本文選題：鉛鋅脅迫 + 蓖麻�。� 參考：《中南林業(yè)科技大學(xué)》2017年碩士論文

【摘要】：蓖麻(Ricimus communist L.)屬大戟科(Euphorbiaceae)蓖麻屬(Ricinus)一年生或多年生草本植物。其生物量大,根系發(fā)達(dá)且抗逆性強(qiáng),對(duì)多種重金屬具有較強(qiáng)的耐受性和富集作用,是一種具有重要開(kāi)發(fā)應(yīng)用前景的重金屬污染土壤修復(fù)工業(yè)油料植物。本研究以蓖麻“秀蓖2號(hào)”品種為試驗(yàn)材料,栽種于細(xì)沙和珍珠巖體積比5:4混合、添加不同濃度單一和復(fù)合Pb2+、Zn2+的基質(zhì)中,定期觀測(cè)蓖麻種子胚根伸長(zhǎng)與萌發(fā)變化、根組織結(jié)構(gòu)與根系形態(tài)結(jié)構(gòu)的變化、植株對(duì)Pb2+、Zn2+及主要營(yíng)養(yǎng)元素的吸收分配、植株生長(zhǎng)勢(shì)變化,分析蓖麻根生長(zhǎng)和形態(tài)結(jié)構(gòu)與重金屬吸收累積、主要營(yíng)養(yǎng)元素含量以及植物生長(zhǎng)勢(shì)的相關(guān)性,探明不同鉛鋅脅迫濃度下,蓖麻根系對(duì)Pb2+、Zn2+重金屬的反饋與適應(yīng)性變化,以期為制定合理的修復(fù)栽培措施,提高蓖麻對(duì)Pb/Zn污染土壤的修復(fù)能力提供參考和指導(dǎo)。主要研究結(jié)果如下:(1)Pb2+、Zn2+脅迫對(duì)胚根的伸長(zhǎng)與種子萌發(fā)產(chǎn)生不同影響。相同濃度下,Zn2+對(duì)蓖麻胚根伸長(zhǎng)的抑制作用較Pb2+的抑制作用強(qiáng),當(dāng)Pb2+為200 mg/kg、400 mg/kg時(shí),胚根的伸長(zhǎng)量和種子萌發(fā)率均大于對(duì)照,其萌發(fā)勢(shì)與對(duì)照無(wú)明顯差異;Zn2+為200 mg/kg時(shí)即對(duì)胚根伸長(zhǎng)、種子發(fā)芽勢(shì)與發(fā)芽率均產(chǎn)生較顯著的抑制作用;脅迫總濃度為400 mg/kg時(shí),對(duì)胚根伸長(zhǎng)的抑制作用由強(qiáng)到弱依次為Zn2+(Pb2++Zn2+復(fù)合脅迫)Pb2+。胚根伸長(zhǎng)和種子萌發(fā)率與Pb2+脅迫濃度成不顯著負(fù)相關(guān)性,與Zn2+處濃度呈極顯著負(fù)相關(guān)(R21=-0.806**,R22=-0.487**)。(2)Pb2+、Zn2+脅迫對(duì)蓖麻總根長(zhǎng)、主根長(zhǎng)、根表面積、根體積、根尖數(shù)產(chǎn)生不同影響。影響力從小到大依次為:Pb2+Zn2+Pb2+、Zn2+復(fù)合。單一脅迫Pb2+為200 mg/kg時(shí),根系表面積、側(cè)根數(shù)相比對(duì)照分別上升了 7.8%和33.3%;單一脅迫Zn2+≥200 mg/kg脅迫時(shí),根系的各項(xiàng)形態(tài)指標(biāo)都受到抑制,抑制效應(yīng)隨著Zn2+濃度的增加而加強(qiáng)。Pb2+、Zn2+復(fù)合脅迫下,根系各形態(tài)指標(biāo)均隨著脅迫濃度升高而降低。(3)Pb2+、Zn2+脅迫引起根解剖結(jié)構(gòu)發(fā)生改變。隨著Pb2+、Zn2+脅迫處理濃度的增加,根冠細(xì)胞體積、根冠體積逐漸變小,細(xì)胞排列不規(guī)則;根尖分生組織細(xì)胞變小、細(xì)胞著色深,排列欠整齊;表皮細(xì)胞和外皮層細(xì)胞的細(xì)胞壁木栓化程度逐漸增強(qiáng),皮層薄壁細(xì)胞變小,細(xì)胞內(nèi)結(jié)晶顏色加深,顆粒變大,嚴(yán)重時(shí)結(jié)晶顆粒占居整個(gè)細(xì)胞;內(nèi)皮層及中柱鞘細(xì)胞細(xì)胞壁木栓化逐漸加厚。(4)Pb2+、Zn2+復(fù)合脅迫對(duì)Pb2+、Zn2+在蓖麻不同部位的累積量產(chǎn)生不同影響,且與根系形態(tài)指標(biāo)密切相關(guān)。Pb2+、Zn2+在植株地下與地上部分的累積量均與其栽培基質(zhì)中的Pb2+、Zn2+濃度呈極顯著正相關(guān);總根長(zhǎng)、表面積、根尖數(shù)與地下部分Pb積累量呈不顯著負(fù)相關(guān),與地上部分的累積量呈不顯著正相關(guān);根系各形態(tài)指標(biāo)與Zn地上地下部分積累量均呈極顯著負(fù)相關(guān)。(5)Pb2+、Zn2+脅迫影響植株對(duì)N、P、K的吸收與分配,進(jìn)而影響植株的生長(zhǎng)。單一 Pb2+、Zn2+脅迫濃度≤400mg/kg時(shí),植株地上與地下部分全N含量顯著高于對(duì)照植株,復(fù)合處理下和濃度為600 mg/kg的Pb2+、Zn2+單一處理下,全N含量均低于對(duì)照;植株全P含量在Pb2+、Zn2+單一處理時(shí)的均高于對(duì)照,在復(fù)合處理時(shí)均低于對(duì)照組;植株全K含量在Pb2+、Zn2+單一與復(fù)合脅迫下均高于對(duì)照,且根部的積累量大于地上部分。隨著Pb2+、Zn2+脅迫濃度上升,對(duì)植株地徑生長(zhǎng)的影響不明顯,但株高和節(jié)間長(zhǎng)顯著降低。同時(shí)葉片的總厚度變薄,柵欄層組織厚度變薄,細(xì)胞趨向于變小、排列疏松,海綿層組織厚度變厚,輸導(dǎo)組織橫切面積變小(薄壁細(xì)胞數(shù)量、導(dǎo)管數(shù)量減少)。
[Abstract]:Ricimus Communist L. is an annual or perennial herb of the family euphorbifamily (Euphorbiaceae) of the genus Castor (Ricinus). It has a large biomass, developed root system and strong resistance to stress. It has strong tolerance and enrichment to a variety of heavy metals. It is a heavy heavy metal contaminated soil remediation industrial oil plant with important development and application prospects. In this study, the varieties of Ricinus ricinus 2 were used as experimental materials, planted in the mixture of fine sand and perlite volume ratio 5:4, adding different concentrations of single and compound Pb2+, Zn2+, to observe the root elongation and germination of Castor seeds, the changes of root structure and root morphology, and the plant to Pb2+, Zn2+ and the main nutrient elements. The relationship between the growth and morphological structure of castor root and the accumulation of heavy metals, the content of main nutrients and the growth potential of plant, and the feedback and adaptability of castor root to Pb2+ and Zn2+ heavy metals under different concentrations of lead and zinc were analyzed. The main results are as follows: (1) Pb2+, Zn2+ stress has different effects on the elongation of radicle and seed germination. Under the same concentration, the inhibitory effect of Zn2+ on the elongation of castor bean radicle is stronger than that of Pb2+, when Pb2+ is 200 mg/kg, 400 mg/kg, the elongation and species of radicle. The Zi Mengfa rate was greater than that of the control, and the germination potential was not significantly different from that of the control. When Zn2+ was 200 mg/kg, the root elongation, seed germination potential and germination rate were significantly inhibited. When the total stress concentration was 400 mg/kg, the inhibitory effect of the root elongation was from strong to weak to Zn2+ (Pb2++Zn2+ compound stress) Pb2+. radicle elongation and seed. There was no significant negative correlation between the germination rate and the concentration of Pb2+ stress, which was significantly negatively correlated with the concentration of Zn2+ (R21=-0.806**, R22=-0.487**). (2) Pb2+, Zn2+ stress had different effects on the length of the total root, the length of the root, the root surface area, the root volume and the number of root tips. The influence was from small to large in order of Pb2+Zn2+Pb2+ and Zn2+. The single stress Pb2+ was 200 mg/kg. The root surface area and the number of lateral roots increased by 7.8% and 33.3%, respectively. When single stress Zn2+ > 200 mg/kg stress, the various morphological indexes of root system were inhibited, and the inhibitory effect was enhanced with the increase of Zn2+ concentration. Under Zn2+ compound stress, the index of root forms decreased with the increase of stress concentration. (3) Pb2+, Zn2+ stress. The root anatomic structure changed. With the increase of Pb2+, Zn2+ stress treatment concentration, the volume of root cap cells, the root cap volume gradually smaller, the cells arranged irregular, the apical meristem cells became smaller, the cells were coloured and arranged poorly, the cell wall of epidermal cells and outer layer cells increased gradually, and the cortex parenchyma cells changed. The crystallinity of the cells was deepened and the particles became larger, and the crystalline particles occupied the whole cell when the cells were serious. The endothelium and the cell wall of the middle column sheath cells were thickened gradually. (4) Pb2+, Zn2+ compound stress had different effects on the accumulation of Pb2+ and Zn2+ in different parts of castor, and it was closely related to the morphological indexes of the root system.Pb2+, Zn2+ in the underground and ground of the plant. The accumulation of the upper part was significantly positively correlated with the concentration of Pb2+ and Zn2+ in the cultivation matrix, and the total root length, surface area, and the number of root tips were not negatively correlated with the accumulation of Pb in the underground part, and had no significant positive correlation with the accumulation of the upper part of the ground, and the root morphology indexes were significantly negatively correlated with the accumulation of the underground part of the ground part of Zn. (5) Pb2+, Zn 2+ stress affects the absorption and distribution of N, P, and K, and then affects the growth of plants. When single Pb2+, Zn2+ stress concentration is less than 400mg/kg, the total N content on the ground and underground part of the plant is significantly higher than that of the control plant. The total N content is lower than the control under the compound treatment and the concentration of 600 mg/kg, under the Zn2+ single treatment. The single treatment was all higher than the control in the compound treatment. The total K content of the plant was higher than the control under Pb2+, Zn2+ single and compound stress, and the accumulation of root was greater than that in the upper part. With the increase of Pb2+, the growth of plant height was not obvious with the increase of Zn2+ stress, but the plant height and internode length decreased significantly. Leaves at the same time leaves and leaves. The thickness of the total thickness of the palisade layer thinner, the cells tend to be smaller, the arrangement of the tissue is loose, the thickness of the tissue in the sponge layer becomes thicker, the cross cutting area of the conduction tissue is smaller (the number of parenchyma cells and the decrease of the number of ducts).
【學(xué)位授予單位】：中南林業(yè)科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：X173;S565.6
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本文編號(hào)：1902912