【作者】 黄昀；

【导师】 李道高；

【作者基本信息】 西南农业大学 ， 果树学， 2003， 博士

【摘要】 柑桔是世界上最重要的果树作物之一。我国是柑桔的原产地，柑桔栽培历史悠久。2001年，我国柑桔栽培面积居世界首位，总产量居世界第三。柑桔生产已经成为我国南方农村的支柱产业之一，对促进农村经济、社会发展以及山区农民脱贫致富起到了重要作用。柑桔也是重庆市栽培的重要水果，重庆市三峡库区河谷地带是柑桔特别是甜橙的最适宜生态区，被农业部确定为长江上—中游优势柑桔带。 随着我国国民经济的高速发展，人民生活水平的不断提高，人们对食品的安全卫生等提出了更严格的要求，果品也不例外。加入WTO之后，重庆市以柑桔为代表的果品业，客观上已登上国际竞争的大舞台。面对外国果品和本国果品的激烈竞争，有机果品、绿色果品、无公害果品的生产销售已成为国内外果品业的时尚。在这个新形势下，为了使重庆市三峡库区柑桔产业做大做强，在提高单位面积产量、改善果品质量的同时，还必须在防止环境污染、农业自身污染，生产有机果品、绿色果品、无公害果品等提高果品的食用安全性方面下功夫。这是打破发达国家或地区果品市场设置技术壁垒，提高我国和重庆市柑桔果品市场竞争力的战略性措施。在果树生态环境质量的污染与防治、果树对土壤重金属的吸收富集能力、重金属在土壤—果树系统中的分布等系统性的基础研究，目前在国内尚未见报道。针对这一薄弱环节，本文采用痕量、微量等现代分析技术，研究重庆三峡库区土壤—柑桔系统重金属生态行为，主要对重庆三峡库区柑桔生态环境质量、土壤—柑桔系统重金属分布特征、柑桔不同部位、不同品种重金属富集能力进行研究和探讨。研究区域为奉节县、江津市、忠县和长寿区的柑桔主产地。本项目的研究成果，将为三峡库区柑桔产业的可持续发展，为重庆市绿色柑桔果品和一l无公害柑桔果品的生产与发展等提供新的生态学和生物学依据。主要研究结果如’卜: l、柑桔园生态环境质量研究与评价 柑桔园土壤重金属平均含量的大小顺序为锌>铬>镍>!{1司>错>砷>镐>汞。柑桔园黄壤铜、锌、错、锅、镍、汞、砷、铬8种重金属的储量均大于紫色土。柑桔园灌溉水重金属平均含量的大小顺序为锌>六价铬>铜>镍>砷>错>汞>镐。 柑桔园土壤重金属平均含量与全国、全球土壤重金属平均含量的对比分析结果表明，柑桔园土壤锌、铅、汞、砷的平均含量低于全国平均值，锅含量是全国的2.16倍，铬含量与全国接近。柑桔园土壤铜、铬平均含量低于全球平均值，锌、福含量明显高于全球，锅含量是全球的3.5倍，错、砷的含量与全球接近。以GB15618一1995《土壤环境质量标准》二级指标为评价标准，以单项污染指数和综合污染指数为评价方法，对全区柑桔园土壤各重金属元素含量的平均值进行评价，评价结果为研究区域柑桔园土壤重金属单项污染指数均小于!.0，综合污染指数小于0.7，污染等级为安全，污染水平为清洁。这说明，重庆三峡库区柑桔产地生态环境质量良好，发展绿色柑桔果品生产潜力巨大。但土壤中镍、福含量相对较高，接近标准限量值，应引起重视。 以NY/T 391一2000《绿色食品产地环境技术条件》为评价标准，对每个土壤样和灌溉水样逐一进行评价，评价方法采用单项污染指数法和综合污染指数法，土壤评价参数为铅、锅、汞、砷、铬、铜，灌溉水评价参数为pH值、铅、锅、汞、砷、六价铬。评价结果，所有样品单项污染指数均小于I，除3个水样和l个土样综合污染指数评价结果为尚清洁外，其余样品均为清洁。评价结果表明，研究区域柑桔园的生态环境质量符合NY/T 391一2000 《绿色食品产地环境技术条件》标准要求，适宜发展绿色果品生产。 2、柑桔园土壤重金属行为特征研究 柑桔园同层土壤有效态重金属元素间的相关性分析结果表明，有效态铜、锌、铅、锅相互之间在O一30cm和30一60cm土层均显著相关，说明柑桔园土壤中有效态铜、有效态锌、有效态铅、有效态锅的释放机理是相同的，环境因素对它们的影响是一致的。有效态铜、锌、铅、福相互之间相关性在30一60cm土层强于0一30cm，说明0一30cm土层受环境影响强于30一60cm土层。柑桔园不同土层重金属含量相关性分析结果表明，30一60cm与O一30cm土层重金属铜、有效态铜、锌、有效态锌、铅、有效态铅、福、有效态锅、镍、汞、砷、铬的相 一2-关系数分别为0.583’‘、0.659”、0.752”、0.882’‘、0.225、0.725”、0.247、0.970’‘、0.752”、0.802，，、0.917，’、0.“了，，其中除铅、镐无显著相关性外，其余元素在两土层间都极显著相关，这体现了土壤与成土母岩之间化学成分的继承性。土壤pH值与有效态重金属含量间的相关性分析结果表明，柑桔园土壤pH值与有效态铜、锌、错、福的含量在O一30cm和30一60cm土层呈负相关或显著负相关，即土壤pH值越低，土壤中铜、锌、铅、镐的有效态含晕就越高。这说明低pH值有利于土壤重金属解吸的原理在土壤一柑桔系统中也是成立的。 柑桔园土壤重金属有效态含量与全量相关性分析结果表明，柑桔园土?更多还原

【Abstract】 Green food and organic food production has been more and more important for people since economic development and live level increase. China is one of the important original region for citrus production where the plant area is the first and productive output is the third in the world. In the Three-Gorge Reservoir Region of Chongqing citrus production has been pillar industry for agriculture. Accompany with the life level increase, environmental condition and ecological system will be pay more attention to citrus production. Non-polluted agricultural production is the most important approach for high quality and high efficiency, while soil environmental quality standards of heavy metal is imperative for environment monitoring and assessment.In the soil-plant system litter of heavy metal is enriched by plant, most of them will exist in the soil a long time. It is necessary to understand the form and distribution of heavy metal pollution, as well as the characteristics and the law of varied plant absorbing the heavy metal. Soin this paper the research has been done about the heavy metal ecological behaviors of soil-citrus system of the Three-gorge Reservoir Region in Chongqing.Heavy metal ( Hg, As, Cd, Pb and others) have a great effect to human being health through food links. Heavy metal also effect crop output and quality in the soil-plant system, the factors were analyzed which influence the transport and transformation of heavy metal. Combined pollution caused by organic pollutant and heavy metal and interaction of heavy metal is one of the important environmental pollution forms. Phytoextraction and remedy of polluted soils by heavy metal was also discussed.Among heavy metal elements of polluted soil, cadmium (Cd) toxicity is famous. Some aspects related to the mechanisms of Cd toxicity the plants, e.g., plant growth, photosysthesis, stomatal action, water relations, efflux of cation and enzyme activity were effected by Cd. It was demonstrated that bioavailability of Cd is related with pH, microorganisms, and other elements in rhizosphere of soils. The way of mercury (Hg) pollution, transportation and harness method in soil were discussed witch including atmospheric deposition, emissions of Hg from soil, effect of Hg on plant growth and development. Copper (Cu) is one of necessary elements, but Cu is also a high toxicity and wide-spread heavy metal pollutant, excessive Cu can decrease the membrane integrity, the activity of enzymes, change the synthesis of chlorophyll and the efficiency of the primary photochemical reactions. Zinc (Zn) and nitrogen interaction has the influence to plant growth and the uptake of P, K, Fe and other elements. The effects of Nickel (Ni), Lead (Pb), Arsenic (As) and Chromium (Cr) to plant and soil are also discussed. Heavy metal impact on the cytoplasmic function in a number of different ways, principally by their binding to protein sulfhydryl groups, by producing a deficiency of ions, by substituting the essential ions. Other modes of toxicity are including disruption of cell transport processes and oxidative damage by free radicals.This paper analyze the heavy metal content of citrus different organs, citrus different strains and ecological environment of the Three-gorge Reservoir Region in Chongqing. The heavy metal ecological behave in soil-citrus ecological system was research by studying in soil-citrus ecological system. The area of citrus research is Feng Jie county, Zhong county, Chang Shou county and Jiang Jin county in Chongqing.The object is to obtain a scientific evaluate for environmental quality of citrus orchards and citrus fruit security of the Three-gorge Reservoir Region in Chongqing by the current effective standards of China. The discuss is also done to understand the way of soil heavy metal pollution incitrus orchards and citrus fruit, the biological influence of heavy metal to soil-citrus ecological system to build a ecological model of security high quality citrus production in the Three-gorge Reservoir Region.1. Investigation a更多还原