【摘要】：象草(Pennisetum purpureum Schum)、雜交狼尾草(Pennisetum americanum×P.purpureum)作為優(yōu)質牧草和能源植物原料,在畜牧業(yè)、生物質能源與材料以及造紙工業(yè)都有較為廣泛的應用價值和潛力。但是,其在鹽堿等邊際性土地的規(guī)�；a業(yè)化種植,卻面臨著生物質產量低,耐鹽能力差的問題。植物內生菌是一種重要的根際微生物,能促進植物生長、提高宿主抗逆性,同時還能有效地改造鹽堿地。我們研究所的前期工作已從象草根際成功篩選出能夠促進雜交狼尾草生長的泛菌屬(Pantoea sp.)PP04菌株,并對其進行了促生特性、植物內定殖能力等初步研究,發(fā)現(xiàn)其具有固氮、溶磷的能力和較高的ACC脫氨酶活性。但是,該內生菌在植物規(guī)�；N植中的應用途徑、相關技術與機制仍未明確,針對這一問題,本研究試圖明確其在不同鹽脅迫條件下,對宿主植物種子萌發(fā)和幼苗生長的影響及其緩解鹽脅迫的作用機制,為象草、雜交狼尾草內生菌生物肥料開發(fā)及應用奠定理論基礎。具體結果如下:1.泛菌屬PP04內生菌能夠有效緩解中(200 mmol·L-1)、低(100 mmol·L-1)鹽濃度脅迫對雜交狼尾草種子萌發(fā)的毒害作用,對種子的發(fā)芽率、發(fā)芽指數(shù)、胚芽長度都有顯著的增益和改善作用。在低鹽濃度脅迫下,施加內生菌(E+),種子發(fā)芽率、發(fā)芽指數(shù)和胚芽長度較E-(未施加內生菌處理)組分別高出16.25%、19.59%、20.98%,在中鹽脅迫條件下,E+植物發(fā)芽率提高21.28%,發(fā)芽指數(shù)提高35.75%,胚芽長度是E-處理的3.36倍。然而,在高鹽(300 mmol·L-1)脅迫條件下,內生菌緩解鹽脅迫的毒害能力作用下降或不明顯。2.泛菌屬PP04顯著降低鹽脅迫對雜交狼尾草生物量的影響,增加其葉綠素含量和根系活力。尤其在100、200 mmol·L-1的NaCl濃度下時,內生菌促生長作用最明顯,E+組株高較E-組增加29.24%、18.33%,鮮重增加59.44%、49.00%。3.在不同濃度鹽脅迫下,泛菌屬PP04能夠通過誘導增加雜交狼尾草體內過氧化氫酶(CAT)、抗壞血酸酶(APX)、超氧化物歧化酶(SOD)和過氧化物酶(POD)活性。在100 mmol·L-1鹽處理下,E+組的上述四種酶活性較E-組分別增加64.18%、73.14%、32.34%和65.40%,表明PP04通過調節(jié)植物體內的抗氧化酶活性,減少膜脂過氧化產物MDA的積累,從而緩解鹽環(huán)境對雜交狼尾草造成的氧化脅迫,增強其耐鹽能力。4.PP04可通過增加雜交狼尾草滲透調節(jié)物質的含量來提高植物對鹽脅迫的耐受能力。特別是在中、高鹽濃度下,E+處理顯著提高脯氨酸、可溶性蛋白和可溶性糖的含量。在低、中鹽濃度下,E+處理的雜交狼尾草地上部分P含量的積累增加,從一定程度上提高其耐鹽能力。低濃度的NaCl使得植物體內K+/Na+與無鹽脅迫相比降低了62.08%,但施加內生菌能夠使雜交狼尾草的K+/Na+比未施加內生菌顯著提高47.14%。本文初步明確了泛菌屬PP04內生菌通過誘導雜交狼尾草體內的幾種主要抗氧化保護酶的活性、增強其滲透調節(jié)能力及調節(jié)離子平衡等三種作用機制,顯著緩解了鹽脅迫條件對雜交狼尾草生長的毒害,進而促進和保證了雜交狼尾草種子正常萌發(fā)及幼苗生長。研究結果表明,該菌株是優(yōu)良的雜交狼尾草植物的促生內生菌,但實際生產應用中還需考慮多方面的因素,進行實際的大田試驗環(huán)節(jié),以期實現(xiàn)內生菌的產業(yè)化,對于該菌株將來在各種生態(tài)環(huán)境中發(fā)揮長期穩(wěn)定的作用具有十分重要的現(xiàn)實意義。
[Abstract]:As a raw material of high-quality forage and energy plant, the pennisetum purpureum Schum and the Pennisetum americanum (P. purpureum) have a wide application value and potential in the animal husbandry, the biomass energy source and the material and the paper industry. However, the large-scale and industrialized planting of marginal land, such as saline and alkali, faces the problems of low biomass yield and poor salt tolerance. The plant endophytic bacteria is an important rhizosphere microorganism, which can promote the growth of the plant, improve the stress resistance of the host, and can effectively transform the saline-alkali soil. The preliminary work of our institute has been successfully screened from the grass-roots level to promote the growth of the hybrid Pennisetum (Pantanea sp.). ) The P04 strain and its growth-promoting property and the ability to colonize the plant were studied, and it was found that it had the ability of nitrogen fixation, phosphorus-dissolving and high ACC deaminase activity. However, the application of the endophytic bacteria in the large-scale plant cultivation of the plant remains unclear. In response to this problem, the present study attempts to clarify the effect of the endophytic bacteria on the germination of the host plant seeds and the growth of the seedlings under different salt stress conditions and the mechanism of the action to alleviate the salt stress. In ord to lay a theoretical foundation for that development and application of the endophytic bacteria, such as grass and hybrid Pennisetum. The specific results are as follows:1. Pan-type PP04 endophytic bacteria can effectively relieve the toxic effects of the medium (200 mmol 路 L-1) and low (100 mmol 路 L-1) salt concentration on the germination of the hybrid Pennisetum. The germination rate, the germination index and the germ length of the seeds have significant gain and improved effect. Under the stress of low salt concentration, the germination percentage, the germination index and the germ length of E + were 16.25%, 19.59% and 20.98%, respectively. Under the condition of medium salt stress, the germination percentage of E + plants increased by 21.28%. The germination index was increased by 35.75%, and the length of the germ was 3.36 times that of E-treatment. However, under the condition of high salt (300 mmol 路 L-1) stress, the toxic ability of endophytic bacteria to relieve the salt stress is reduced or not obvious. The effect of salt stress on the biomass of the hybrid Pennisetum was significantly reduced by the pan-strain PP04, and the content of chlorophyll and the activity of the root system were increased. In the concentration of 100,200 mmol 路 L-1, the growth of endophytic fungi was the most obvious. The higher E-group of E + group increased 29.24%, 18.33% and the fresh weight was 59.44%, 49.00%. Under the stress of different concentration of salt, the P04 can increase the activity of catalase (CAT), ascorbic acid (APX), superoxide dismutase (SOD) and peroxidase (POD) by inducing the increase of the in-vivo catalase (CAT), ascorbic acid (APX), superoxide dismutase (SOD) and peroxidase (POD). Under the treatment of 100 mmol 路 L-1 salt, the above four enzyme activities of E + group increased by 64.18%, 73.14%, 32.34% and 65.40%, respectively, indicating that PP04 can reduce the accumulation of MDA in the membrane lipid peroxidation products by adjusting the antioxidant enzyme activity in the plant, And the resistance of the plant to salt stress can be improved by increasing the content of the osmotic adjusting substance of the hybrid Pennisetum. In particular, in that medium and high salt concentration, E + treatment significantly improve the content of proline, soluble protein and soluble sugar. Under the low and medium salt concentration, the accumulation of P content in the ground part of the hybrid of the E + was increased, and the salt tolerance was improved to a certain extent. The low concentration of NaCl reduced the K +/ Na + in the plant by 62.08%, but the application of endophytic bacteria could increase the K +/ Na + ratio of the hybrid Pennisetum to 47.14%. In this paper, the activity of the main anti-oxidation protective enzymes of the P04 endophytic bacteria of the genus P04 through induction, the osmotic adjustment ability and the regulation of the ion balance are enhanced, and the toxicity of the salt stress condition to the growth of the hybrid Pennisetum is obviously relieved. So as to promote and ensure the normal germination of the hybrid Pennisetum and the growth of the seedlings. The results of the study show that the strain is an excellent endophytic bacterium of the hybrid Pennisetum, but it is also necessary to take into account various factors in the practical production application, so as to realize the industrialization of endophytic bacteria. It is of great practical significance for the strain to play a long-term and stable role in various ecological environments in the future.
【學位授予單位】：江蘇大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：S54

【參考文獻】

相關期刊論文 前10條

1 華智銳;李小玲;;鹽旱交叉脅迫對小麥種子萌發(fā)及幼苗保護酶活性的影響[J];江西農業(yè)學報;2017年02期

2 溫海峰;范希峰;朱毅;滕文軍;韓壯;侯新村;;雜交狼尾草作為能源植物的研究進展[J];中國農學通報;2017年03期

3 張紫薇;龐春花;張永清;倪瑞軍;楊世芳;王璐瑗;劉麗琴;;等滲NaCl和PEG脅迫及復水處理對藜麥種子萌發(fā)及幼苗生長的影響[J];作物雜志;2017年01期

4 申紅妙;李正楠;賈招閃;楊佳瑤;冉隆賢;;內生枯草芽孢桿菌JL4在葡萄葉上的定殖及其對葡萄霜霉病的防治[J];應用生態(tài)學報;2016年12期

5 王遠蘭;;菌根在土壤污染修復方面的研究[J];化工管理;2016年10期

6 鄧勛;宋小雙;尹大川;崔文峰;宋瑞清;;鹽脅迫下深色有隔內生真菌D575對樟子松生長及耐鹽性的影響[J];森林工程;2015年06期

7 叢國強;尹成林;何邦令;李玲;高克祥;;水分脅迫下內生真菌球毛殼ND35對冬小麥苗期生長和抗旱性的影響[J];生態(tài)學報;2015年18期

8 吳娟子;張建麗;潘玉梅;劉智微;鐘小仙;;象草和雜交狼尾草細胞壁組分及乙醇理論產量動態(tài)分析[J];草業(yè)學報;2014年04期

9 李嬌;張寶龍;趙穎;辛士剛;陳強;宋寧寧;李雪梅;;內生菌對提高植物抗鹽堿性的研究進展[J];生物技術通報;2014年04期

10 彭程;;鹽脅迫對植物的影響及植物耐鹽研究進展[J];山東商業(yè)職業(yè)技術學院學報;2014年02期

相關會議論文 前1條

1 王殿;袁芳;陳敏;王寶山;;能源植物雜交狼尾草對NaCl脅迫的響應及其耐鹽閾值[A];山東植物生理學會第七次代表大會暨植物生物學與現(xiàn)代農業(yè)研討會論文集[C];2012年

相關博士學位論文 前1條

1 許明雙;番茄和水稻種子可培養(yǎng)內生細菌的多樣性分析及促生菌功能研究[D];中國農業(yè)大學;2014年

相關碩士學位論文 前5條

1 李嬌;堿蓬內生菌對Na_2CO_3脅迫下水稻幼苗生長的緩解作用[D];沈陽師范大學;2014年

2 郭春曉;菊花對鹽脅迫的響應及外源SA的緩解效應研究[D];山東農業(yè)大學;2011年

3 郭英;生防芽孢桿菌對作物耐鹽性的影響及其抗鹽機理的研究[D];山東師范大學;2009年

4 楊遠昭;新疆三種鹽生植物種子萌發(fā)對主要生態(tài)因子響應的研究[D];新疆農業(yè)大學;2007年

5 陳潔;水稻幼苗耐鹽性的定量鑒定及耐鹽生理生化研究[D];華南熱帶農業(yè)大學;2003年

，

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