發(fā)布時(shí)間：2018-03-24 01:19

  本文選題：Cd　切入點(diǎn)：水稻生長　出處：《湖南農(nóng)業(yè)大學(xué)》2015年碩士論文

【摘要】：為了解析水稻米鎘的積累時(shí)期,尋找適合的阻控Cd的改良劑,本文通過不同濃度的Cd脅迫對(duì)水稻種子萌發(fā)的試驗(yàn)及對(duì)幼苗培育試驗(yàn),分析Cd脅迫對(duì)種子及幼苗的影響,選擇合適的Cd濃度進(jìn)行全生育期營養(yǎng)液培養(yǎng)試驗(yàn),再通過不同生育期后添加外源Cd及不同生育期后不添加外源Cd兩種試驗(yàn),利用理論“減法”,相互驗(yàn)證,得到不同生育期對(duì)水稻中米鎘積累的貢獻(xiàn)率,并開展了生物菌肥與石灰配施對(duì)水稻米鎘積累的影響研究,為開展米鎘控制工作提供理論依據(jù)及實(shí)用技術(shù)參考,主要試驗(yàn)結(jié)果如下：(1)通過水稻種子萌發(fā)試驗(yàn)及幼苗培育實(shí)驗(yàn),使水稻種子在萌芽中及幼苗階段接受不同濃度的Cd脅迫,研究Cd對(duì)種子萌芽及幼苗生長的影響,結(jié)果表明：5 mg·L~(-1)的外源Cd濃度為抑制種子萌發(fā)的臨界濃度。水稻種子萌發(fā)環(huán)節(jié)可承受的Cd脅迫濃度范圍0-5 mg·L~(-1)。且1mg·L~(-1)的Cd濃度為顯著影響水稻幼苗根長、苗高及生物量(干重)臨界濃度,幼苗正常生長情況下積累的Cd隨著Cd濃度的增加,其中Cd濃度為0.05 mg·L~(-1)能較真實(shí)的反映出水稻正常積累、吸收Cd的情況。(2)通過水稻(玉針香)不同生育期后添加50μg·L~(-1)外源Cd對(duì)水稻生長及吸收積累Cd的影響,結(jié)果表明：水稻各部位Cd濃度隨著接受Cd脅迫的時(shí)間長短而變化,與接受Cd脅迫的時(shí)間具有顯著的正相關(guān)；且各部位對(duì)Cd的吸收積累表現(xiàn)出一致的梯度變化,稻桿部分：根部莖鞘葉片；稻穗部分：谷殼糙米；谷殼中的Cd 56.27%來自分蘗拔節(jié)期,18.69%來自抽穗揚(yáng)花期,而糙米中Cd 35.11%來自分蘗拔節(jié)期,26.61%來自灌漿乳熟期。(3)通過(湘晚秈13號(hào))不同生育期后水稻不添加對(duì)水稻生長及吸收積累Cd的影響,結(jié)果表明：外源Cd濃度控制為50μg·L~(-1),不會(huì)顯著影響水稻的正常生長：植株內(nèi)積累的Cd濃度隨著接受Cd脅迫的時(shí)間長短而變化,具有一定的線性關(guān)系；各部位積累的Cd含量表現(xiàn)為：根部莖鞘葉片谷殼糙米；谷殼中Cd43.64%來自成熟期,24.06%來自分蘗期積累,14.21%來自抽穗期,而糙米中Cd 36.36%來自分蘗期,18.18%來自灌漿期,16.36%成熟期。(4)采用田間隨機(jī)區(qū)組實(shí)驗(yàn)的方法,研究了基施生物菌肥(Bi)與追施石灰處理(L)及其配合施用(L+Bi)對(duì)水稻(湘晚秈12號(hào))生物量、水稻對(duì)土壤Cd的富集情況、4個(gè)生育期內(nèi)器官間轉(zhuǎn)運(yùn)系數(shù)以及各部位中Cd的含量的影響。結(jié)果表明,與CK相比,試驗(yàn)處理組都對(duì)水稻體的生物量無明顯影響,而且對(duì)水稻各部位的Cd含量有顯著的阻控作用,能夠有效的降低水稻各部位對(duì)土壤中Cd的富集,顯著降低了水稻谷殼中Cd的含量。其中生物菌肥與石灰配施(L+Bi)的處理糙米中Cd含量降低率為84.76%,效果最佳。
[Abstract]:In order to analyze the accumulation period of cadmium in rice and to find a suitable modifier for inhibiting CD, the effects of CD stress on seed germination and seedling cultivation of rice were analyzed by CD stress of different concentrations. The suitable concentration of CD was selected for the whole growth period nutrient liquid culture experiment, and then through the experiment of adding exogenous CD after different growth period and not adding exogenous CD after different growth period, the theory "subtraction" was used to verify each other. The contribution rate of cadmium accumulation in rice at different growth stages was obtained, and the effects of combined application of biological bacterial fertilizer and lime on cadmium accumulation in rice were studied, which provided theoretical basis and practical technical reference for rice cadmium control. The main results were as follows: (1) through rice seed germination test and seedling cultivation experiment, rice seeds were subjected to different concentrations of CD stress during germination and seedling stage, and the effects of CD on seed germination and seedling growth were studied. The results showed that the exogenous CD concentration of 5 mg / L (1) was the critical concentration to inhibit the seed germination. The CD concentration of rice seed germination was 0-5 mg / L ~ (-1) and the CD concentration of 1mg / L ~ (-1) significantly affected the root length of rice seedlings. The critical concentration of seedling height and biomass (dry weight), CD accumulation under normal growth condition, and CD concentration of 0.05 mg / L ~ (-1) could truly reflect the normal accumulation of rice. The effect of exogenous CD on the growth and uptake of CD in rice was studied. The results showed that CD concentration in different parts of rice changed with the duration of CD stress. There was a significant positive correlation between CD stress and CD uptake and accumulation, and there was a consistent gradient change in CD uptake and accumulation in different parts of rice, including root, stem and sheath leaves, rice panicle, husk brown rice. 56.27% of CD in husk came from tiller jointing stage and 18.69% from heading and flowering stage. However, 35.11% of CD in brown rice came from tiller and jointing stage and 26.61% from milk-filling stage. The results showed that the control of exogenous CD concentration at 50 渭 g / L could not significantly affect the normal growth of rice. There was a linear relationship between the CD concentration accumulated in the plant and the duration of CD stress. The CD content in the roots, stem and sheath leaves of brown rice, CD 43.64% in the husk came from the mature stage and 24.06% from the tillering stage, and 14.21% from the heading stage. While 36.36% of CD in brown rice came from tillering stage, 18.18% from grain filling stage, and 16.36% from maturing stage. Using the method of random block experiment in the field, the biomass of rice (Xiangduan indica 12) was studied by basal application of biological microbial fertilizer (Bi) and lime treatment (LL) and its combined application. The effects of rice on CD enrichment in soil, translocation coefficient between organs and CD content in different parts of rice during four growth periods were studied. The results showed that compared with CK, the biomass of rice body was not significantly affected by the treatment group. Moreover, CD content in different parts of rice could be significantly inhibited and controlled, which could effectively reduce the accumulation of CD in soil in different parts of rice. CD content in rice husk was significantly decreased, among which the CD content in brown rice treated with bio-microbial fertilizer and lime combined with LBi) was 84.76, and the effect was the best.
【學(xué)位授予單位】：湖南農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：S511;X56

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本文編號(hào)：1656068