本文選題：富集系數(shù) + 轉(zhuǎn)運(yùn)系數(shù)�。� 參考：《中國(guó)農(nóng)業(yè)科學(xué)院》2015年碩士論文

【摘要】：土壤鎘(Cd)污染對(duì)水稻的環(huán)境風(fēng)險(xiǎn)已受到了廣泛的關(guān)注,但我國(guó)還缺乏切實(shí)可行的稻田Cd風(fēng)險(xiǎn)評(píng)價(jià)體系,且針對(duì)不同性質(zhì)土壤的Cd風(fēng)險(xiǎn)閾值研究還相對(duì)薄弱。因此,本研究依據(jù)我國(guó)地域土壤性質(zhì)(土壤p H、有機(jī)碳等)差異,選取我國(guó)8個(gè)不同地區(qū)的典型農(nóng)田表層(0-20 cm)土壤,同時(shí)選取了我國(guó)水稻主產(chǎn)區(qū)的3種對(duì)Cd敏感性不同的水稻品種為試材,結(jié)合Log-logistic模型擬合得到水稻Cd毒性與土壤中Cd濃度的劑量-效應(yīng)關(guān)系,進(jìn)而獲得土壤Cd污染對(duì)水稻的毒性閾值(EC10、EC50)。并通過(guò)逐步回歸分析,確定水稻Cd毒性與土壤性質(zhì)間的相互關(guān)系,探明水稻Cd毒性的土壤主控因子,并建立了水稻Cd毒性與土壤主控因子的毒性閾值預(yù)測(cè)模型。同時(shí)選取20種不同品種水稻開(kāi)展了基于籽粒Cd含量的水稻Cd吸收敏感性研究,并通過(guò)BurrIII分布函數(shù)擬合獲得了土壤中Cd對(duì)水稻毒性的物種敏感性分布(SSD),依據(jù)國(guó)家食品衛(wèi)生稻米Cd限量標(biāo)準(zhǔn)推導(dǎo)出土壤中Cd濃度的閾值,為我國(guó)稻田土壤Cd污染防控及土壤Cd污染限量標(biāo)準(zhǔn)的修訂提供參考。主要研究結(jié)果如下:1.不同性質(zhì)土壤對(duì)Cd的水稻毒性有顯著影響,Cd敏感性水稻品種T優(yōu)167的毒性閾值EC10變化為1.40-5.25 mg·kg-1,EC50變化為17.83-46.93 mg·kg-1;Cd非敏感性品種湘早45的毒性閾值EC10變化為1.72-8.22 mg·kg-1,EC50變化為26.96-68.16 mg·kg-1。通過(guò)水稻Cd毒性閾值ECx與土壤性質(zhì)間的多元回歸分析證實(shí)了土壤p H、有機(jī)碳含量(OC)、陽(yáng)離子交換量(CEC)是控制水稻Cd毒性的主控因子。其水稻Cd毒性預(yù)測(cè)模型為:Log(EC50)=0.078 pH+0.208 log(CEC)+0.202 log(OC)+0.705(R2=0.94,n=24),且pH、OC、CEC可以控制Cd毒性預(yù)測(cè)模型94.1%的變異性。2.在Cd濃度4.8 mg·kg-1以下的土壤上種植水稻不會(huì)顯著降低水稻籽粒的產(chǎn)量,其籽粒產(chǎn)量的變化為20.69-37.22 g·pot-1。相同品種水稻在不同Cd濃度處理下,其根、莖葉、籽粒中Cd濃度逐漸增加,而相同Cd濃度處理下,不同品種水稻的根、莖葉、籽粒中Cd濃度存在顯著的差異,在不同Cd濃度處理下Cd濃度相差1.52-4.11倍;1.68-3.52倍;3.54-6.00倍。Cd由根遷移轉(zhuǎn)運(yùn)至莖葉的轉(zhuǎn)運(yùn)系數(shù)TFstraw在不同品種間存在顯著的差異,不同品種間TFstraw的變異系數(shù)為:41.02%-71.18%。而Cd由莖葉遷移轉(zhuǎn)運(yùn)至籽粒的轉(zhuǎn)運(yùn)系數(shù)TFgrain不同品種間差異不顯著,其變異系數(shù)為:10.82%-27.50%。故轉(zhuǎn)運(yùn)系數(shù)TFstraw比TFgrain更能真實(shí)準(zhǔn)確的反映不同品種水稻對(duì)Cd的吸收轉(zhuǎn)運(yùn)能力的差異,且不同品種水稻籽粒Cd積累量的差異主要是由于Cd由根遷移轉(zhuǎn)運(yùn)至莖葉的能力不同引起的。3.不同品種水稻對(duì)Cd的富集系數(shù)(BCF)存在顯著差異,其變化為0.28-1.54。BCF在不同Cd濃度處理中的變異系數(shù)為10.79%-27.72%。水稻籽粒Cd濃度高的品種具有較高的轉(zhuǎn)運(yùn)系數(shù)和富集系數(shù),反之,具有較低的轉(zhuǎn)運(yùn)系數(shù)和富集系數(shù)。故BCF可以較好的反映出不同品種水稻對(duì)Cd敏感性的差異。通過(guò)BurrIII分布函數(shù)可以很好的擬合1/BCF的物種敏感度分布,擬合函數(shù)的R2達(dá)0.9977�；谒咀蚜d濃度,以國(guó)家食品衛(wèi)生稻米Cd限量標(biāo)準(zhǔn)(0.2mg·kg-1)為基準(zhǔn),反推出土壤中Cd的限量上限濃度值為0.57 mg·kg-1,從而可以確保95%的水稻籽粒Cd濃度符合標(biāo)準(zhǔn)。
[Abstract]:Soil cadmium (Cd) pollution has been widely concerned about the environmental risk of rice, but there is still a lack of practical Cd risk assessment system in our country, and the research on the Cd risk threshold for different soils is relatively weak. Therefore, this study is based on the differences of the regional soil properties of China (soil P H, organic carbon, etc.), and selects 8 different areas of our country. The typical farmland (0-20 cm) soil in the region, and 3 varieties of rice varieties with different sensitivity to Cd in the main rice producing area of our country were selected, and the dose effect relationship between the Cd toxicity of rice and the concentration of Cd in the soil was fitted with the Log-logistic model, and the toxicity threshold (EC10, EC50) of soil Cd contamination (EC10, EC50) was obtained. Regression analysis was used to determine the relationship between Cd toxicity and soil properties, to explore the main control factors of soil Cd toxicity and to establish a model for predicting the toxicity threshold of rice Cd toxicity and soil principal control factors. At the same time, 20 different varieties of rice were selected to carry out the study on the Cd absorption sensitivity of rice based on the Cd content of grain and through BurrIII. The distribution function fitting obtained the species sensitivity distribution of Cd to rice in the soil (SSD). According to the national food hygienic rice Cd limit standard, the threshold of Cd concentration in soil was derived, which provided a reference for the prevention and control of Cd pollution in paddy soil and the revision of the standard of soil Cd pollution limit. The main results are as follows: 1. different properties of soil to Cd The toxic threshold of Cd sensitive rice variety T you 167 changed to 1.40-5.25 mg. Kg-1, EC50 changed to 17.83-46.93 mg kg-1, and the toxicity threshold of Xiang Zao 45, which was not sensitive, was changed to 17.83-46.93. Multivariate regression analysis confirmed that soil P H, organic carbon content (OC) and cation exchange amount (CEC) are the main controlling factors for controlling Cd toxicity of rice. The Cd toxicity prediction model of rice is Log (EC50) =0.078 pH+0.208 log (CEC). The yield of rice grain was not significantly reduced by planting rice under.8 mg / kg-1. The variation of grain yield was 20.69-37.22 G. Pot-1.. The concentration of Cd in root, stem, leaf and grain increased gradually under the treatment of different Cd concentrations. The concentration of Cd in the roots, stems, leaves and grains of different varieties of rice was stored under the same Cd concentration treatment. In the significant difference, the difference of Cd concentration was 1.52-4.11 times of different Cd concentration and 1.68-3.52 times, and the transport coefficient TFstraw of 3.54-6.00 times.Cd from root migration to stem and leaf was significant difference among different varieties. The variation coefficient of TFstraw in different varieties was 41.02%-71.18%. while Cd was transported from stem and leaf to grain, and the transport coefficient TFgra was TFgra. The variation coefficient of in is not significant, and its coefficient of variation is 10.82%-27.50%. so that the transfer coefficient TFstraw is more true and accurate than TFgrain to reflect the difference in the absorption and transport capacity of different varieties of rice to Cd, and the difference in the accumulation of Cd in the grain of different varieties of rice is mainly caused by the.3. of Cd from the transfer of root migration to the stem and leaf. The enrichment coefficient (BCF) of different varieties of rice (Cd) has significant difference. The variation is that the variation coefficient of 0.28-1.54.BCF in different Cd concentrations is higher in 10.79%-27.72%. rice grain with higher Cd concentration and higher in transport coefficient and enrichment factor. On the contrary, it has a lower transfer coefficient and enrichment factor. Therefore, BCF can be better reflected. The difference in sensitivity of different varieties of rice to Cd was found. Through the BurrIII distribution function, the species sensitivity distribution of 1/BCF could be well fitted. The R2 of the fitting function was based on the Cd concentration of rice grain, based on the national food hygienic rice Cd limit standard (0.2mg. Kg-1), and the limit limit concentration of Cd in the soil was 0.57 mg. This can ensure that 95% of the Cd concentration of rice seeds meets the standards.

【學(xué)位授予單位】：中國(guó)農(nóng)業(yè)科學(xué)院
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：X53

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 蔣丹烈;岳龍;馬迪;朱yN聰;尹大強(qiáng);;應(yīng)用物種敏感性分布法分析太湖及天目湖水體的生態(tài)風(fēng)險(xiǎn)[J];環(huán)境化學(xué);2012年03期

2 張良運(yùn);李戀卿;潘根興;;南方典型產(chǎn)地大米Cd、Zn、Se含量變異及其健康風(fēng)險(xiǎn)探討[J];環(huán)境科學(xué);2009年09期

3 黃丹丹;葛瀅;周權(quán)鎖;;淹水條件下土壤還原作用對(duì)鎘活性消長(zhǎng)行為的影響[J];環(huán)境科學(xué)學(xué)報(bào);2009年02期

4 李坤權(quán),劉建國(guó),陸小龍,楊建昌,張祖建,朱慶森;水稻不同品種對(duì)鎘吸收及分配的差異[J];農(nóng)業(yè)環(huán)境科學(xué)學(xué)報(bào);2003年05期

5 陳寶玉;王洪君;曹鐵華;梁p芎，

本文編號(hào)：1865101