿作用,然后再显现等量补偿作用;灌浆期水分胁迫5d导致豌豆叶片可溶性糖含量增加,水分胁迫10d导致可溶性糖含量减少。复水后产生部分补偿效应或等量补偿效应。7.苗期和花期豌豆在土壤水分胁迫下,籽粒干物质的动态变化呈“S”型曲线,各项灌浆参数均发生变化。苗期适度的水分胁迫有利于提高产量。苗期和花期水分胁迫降低了豌豆籽粒干物质积累速率,随着水分胁迫时间延长和胁迫程度加重影响程度加大。重度长历时胁迫对豌豆灌浆特性的影响最大,轻度长历时胁迫次之,短历时水分胁迫影响最小。依据籽粒干物质积累曲线,拟合了苗期和花期水分胁迫下描述籽粒干物质积累过程的三次多项式方程。苗期适度水分胁迫虽降低了百粒重,但有效提高了每株豆荚数和每荚粒数,显著提高了单株产量。更多还原

【Abstract】 Soil water is the main biological factor limiting crop production and distribution in dry area. It is essential to reveal crop’s response to water stress and rewater effect for breeding and setting up hi-yield and water-saving technology system. The pot experiment, characterized by artificial water control and simulated water stress and rewater condition, was conducted in agronomic experimental base of Gansu Agriculture University from March to August, 2008. Several treatments were designed, covering stage of exerting water stress and rewater, water stress degree and duration. Response to changes of soil water and rewater effect of pea were also analysised in this paper basing on determining its growing shape and relevant physiological and biochemical characters.1. Water stress altered the outer characteristics of pea, and existed hysteresis effect. Rewater made compensation effect. Water stress in each stage resulted in a decrease in the height of plant, the number of branches, the diameter of main stem , main root and leaf area, but an increase in the length of main and lateral roots and the number of lateral root, the serious the water stress and the longer the stress duration, the more obvious the variation. The effect of water stress on outer characters of pea in seedling stage topped the list of all period, followed by that of flowering stage, the effect of filling stage was unnoticeable. Rewater made compensation to changes of outer characters caused by water stress, and the compensation appeared the same intendancy of the effect above. Rewater weakened the effect of water stress on main and lateral roots to some extent.2. Water stress decreased canopy weight, increased root weight as well as raised ratio of root to canopy, and existed hysteresis effect. Rewater improved growth between root and canopy. Water stress didn’t change the total intendancy of dry matter accumulation of root and canopy,but increased the number of lateral roots, the length of total lateral roots as well as the mass growth of roots,while decreased the plant height. the number of branch, the diameter of main stem, the leaf area,and the canopy dry weight. In term of ratio of root to canopy under slight stress, rewater made over-compensation effect in seedling stage, and equivalent compensation effect in flowering stage under slight stress for 5d. But equivalent compensation effect in seedling and flowering stage under serious stress and in filling stage under all kinds of stresses, concentrating on the coordination of growth between root and canopy.3. Water stress declined the vitality of root and altered the water retention capacity of leaf and content of chlorophylls. The total root absorption area, active absorption area and the ratio of active absorption area all appeared in declining trend, influencing the growth of root nodule. Rewater produced compensation effect. In any stage,The root vitality showed a decline which rate became larger as water stress enhanced. Rewater made over-compensation effect in seedling stage and equivalent compensation effect in flowering and filling stage. Serious water stress caused significant change in water retention capacity of leaves, and equivalent compensation effect appeared after rewater. The content of chlorophyll showed an intendancy of increase under water stress in seedling and flowering stage, but the content of chlorophyll a and b changed little. In filling stage, water stress led to a decrease in content of chlorophyll a, chlorophyll b and total chlorophyll, and rewater made equivalent compensation or even over-compensation effect. The total root absorption area, active absorption area and the ratio of active absorption area all appeared in a tendency of decrease under water stress, rewater made part-compensation effect. Water stress declined the number of root nodule in each stage, enlarged the diameter of max-root nodule in seedling and flowering stage, and narrowed the max-root nodule diameter in filling stage. Rewater promoted the growth of root nodule diameter.4. Water stress increased the content of ABA and IAA,decreased the content of GA and ZT, and changed the ratio between any two endogenous hormones,rewater induced compensation effect. The impact of water stress on content of each endogenous hormone appeared hysteresis effect. The compensation effect after rewater varied with growing stage, water stress degree and rewater time. For the content of some endogenous hormones, rewater for 5d caused part-compensation effect, and equivalent compensation effect when for 10d. For the change of ratio of any two endogenous hormones, rewater produced part-compensation effect.5. Water stress impacted protective enzymes activity, degree of membrane lipid proximate,and antioxidant capability. Rewater produced compensation to each protective enzyme activity. In seedling and filling stage, water stress resulted in a decline in SOD activity and an increase in CAT and POD activity, which range or rate raised with the stress became more serious and its duration got longer. The stress also had hysteresis effect, and rewater made reasonable compensation to all protective enzymes. Water stress increased the content of MDA and promoted the cell membrane permeability, and the increasing rate of them went up as the stress got more serious and the time got longer. The compensation on MDA and RC emerged within 5d after rewater,thus effectively improving antioxidant capability.6. Water stress caused soluble protein accumulation of pea plant cell decreased and the content of prolin and soluble sugar increased,and appeared hysteresis effect. Rewater made compensation. Water stress caused visible change of soluble protein content in any stage, and rewater produced equivalent compensation effect. Water stress increased the content of prolin in any stage, and the intendancy was kept till to the time after rewater for 5d, and then produced compensation at the time after rewater for 10d. In flowering stage, slight stress for 10d and serious stress treatments firstly showed over-compensation effect after rewater, then the equivalent effect. For soluble sugar in filing stage, 5d stress led to an increase while 10d stress led to a decrease. Rewater induced part-compensation or equivalent compensation effect.7. Under water stress in seedling and flowering stage, grain dry weight changed dynamically in s-like curve. Appropriate degree of water stress was favorite to improving out put. Water stress in seedling and flowering stage declined grain dry substance accumulation rate, and the influencing degree enhanced with the stress time extended and its degree intensified. Serious degree of water stress for long time topped the impact on filling characteristics, followed by that of slight degree for long time. The affection caused by short-time stress was not obvious. A cubic polynomial equation which can give objective demonstration of grain dry substance accumulation in seedling and flowering stage under water stress evolved basing on the grain dry substance accumulation curve. Although appropriate degree of water stress in seedling stage decreased hundred grain weights, the pod number of per hill and grain number of per pod considerably increased, significantly raising the unit yield at last.更多还原