楊如意,郭富裕,昝樹(shù)婷,孫雯雯,周 剛,唐建軍,陳 欣
(1. 安徽師范大學(xué)環(huán)境科學(xué)與工程學(xué)院,蕪湖 241003;2. 浙江大學(xué)生命科學(xué)學(xué)院,杭州 310058)
叢枝菌根真菌(AMF)是自然界中一類(lèi)廣泛分布的根際微生物,能夠與80%以上的陸生植物根系形成共生體——菌根,具有非常重要的生態(tài)功能[1-2]。AMF必須依賴(lài)宿主根系提供的光合產(chǎn)物生存,作為回報(bào)AMF能夠顯著提高宿主對(duì)礦質(zhì)養(yǎng)分(尤其是磷)的攝取能力[3],增強(qiáng)宿主對(duì)干旱、重金屬、高鹽等脅迫環(huán)境的耐性[4-6],抑制土傳病原菌[7],改良土壤結(jié)構(gòu)[8-9]。AMF對(duì)宿主幾乎沒(méi)有選擇性,可以同時(shí)侵染多個(gè)宿主,并利用外生菌絲網(wǎng)(hyphal network)將植物群落連成一個(gè)整體。同時(shí),可以通過(guò)菌絲傳遞C、N、P等營(yíng)養(yǎng)物質(zhì),影響資源分配,從而對(duì)植物間相互作用的方向(如競(jìng)爭(zhēng)或互惠)和強(qiáng)度進(jìn)行調(diào)節(jié)[10-12]。
植物-土壤-AMF是一個(gè)復(fù)合系統(tǒng),影響AMF功能的因素主要包括AMF(如AMF的種類(lèi)、群落組成等)、宿主植物(包括宿主特征、AMF與宿主植物的關(guān)系等),以及其他生物與非生物環(huán)境(如土壤營(yíng)養(yǎng)狀況、鄰體植物特征、其他根際微生物等)3個(gè)方面[12-15]。近年來(lái),大量研究表明不同來(lái)源AMF的功能有顯著差異[16-18],但目前國(guó)內(nèi)外對(duì)來(lái)源造成AMF功能分化的原因、維持機(jī)制和生態(tài)學(xué)意義尚未進(jìn)行系統(tǒng)總結(jié)和深入分析。本文綜述了該領(lǐng)域的最新研究成果,從基因變異和表型可塑性?xún)煞矫嫣接懥藖?lái)源影響AMF功能的機(jī)制,分析了不同來(lái)源的AMF對(duì)宿主的環(huán)境適應(yīng)能力,以及植物間相互作用的影響,提出了當(dāng)前研究中亟待解決的關(guān)鍵問(wèn)題,并對(duì)未來(lái)的研究重點(diǎn)和方向進(jìn)行了討論和展望,期望可以為更加清晰、全面地認(rèn)識(shí)AMF在生態(tài)系統(tǒng)中的功能提供參考。
土壤環(huán)境和宿主的差異是造成不同來(lái)源的AMF功能分化的重要原因。目前,研究的熱點(diǎn)集中在不同土壤環(huán)境,尤其是脅迫環(huán)境下AMF功能的變化,對(duì)宿主的影響關(guān)注的很少。通常,脅迫環(huán)境中的AMF會(huì)進(jìn)化出各種應(yīng)對(duì)脅迫因子的機(jī)制,具有較高的耐受性,對(duì)宿主的侵染能力更強(qiáng),促生作用也更顯著[19-21]。高鹽土壤中的本地AMF能夠從基因和生理水平上顯著緩解鹽脅迫對(duì)宿主的損傷,增強(qiáng)宿主的耐受性,接種效果明顯高于常規(guī)條件下保藏的同種AMF[22-23]。同樣,與外來(lái)AMF相比,半干旱環(huán)境中的本地AMF應(yīng)對(duì)干旱脅迫的能力更強(qiáng),可以通過(guò)調(diào)節(jié)氣體交換,增加N、P、K攝取、水分利用效率和地上部分生物量等方式,提高植物在半干旱生境中的定植成功率[24-25]。近年來(lái),對(duì)來(lái)源于重金屬污染區(qū)域的AMF功能和特征開(kāi)展了深入研究。重金屬?gòu)U棄地通常會(huì)受到多種重金屬的復(fù)合污染,同時(shí)還伴有干旱、營(yíng)養(yǎng)貧瘠、土壤微生物量和多樣性低等多種不利于植物生存的復(fù)雜因素[26]。因此,與其他單因子脅迫相比,對(duì)植物定植和生長(zhǎng)的影響更大。AMF對(duì)重金屬脅迫的適應(yīng)能力有明顯差異,不同污染水平下AMF的侵染率、孢子密度、群落結(jié)構(gòu)和多樣性均有所不同[27]。來(lái)源于重金屬污染環(huán)境下的AMF能夠減少宿主對(duì)重金屬的吸收和向地上部分的運(yùn)輸,降低對(duì)宿主的毒害;同時(shí),促進(jìn)對(duì)P等營(yíng)養(yǎng)物質(zhì)的攝取,加速植物生長(zhǎng),從而增強(qiáng)植物對(duì)重金屬的耐性[28-29]。Orlowska等還發(fā)現(xiàn),不同來(lái)源的AMF在緩解As對(duì)植物根部生長(zhǎng)的抑制作用方面表現(xiàn)出明顯差異。不接種AMF時(shí),長(zhǎng)葉車(chē)前(PlantagolanceolataL.)側(cè)根變短、腫脹、發(fā)黑、變硬現(xiàn)象明顯,而接種來(lái)自非污染環(huán)境的根內(nèi)球囊霉(Rhizophagusintraradices即原分類(lèi)系統(tǒng)中的G.intraradices)對(duì)上述抑制作用有輕度改善,接種分離自鹽堿、Zn、Pb和As污染下的3種AMF則表現(xiàn)出更強(qiáng)的緩解作用[30]。國(guó)內(nèi)關(guān)于這方面的研究也很多,楊秀梅等發(fā)現(xiàn)分離自銅尾礦的G.intraradices與普通土壤中的G.intraradices相比,更有利于植物的生長(zhǎng)和對(duì)銅的吸收[31]。但是,AMF對(duì)脅迫環(huán)境的耐性和功能優(yōu)勢(shì)在消除環(huán)境的選擇壓力后會(huì)很快喪失。高堿生境中的地球囊霉(G.geosporum)在沸石中培養(yǎng)14個(gè)月后,其序列多樣性發(fā)生了顯著變化,侵染率、孢子產(chǎn)量和外生菌絲長(zhǎng)度均顯著下降,對(duì)宿主P的攝取和生長(zhǎng)的促進(jìn)作用明顯減弱[32],這也說(shuō)明AMF具有快速適應(yīng)新環(huán)境的能力。
非脅迫環(huán)境下,不同來(lái)源的AMF之間也存在十分明顯的種內(nèi)差異。貧瘠土壤中的隱球囊霉(G.occultum)對(duì)宿主N、P攝取和生長(zhǎng)的促進(jìn)作用顯著高于肥沃土壤中的同種AMF,且培養(yǎng)基質(zhì)的P水平越低差異越明顯[33],這可能與營(yíng)養(yǎng)條件較好時(shí)AMF的作用會(huì)顯著下降有關(guān)。Yao等發(fā)現(xiàn),草地上的優(yōu)勢(shì)植物對(duì)本地地表球囊霉(G.versiforme)的依賴(lài)性顯著高于外來(lái)的G.versiforme,宿主根部的P攝取量和生物量在接種本地AMF時(shí)增加更為明顯[34],說(shuō)明植物的群落組成也是影響AMF功能的原因之一。在更大的空間尺度上,來(lái)自不同氣候條件或溫度帶的同種AMF會(huì)產(chǎn)生不同的生態(tài)型,其功能也明顯不同[35-36]。從上述研究可以看出,對(duì)特定生存環(huán)境和宿主的適應(yīng),或稱(chēng)為本土化(local adaptation)是造成不同來(lái)源的AMF功能趨異的主要原因[37-38]。
但也有一些研究顯示,不同來(lái)源的AMF對(duì)宿主的影響并無(wú)顯著差異。Schreiner發(fā)現(xiàn)在高P條件下,兩種摩西球囊霉(G.mosseae)對(duì)葡萄(VitisviniferaL.)P吸收和生長(zhǎng)的促進(jìn)作用相同,但P水平較低時(shí)來(lái)自高P環(huán)境的G.mosseae功能更強(qiáng)[39],表明土壤營(yíng)養(yǎng)狀況也是決定研究結(jié)果的關(guān)鍵因素之一。另有研究發(fā)現(xiàn),來(lái)自脅迫環(huán)境的AMF有時(shí)并不能有效減輕脅迫因子對(duì)宿主的影響,甚至可能會(huì)加重其損傷[40-43]。導(dǎo)致上述研究結(jié)果不一致的原因可能包括研究涉及的環(huán)境因子類(lèi)型、水平,所選擇的AMF和宿主的類(lèi)型,研究的時(shí)空尺度,以及測(cè)定的參數(shù)等多種復(fù)雜因素[14,44-45]。
大多數(shù)研究表明,來(lái)源對(duì)AMF的功能產(chǎn)生了重要影響。導(dǎo)致此現(xiàn)象的原因可能源于以下兩個(gè)方面。
即不同來(lái)源的AMF基因結(jié)構(gòu)或功能存在變異。這種變異可能發(fā)生在物種、個(gè)體(即種內(nèi)多樣性或基因型多樣性)、甚至個(gè)體內(nèi)水平(即由同一孢子產(chǎn)生的不同個(gè)體間的多樣性)[46],而驅(qū)動(dòng)基因變異的原因大多來(lái)自環(huán)境的選擇壓力[47]。AMF的特殊之處在于其孢子有多個(gè)相互隔離的細(xì)胞核,產(chǎn)生新孢子時(shí)可能發(fā)生基因重組,菌絲網(wǎng)上不同的孢子間也可能發(fā)生基因融合,從而使AMF在不同水平上發(fā)生變異的機(jī)率增大[48-49],這也可能是AMF分布范圍廣和環(huán)境適應(yīng)性強(qiáng)的重要原因之一。生存環(huán)境的變化是造成AMF特征和功能變異的重要誘因。研究發(fā)現(xiàn),耐堿的G.geosporum在堿脅迫和正常環(huán)境下進(jìn)行傳代培養(yǎng)后,基因型、表型,以及對(duì)宿主的功能均發(fā)生了明顯變化[32]。需要注意的是AMF種內(nèi)或種間多樣性與功能多樣性之間并不具有一致性。一方面,不同來(lái)源的同種AMF各菌株間的基因差異并不大,但卻存在很高的功能多樣性,對(duì)宿主的影響明顯不同[50]。另一方面,單個(gè)孢子在同等條件下培養(yǎng)幾代后也很會(huì)產(chǎn)生明顯的表型和基因變異[51],它們對(duì)宿主的作用甚至截然相反[52],不同菌株的侵染還會(huì)改變?nèi)∈忱ハx(chóng)對(duì)植物的選擇[53]。由此可見(jiàn),環(huán)境變化并非導(dǎo)致AMF功能變異的唯一原因,遺傳漂變的作用同樣不可忽視[32]。此外,宿主的變化和核的隔離作用也會(huì)改變AMF的功能[46]。Ehinger等發(fā)現(xiàn),源自同一環(huán)境的G.intraradices在侵染不同宿主時(shí)的表現(xiàn)有明顯差異[54]。通過(guò)核隔離和交換作用得到的一系列G.intraradices菌株,接種后使水稻(Oryzasativa)的生物量相差2到5倍,某些菌株甚至對(duì)水稻特定基因的轉(zhuǎn)錄產(chǎn)生不同影響[48]。
除基因變異以外,AMF功能的差異也可能源于表型可塑性或環(huán)境飾變,即AMF的基因并未發(fā)生改變,但其表型會(huì)產(chǎn)生與生存環(huán)境相適應(yīng)的變化。Avio等分別研究了G.mosseae和G.intraradices的兩個(gè)不同來(lái)源的菌株,發(fā)現(xiàn)AMF的功能存在種間和種內(nèi)差異。不同菌株的表型(如外生菌絲長(zhǎng)度、密度、接合數(shù)等)與植物的生物量和P含量呈顯著正相關(guān)[17]。其他研究者也認(rèn)為AMF對(duì)宿主N、P攝取的影響與其外生菌絲的表型和功能特征有關(guān)[55-56],但上述研究均沒(méi)有明確不同菌株是否存在基因差異?;蜃儺惡捅硇涂伤苄?xún)煞N機(jī)制之間存在復(fù)雜的相互聯(lián)系,任何表型的變化都是由環(huán)境和基因兩方面因素造成的。與其他主要依賴(lài)環(huán)境可塑性應(yīng)對(duì)環(huán)境變化的生物不同,AMF主要通過(guò)改變核型頻率(即產(chǎn)生不同的基因型)提高對(duì)環(huán)境的適應(yīng)能力。Angelard等發(fā)現(xiàn),宿主的改變會(huì)很快引起不同品系的AMF基因型發(fā)生變化,子代與親代AMF的基因型和表型對(duì)環(huán)境變化的響應(yīng)有所不同,子代AMF的環(huán)境可塑性更高[57]。這種由生物或非生物環(huán)境變化造成的功能或表型特征的變異是AMF適應(yīng)環(huán)境的一種方式,它的維持機(jī)制與后續(xù)的生存環(huán)境密切相關(guān)[32,58]。
由于人類(lèi)活動(dòng)的強(qiáng)烈干擾,全球范圍內(nèi)生物多樣性降低、物種滅絕和生態(tài)系統(tǒng)退化等現(xiàn)象越來(lái)越頻繁。AMF是決定植物群落多樣性和生態(tài)系統(tǒng)生產(chǎn)力的重要因素之一[59]。植物與AMF之間經(jīng)過(guò)長(zhǎng)期的協(xié)同進(jìn)化,本地AMF在緩解宿主面臨的選擇壓力,增強(qiáng)植物耐性和適應(yīng)能力,提高植物多樣性等方面有明顯優(yōu)勢(shì),這對(duì)退化生態(tài)系統(tǒng)的恢復(fù)和重建具有重要意義[60-62]。另外,由于AMF對(duì)宿主植物具有多重生態(tài)功能,并且分布范圍廣、對(duì)宿主選擇性低、適應(yīng)能力強(qiáng),因此利用AMF降低瀕危植物的滅絕風(fēng)險(xiǎn)受到學(xué)者的廣泛關(guān)注。瀕危植物的生境通常較為特殊,來(lái)源于該生境的AMF在改善植物生存條件和恢復(fù)種群方面將具有更大潛力[63-64],但該方法的實(shí)際應(yīng)用目前還面臨著諸多困難。
植物間的相互作用主要包括競(jìng)爭(zhēng)與互惠,AMF對(duì)植物間的相互作用具有重要的調(diào)節(jié)功能[11],因此必將對(duì)植物群落的組成和動(dòng)態(tài)產(chǎn)生深遠(yuǎn)影響。不同來(lái)源的AMF在入侵植物與本地植物的競(jìng)爭(zhēng)過(guò)程中扮演著重要角色。由于缺少天敵,加上入侵地AMF的正反饋?zhàn)饔檬谷肭种参锏母?jìng)爭(zhēng)能力顯著增強(qiáng)[65]。而且,入侵植物還能夠通過(guò)改變本地土壤中的AMF群落組成,弱化本地植物的競(jìng)爭(zhēng)能力,從而有利于其種群的進(jìn)一步擴(kuò)張[12]。干旱、重金屬污染、鹽堿等嚴(yán)酷的生存條件下,植物間的相互作用通常由競(jìng)爭(zhēng)轉(zhuǎn)變?yōu)榛セ輀66]。本地AMF對(duì)脅迫環(huán)境的耐性較強(qiáng),有助于先鋒植物成功定植[67],強(qiáng)大的外生菌絲網(wǎng)對(duì)改善根際微環(huán)境,以及在植物之間建立穩(wěn)定的互惠關(guān)系至關(guān)重要[11,68]?;セ葑饔脤?duì)提高敏感型植物的耐性水平,增加植物多樣性,加速群落演替進(jìn)程,縮短退化生態(tài)系統(tǒng)的恢復(fù)周期有顯著影響。
雖然,已有大量研究證實(shí)了來(lái)源對(duì)AMF功能的影響,但當(dāng)前研究中仍然有幾個(gè)關(guān)鍵問(wèn)題亟待解決。
前人的研究多數(shù)是對(duì)來(lái)源于不同環(huán)境的AMF物種或菌株進(jìn)行比較,而不是AMF群落。但自然條件下,AMF是以群落而不是單個(gè)物種的形式存在的,從群落水平對(duì)AMF的功能進(jìn)行研究更具有現(xiàn)實(shí)意義。由于不同的AMF之間會(huì)產(chǎn)生功能互補(bǔ)、協(xié)同作用和競(jìng)爭(zhēng)關(guān)系,因此AMF種群和群落在功能上會(huì)有明顯差異[18,69]。對(duì)于一種特定的宿主植物而言,由于某些AMF對(duì)其更有利,宿主植物會(huì)把光合產(chǎn)物更多地分配給這些AMF,從而導(dǎo)致它們之間產(chǎn)生一種特殊的AMF-宿主關(guān)系,即偏好性[12]。自然條件下,植物根際的AMF群落組成會(huì)同時(shí)受到生物與非生物因子的影響。土壤環(huán)境的異質(zhì)性,如土壤類(lèi)型、質(zhì)地、pH值、有機(jī)質(zhì)含量等都會(huì)顯著影響土壤中AMF孢子的密度、豐度、侵染率和群落組成[70-71]。外來(lái)物種入侵對(duì)本地AMF群落也有很大影響,這可能與外來(lái)物種根際微環(huán)境(如根際分泌物類(lèi)型和數(shù)量)與本地植物不同有關(guān)[12,65]。Hawkes等研究發(fā)現(xiàn),兩種外來(lái)入侵種裂稃燕麥(Avenabarbata)和大麥狀雀麥(Bromushordeaceus)顯著改變了本地植物根際的AMF群落組成[72]。蔥芥(Alliariapetiolata)和加拿大一枝黃花(SolidagocanadensisL.)等入侵種則利用對(duì)某些AMF的偏好性,改變了當(dāng)?shù)氐腁MF群落,影響了本地植物與AMF的關(guān)系,從而更有利于外來(lái)物種的入侵[12,73]。目前,只有少數(shù)涉及AMF功能的研究是在群落水平上開(kāi)展的[12, 18,74]。筆者通過(guò)人工構(gòu)建的AMF群落發(fā)現(xiàn),銅脅迫下R.intraradices和G.etunicatum的孢子密度最大,而普通土壤中Funneliformismosseae(即原分類(lèi)系統(tǒng)中的G.mosseae)為優(yōu)勢(shì)種。源自脅迫環(huán)境的AMF群落在脅迫條件下對(duì)宿主更有利,原因是減輕了銅對(duì)植物根部生長(zhǎng)的抑制作用,增加了生物量,同時(shí)對(duì)葉綠素含量、脂質(zhì)過(guò)氧化存在顯著的緩解作用,但在非脅迫條件下上述現(xiàn)象并不明顯[75]。
研究AMF來(lái)源對(duì)其功能的影響,需要確保這些AMF屬于同一物種或相同的AMF群落。但國(guó)內(nèi)外均有部分研究將不同物種的AMF,或單個(gè)物種與AMF群落進(jìn)行對(duì)比[19,24,30,76-77]。如上所述,不同的AMF本身就存在特性和功能差異[7, 13],單個(gè)物種更無(wú)法與AMF群落進(jìn)行對(duì)等比較,因?yàn)锳MF群落對(duì)宿主的作用通常要強(qiáng)于單個(gè)物種[69,78]。
有必要將群落結(jié)構(gòu)和來(lái)源對(duì)AMF功能的不同影響區(qū)分開(kāi)。Ji等通過(guò)移栽試驗(yàn)比較了來(lái)自蛇紋巖草地和高桿草原的兩種AMF群落,發(fā)現(xiàn)AMF群落均對(duì)本地土壤環(huán)境的適應(yīng)能力更強(qiáng),對(duì)宿主植物的促生作用也更顯著,但新環(huán)境下AMF群落組成會(huì)發(fā)生明顯變化,功能也有所減弱[18]。與此類(lèi)似,Moora等發(fā)現(xiàn)不同來(lái)源的AMF群落對(duì)同屬的腎葉白頭翁(Pulsatillapatens,稀有種)和洋白頭翁(P.pratensis, 常見(jiàn)種)的作用有顯著差異,兩種植物根部的AMF群落組成也不同,因此推測(cè)這可能是決定植物優(yōu)勢(shì)度的重要原因[74]。但上述AMF群落功能的差異并不完全取決于其來(lái)源,研究中涉及的AMF群落本身在組成上就有所不同,AMF的種間或種內(nèi)相互作用也可能是導(dǎo)致其功能產(chǎn)生差異的重要原因[69,78]。由于目前對(duì)不同來(lái)源的AMF群落的研究還很少,因此需要進(jìn)一步提高對(duì)此問(wèn)題的關(guān)注。筆者將人工構(gòu)建的AMF群落分別在銅脅迫和非脅迫環(huán)境下進(jìn)行培養(yǎng),研究了其對(duì)玉米生理、生長(zhǎng)和抗逆性的影響。由于AMF群落最初的組成是一致的,因此可以推斷AMF群落結(jié)構(gòu)和功能的變化均是由不同的培養(yǎng)環(huán)境造成的[75]。
研究表明,宿主的變化會(huì)造成AMF基因型和表型迅速改變,從而提高對(duì)環(huán)境的適應(yīng)能力[54,57]。Hausmann等進(jìn)一步發(fā)現(xiàn),3種1年生的鄰體植物對(duì)Nassellapulchra根際AMF群落結(jié)構(gòu)的影響截然不同[79]。因此,不能忽視宿主植物,甚至鄰體植物對(duì)AMF功能的影響。換言之,即使從同一種生境中分離的AMF,如來(lái)自不同宿主植物的根際,在功能上可能也存在顯著差異。AMF與特定的植物之間經(jīng)過(guò)長(zhǎng)期的協(xié)同進(jìn)化,在形態(tài)、生理、表型、功能等很多方面可能都已產(chǎn)生了相應(yīng)的適應(yīng)性變化[80-81]。宿主對(duì)AMF的影響可能是通過(guò)植物根系所形成的特定微環(huán)境產(chǎn)生的,但具體的機(jī)制還需要今后更多的研究來(lái)證實(shí)。目前,國(guó)內(nèi)外關(guān)于宿主影響AMF功能的研究逐漸增多,但在分離AMF時(shí)通常只關(guān)注非生物環(huán)境的差異,對(duì)宿主的影響未引起足夠重視。
AMF作為一種十分重要的根際微生物,其功能的變化將會(huì)對(duì)陸地生態(tài)系統(tǒng)的物質(zhì)循環(huán)、群落演替、植物入侵、生態(tài)恢復(fù)等過(guò)程產(chǎn)生重要影響[82]。因此,研究AMF來(lái)源與功能的關(guān)系具有重要意義。多數(shù)情況下不同來(lái)源的AMF功能有所不同,因?yàn)锳MF為適應(yīng)新的理化和宿主環(huán)境,在個(gè)體或個(gè)體內(nèi)水平上會(huì)產(chǎn)生基因變異或表型變化,群體水平上則會(huì)改變AMF群落結(jié)構(gòu)與組成,兩種情況下均導(dǎo)致AMF功能的差異,但這種差異又會(huì)隨著環(huán)境的趨同而消失。
在今后的研究當(dāng)中,以下兩個(gè)方面值得進(jìn)一步深入研究和探討:
(1)研究方法 目前,大部分研究用土壤中的孢子數(shù)量表示AMF的群落組成,通過(guò)形態(tài)對(duì)孢子進(jìn)行分類(lèi)有一定困難,而且土壤中的孢子數(shù)量并不能反映AMF侵染植物的實(shí)際狀況,因此可結(jié)合分子生物學(xué)手段進(jìn)行研究。
(2)研究尺度 AMF具有快速適應(yīng)新環(huán)境的能力,因此涉及AMF來(lái)源與功能的研究大部分屬短期實(shí)驗(yàn)。但不同的AMF適應(yīng)能力有別,部分研究未發(fā)現(xiàn)來(lái)源對(duì)AMF的功能有影響,可能與研究的時(shí)間尺度有關(guān)。另外,目前只注意到不同來(lái)源的AMF對(duì)植物個(gè)體的影響,對(duì)植物間的相互作用以及生態(tài)過(guò)程的影響關(guān)注不夠。
:
[1]Verbruggen E, Kiers E T. Evolutionary ecology of mycorrhizal functional diversity in agricultural systems. Evolutionary Applications, 2010, 3(5/6): 547-560.
[2]Finlay R D. Mycorrhizal fungi and their multifunctional roles. Mycologist, 2004, 18(2): 91-96.
[3]Smith S E, Read D J. Mycorrhizal Symbiosis. Cambridge, UK: Academic Press, 2008.
[4]Miransari M. Contribution of arbuscular mycorrhizal symbiosis to plant growth under different types of soil stress. Plant Biology, 2010, 12(4): 563-569.
[5]Estrada B, Aroca R, Maathuis F J M, Barea J M, Ruiz-Lozano J M. Arbuscular mycorrhizal fungi native from a Mediterranean saline area enhance maize tolerance to salinity through improved ion homeostasis. Plant, Cell and Environment, 2013, 36(10): 1771-1782.
[6]Zhang Q, Xu L M, Tang J J, Bai M G, Chen X. Arbuscular mycorrhizal mediation of biomass-density relationship ofMedicagosativaL. under two water conditions in a field experiment. Mycorrhiza, 2011, 21(4): 269-277.
[7]Lewandowski T J, Dunfield K E, Antunes P M. Isolate identity determines plant tolerance to pathogen attack in assembled mycorrhizal communities. PLoS ONE, 2013, 8(4): e61329. doi: 10.1371/journal.pone.0061329.
[8]Peng S L, Shen H, Zhang Y T, Guo T. Compare different effect of arbuscular mycorrhizal colonization on soil structure. Acta Ecologica Sinica, 2012, 32(3): 863-870.
[9]Ye J S, Li T, Hu Y J, Hao Z P, Gao Y Z, Wang Y S, Chen B D. Influences of AM fungi on plant growth and water-stable soil aggregates under drought stresses. Acta Ecologica Sinica, 2013, 33(4): 1080-1090.
[10]Zabinski C A, Quinn L, Callaway R M. Phosphorus uptake, not carbon transfer, explains arbuscular mycorrhizal enhancement ofCentaureamaculosain the presence of native grassland species. Functional Ecology, 2002, 16(6): 758-765.
[11]van der Heijden M G A, Horton T R. Socialism in soil? The importance of mycorrhizal fungal networks for facilitation in natural ecosystems. Journal of Ecology, 2009, 97(6): 1139-1150.
[12]Zhang Q, Yang R Y, Tang J J, Yang H S, Hu S J, Chen X. Positive feedback between mycorrhizal fungi and plants influences plant invasion success and resistance to invasion. PloS ONE, 2010, 5(8): e12380. doi:10.1371/journal.pone.0012380.
[13]Lingua G, Franchin C, Todeschini V, Castiglione S, Biondi S, Burlando B, Parravicini V, Torrigiani P, Berta G. Arbuscular mycorrhizal fungi differentially affect the response to high zinc concentrations of two registered poplar clones. Environmental Pollution, 2008, 153(1): 137-147.
[14]Doubková P, Suda J, Sudová R. Arbuscular mycorrhizal symbiosis on serpentine soils: the effect of native fungal communities on differentKnautiaarvensisecotypes. Plant and Soil, 2011, 345(1/2): 325-338.
[15]Morris E K, Buscot F, Herbst C, Meiners T, Obermaier E, W?schke N W, Wubet T, Rillig M C. Land use and host neighbor identity effects on arbuscular mycorrhizal fungal community composition in focal plant rhizosphere. Biodiversity and Conservation, 2013, 22(10): 2193-2205.
[16]van der Heijden E W, Kuyper T W. Does origin of mycorrhizal fungus or mycorrhizal plant influence effectiveness of the mycorrhizal symbiosis? Plant and Soil, 2001, 230(2): 161-174.
[17]Avio L, Pellegrino E, Bonari E, Giovannetti M. Functional diversity of arbuscular mycorrhizal fungal isolates in relation to extraradical mycelial networks. New Phytologist, 2006, 172(2): 347-357.
[18]Ji B M, Bentivenga S P, Casper B B. Evidence for ecological matching of whole AM fungal communities to the local plant-soil environment. Ecology, 2010, 91(10): 3037-3046.
[19]Marulanda A, Porcel R, Barea J M, Azcón R. Drought tolerance and antioxidant activities in lavender plants colonized by native drought-tolerant or drought-sensitiveGlomusspecies. Microbial Ecology, 2007, 54(3): 543-552.
[20]Doubková P, Suda J, Sudová R. The symbiosis with arbuscular mycorrhizal fungi contributes to plant tolerance to serpentine edaphic stress. Soil Biology and Biochemistry, 2012, 44(1): 56-64.
[21]Doubková P, Vlasáková E, Sudová R. Arbuscular mycorrhizal symbiosis alleviates drought stress imposed onKnautiaarvensisplants in serpentine soil. Plant and Soil, 2013, 370(1/2): 149-161.
[22]Estrada B, Aroca R, Barea J M, Ruiz-Lozano J M. Native arbuscular mycorrhizal fungi isolated from a saline habitat improved maize antioxidant systems and plant tolerance to salinity. Pant Science, 2013, 201-202: 42-51.
[23]Estrada B, Barea J M, Aroca R, Ruiz-Lozano J M. A nativeGlomusintraradicesstrain from a Mediterranean saline area exhibits salt tolerance and enhanced symbiotic efficiency with maize plants under salt stress conditions. Plant and Soil, 2013, 366(1/2): 333-349.
[24]Caravaca F, Barea J M, Palenzuela J, Figueroa D, Alguacil M M, Roldán A. Establishment of shrub species in a degraded semiarid site after inoculation with native or allochthonous arbuscular mycorrhizal fungi. Applied Soil Ecology, 2003, 22(2): 103-111.
[25]Querejeta J I, Allen M F, Caravaca F, Roldán A. Differential modulation of host plantδ13C andδ18O by native and nonnative arbuscular mycorrhizal fungi in a semiarid environment. New Phytologist, 2006, 169(2): 379-387.
[26]Ye Z H, Shu W S, Zhang Z Q, Lan C Y, Wong M H. Evaluation of major constraints to revegetation of lead/zinc mine tailings using bioassay techniques. Chemosphere, 2002, 47(10): 1103-1111.
[27]Zarei M, K?nig S, Hempel S, Nekouei M K, Savaghebi G, Buscot F. Community structure of arbuscular mycorrhizal fungi associated toVeronicarechingeriat the Anguran zinc and lead mining region. Environmental Pollution, 2008, 156(3): 1277-1283.
[28]Vivas A, V?r?s I, Biró B, Campos E, Barea J M, Azcón R. Symbiotic efficiency of autochthonous arbuscular mycorrhizal fungus (G.mosseae) andBrevibacillus sp. isolated from cadmium polluted soil under increasing cadmium levels. Environmental Pollution, 2003, 126(2): 179-189.
[29]Redon P O, Béguiristain T, Leyval C. Differential effects of AM fungal isolates onMedicagotruncatulagrowth and metal uptake in a multimetallic (Cd, Zn, Pb) contaminated agricultural soil. Mycorrhiza, 2009, 19(3): 187-195.
[31]Yang X M, Chen B D, Zhu Y G, Wang D M, Wang Y S. Effect of arbuscular mycorrhizal fungi (Glomusintraradices) on growth and mineral nutrition of maize plants in copper contaminated soils. Acta Ecologica Sinica, 2008, 28(3): 1052-1058.
[32]Oliveira R S, Boyer L R, Carvalho M F, Jeffries P, Vosátka M, Castro P M L, Dodd J C. Genetic, phenotypic and functional variation within aGlomusgeosporumisolate cultivated with or without the stress of a highly alkaline anthropogenic sediment. Applied Soil Ecology, 2010, 45(1): 39-48.
[33]Boerner R E J. Role of mycorrhizal fungus origin in growth and nutrient uptake byGeraniumrobertianum. American Journal of Botany, 1990, 77(4): 483-489.
[34]Yao Q, Zhu H H, Hu Y L, Li L Q. Differential influence of native and introduced arbuscular mycorrhizal fungi on growth of dominant and subordinate plants. Plant Ecology, 2008, 196(2): 261-268.
[35]Tchabi A, Coyne D, Hountondji F, Lawouin L, Wiemken A, Oehl F. Efficacy of indigenous arbuscular mycorrhizal fungi for promoting white yam (Dioscorearotundata) growth in West Africa. Applied Soil Ecology, 2010, 45(2): 92-100.
[36]Antunes P M, Koch A M, Morton J B, Rillig M C, Klironomos J N. Evidence for functional divergence in arbuscular mycorrhizal fungi from contrasting climatic origins. New Phytologist, 2011, 189(2): 507-514.
[37]Klironomos J N. Variation in plant response to native and exotic arbuscular mycorrhizal fungi. Ecology, 2003, 84(9): 2292-2301.
[38]Johnson N C, Wilson G W T, Bowker M A, Wilson J A, Miller R M. Resource limitation is a driver of local adaptation in mycorrhizal symbioses. Proceedings of the National Academy of Sciences of the United States of America, 2010, 107(5): 2093-2098.
[39]Schreiner R P. Effects of native and nonnative arbuscular mycorrhizal fungi on growth and nutrient uptake of ‘Pinot noir’(VitisviniferaL.) in two soils with contrasting levels of phosphorus. Applied Soil Ecology, 2007, 36(2/3): 205-215.
[40]Carvalho L M, Ca?ador I, Martins-Lou??o M A. Arbuscular mycorrhizal fungi enhance root cadmium and copper accumulation in the roots of the salt marsh plantAstertripoliumL. Plant and Soil, 2006, 285(1/2): 161-169.
[41]Sudová R, Doubková P, Vosátka M. Mycorrhizal association ofAgrostiscapillarisandGlomusintraradicesunder heavy metal stress: combination of plant clones and fungal isolates from contaminated and uncontaminated substrates. Applied Soil Ecology, 2008, 40(1): 19-29.
[42]Hua J F, Lin X G, Yin R, Jiang Q, Shao Y F. Effects of arbuscular mycorrhizal fungi inoculation on arsenic accumulation by tobacco (NicotianatabacumL.). Journal of Environmental Sciences, 2009, 21(9): 1214-1220.
[43]Tian C Y, Feng G, Li X L, Zhang F S. Different effects of arbuscular mycorrhizal fungal isolates from saline or non-saline soil on salinity tolerance of plants. Applied Soil Ecology, 2004, 26(2): 143-148.
[44]Requena N, Pérez-Solís E, Azcón-Aguilar C, Jeffries P, Barea J M. Management of indigenous plant-microbe symbioses aids restoration of desertified ecosystems. Applied and Environmental Microbiology, 2001, 67(2): 495-498.
[45]Alguacil M M, Hernández J A, Caravaca F, Portillo B, Roldán A. Antioxidant enzyme activities in shoots from three mycorrhizal shrub species afforested in a degraded semi-arid soil. Physiologia Plantarum, 2003, 118(4): 562-570.
[46]Johnson D, Martin F, Cairney J W G, Anderson I C. The importance of individuals: intraspecific diversity of mycorrhizal plants and fungi in ecosystems. New Phytologist, 2012, 194(3): 614-628.
[47]Sanders I R. Intraspecific genetic variation in arbuscular mycorrhizal fungi and its consequences for molecular biology, ecology, and development of inoculum. Canadian Journal of Botany, 2004, 82(8): 1057-1062.
[48]Angelard C, Colard A, Niculita-Hirzel H, Croll D, Sanders I R. Segregation in a mycorrhizal fungus alters rice growth and symbiosis-specific gene transcription. Current Biology, 2010, 20(13): 1216-1221.
[49]Giovannetti M, Fortuna P, Citernesi A S, Morini S, Nuti M P. The occurrence of anastomosis formation and nuclear exchange in intact arbuscular mycorrhizal networks. New Phytologist, 2001, 151(3): 717-724.
[50]Munkvold L, Kj?ller R, Vestberg M, Rosendahl S, Jakobsen I. High functional diversity within species of arbuscular mycorrhizal fungi. New Phytologist, 2004, 164(2): 357-364.
[51]Koch A M, Kuhn G, Fontanillas P, Fumagalli L, Goudet I, Sanders I R. High genetic variability and low local diversity in a population of arbuscular mycorrhizal fungi. Proceedings of National Academy of Sciences of the United States of America, 2004, 101(8): 2639-2374.
[52]Koch A M, Croll D, Sanders I R. Genetic variability in a population of arbuscular mycorrhizal fungi causes variation in plant growth. Ecology Letters, 2006, 9(2): 103-110.
[53]Roger A, Gétaz M, Rasmann S, Sander I R. Identity and combinations of arbuscular mycorrhizal fungal isolates influence plant resistance and insect preference. Ecological Entomology, 2013, 38(4): 330-338.
[54]Ehinger M, Koch A M, Sanders I R. Changes in arbuscular mycorrhizal fungal phenotypes and genotypes in response to plant species identity and phosphorus concentration. New Phytologist, 2009, 184(2): 412-423.
[55]Hodge A, Campbell C D, Fitter A H. An arbuscular mycorrhizal fungus accelerates decomposition and acquires nitrogen directly from organic material. Nature, 2001, 413(6853): 297-299.
[56]Smith S E, Smith F A, Jakobsen I. Functional diversity in arbuscular mycorrhizal (AM) symbioses: the contribution of the mycorrhizal P uptake pathway is not correlated with mycorrhizal responses in growth or total P uptake. New Phytologist, 2004, 162(2): 511-524.
[57]Angelard C, Tanner C J, Fontanillas P, Niculita-Hirzel H, Masclaux F, Sanders I R. Rapid genotypic change and plasticity in arbuscular mycorrhizal fungi is caused by a host shift and enhanced by segregation. The ISME Journal, 2014, 8(2): 284-294.
[58]Malcová R, Rydlová J, Vosátka M. Metal-free cultivation ofGlomussp. BEG 140 isolated from Mn-contaminated soil reduces tolerance to Mn. Mycorrhiza, 2003, 13(3): 151-157.
[59]van der Heijden M G A, Klironomos J N, Ursic M, Moutoglis P, Streitwolf-Engel R, Boller T, Wiemken A, Sanders I R. Mycorrhizal fungal diversity determines plant biodiversity, ecosystem variability and productivity. Nature, 1998, 396(6706): 69-72.
[61]Rowe H I, Brown C S, Claassen V P. Comparisons of mycorrhizal responsiveness with field soil and commercial inoculum for six native Montane species andBromustectorum. Restoration Ecology, 2007, 15(1): 44-52.
[62]Amir H, Lagrange A, Hassa?ne N, Cavaloc Y. Arbuscular mycorrhizal fungi from New Caledonian ultramafic soils improve tolerance to nickel of endemic plant species. Mycorrhiza, 2013, 23(7): 585-595.
[63]Bothe H, Turnau K, Regvar M. The potential role of arbuscular mycorrhizal fungi in protecting endangered plants and habitats. Mycorrhiza, 2010, 20(7): 445-457.
[64]Shen S K, Wang Y H. Arbuscular mycorrhizal (AM) status and seedling growth response to indigenous AM colonization ofEuryodendronexcelsumin China: implications for restoring an endemic and critically endangered tree. Australian Journal of Botany, 2011, 59(5): 460-467.
[65]Callaway R M, Thelen G C, Rodriguez A, Holben W E. Soil biota and exotic plant invasion. Nature, 2004, 427(6976): 731-733.
[66]Brooker R W, Maestre F T, Callaway R M, Lortie C L, Cavieres L A, Kunstler G, Liancourt P, Tielb?rger K, Travis J M J, Anthelme F, Armas C, Coll L, Corcket E, Delzon S, Forey E, Kikvidze Z, Olofsson J, Pugnaire F, Quiroz C L, Saccone P, Schiffers K, Seifan M, Touzard B, Michalet R. Facilitation in plant communities: the past, the present, and the future. Journal of Ecology, 2008, 96(1): 18-34.
[67]Yang R Y, Zan S T, Tang J J, Chen X, Zhang Q. Variation in community structure of arbuscular mycorrhizal fungi associated with a Cu tolerant plant-Elsholtziasplendens. Applied Soil Ecology, 2010, 44(3): 191-197.
[68]Montesinos-Navarro A, Segarra-Moragues J G, Valiente-Banuet A, Verdú M. Plant facilitation occurs between species differing in their associated arbuscular mycorrhizal fungi. New Phytologist, 2012, 196(3): 835-844.
[69]Jansa J, Smith F A, Smith S E. Are there benefits of simultaneous root colonization by different arbuscular mycorrhizal fungi? New Phytologist, 2008, 177(3): 779-789.
[70]Moebius-Clune D J, Moebius-Clune B N, van Es H M, Pawlowska T E. Arbuscular mycorrhizal fungi associated with a single agronomic plant host across the landscape: community differentiation along a soil textural gradient. Soil Biology and Biochemistry, 2013, 64: 191-199.
[71]Hazard C, Gosling P, van der Gast C J, Mitchell D T, Doohan F M, Bending G D. The role of local environment and geographical distance in determining community composition of arbuscular mycorrhizal fungi at the landscape scale. The ISME Journal, 2013, 7(3): 498-508.
[72]Hawkes C V, Belnap J, D′Antonio C, Firestone M K. Arbuscular mycorrhizal assemblages in native plant roots change in the presence of invasive exotic grasses. Plant and Soil, 2006, 281(1/2): 369-380.
[73]Stinson K A, Campbell S A, Powell J R, Wolfe B E, Callaway R M, Thelen G C, Hallett S G, Prati D, Klironomos J N. Invasive plant suppresses the growth of native tree seedlings by disrupting belowground mutualisms. PLoS Biology, 2006, 4(5): e140. doi:10.1371/journal.pbio. 0040140.
[74]Moora M, ?pik M, Sen R, Zobel M. Native arbuscular mycorrhizal fungal communities differentially influence the seedling performance of rare and commonPulsatillaspecies. Functional Ecology, 2004, 18(4): 554-562.
[75]Sun W W. The Significance of Origin on the Functioning of Arbuscular Mycorrhizal Fungi: A Community Level Perspective [D]. Wuhu: Anhui Normal University, 2013.
[76]Wang F Y, Lin X G, Yin R, Wu L H. Effects of arbuscular mycorrhizal inoculation on the growth ofElsholtziasplendensandZeamaysand the activities of phosphatase and urease in a multi-metal-contaminated soil under unsterilized conditions. Applied Soil Ecology, 2006, 31(1/2): 110-119.
[77]Meier S, Azcón R, Cartes P, Borie F, Cornejo P. Alleviation of Cu toxicity inOenotherapicensisby copper-adapted arbuscular mycorrhizal fungi and treated agrowaste residue. Applied Soil Ecology, 2011, 48(2): 117-124.
[78]Koide R T. Functional complementarity in the arbuscular mycorrhizal symbiosis. New Phytologist, 2000, 147(2): 233-235.
[79]Hausmann N T, Hawkes C V. Plant neighborhood control of arbuscular mycorrhizal community composition. New Phytologist, 2009, 183(4): 1188-1200.
[80]Lambers H, Mougel C, Jaillard B, Hinsinger P. Plant-microbe-soil interactions in the rhizosphere: an evolutionary perspective. Plant and Soil, 2009, 321(1/2): 83-115.
[81]Hoeksema J D. Ongoing coevolution in mycorrhizal interactions. New Phytologist, 2010, 187(2): 286-300.
[82]Rillig M C. Arbuscular mycorrhizae and terrestrial ecosystem processes. Ecology Letters, 2004, 7(8): 740-754.
參考文獻(xiàn):
[8]彭思利, 申鴻, 張宇亭, 郭濤. 不同叢枝菌根真菌侵染對(duì)土壤結(jié)構(gòu)的影響. 生態(tài)學(xué)報(bào), 2012, 32(3): 863-870.
[9]葉佳舒, 李濤, 胡亞軍, 郝志鵬, 高彥征, 王幼珊, 陳保冬. 干旱條件下AM真菌對(duì)植物生長(zhǎng)和土壤水穩(wěn)定性團(tuán)聚體的影響. 生態(tài)學(xué)報(bào), 2013, 33(4): 1080-1090.
[31]楊秀梅, 陳保冬, 朱永官, 王冬梅, 王幼珊. 叢枝菌根真菌(Glomusintraradices)對(duì)銅污染土壤上玉米生長(zhǎng)的影響. 生態(tài)學(xué)報(bào), 2008, 28(3): 1052-1058.
[75]孫雯雯. 起源對(duì)叢枝菌根真菌功能的影響: 群落水平研究 [D]. 蕪湖: 安徽師范大學(xué), 2013.