發(fā)布時間：2018-01-21 08:57

  本文關(guān)鍵詞： 土壤臨界磷濃度 磷再轉(zhuǎn)移 菌根真菌 根系轉(zhuǎn)錄組 微生物群落結(jié)構(gòu) 玉米　出處：《中國農(nóng)業(yè)大學(xué)》2017年博士論文　論文類型：學(xué)位論文

【摘要】：確定合理的磷肥施用量及土壤有效磷濃度對生產(chǎn)中磷肥減施增效,發(fā)揮作物自身及土壤微生物的生物學(xué)潛力,保證農(nóng)業(yè)生態(tài)系統(tǒng)可持續(xù)發(fā)展具有重要意義。本研究以玉米為材料,在中國農(nóng)業(yè)大學(xué)上莊試驗站通過多年田間定位試驗,確定了保證玉米高產(chǎn)的磷肥臨界施用量及相應(yīng)的土壤臨界磷濃度;研究了不同供磷量對玉米吐絲后地上部磷再轉(zhuǎn)移、分配及葉/穗碳水化合物濃度的影響;應(yīng)用分子生物學(xué)方法,比較研究了不同供磷量(0-300 kg/ha)及土層(0-20 cm,20-40 cm)間玉米根中菌根真菌群落結(jié)構(gòu)和供磷潛力的差異;采用RNA-Seq、16S、ITS測序技術(shù)以及土壤輻照滅菌技術(shù),比較了缺磷和充足供磷下,玉米軸根和側(cè)根轉(zhuǎn)錄組、微生物群落結(jié)構(gòu)以及微生物對玉米生長的作用。主要結(jié)果如下:1)保證玉米高產(chǎn)的當(dāng)?shù)亓追?P205)臨界施用量為75-100 kg/ha,對應(yīng)的0-20 cm 土層Olsen-P濃度為6-10 mg/kg。超過臨界值后,繼續(xù)增加施磷量不會增加玉米產(chǎn)量,導(dǎo)致磷肥利用率下降。20-40 cm土層的Olsen-P濃度在充足甚至過量施磷條件下仍維持在3-6 mg/kg的虧缺水平。適宜施磷量的玉米地上部總磷濃度從八葉期(生物量為2 t/ha左右)的3 mg/g降低至吐絲期(生物量為8 t/ha)后的1.6mg/g,之后保持不變至成熟。2)缺磷顯著提高玉米吐絲后早期下部葉片的磷再轉(zhuǎn)移效率,對莖和上部葉片磷再轉(zhuǎn)移效率以及成熟時的磷收獲指數(shù)無顯著影響。缺磷未顯著影響玉米吐絲后穗位葉光合速率,但促進吐絲后早期葉/穗中淀粉合成。乳熟期玉米體內(nèi)的磷再轉(zhuǎn)移以及葉/穗碳水化合物濃度均不受供磷水平影響。3)玉米根系菌根真菌侵染率、叢枝豐度、菌根真菌酸性/堿性磷酸酶活性以及根系ZmPht1;6(菌根真菌侵染誘導(dǎo)表達的磷轉(zhuǎn)運蛋白基因)和ZmCCD8a(獨角金內(nèi)酯合成基因)相對表達量隨施磷量增加而顯著降低。當(dāng)施磷量超過75-100 kg/ha時均達到最低值,并且不再隨施磷量增加而變化。20-40 cm 土層玉米根系中上述指標所反映的菌根真菌供磷潛力明顯高于0-20 cm 土層的根系。與上述指標的變化不同,玉米根中菌根真菌OUT數(shù)目和香農(nóng)指數(shù)在不同磷水平或土層間均無顯著差異,但真菌群落組成和OUT相對豐度在供磷水平間有顯著差異,群落組成在土層間沒有顯著差異。4)玉米軸根和側(cè)根轉(zhuǎn)錄組以及真菌群落結(jié)構(gòu)有明顯差異,并且差異大于不同供磷水平造成的差異。在轉(zhuǎn)錄水平,充足供磷時,軸根細胞壁代謝、次生代謝及生物脅迫防御代謝顯著弱于側(cè)根。缺磷脅迫導(dǎo)致玉米軸根、側(cè)根大量基因表達上調(diào),軸根中差異表達基因數(shù)目顯著多于側(cè)根且主要富集于生物脅迫防御代謝。菌根真菌主要侵染側(cè)根而不是軸根,缺磷脅迫主要改變側(cè)根中的真菌群落結(jié)構(gòu)。5)盆栽結(jié)合土壤輻照滅菌研究表明,缺磷土壤滅菌進一步抑制玉米生長并導(dǎo)致植株極度缺磷,而充足供磷土壤滅菌則促進玉米生長。根系轉(zhuǎn)錄組分析結(jié)果表明,土壤滅菌導(dǎo)致根系大量基因表達下調(diào)。充足供磷土壤滅菌后表達顯著下調(diào)的基因富集于生物脅迫防御、蛋白水解、幾丁質(zhì)代謝、氧化還原等生物過程。缺磷土壤滅菌后表達顯著下調(diào)的基因富集于DNA復(fù)制,脂肪酸代謝、細胞壁合成等過程。缺磷和充足供磷時根中細菌和真菌群落結(jié)構(gòu)無顯著差異。綜上,合理的磷肥施用不僅能夠獲得高產(chǎn),同時能夠大幅度提高磷肥利用率。缺磷及過量施磷均不能提高磷收獲指數(shù)。在充足甚至過量施磷條件下,20-40 cm 土層玉米根系中菌根真菌供磷潛力顯著高于0-20 土層的根系。缺磷時土壤微生物幫助玉米獲取磷的有益作用大于有害作用,而供磷充足時則相反。充足供磷時,側(cè)根中真菌侵染及生物脅迫防御代謝均強于軸根,缺磷脅迫主要改變側(cè)根中真菌群落結(jié)構(gòu),誘導(dǎo)軸根生物脅迫防御代謝。說明供磷既可以影響玉米軸根、側(cè)根的功能分離,也能影響土壤微生物提高土壤磷利用的生物學(xué)潛力。側(cè)根作為植物主要的吸收養(yǎng)分和水分的部位,被真菌侵染的程度和真菌的群落結(jié)構(gòu)更容易受供磷水平的影響,而軸根生物脅迫防御代謝的顯著上調(diào)可以盡可能減少有害微生物的危害。
[Abstract]:To determine the application efficiency of the production of phosphate fertilizer and phosphate fertilizer reduced soil available phosphorus concentration reasonably, crop and soil microorganisms play their biological potential, is an important guarantee of sustainable development of agro ecosystem. In this study, corn as the material, through years of field experiment station in China Agricultural University on the test, confirming the critical application amount of phosphate fertilizer high yield of maize and the corresponding critical soil phosphorus concentration; of different phosphorus content on Maize shoot p re transfer, distribution and effect of ear leaf / carbohydrate concentration; with molecular biology methods, comparative study of different phosphorus content (0-300 kg/ha) and soil layer (0-20 cm, 20-40 cm) difference among the mycorrhizal fungi community structure and potential for phosphorus in maize roots; using RNA-Seq, 16S, ITS sequencing technology and soil irradiation sterilization technology, compares the phosphorus deficiency and sufficient supply of phosphorus, Corn root and root transcriptome, microbial community structure and microbial effects on the growth of maize. The main results are as follows: 1) to ensure the local fertilizer high yield of Maize (P205) critical application amount was 75-100 kg/ha, the corresponding 0-20 cm soil Olsen-P concentration was 6-10 mg/kg. exceeds the critical value, continue to increase the amount of phosphorus does not increase maize the yield, resulting in Olsen-P phosphate fertilizer utilization rate of decline in.20-40 cm soil layer under the condition of adequate or excessive P remained at 3-6 mg/kg level. The suitable amount of phosphorus deficiency of maize aboveground total phosphorus concentration from eight leaf stage (biomass is about 2 t/ha) 3 mg/g reduced to silking (biomass for 8 t/ha) after 1.6mg/g, after unchanged to mature.2) P significantly increased maize early lower leaf phosphorus transfer efficiency, phosphorus harvest index of stem and leaf phosphorus transfer efficiency and when mature No significant effect of phosphorus deficiency did not significantly affect maize ear leaf photosynthetic rate, but the promotion of early leaf / ear after silking in starch synthesis. In milk stage corn phosphorus transfer and leaf / panicle carbohydrate concentrations were not affected by P level.3) maize root arbuscular mycorrhizal fungi colonization rate. The abundance of mycorrhizal fungi, acid / alkaline phosphatase activity and root ZmPht1; 6 (phosphate transporter gene expression induced by mycorrhizal fungi (ZmCCD8a) and strigolactone synthetic gene) expression significantly decreased with the increase of phosphorus fertilizer application. When phosphorus was more than 75-100 when kg/ha reached the lowest value, and is no longer with the application the amount of P increases the index of.20-40 mycorrhizal fungi cm soil of maize root of P potential was significantly higher than that in 0-20 cm soil layer. The root changes with the above index of different number of mycorrhizal fungi in roots of maize and sweet OUT The agricultural index showed no significant difference in different phosphorus levels or layers, but OUT fungal community composition and relative abundance of significant differences in P level, the community composition.4 has no significant difference in the soil) have obvious difference of maize root and root transcriptome and fungal community structure, and the difference is greater than the difference caused by different phosphorus levels. At the transcriptional level, adequate supply of phosphorus, root cell wall metabolism, secondary metabolism and biological stress defense metabolism was significantly weaker than that of lateral roots. Phosphorus deficiency stress leads to upregulation of lateral root of corn, a large number of genes differentially expressed in root, lateral root and the number of genes significantly more than mainly enriched in biological stress defense metabolism. Mycorrhizal fungi mainly infect rather than root root, phosphorus stress.5 fungal community structure changes in the main root) of soil pot irradiation showed that phosphorus deficient soil sterilization to further suppress the jade The growth of plants and lead to extreme M P, and adequate phosphorus soil sterilization promote maize growth. Root transcriptome analysis results showed that soil sterilization resulted in down-regulation of gene expression. A large number of roots significantly down regulated genes enriched in biological stress defense, protein hydrolysis, chitin metabolism of adequate supply of phosphorus in soil after sterilization, redox and other biological process. Pdeficient soil sterilization significantly down regulated genes enriched in DNA replication, fatty acid metabolism, cell wall synthesis process. The phosphorus and phosphorus supplying adequate root bacterial and fungal community structure have no significant difference. In conclusion, the reasonable application of phosphate fertilizer can not only get high yield, and can greatly improve the utilization ratio of phosphate fertilizer. Phosphorus deficiency and excess phosphorus can increase phosphorus harvest index. In adequate or excessive phosphate fertilizer conditions, 20-40 cm soil of maize root mycorrhizal fungi were significantly higher than that in 0-20 soil phosphorus supply potential The beneficial effect of phosphorus in roots. When soil microbes help corn phosphorus acquisition is greater than the harmful effect, and phosphorus sufficient opposite. Adequate supply of phosphate, the plant fungal infection and biological stress defense Xie Junqiang in root, phosphorus stress change in main root fungal community structure, metabolism of individual biological stress induced defense that P can affect maize root, root separation function, also can improve the effect of soil microbial biological potential of soil phosphorus utilization. As the plant root absorption of nutrients and water are the main parts of the community structure, and the degree of fungal infection are more easily affected by phosphorus levels, and increased defensive metabolism individual biological stress can minimize the hazards of harmful microorganisms.

【學(xué)位授予單位】：中國農(nóng)業(yè)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：S513

【參考文獻】

相關(guān)期刊論文 前10條

1 陳丹梅;段玉琪;楊宇虹;晉艷;黃建國;袁玲;;長期施肥對植煙土壤養(yǎng)分及微生物群落結(jié)構(gòu)的影響[J];中國農(nóng)業(yè)科學(xué);2014年17期

2 Alexa M.Schmitz;Maria J.Harrison;;Signaling events during initiation of arbuscular mycorrhizal symbiosis[J];Journal of Integrative Plant Biology;2014年03期

3 劉俊杰;王光華;金劍;劉居?xùn)|;張秋英;劉曉冰;;磷濃度處理對大豆根際土壤微生物群落結(jié)構(gòu)的影響[J];大豆科學(xué);2008年05期

4 張福鎖;王激清;張衛(wèi)峰;崔振嶺;馬文奇;陳新平;江榮風(fēng);;中國主要糧食作物肥料利用率現(xiàn)狀與提高途徑[J];土壤學(xué)報;2008年05期

5 晉齊鳴;宋淑云;李紅;蘇前富;張偉;王立新;隋晶;;不同耕作方式玉米田土壤病原菌數(shù)量分布與病害相關(guān)性研究[J];玉米科學(xué);2007年06期

6 王光華;金劍;徐美娜;劉曉冰;;植物、土壤及土壤管理對土壤微生物群落結(jié)構(gòu)的影響[J];生態(tài)學(xué)雜志;2006年05期

7 胡江春,薛德林,馬成新,王書錦;植物根際促生菌(PGPR)的研究與應(yīng)用前景[J];應(yīng)用生態(tài)學(xué)報;2004年10期

8 朱教君,徐慧,許美玲,康宏樟;外生菌根菌與森林樹木的相互關(guān)系[J];生態(tài)學(xué)雜志;2003年06期

9 沈宏,施衛(wèi)明,王校常,曹志洪;不同作物對低磷脅迫的適應(yīng)機理研究[J];植物營養(yǎng)與肥料學(xué)報;2001年02期

10 劉建玲,張福鎖;小麥-玉米輪作長期肥料定位試驗中土壤磷庫的變化 Ⅰ.磷肥產(chǎn)量效應(yīng)及土壤總磷庫、無機磷庫的變化[J];應(yīng)用生態(tài)學(xué)報;2000年03期

，

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