甘薯套作對(duì)根際土壤細(xì)菌群落多樣性及植株氮素吸收的影響

1、作物學(xué)報(bào)ACTAAGRONOMICASINICA2012，38(2)：333—343ISSN0496—3490；CODENTSHPA9http：／／wwwchinacropsorg／zwxb／E—mail：xbzw@chinajournaLnetcnDoI103724／SPJ1006201200333小麥／T米／大豆和小麥／t米／甘薯套作對(duì)根際土壤細(xì)菌群落多樣性及植株氮素吸收的影響雍太文楊文鈺向達(dá)兵朱貞穎四川農(nóng)業(yè)大學(xué)農(nóng)學(xué)院，四川溫江61

2、1130摘要：為探討小麥／玉米／大豆和小麥／玉米／甘薯套作體系中根際細(xì)菌群落多樣性與作物氮素高效吸收的差異特性及二者間的關(guān)系，應(yīng)用變性梯度凝膠電泳(DGGE)技術(shù)研究了小麥一大豆(A1)、小麥一甘薯(A2)、玉米(A3)、小麥／t米／大豆(A4)和小麥／t米／甘薯(A5)5種種植模式的根際細(xì)菌群落多樣性。結(jié)果表明，與A1、A2、A3及A5相比，A4套作提高了各作物在開花期(或吐絲期)與成熟期的籽粒吸氮量、地上部總吸氮量和Shannon—

3、Weinerindex多樣性指數(shù)(H)。處理間的吸氮量與日的變化規(guī)律為套作單作、大豆茬口甘薯茬口，以A4處理最高。不同種植模式下DGGE圖譜條帶的數(shù)量及亮度有較大區(qū)別，且有幾條特征性條帶發(fā)生了明顯變化。不同種植模式間的細(xì)菌群落結(jié)構(gòu)相似性較低，群落相似度系數(shù)()表現(xiàn)為套作與套作間套作與單作間；A4與A5間的相對(duì)較小，二者間的細(xì)菌群落結(jié)構(gòu)差異較大。A4模式有利于提高根際細(xì)菌群落多樣性，增強(qiáng)植株對(duì)氮素的吸收能力。關(guān)鍵詞：小麥／t米／大豆套作；

4、氮素吸收；細(xì)菌群落多樣性；PCR—DGGEEffectofWheat／Maize／SoybeanandWheat／Maize／SweetPotatelayStripIntercroppingonBacterialCommunityDiversityofRhizosphereSoilandNitrogenUptakeofCropsYONGTai—Wen，YANGWen—Yu，XIANGDaBing，andZHUZhen—YingAgron

5、omyCollege，SichuanAgriculturalUniversityWenjiang611130，ChmaAbstract：Theaimofthisstudywastounderstandtherelationshipbetweendiversityofrhizospherebacterialcomr0unityandnitrogenuptakeofcropsintwelaystripintercroppingsystems

6、：wheat／maize／soybearlandwheat／maize／sweetpotatoWeanalyzedthediversitiesofrhizospherebacterialcommunityinfivecroppingsystemsusingdenaturinggradientgelelectrophoresis(DGGE)basedon16SrDNAThecroppingsystemsincludedwheatsoybe

7、an(A1)，wheatsweetpotato(A2)，maizesinglecrop—ping(A3)，wheat／maize／soybearl(A4)，andwheat／maize／sweetpotato(A5)Comparedtothesolecroppingsystems(A1，A2，andA3treatments)，theA4treatmentshowedincreasesingrainnitrogenuptakeandtot

8、alnitrogenuptakeamountsofabovegroundofcropsatbothflowering(orsilking)andmatnritystages，andtheShannon—WeinerindicesforrhizospherebacterialcommunitydiversitywasalsoincreasedsignificantlyThevaluesofnitrogenuptakeandtheShann

9、on—Weinerindexintherelaystripintercroppingsystemsweregreaterthanthoseinsolecroppingsystemsandthevaluesinthetreatmentwjtl1soybearlstubbleweregreaterthanthoseinthetreatmentwithsweetpotatostubbleThenumberandstrengthoftheDNA

10、bandsfromDGGEprofilesvariedwiththecroppingsystems，especiallyforthedistinguishedbandsThecomparabifityofrhizospherebacterialcommunitycompositionwaslowamongdifferentcroppingsystemsThesimilaritycoeficient(Cs)washigherbetween

11、twelaystripintercroppingsystemsthanbetweenrelaystripintercroppingsystemandsolecroppingsystem，buttheCsvaluewaslowbetweenA4andA5treatmentsHowevertherewasobviousdifferenceofrhizospherebacterialcommunitycompositionbetweenA4a

12、ndA5treatments，andtheA4treatmentwaspropitioustoenhancingrhizospherebacterialcommunitydiversityandincreasingnitrogenuptakesofcropsKeywords：Wheat／maize／soybeanrelaystripintercropping；Nitrogenuptake；Bacterialcommunitydivers

13、ity；PCR—DGGE本研究由國家重點(diǎn)基礎(chǔ)研究發(fā)展計(jì)~(973計(jì)劃)項(xiàng)目(2011CB100400)~1]大豆產(chǎn)業(yè)技術(shù)體系專項(xiàng)(CARS一04PS19)資助。通訊作~：(Correspondingauthor)：楊文鈺Email：wenyuyang@263net第一作者聯(lián)系方式：E—mail：y0ngtaiwen@sicaueducnReceived(收稿日期)：201103—29；Accepted(接受日期)：20110911；Pu

14、blishedonline(~]絡(luò)出版日期)：201112—01URL：http：／／wwwcnkinetlkcms／detail／111809S201112010924020html第2期雍太文等：小麥／玉米／大豆和小麥／玉米／甘薯套作對(duì)根際土壤細(xì)菌群落多樣性及植株氮素吸收的影響335月20日播種、8月上旬收獲，大豆或甘薯5月22日播種或栽插、10月下旬收獲，大豆、甘薯于小麥?zhǔn)蘸筇追N于玉米空行中。20072008年度套作時(shí)換茬輪作，即

15、小麥種在原玉米茬口上，玉米種在原大豆(或甘薯)茬口上。12取樣方法和植株樣品分析于小麥拔節(jié)期、開花期和成熟期，玉米拔節(jié)期、吐絲期和成熟期，大豆分枝期、開花盛期和成熟期，采用傳統(tǒng)挖掘法取根際土壤樣品。20062007年度由于前茬相同，小麥拔節(jié)期尚未與玉米共生，未對(duì)該時(shí)期取樣；甘薯采樣時(shí)期與大豆相同。套作小麥分邊2行和中3行分別取樣，單作小麥取中3行；套作大豆分邊2行和中1行分別取樣，單作大豆取中2行。選好取樣區(qū)后，小麥和大豆在小區(qū)內(nèi)選長勢(shì)

16、一致的樣段隨機(jī)取兩段，每段取連續(xù)2穴。玉米、甘薯套作與單作取樣方法相同，每小區(qū)選長勢(shì)一致的樣段隨機(jī)取兩段，每段取對(duì)稱2行的連續(xù)2穴。取樣時(shí)將根系從土壤中整體挖出，抖掉與根系松散結(jié)合的土體土，然后用經(jīng)火焰滅菌的鑷子刮取附在根系的一薄層(A5和AIA2。從邊、中行效應(yīng)來看，各生育期A4和A5的邊行的莖葉吸氮量和籽粒吸氮量均高于相應(yīng)處理的中行及單作，以A4的邊行的吸氮量最高，20072008年度，A4—1的籽粒吸氮量比A1和A2高358％和6