【作者】 孙艳琦；

【导师】 冯浩； 刘福来；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2013， 博士

【摘要】 淡水资源短缺是限制农业生产的主要因素，在我国的一些干旱与半干旱地区这一问题尤为突出，如何提高灌溉水利用效率，使每一滴水生产出更多更好的粮食，是保证我国粮食安全和食品质量的有效途径。本论文以温室盆栽番茄（Solanum lycopersicum L.）为试验材料，在开花/初果到果实成熟期实施非充分灌溉（分根区交替灌溉和常规亏缺灌溉，以下用PRD和DI表示）和三个施Ca水平处理（即每千克土壤施用0、100和200毫克钙，以下分别用Ca0、Ca1和Ca2表示），探讨不同施肥与灌溉处理及它们的交互作用如何影响叶片和根系的生长，叶片水分关系特性，干物质重，植株不同器官N、P、C含量，¹⁵N、¹³C自然同位素丰度和植物N、P利用效率；叶片和根系水分状况，气孔导度，木质部汁液脱落酸和离子浓度，果实、叶、茎和根中K、Ca、Mg含量及其在各器官中的分配，果实蒂腐病发生率；果实硬度，果实干物质含量，果汁pH，TSS含量，果汁中还原糖、有机酸以及矿物质含量。具体结果如下：（1）研究了三个施Ca水平下，非充分灌溉制度（PRD和DI）对番茄叶水势，作物生长，植株不同器官N、P、C含量，¹⁵N、¹³C自然同位素丰度(¹⁵N和¹³C)及植物N、P利用效率的影响。与DI相比，PRD维持了更好的叶片水分状况。不考虑两种灌溉处理，与Ca0和Ca1比较，Ca2植物的叶渗透势显著更高，但叶片膨压显著更低。在Ca1和Ca2水平下，PRD显著提高了叶片伸长生长。PRD和DI处理的根长和根表面积相同；比较三个施Ca处理，Ca1最大，Ca2其次，Ca0最小。灌溉和施Ca处理不影响作物地上部分的干重，但Ca1和Ca2的根干重显著高于Ca0。植物中的N、P含量不受任何处理影响，只有根中的P含量随着施Ca水平的增加而减少。PRD处理的叶C含量显著高于DI处理，而茎中C含量与这相反。根和果实中的C含量不受灌溉影响，但受施Ca水平显著影响。研究发现，在番茄茎和果实中，PRD比DI植株有稍高的¹⁵N。施Ca处理对叶和茎¹⁵N没有影响，但显著影响了根和果实中的¹⁵N，即Ca1与Ca2处理的¹⁵N显著高于Ca0处理。另外，在叶片和果实中¹⁵N显著高于茎和根中。在番茄叶片中，与DI处理相比，PRD显著降低了叶片¹³C；但在果实中，PRD有提高果实¹³C的趋势。施Ca水平以及灌溉与施Ca水平交互作用对番茄各器官中¹³C没有影响。值得注意的是叶片中¹³C比其它器官中¹³C更低。植物N、P利用效率不受任何处理的影响。本研究结果表明，和DI相比，PRD更好地维持植物水分状况和叶片的伸长生长，但这些影响没有提高植物干重，N、P积累，水分和N、P利用效率。（2）研究了三个施Ca水平下，非充分灌溉制度（PRD和DI）对番茄蒂腐病（Blossom-End Rot,简称BER）发生率的影响。结果表明，BER发生率不受施Ca水平影响，但受灌溉处理影响显著。与DI相比，PRD显著降低了BER的发生率，这与PRD处理下较高的果实Ca含量相关。相对于DI植株，PRD处理的植株中木质部脱落酸（AbscisicAcid，简称ABA）浓度更高，气孔导度更低，植株水分状况维持在较高水平，这些都可能导致果实中Ca含量的增加，从而降低了BER的发生。另外，果实中的Mg：Ca比和K：Ca比与BER发生率呈正相关关系，表明除Ca含量外，果实中的Mg：Ca比和K：Ca比对BER的发生也有显著影响。（3）研究了三个施Ca水平下，非充分灌溉制度（PRD和DI）处理对番茄果实品质的影响。结果表明，灌溉和施Ca处理对番茄产量、植物用水量、水分利用效率（Water UseEfficiency,简称WUE）、果实数量和果实大小没有显著的影响。然而，与DI处理相比，PRD显著增加了果汁中的总可溶性固形物（Total Soluble Solid,简称TSS）、还原糖（葡萄糖和果糖）、有机酸（柠檬酸和苹果酸）及矿物质（P、K和Mg）含量。尤其是在Ca2下，增加幅度更为明显。而果汁中Ca的含量，既不受灌溉影响，也不受施Ca处理的影响。果实干物质含量与果实硬度之间存在极显著线性正相关关系；与此类似，果实干物质含量和果汁TSS含量也呈极显著线性正相关关系。另外，果汁中的TSS、P、K、Mg含量随着钙肥水平的增加而增加，而果汁中总有机酸含量和总矿物质含量呈正线性相关关系。本研究结果表明，和DI相比，尽管PRD没有显著提高番茄果实产量和水分利用效率，但其显著提高了果实的品质。更多还原

【Abstract】 Shortage of freshwater resource is a major factor constrainting agricultural production.This is particularly true in some drought-prone regions in China. Therefore, how to uselimited irrigation water resource more efficiently, namely to ‘produce more crops per drop’, isessential for ensuring food security in China. In the present study, tomato plants （Solanumlycopersicum L.） were grown in split-root pots in a climate controlled glasshouse. Fromflowering to fruit maturity stages, the plants were exposed to partial root-zone drying （PRD）and deficit irrigation （DI） in combination with three Ca fertilization rates, viz.,0,100, and200mg Ca kg-1soil （denoted as Ca0, Ca1and Ca2, respectively）. The effects of thetreatments on stomatal conductance, plant water relations, leaf and root growth, N, P, Caccumulation and¹⁵N and¹³C natural isotope composition (¹⁵N and¹³C, respectively) inplant organs, plant N and P use efficiencies, incidence of blossom-end rot （BER）, K, Ca, andMg contents and partitioning in plant organs, and fruit quality attributes including fruitfirmness, dry matter content, fruit juice pH, total soluable solid （TSS）, reducing sugars andorganic acid, as well as mineral contents （P, K, Ca, and Mg） were investigated. The resultsshowed that:（1）Compared to DI, PRD tended to better maintain leaf water status. Across the twoirrigation regimes, Ca2plants had higher leaf osmotic potential but lower leaf turgor than didCa0and Ca1plants. Leaf elongation was enhanced by PRD compared to DI in Ca1and Ca2but not in Ca0. Root length and surface area were identical between PRD and DI, and thehighest for Ca1, intermediate for Ca2, and lowest for Ca0. The irrigation and Ca fertilizationtreatments did not affect dry weights of above ground organs; while that for root wassignificantly higher for Ca1and Ca2than for Ca0. N and P contents in plant organs wereunresponsive to the either irrigation or Ca fertilization treatments, only root P contentdecreased with increasing Ca fertilization rate. C content was higher for PRD than for DI inleaf, while the reverse was true in stem. Root and fruit C contents were unaffected byirrigation regime but were significantly affected by Ca fertilization rate. Basically, irrigationregimes did not affect¹⁵N in plant organs but with a trend that PRD plants had slightlyhigher¹⁵N in the stem and fruits. Across the two irrigation regimes, Ca fertilization rate had no effect on¹⁵N in the leaves and stem, but significantly affected it in the roots and fruits,namely root and fruit¹⁵N were significantly higher for Ca1and Ca2as compared with Ca0.In leaves,¹³C was significantly higher for PRD than for DI, whilst the reverse was the casein the fruits. Ca fertilization rate had no effect on¹³C in plant organs of tomato. In addition,neither irrigation nor Ca fertilization treatments affected N and P use efficiencies of tomatoplants. It was concluded that, compared to DI, PRD better maintained plant water status andleaf elongation growth; however, such effects did not bring about increases of plant drybiomass, N, P and C accumulation, and N and P use efficiencies.（2）In comparison with DI treatment, PRD significantly reduced BER incidence in tomatofruits. A greater xylem sap ABA concentration, a lower stomatal conductance, and higherplant water status in the PRD in relation to the DI plants might have contributed to theenhanced fruit Ca uptake, which could have reduced BER development in tomato fruits. Inaddition, besides fruit Ca content, the ratios of Mg to Ca and K to Ca in the fruits wereinvolved in inducing BER in tomatoes. Therefore, under conditions of limited freshwaterresources, application of PRD irrigation could be a promising approach for saving water andfor preventing BER development in tomatoes.（3） Both irrigation and Ca-fertilization treatments had no significant effect on fruit yield,plant water use, and water use efficiency （WUE）, fruit number and fruit size. However, PRDregime significantly increased the TSS, sugars （glucose and fructose）, organic acids （citric andmalate acids）, minerals including P, K, and Mg contents in the fruit juice as compared withthe DI treatment, particularly at high Ca-fertilization rate （i.e., Ca2）, the increase was morepronounced. Whereas Ca content in tomato juice was neither affected by irrigation norCa-fertilization treatments. Across the two irrigation regimes, Ca-fertilization significantlyincreased TSS, P, K, and Mg contents in the fruit juice being that the contents of thoseconstitutes were enhanced with increasing Ca fertilization rate. Collectively, our resultsindicated that even though PRD did not over perform DI in terms of improving fruit yield andWUE, the irrigation treatment significantly increased several fruit quality attributes, resultingin better flavour fruits than the DI practice.更多还原