【作者】 岳利军；

【导师】 王锁民；

【作者基本信息】 兰州大学 ， 草地营养生物学， 2009， 硕士

【摘要】 梭梭（Haloxylon ammodendron）、白刺（Nitraria tangutorum）和红砂（Reaumuria soongorica）是分布于我国荒漠地区的重要资源植物,然而由于人类的掠夺式开发和自然环境的恶化,已使这些植物逐渐退化。近年来研究表明,Na⁺在荒漠植物抗旱性方面起着重要的作用。进一步的砂培实验也证实,适宜浓度的钠不但显著促进了荒漠植物霸王的生长,而且提高了其抗胁迫能力。随后,经过一系列的调试和鉴定,获得了一种既可显著促进霸王生长、又能提高其抗旱性的钠复合肥。在以上工作的基础上,本论文以梭梭、白刺和红砂为实验材料,研究了盆栽条件下钠复合肥对其生长及抗旱性的作用;同时,还对三种不同的钠复合肥进行了比较研究,进而扩大了钠复合肥的施用范围。结果表明,三种植物经正常浇水11-12周,干旱胁迫20-22天后,钠复合肥1、2和3均显著促进了它们的生长,并提高了其抗旱性,其中钠复合肥1的效果最佳:梭梭:在干旱胁迫下,与未施肥处理相比,钠复合肥1的施用使梭梭株高、同化枝的面积、鲜重、干重、含水量和相对有机干重分别显著增加了38%、79%、148%、100%、25%和8.7%;使其根的鲜重和干重分别显著增加了63%和45%;同时,使其同化枝的过氧化氢酶（CAT）、过氧化物酶（POD）和超氧化物歧化酶（SOD）活性分别显著提高了32%、58%和37%,丙二醛（MDA）含量和相对质膜透性分别显著降低了33%和34%;光合关键酶磷酸烯醇式丙酮酸羧化酶（PEPCase）活性、光合速率（Pn）和水分利用效率（WUE）分别显著提高了301%、200%和445%。白刺:在干旱胁迫下,与未施肥处理相比,钠复合肥1的施用使白刺株高、叶的面积、鲜重、干重、含水量和相对有机干重分别显著增加了89%、209%、318%、218%、34%和6.8%;使其根的鲜重、干重和含水量分别显著增加了217%、138%和43%;同时,使其叶的CAT、POD和SOD活性分别显著提高了23%、30%和25%,MDA含量和相对质膜透性分别显著降低了30%和37%,光系统Ⅱ的稳定性显著增强,Pn和WUE分别显著提高了420%和915%。红砂:在干旱胁迫下,与未施肥的处理相比,钠复合肥1的施用使红砂株高、叶的面积、鲜重、干重和含水量分别显著增加了321%、763%、800%、667%和34%;使其根的鲜重和干重分别显著增加了719%和628%;同时,使其叶的Pn和WUE分别显著提高了38%和159%。在干旱胁迫下,钠复合肥1的施用显著改善了三种植物的渗透调节能力、光合能力和WUE,增强了梭梭和白刺的活性氧清除能力,从而提高了其抗旱性。此外,在钠复合肥实验过程中,我们发现白刺种子的休眠率极高,而目前关于白刺种子催芽方法的报道却很少。因此,本论文也进行了白刺种子催芽方法的研究,进而建立了一套促进白刺种子快速萌发的技术体系,结果如下:在常温（20-25℃）下,经蒸馏水浸种催芽,白刺种子的发芽率为0%;而用浓H₂SO₄泡种55min后,在25/5℃（12/12h）变温条件下,经150mg/L赤霉素（GA₃）浸泡48h,在10天内白刺种子的萌发率达到69%,且发芽整齐。尽管如此,31%的白刺种子仍处于休眠状态,这表明白刺种子的休眠属综合休眠,但可判定种皮的机械阻碍是白刺种子休眠的主要原因。本论文研究的钠复合肥和白刺种子快速萌发技术体系可用于培育荒漠植物的强抗旱苗,推广应用前景广阔。更多还原

【Abstract】 Haloxylon ammodendron,Nitraria tangutorum and Reaumuria soongorica are all very important resource species in the desert regions of our country.However,they have begun to gradually degenerate due to human activity and deteriorating natural environment in native regions.Recently,it have been identified that sodium plays an important role in the drought stress resistance of desert species.Our further experiments under sand culture in laboratory also proved that suitable sodium can not only stimulated the growth but also improved the osmotic stress resistance of the desert plant Zygophyllum xanthonylon.Subsequently,a sodium compound fertilizer was developed after a series of experiments.This fertilizer significantly promoted the growth and enhanced the drought stress resistance of Z.xanthonylon.Based on above works,in the present study,the roles of sodium compound fertilizer in the growth and drought resistance of the desert species H.ammodendron, N.tangutorum and R.soongorica were investigated under pots;meanwhile,the comparative studies of three kinds of sodium compound fertilizers were also carried out;based on these works,the application scope of sodium compound fertilizer was further expanded.The results showed that,after these three plants were exposed to drought stress for 20-22 days following normally watered for 11-12 weeks,the addition of sodium compound fertilizer 1,2 and 3 all promoted their growth and enhanced their drought stress resistance,but the sodium compound fertilizer 1 is the best one:H.ammodendron:under drought stress,compared with the treatment without fertilizer,the application of sodium compound fertilizer 1 significantly increased its plant height,photosynthesizing branch area,fresh weight,dry weight,water content and organic weight by 38%,79%,148%,100%,25%and 8.7%respectively; increased root fresh weight and dry weight by 63%and 45%respectively;meanwhile, the presence of sodium compound fertilizer 1 significantly increased the catalase （CAT）,peroxidase（POD） and superoxide dismutase（SOD） activity by 32%,58%and 87%respectively;decreased the malondialdehyde（MDA） content and relative membrane permeability by 33%and 34%respectively;increased the phosphoenolpyruvate carboxylase activity,net photosynthetic rate（Pn） and water use efficiency（WUE） by 301%,200%and 445%respectively in its photosynthesizing branches. N.tangutorum:under drought stress,compared with the treatment without fertilizer, the application of sodium compound fertilizer 1 significantly increased its plant height, leaf area,fresh weight,dry weight,water content and organic weight by 89%,209%, 318%,218%,34%and 6.8%respectively;increased root fresh weight,dry weight and water content by 217%,138%and 43%respectively;meanwhile,the presence of sodium compound fertilizer 1 significantly increased the CAT,POD and SOD activity by 23%,30%and 25%respectively;decreased the MDA content and relative membrane permeability by 30%and 37%respectively;enhenced the stability of photosynthetic systemⅡ,increased Pn and WUE by 420%and 915%respectively in its leaves.R.soongorica:under drought stress,compared with the treatment without fertilizer, the application of sodium compound fertilizer 1 significantly increased its plant height, leaf area,fresh weight,dry weight and water content by 321%,763%,800%,667% and 34%respectively;increased root fresh weight and dry weight by 719%and 628% respectively;meanwhile,the presence of sodium compound fertilizer 1 increased Pn and WUE by 38%and 159%respectively in its leaves.Under drought stress,the application of sodium compound fertilizer 1 increased the osmotic adjustment capacity,photosynthetic capacity and WUE of these three species and enhanced reactive oxygen species-scavenging capacity in H.ammodendron and N. tangutorum,which effectively enhances the drought resistance of these three species.In the process of sodium compound fertilizer experiments,we found that the N. tangutorum seeds present the extremely high dormancy rate.However,so far,there are only a few reports about the method of promoting seed germination of N. tangutorum.Threrefore,the studies on the method of promoting the N.tangutorum seed germination was also carried out in this paper,and then a rapid germination technical system of N.tangutorum seeds was established,the results as following:the seeds of N.tangutorum weren’t germinated when dipped in distilled water under normal temperature（20-25℃）.However,after seeds were soaked in 98%H₂SO₄ for 55 min and then dipped in 150mg/L GA₃ for 48 h,the germination reached a peak as 69%under the fluctuating temperature of 25/5℃（12h/12h） within 10 days,and seeds germinated more trimly than control.However,31%of seeds still remain dormancy, suggesting that N.tangutorum seeds have multiple dormancy mechanisms. Meanwhile,it was identified that the mechanical restriction of seed coat is the main reasons of N.tangutorum seed dormancy. The sodium compound fertilizer and N.tangutorum seed rapid germination technical system can be used to cultivate the strong drought-resistance seedlings of desert plants.Therefore,they have broad prospects in practice.更多还原