【作者】 崔秀敏；

【导师】 王秀峰；

【作者基本信息】 山东农业大学 ， 园艺学， 2003， 博士

【摘要】 番茄（Lycopersicum esculentum Mill.），茄科番茄属一年生作物，原产热带南美洲地区，根系比较发达，分布广而深。主根受伤后，易生侧根，适应性广，是国内外工厂化穴盘育苗数量最大的蔬菜作物。甜椒（Capsicum annuum L.），茄科辣椒属一年生作物，原产中美及南美湿热带地区，根系不发达，根量少，入土浅，主要根群分布在土表10cm～15cm的土层内，在不良育苗及栽培条件下，根系极易遭到破坏。甜椒既不耐旱，也不耐涝，单株需水量并不太多。由于根系不太发达，因此，对水分要求更加严格。它是工厂化穴盘育苗数量仅次于番茄的蔬菜作物。本研究以上述两种生物学特性不同的蔬菜作物为试材，研究了不同供水下限（RWC分别为90%、75%、60%、45%、30%）对番茄、甜椒生长发育及某些生理生化特性的影响，对不同供水状况下的番茄、甜椒穴盘苗的壮苗指标、物质积累与分配、营养代谢、C、N代谢、渗透调节及光合补偿效应之间的关系进行了分析和探讨。主要结果如下：1. 一次性缺水-复水过程中，随基质水分减少，叶片相对含水量、渗透势、饱和渗透势均逐渐降低，相对电导率、渗透调节则逐渐增高。番茄、甜椒对基质水分变化的反应有所不同，番茄自身含水量较低，水分胁迫时RWC变化较小，而甜椒变幅相对较大，这正使得在同等水分亏缺条件下，番茄叶片能够在较高的RWC下，保持较高的代谢活性，减小质膜伤害；番茄、甜椒对水分亏缺酶反应机制有所不同，POD、SOD、CAT三种活性氧清除酶活性均随水分减少而升高，甜椒酶反应比番茄敏感。三种保护酶中，POD、SOD比CAT活性较高，SOD对水分亏缺最敏感；渗透调节物质中，游离氨基酸、脯氨酸对基质水分变化反应最敏感，随水分减少急剧上升，复水后大幅下降；可溶性蛋白在番茄叶片中以分解为游离氨基酸的形式参与渗透调节，在甜椒叶片中，可直接作为渗调物质。随着基质水分的减少，可溶性糖含量升高，虽然不像游离氨基酸那样显著，但它基数总量大，在渗透调节中也起着重要的作用。复水以后，所有处理的渗调物质含量均有不同程度下降。<WP=9>2. 基质供水减少显著降低番茄、甜椒幼苗根、冠的生长发育，改变干物质在根冠间的分配比例。不同供水状况对根冠功能及结构的影响大致可用功能平衡理论加以解释，即供水量愈少，根冠功能愈差，净光合愈少，根冠生长量愈低。而功能面积减少，进而又影响到根冠干物质生产能力及功能结构建造。番茄、甜椒叶、茎的生物学产量下降大于根系，叶面积和根重是对水分变化最为敏感的指标，番茄以主根为主，甜椒以侧根为主。供水减少使各种以生物学产量为基础的壮苗指数均降低，但和植株抗性相关的指标（如水力构型参数、比叶重等）呈上升趋势，30%供水下限处理，有所下降。60%供水下限处理的番茄和60%、75%供水下限处理的甜椒开花时间均比对照提早2～7天，比30%供水下限处理提早了14天左右。综合番茄、甜椒生长发育，结合主成分分析、灰色系统理论分析、通径分析，初步筛选出壮苗指数：番茄：1.（茎粗/株高）*总重 2. 生长函数ln(G)。甜椒：1.（根/冠+茎粗/株高）*总重 2.（根/冠）*总重3. 基质供水减少使番茄叶片N含量下降，甜椒叶、茎N含量升高，这种差异性只有45%～30%供水下限处理表现比较明显。供水减少增加了N在番茄茎中分配比例，降低了在叶、根中的分配比例。甜椒整株N素的降低主要是由于茎根总量减少所致，甜椒叶N分配比例上升，茎、根N分配比例下降；基质供水状况对番茄P的影响主要是降低了其在叶、茎、根中的含量，对甜椒主要是改变了P在叶、茎、根中的分配，对其含量影响较小。番茄叶、茎随供水减少大量积累K+，甜椒K+含量受供水影响较小，叶片、根系有轻微上升。K+可能在番茄渗透调节中起着重要作用，且这种渗调作用主要发生在叶、茎。基质供水减少主要促进番茄K+由根系向地上部运输，造成K+在叶、茎中大量积累；番茄、甜椒Ca含量随供水减少而降低，但变化幅度不大。供水减少使番茄、甜椒Ca倾向于叶、根分配；除30%供水下限处理番茄叶片Mg含量显著升高外，番茄茎、根Mg含量随供水减少呈现先增高，后降低的趋势，轻中度缺水有利于茎、根Mg含量提高，较为严重的缺水反而促进叶片Mg含量提高，甜椒Mg含量受水分影响较小。30%的供水下限处理番茄叶、茎、根Fe含量急剧上升，甜椒叶片、茎Fe含量随供水减少呈下降趋势，较为严重的缺水条件下，甜椒根系有积累Fe的现象。番茄、甜椒Mn、Cu、Zn含量随供水减少均呈下降趋势，其中Zn下降比例最大。缺水使番茄Mn倾向于茎、根分配，而Cu较多向叶片分配。严重缺水条件下，番茄、甜椒根系有积累Mn、Cu、Zn的现象，可能与向上运输受阻或抗氧化酶促系统启动有关。4. 番茄、甜椒叶片可溶性糖、还原糖含量均随供水减少而上升，二者既可作为C代谢原料，又可以作为渗透调节物质调控细胞内渗透势，其含量增加可以增强逆境适应能力，维持正常代谢。番茄叶片淀粉含量随供水减少而增加，甜椒减少，同总碳水化合物变化趋势一致，很大程度上反映了碳水化合物的积累状况，并且对壮苗有着直接的正向作用。番茄、甜椒非蛋白氮含量随基质供水减少而上升，蛋白氮含量则下降。蛋白氮?更多还原

【Abstract】 Tomato (Lycopersicum esculentum Mill.), belongs to Solanaceae, Lycopersicon，annual vegetable, originates from tropical South America. Its root is strong, extensive, widespread and deep. The lateral root easily regenerates after basal root injured, therefore, tomato has high acclimatization to environment. Tomato nursery area in potting seedlings is the most.Sweet Pepper (Capsicum annuum L.), belongs to Solanaceae, Capsicum, also annual vegetable, originates from Central America and tropical South America. Sweet pepper root is relatively weak, little, and shallow, and mainly allocates 10~15cm deep layer in soil. Under bad nursery and cultural surroundings, root is readily injured. Sweet pepper neither endures drought nor waterlog, not too much water need as well. Since sweet pepper root is not strong enough, consequently strict in water supply. Its nursery area is only less than that of tomato.This experiment used the above two vegetables（tomato and Sweet paper）as material, which are largely different in biological characteristics. We investigated the changes of growth, development, and some physiological, biochemical characteristics under different floor level of water supply in media (RWC is 90%, 75%, 60%, 45%, 30% respectively), and discussed the relation among vigorous index, material accumulation and allocation, nutrition metabolism, carbon and N metabolism, osmotic adjustment and photosynthesis of tomato and sweet pepper seedlings, The main results are as below:1. During transient stress-rewatering, the less water supply, the lower RWC, osmotic potential, saturated osmotic potential, the higher osmotic adjustment and injury degree at the same time. Tomato and sweet pepper had different reaction towards water changes in media. Water content in tomato leaf was relatively lower, so that RWC change was less than sweet<WP=12>pepper towards water deficit, which made tomato keep higher metabolic activity, and reduced injury degree; Enzyme reaction metabolism had some difference between tomato and sweet pepper. The activity of POD、SOD、CAT in tomato increased with decrease of water supply, and of which were more sensitive in sweet pepper. Among the above three protective enzymes, POD and SOD had higher activity than CAT, and SOD was the most sensitive to water deficit; Of all the osmotic solutes, free amino acid and proline were the most sensitive to water change, and their content sharply increased with less water supply, then rapidly reduced after rewatering, basically recovered to the level of CK; Soluble protein might be replaced by free amino acid in tomato to play osmotic role, but it directly worked in sweet pepper. Unlike amino acid, soluble sugar content was basally higher; therefore it possibly made a more important role to osmotic adjustment. After rewatering, osmotic solutes in all treatments reduced to some extent differently.2. Less water supply significantly inhibited growth and development of tomato and sweet pepper seedlings, and changed attribution percentage of dry mass between root and crown. The effect of different status of water supply on function and structure in root and crown could be explained with Function Balance Theory. Namely the less water, the worse function of root and crown, the less net photosynthesis, which led to worse growth and development, and more affected dry matter productivity and function creation. The dry matter of leaf, shoot reduced more than of root. Root and leaf area were the most sensitive indexes to water change, and tomato give priority to basal root, pepper to lateral root. Less water supply reduced all the vigorous indexes based dry matter, but increased endurance indexes (for instance, water architecture features, specific leaf weight et al), and yet in T5 had a little reduction. The anthesis of T3 tomato and T2, T3 sweet pepper was earlier 2~7 days than CK, 14 days than T5. Considering both growth and development, synthesized major constitutes, path analysis, gray systemic theory, we preliminarily screened the vigorous indexes: Tomato: 1.更多还原