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入侵植物与本地植物互作对丛枝菌根真菌AMF侵染率的影响

花匠小妙招
2024-11-12 18:20

丛枝菌根真菌（arbuscular mycorrhiza fungi,AMF）在外来植物入侵过程中起着重要作用（Bücking et al. 2016）。许多外来入侵植物根系能与AMF形成互惠共生体（Fumanal et al. 2006）。AMF与植物共生形成的菌根网络可增大植物根系吸收面积、改善植株营养、增强植物抗旱抗盐能力、驱动土壤养分循环,进而影响植物种间竞争关系（Smith et al. 1999;Roberts et al. 2009;Hodge & Fitter 2010）。进一步研究表明,外来入侵植物改变了入侵地AMF密度和多样性（Vogelsang & Bever 2009;Meinhardt & Gehring 2012）,并通过聚集特定的AMF来促进其生长（Zhang et al. 2018）。斑点矢车菊Centaurea maculosa Lam.的入侵导致了入侵地AMF群落多样性的降低（Mummey et al. 2005）;于文清等（2012）研究发现紫茎泽兰Eupatorium adenophora Spreng.的入侵改变了当地土壤微生物的群落结构,随着紫茎泽兰入侵程度加深,土壤中AMF的优势菌种由膨胀无梗囊霉Acauospora dilatata逐渐转变为近明球囊霉Glomus claroideum;黄顶菊Flaveria bidentis (L.) Kuntze.入侵多年后,其根围土壤通过聚集根内球囊霉Rhizophagus intraradices来促进其对土壤中氮的吸收（Zhang et al. 2017）。此外,外来入侵植物还可通过破坏本地植物与土壤微生物的共生关系而实现其成功入侵（Markus et al. 2014）。Hawkes et al.（2006）指出外来植物Avena barbata Pott和Bromus hordeaceus L.的入侵改变了本地植物根系中AMF群落结构。可见,AMF在入侵植物和本地植物竞争生长过程中举足轻重。

AMF侵染率是评价外来植物入侵过程中竞争能力的重要指标之一。一些研究表明入侵植物常具有较高的侵染率。广州地区7种入侵植物与AMF的共生现象比较普遍,且均具有较高的AMF的侵染率（胡文武等2015）;入侵植物黄顶菊的侵染率均显著高于本地植物狗尾草Setaria viridis,而且寄主植物AMF侵染率与其对养分氮、磷的吸收密切相关,在黄顶菊与狗尾草的竞争生长过程中,竞争降低了本地植物狗尾草的侵染率,从而导致黄顶菊具有较强的竞争能力（Zhang et al. 2017）。但也有一些研究表明入侵植物可以通过降低其自身的AMF侵染来达到入侵的目的。入侵到北美的Hypericum perforatum通过降低根部AMF侵染来增强其在入侵地的繁殖优势（Seifert et al. 2009）,这主要是侵染率与植物根构型有关,AMF侵染使入侵种群根更细,致使其繁殖能力更强。寄主植物AMF侵染率受很多因素的影响,如土壤养分状况、寄主植物种类和栽培密度等（李媛媛 2013）。因此,探究外来植物与本地植物竞争生长过程中对AMF侵染率的影响对于揭示外来入侵植物的入侵能力具有重要的意义,值得进一步试验。

中国外来入侵植物中菊科植物所占比例最多,危害也较严重（万方浩等 2002;徐海根和强胜2011）。黄顶菊Flaveria bidentis、豚草Ambrosia artemisiifolia L.和三叶鬼针草Bidens pilosa L.是中国华北地区危害较大的外来入侵菌根植物,本研究采用同质园试验,选取上述3种入侵菊科植物及本地植物狗尾草Setaria viridis、黄香草木犀Melilotus officinalis (L.) Desr.、藜Chenopodium album L.为研究对象,探究入侵植物与本地植物互作对植物根系AMF侵染率的影响,比较不同入侵植物对本地植物根系的AMF侵染率影响的变化特点,研究结果有助于揭示外来植物的入侵机制,并为外来植物的防控提供理论依据。

1 材料与方法

1.1 试验地点及样品来源

本试验在中国农业科学院廊坊科研中试基地田间同质园试验完成,研究对象为3种菊科入侵植物：黄顶菊Flaveria bidentis、豚草Ambrosia artemisiifolia、三叶鬼针草Bidens pilosa和3种不同功能类型的本地植物：狗尾草Setaria viridis、黄香草木犀Melilotus officinalis、藜Chenopodium album。自2007年开始种植入侵植物与本地植物,以模拟入侵植物的入侵过程,18个处理,每种处理5个重复,共90个样方,处理分别为：黄顶菊单种、豚草单种、三叶鬼针草单种、狗尾草单种、黄香草木犀单种、藜单种、黄顶菊与狗尾草混种、黄顶菊与黄香草木犀混种、黄顶菊与藜混种、黄顶菊同时与3种本地植物混种、豚草与狗尾草混种、豚草与黄香草木犀混种、豚草与藜混种、豚草同时与3种本地植物混种、三叶鬼针草与狗尾草混种、三叶鬼针草与黄香草木犀混种、三叶鬼针草与藜混种、三叶鬼针草同时与3种本地植物混种。2016年8月份采集根样。

1.2 方法

AMF侵染率测定方法：经过根系透明、染色、分色过程。具体步骤：洗净根样,20%氢氧化钠进行透明过程,90℃水浴30min（时间长短视根系透明程度而定）,透明完成用清水漂洗根系3-5次,洗净氢氧化钠,再将洗净根系浸泡在2%盐酸中5min,充分酸化,然后将酸化后的根系放入0.01%酸性品红中染色静置过夜,最后乳酸分色镜检。采用根段频率标准法计数,每个处理需要测定200条根段。在显微镜下检查每条根段的侵染情况,根据每段根系丛枝、泡囊、菌丝结构以及3种的结构总体的多少按0%、10%、20%、30%、…、100%的侵染数量分别给出每条根段的侵染率（Koske & Gemma 1989;刘润进和陈应龙 2007）。0%、10%、20%、30%、…、100%为根段被侵染程度。

侵染率(%)=∑(0%×根段数+10%×根段数+20%×根段数+…+100%×根段数)/观察总根段数

1.3 数据处理

数据采用SPSS 21.0进行独立样本T检验、单因素方差分析（One-way ANOVA）、双因素方差分析（Two-way ANOVA）,并用Ducan多重比较分析各个处理间的差异性。

2 结果与分析

2.1 竞争对入侵植物根系AMF侵染率的影响

2.1.1 竞争对黄顶菊根系AMF侵染率的影响：与黄顶菊单种相比,黄顶菊与藜混种和黄顶菊同时与3种本地植物混种处理中,黄顶菊根系泡囊结构显著增加,而所有混种处理中黄顶菊根系菌丝及总侵染率无显著差异（表1）。

表1 黄顶菊根系AMF侵染率

Table 1 The AMF colonization percentage of Flaveria bidentis

处理
Treatments 丛枝
Arbuscule (%) 泡囊
Vesicule (%) 菌丝
Hypha (%) 总侵染率
Total colonization percentage (%) 黄顶菊
F. bidentis 10.84±2.08ab 1.98±0.30c 43.11±4.05a 43.82±3.96a 黄顶菊+狗尾草
F. bidentis+Setaria viridis 9.45±1.49b 3.87±0.28bc 48.51±2.49a 48.63±2.07a 黄顶菊+黄香草木犀
F. bidentis+Melilotus officinalis 11.60±2.36ab 0.83±0.20c 42.94±4.23a 44.09±5.85a 黄顶菊+藜
F. bidentis+Chenopodium album 13.98±2.63a 6.74±1.66b 48.73±3.65a 48.82±3.46a 黄顶菊+3种本地植物
F. bidentis+three native plants 9.78±1.60b 14.59±3.37a 46.47±4.53a 46.70±4.71a 注：不同小写字母表示不同处理间存在差异,P<0.05. 下同Note: Different lowercase letters indicate a significant difference between different treaments, P<0.05. The same below.

2.1.2 竞争对豚草根系AMF侵染率的影响：与豚草单种相比,豚草与黄香草木犀、豚草与藜以及豚草同时与3种本地植物混种处理中豚草根系丛枝结构均显著增加,豚草与狗尾草混种处理中其根系泡囊结构显著增加,豚草与黄香草木犀和豚草同时与3种本地植物混种处理中,其根系AMF菌丝及总侵染率显著增加（表2）。

表2 豚草根系AMF侵染率

Table 2 The AMF colonization percentage of Ambrosia artemisiifolia

处理
Treatments 丛枝
Arbuscule (%) 泡囊
Vesicule (%) 菌丝
Hypha (%) 总侵染率
Total colonization percentage (%) 豚草
A. artemisiifolia 0.42±0.16c 3.82±1.15bc 28.04±3.56c 28.94±3.39c 豚草+狗尾草
A. artemisiifolia+Setaria viridis 0.00c 9.15±4.80a 34.44±4.29bc 34.71±3.71bc 豚草+黄香草木犀
A. artemisiifolia+Melilotus officinalis 10.56±1.80a 1.70±0.77c 39.86±6.04ab 40.32±6.58ab 豚草+藜
A. artemisiifolia+Chenopodium album 7.97±1.01b 0.67±0.18c 32.38±4.01bc 32.27±3.34bc 豚草+3种本地植物
A. artemisiifolia+three native plants 10.13±1.48a 7.68±1.18ab 47.88±5.18a 48.08±3.80a

2.1.3 竞争对三叶鬼针草根系AMF侵染率的影响：与三叶鬼针草单种相比,三叶鬼针草与黄香草木犀、三叶鬼针草与藜以及三叶鬼针草同时与3种本地植物混种处理中鬼针草根系丛枝结构均显著增加,三叶鬼针草与狗尾草和三叶鬼针草同时与3种本地植物混种处理中三叶鬼针草根系泡囊结构显著增加,而所有混种处理中三叶鬼针草根系AMF菌丝及总侵染率无显著差异（表3）。

表3 三叶鬼针草根系AMF侵染率

Table 3 The AMF colonization percentage of Bidens pilosa

处理
Treatments 丛枝
Arbuscule (%) 泡囊
Vesicule (%) 菌丝
Hypha (%) 总侵染率
Total colonization percentage (%) 三叶鬼针草
B. pilosa 0.09±0.02b 0.15±0.04b 27.63±4.58ab 27.83±5.07ab 三叶鬼针草+狗尾草
B. pilosa+Setaria viridis 0.00b 1.35±0.66a 31.12±4.02a 31.62±3.45a 三叶鬼针草+黄香草木犀
B. pilosa+Melilotus officinalis 6.87±1.79a 0.22±0.12b 31.89±2.73a 31.95±2.89a 三叶鬼针草+藜
B. pilosa+Chenopodium album 5.40±1.56a 0.22±0.13b 22.97±2.18b 23.48±1.68b 三叶鬼针草+3种本地植物
B. pilosa+three native plants 6.12±2.05a 0.87±011a 31.53±3.41a 31.95±4.43a

2.2 竞争对本地植物根系AMF侵染率的影响

2.2.1 竞争对狗尾草根系AMF侵染率的影响：与狗尾草单种处理相比,黄顶菊与狗尾草和黄顶菊同时与3种本地植物混种处理中,狗尾草根系泡囊结构显著增加,黄顶菊同时与3种本地植物混种、豚草同时与3种本地植物混种和三叶鬼针草同时与3种本地植物混种处理中狗尾草根系丛枝结构显著增加,而其根系AMF菌丝及总侵染率都显著降低（表4）。

表4 狗尾草根系AMF侵染率

Table 4 The AMF colonization percentage of Setaria viridis

处理
Treatments 丛枝
Arbuscule (%) 泡囊
Vesicule (%) 菌丝
Hypha (%) 总侵染率
Total colonization percentage (%) 狗尾草
S. viridis 0.00c 0.87±0.23c 36.08±2.65a 36.39±2.64a 黄顶菊+狗尾草
Flaveria bidentis+S. viridis 0.00c 4.00±0.46a 33.86±3.32a 34.60±2.91a 豚草+狗尾草
Ambrosia artemisiifolia+S. viridis 0.00c 1.30±0.28c 36.12±2.04a 35.98±2.02a 三叶鬼针草+狗尾草
Bidens pilosa+S. viridis 0.00c 1.32±0.97c 34.41±4.02a 31.62±3.45a 黄顶菊+3种本地植物
F. bidentis+three native plants 0.63±0.23b 2.63±1.37b 20.93±1.85b 21.64±1.84b 豚草+3种本地植物
A. artemisiifolia+three native plants 1.16±0.39a 1.70±0.26bc 23.08±3.17b 23.72±3.16b 三叶鬼针草+3种本地植物
B. pilosa+three native plants 0.53±0.28b 0.66±0.17c 20.35±2.33b 21.11±1.70b

2.2.2 竞争对黄香草木犀根系AMF侵染率的影响：与黄香草木犀单种相比,黄顶菊与黄香草木犀混种处理中其根系丛枝、AMF菌丝结构及总侵染率都显著降低,豚草与黄香草木犀混种处理中其根系丛枝结构显著降低,但其泡囊结构显著增加,AMF菌丝及总侵染率无显著差异,三叶鬼针草与黄香草木犀混种处理中其丛枝结构显著增加,黄顶菊同时与3种本地植物、豚草同时与3种本地植物和三叶鬼针草同时与3种本地植物混种处理中其根系泡囊侵染率显著增加,但其根系AMF菌丝及总侵染率都显著降低（表5）。

表5 黄香草木犀根系AMF侵染率

Table 5 The AMF colonization percentage of Melilotus officinalis

处理
Treatments 丛枝
Arbuscule (%) 泡囊
Vesicule (%) 菌丝
Hypha (%) 总侵染率
Total colonization percentage (%) 黄香草木犀
M. officinalis 4.12±0.75c 2.02±0.62d 63.53±2.67ab 64.19±2.58a 黄顶菊+黄香草木犀
Flaveria bidentis+M. officinalis 1.75±0.41d 1.88±0.45d 54.77±3.91cd 55.24±4.39bc 豚草+黄香草木犀
Ambrosia artemisiifolia+M. officinalis 0.18±0.04d 14.67±1.19a 65.65±3.40a 66.11±3.48a 三叶鬼针草+黄香草木犀
Bidens pilosa+M. officinalis 7.66±1.03b 2.58±0.49d 61.15±3.95abc 61.96±3.56ab 黄顶菊+3种本地植物
F. bidentis+three native plants 7.33±1.43b 6.06±1.16c 52.66±5.60d 53.05±5.43bc 豚草+3种本地植物
A. artemisiifolia+three native plants 0.95±0.36d 9.53±1.81b 56.31±4.31cd 56.82±4.21bc 三叶鬼针草+3种本地植物
B. pilosa+three native plants 5.23±0.98c 13.40±2.34a 55.76±2.83cd 56.25±2.30c

2.2.3 竞争对藜AMF侵染率的影响：无论单种还是混种,藜根系中几乎不存在丛枝结构。与藜单种相比,藜与豚草混种处理中其根系AMF菌丝及总侵染率显著增加,豚草同时与3种本地植物和三叶鬼针草同时与3种本地植物混种处理中,藜根系AMF菌丝和总侵染率显著增加（表6）。

表6 藜根系AMF侵染率

Table 6 The AMF colonization percentage of Chenopodium album

处理
Treatments 丛枝
Arbuscule (%) 泡囊
Vesicule (%) 菌丝
Hypha (%) 总侵染率
Total colonization percentage (%) 藜
C. album 0.00 0.04±0.02cd 1.38±0.47d 1.45±0.41d 黄顶菊+藜
Flaveria bidentis+C. album 0.00 0.05±0.01cd 1.52±0.21d 1.55±0.19d 豚草+藜
Ambrosia artemisiifolia +C. album 0.00 0.32±0.06bcd 3.00±0.33bc 3.03±0.33bc 三叶鬼针草+藜
Bidens pilosa+C. album 0.00 0.13±0.02bcd 1.47±0.28d 1.29±0.37d 黄顶菊+3种本地植物
F. bidentis+three native plants 0.00 0.66±0.18bc 1.58±0.40d ±0.39d 豚草+3种本地植物
A. artemisiifolia+three native plants 0.00 0.73±0.13b 3.73±0.72b ±0.73b 三叶鬼针草+3种本地植物
B. pilosa+three native plants 0.00 0.00d 2.52±0.60c 2.56±0.62c

2.3 植物物种多样性效应对植物根系AMF侵染率的影响

除不同入侵植物与植物物种多样性的交互作用对入侵植物根系丛枝侵染率无显著影响,植物物种多样性、不同本地植物与植物物种多样性的交互作用对本地植物根系丛枝侵染率无显著影响外,入侵植物或本地植物种类的变化以及其与植物物种多样性间的交互作用对入侵植物或本地植物的根系丛枝、泡囊、菌丝及总侵染率均有显著的影响（表7,表8）。

表7 不同入侵植物、本地植物物种多样性及两者交互作用对入侵植物根系AMF侵染率的影响

Table 7 Effects of different invasive plants, native plant species diversity and interation of invasive plants and native plants on AMF colonization percentage of invasive plant roots

不同因子
Different factors 丛枝
Arbuscule 泡囊
Vesicule 菌丝
Hypha 总侵染率
Total colonization percentage 入侵植物种类
Invasive plant species df 2 2 2 2 F 147.68 15.45 34.31 33.85 P <0.0001 <0.0001 <0.0001 <0.0001 本地植物物种多样性
Native plant species diversity df 2 2 2 2 F 5.91 12.53 8.39 7.59 P 0.006 <0.0001 0.001 0.001 入侵植物种类×本地植物物种多样性
Invasive plant species × native plant species diversity df 4 4 4 4 F 2.20 4.99 3.386 3.14 P 0.088 0.003 0.019 0.026 表8 不同本地植物、植物物种多样性及两者交互作用对本地植物根系AMF侵染率的影响

Table 8 Effects of different native plants, plant species diversity and their interation on AMF colonization percentage of native plant roots

不同因子
Different factors 丛枝
Arbuscule 泡囊
Vesicule 菌丝
Hypha 总侵染率
Total colonization percentage 植物种类
Plant species df 2 2 2 2 F 25.27 17.79 1 315.41 1 397.57 P <0.0001 <0.0001 <0.0001 <0.0001 植物物种多样性
Plant species diversity df 2 2 2 2 F 1.05 3.62 31.55 32.51 P 0.358 0.034 <0.0001 <0.0001 植物种类×植物物种多样性
Plant species × plant species diversity df 4 4 4 4 F 0.36 2.942 13.44 13.72 P 0.837 0.028 <0.0001 <0.0001

3 讨论

植物种类是影响AMF侵染的重要因素。大多数外来入侵植物都是菌根植物,能够与新生境土壤中AMF形成互利共生关系。本研究结果表明黄顶菊、豚草、三叶鬼针草3种入侵植物和狗尾草、藜、黄香草木犀3种本地植物侵染率明显不同,其中黄香草木犀侵染率最高,其次是黄顶菊、狗尾草、豚草,藜的侵染率最低。Hartmann et al.（2009）认为植物根系分泌物是影响根围土壤微生物变化的重要因素,根系可以分泌微生物生长所需要的碳源和能源等营养条件,也可以改变根围土壤的pH。因而,根系微生物的空间分布、种类和数量受根系释放有机物的种类和数量的影响（黄奔立等 2007;吴玉香等 2007;周宝利等 2010）。植物种类不同,根系分泌物组成也不同,则其根围土壤微生物群落结构也不同（王光华等 2006）。Zhang et al.（2017,2018）研究表明3种入侵植物黄顶菊、豚草和三叶鬼针草根围土壤AMF群落结构不同,根系和根围土壤聚集的AMF优势菌也不同,这与3种植物根系分泌物组分不同密切相关。本研究发现3种入侵植物根系AMF侵染率不同,同时我们发现入侵植物AMF侵染率并不总是高于本地植物。该研究利用长期定位同质园试验,排除了环境异质性的影响,侵染率的变化主要由植物种类引起的。

竞争也是影响寄主AMF侵染率的重要因素。黄顶菊与狗尾草的竞争降低了狗尾草的侵染率（Zhang et al. 2017）;随着种内竞争能力的增大,在种群水平上植物AM真菌侵染率显著降低（Eissenstat & Newman 1990;Facelli et al. 1999;Facelli & Facelli 2002;Ayres et al. 2010）。此外,AMF侵染率的变化与入侵域植物多样性密切相关。当入侵植物分别与某一种本地植物竞争生长时,入侵植物黄顶菊和三叶鬼针草总侵染率变化不明显,但豚草与黄香草木犀和豚草同时与3种本地植物混种处理中,豚草根系菌丝及总侵染率显著增加;且对本地植物侵染率的影响与植物种类有关,除了豚草与藜混种处理中的藜和黄顶菊与黄香草木犀混种处理中的黄香草木犀外,3种入侵植物对本地植物的侵染率没有影响。而当入侵植物分别同时与3种本地植物竞争时,豚草的侵染率显著增加,黄顶菊和三叶鬼针草侵染率变化不明显;而对本地植物而言,狗尾草根系菌丝及总侵染率都显著降低、黄香草木犀泡囊侵染率显著增加,但其菌丝及总侵染率都显著降低;豚草和鬼针草分别同时与3种本地植物竞争处理中,藜的菌丝和总侵染率显著增加,且通过对植物物种多样性进行双因素方差分析,其对本地植物根系泡囊、菌丝及总侵染率存在显著影响,说明当入侵植物与多种本地植物竞争时,竞争显著降低本地菌根植物狗尾草和黄香草木犀的侵染率。

综上可知,植物种类是影响AMF侵染率的主要因素,入侵植物与本地植物的竞争可改变影响本地植物根系AMF菌丝和其总侵染率,且这种改变与本地植物种类有关,植物种类的增加降低了本地植物根系AMF菌丝及其总侵染率,但对入侵植物的AMF侵染率影响不显著。

=2" class="main_content_center_left_zhengwen_bao_erji_title main_content_center_left_one_title" style="font-size: 16px;">{{custom_sec.title}}{{custom_sec.content}}1Ayres RL

Gange AC

Aplin DM

, 2010. Interactions between arbuscular mycorrhizal fungi and intraspecific competition affect size, and size inequality, of Plantago lanceolata L. Journal of Ecology, 94(2):285-294

Mensah JA

Fellbaum CR

, 2016. Common mycorrhizal networks and their effect on the bargaining power of the fungal partner in the arbuscular mycorrhizal symbiosis. Communicative & Integrative Biology, 9(1):e1107684

The aim was to explore the ways young adult survivors of childhood cancer with risk of being infertile understand their ability to have children.

Newman EI

, 1990. Seedling establishment near large plants: effects of vesicular-arbuscular mycorrhizas on the intensity of plant competition. Functional Ecology, 4(1):95-99

Facelli JM

, 2002. Soil phosphorus heterogeneity and mycorrhizal symbiosis regulate plant intra-specific competition and size distribution. Oecologia, 133(1):54-61

We investigated the interactive effects of soil phosphorus (P) heterogeneity, plant density and mycorrhizal symbiosis on plant growth and size variability of Trifolium subterraneum. We set up mesocosms (trays 49×49 cm and 12 cm deep) with the same amount of available P, but distributed either homogeneously or heterogeneously, in randomly arranged cells (7×7 cm each) with high or low available P. The trays were planted with either 1 or 4 seedlings of T. subterraneum per cell. Half of the trays were inoculated with spores of the mycorrhizal fungus Gigaspora margarita. We harvested the plants when leaves just started to overlap, 8 weeks after planting. Plants growing in high P cells had the lowest percentage infection, but the highest mean shoot and root biomass and root length. The mean size of the plants in each cell was determined mainly by local P concentration. However, in plants growing in high density, low P cells, ca. 20% of the variability in plant biomass was explained by the number of adjacent cells with high P. Patchy trays had the highest total shoot biomass, independently of mycorrhizal infection or plant density. Inoculated trays (M) had higher total shoot biomass and relative competition intensity (measured as reduction in plant biomass due to increased density) than non-inoculated trays (NM). Plant density reduced the plant response to mycorrhizal infection, and its effect was independent of P distribution. All populations growing in patchy trays, and low density mycorrhizal ones, had the highest plant-size inequality, presumably because patchy distribution of P and mycorrhizal infection increased competitive asymmetry. We conclude that mycorrhizal symbiosis has the potential to strongly influence plant population structure when soil nutrient distribution is heterogeneous because it promotes pre-emption of limiting resources.

Facelli JM

Smith SE

Mclaughlin MJ

, 1999. Interactive effects of arbuscular mycorrhizal symbiosis, intraspecific competition and resource availability on Trifolium subterraneum cv. mt. Barker. New Phytologist, 141(3):535-547

Plenchette C

Chauvel B

Bretagnolle F

, 2006. Which role can arbuscular mycorrhizal fungi play in the facilitation of Ambrosia artemisiifolia L. invasion in France? Mycorrhiza, 17(1):25-35

Ambrosia artemisiifolia L. (common ragweed), an annual invasive plant, was introduced more than 100 years ago from North America to Europe. Like the majority of other invasive plants in Europe, it develops in open, disturbed areas such as fields, wastelands, roadsides, and riverbanks. Recently, arbuscular mycorrhizal fungi (AMF) have been suspected to play a role in some plant invasion processes. As the common ragweed is known to be colonized by AMF in its native range, the intensity of mycorrhizal root colonization was studied in 35 natural populations in eastern France. About 94% of the A. artemisiifolia populations sampled were mycorrhizal. Root colonization levels varied from 1 to 40% depending on the ecological sites, with lower levels for agricultural habitats and higher levels in disturbed sites, such as wastelands or roadsides. A subsequent greenhouse experiment showed positive impacts of AMF on the growth and development of A. artemisiifolia. It is proposed that the spread of this invasive plant species could be facilitated by AMF, underlining the need to integrate symbiotic interactions in future work on invasive plant processes.

Schmid M

van Tuinen D

Berg G

, 2009. Plant-driven selection of microbes. Plant and Soil, 321(1-2):235-257

The rhizodeposition of plants dramatically influence the surrounding soil and its microflora. Root exudates have pronounced selective and promoting effects on specific microbial populations which are able to respond with chemotaxis and fast growth responses, such that only a rather small subset of the whole soil microbial diversity is finally colonizing roots successfully. The exudates carbon compounds provide readily available nutrient and energy sources for heterotrophic organisms but also contribute e.g. complexing agents, such as carboxylates, phenols or siderophores for the mobilization and acquisition of rather insoluble minerals. Root exudation can also quite dramatically alter the pH- and redox-milieu in the rhizosphere. In addition, not only specific stimulatory compounds, but also antimicrobials have considerable discriminatory effect on the rhizosphere microflora. In the “biased rhizosphere” concept, specific root associated microbial populations are favored based on modification of the root exudation profile. Rhizosphere microbes may exert specific plant growth promoting or biocontrol effects, which could be of great advantage for the plant host. Since most of the plant roots have symbiotic fungi, either arbuscular or ectomycorrhizal fungi, the impact of plants towards the rhizosphere extends also to the mycorrhizosphere. The selective effect of the roots towards the selection of microbes also extends towards the root associated and symbiotic fungi. While microbes are known to colonize plant roots endophytically, also mycorrhiza are now known to harbor closely associated bacterial populations even within their hyphae.

The general part of the manuscript is followed by the more detailed presentation of specific examples for the selection and interaction of roots and microbes, such as in the rhizosphere of strawberry, potato and oilseed rape, where the soil-borne plant pathogen Verticillium dahliae can cause high yield losses; the potential of biocontrol by specific constituents of the rhizosphere microbial community is demonstrated. Furthermore, plant cultivar specificity of microbial communities is described in different potato lines including the case of transgenic lines. Finally, also the specific selective effect of different Medicago species on the selection of several arbuscular mycorrhizal taxa is presented.

Belnap J

Carla D’Antonio

Firestone MK

, 2006. Arbuscular mycorrhizal assemblages in native plant roots change in the presence of invasive exotic grasses. Plant and Soil, 281(1-2):369-380

Plant invasions have the potential to significantly alter soil microbial communities, given their often considerable aboveground effects. We examined how plant invasions altered the arbuscular mycorrhizal fungi of native plant roots in a grassland site in California and one in Utah. In the California site, we used experimentally created plant communities composed of exotic (Avena barbata, Bromus hordeaceus) and native (Nassella pulchra, Lupinus bicolor) monocultures and mixtures. In the Utah semi-arid grassland, we took advantage of invasion by Bromus tectorum into long-term plots dominated by either of two native grasses, Hilaria jamesii or Stipa hymenoides. Arbuscular mycorrhizal fungi colonizing roots were characterized with PCR amplification of the ITS region, cloning, and sequencing. We saw a significant effect of the presence of exotic grasses on the diversity of mycorrhizal fungi colonizing native plant roots. In the three native grasses, richness of mycorrhizal fungi decreased; in the native forb at the California site, the number of fungal RFLP patterns increased in the presence of exotics. The exotic grasses also caused the composition of the mycorrhizal community in native roots to shift dramatically both in California, with turnover of Glomus spp., and Utah, with replacement of Glomus spp. by apparently non-mycorrhizal fungi. Invading plants may be able to influence the network of mycorrhizal fungi in soil that is available to natives through either earlier root activity or differential carbon provision compared to natives. Alteration of the soil microbial community by plant invasion can provide a mechanism for both successful invasion and the resulting effects of invaders on the ecosystem.

Fitter AH

, 2010. Substantial nitrogen acquisition by arbuscular mycorrhizal fungi from organic material has implications for N cycling. Proceedings of the National Academy of Sciences, 107(31):13754-13759

Xin GR

Guo JH

Peng X

, 2015. Habitat difference analysis of arbuscular mycorrhizal colonization and spore density for seven compositae invasive species in Guangzhou. Journal of Tropical and Subtropical Botany, 23(2):183-190 (in Chinese)

In order to understand the symbiosis of arbuscular mycorrhizal fungi (AMF) with Compositae invasive plants in Guangzhou, the AMF colonization rate and spore density of 7 Compositae invasive plant species in four habitats were studied, and the effect of soil factors on AMF was also analyzed. The results showed that all the investigated plants were colonized by AMF, AMF spores were detected from all soil samples. AMF colonization rate showed significant difference among hosts, but not among habitats. AMF spore density was significantly different both among hosts and habitats, among which, spore density was significantly higher in artificial green land, farmland and orchard than that in forest surround and coastal area. Correlation analysis showed that spore density was negatively correlated with soil organic matter content in farmland and orchard, AMF colonization rate was positively correlated with total N content in forest surround, AMF colonization rate was negatively correlated with available N content and available P content in artificial green land and coastal area, respectively. These could play an important role in understanding the invasion mechanisms of Compositae species.

Xu YD

Wu Y

Zhang SQ

Chen XH

, 2007. Effects of root exudates from cucumber and squash on Fusarium wilt occurrence. Chinese Journal of Applied Ecology, 18(3):559-563 (in Chinese)

With the root exudates of two cucumber varieties Jinyan 4 (susceptible variety) and Jin-
chun 4 (resistant variety) and of black seed squash variety as test materials, this paper studied
their effects and action mechanisms on the occurrence of Fusarium wilt on Jinyan 4. The results
showed that the occurrence of Fusarium wilt was earlier when treated with the root exudates of
Jinyan 4, and the infection rate was significantly higher at 15 days after inoculation, but nearly the
same as the control at 20 days after inoculation. On the contrary, the infection rate was significantly
lower than the control when treated with the root exudates of Jinchun 4. The plant height and fresh
mass of Jinyan 4 treated with its own root exudates were lower than those of the control, and the root
vigor decreased but conductance increased. No significant effect was observed in the plant height
and fresh mass of Jinyan 4 treated with the root exudates of Jinchun 4 and black seed squash. It
could be concluded that the root exudates of susceptible cucumber variety stimulated the growth of
Fusarium oxysporum pathogen, while those of resistance cucumber variety and black seed squash
were in adverse.

Gemma JN

, 1989. A modified procedure for staining roots to detect VA mycorrhizas. Mycological Research, 92(4):486-488

, 2013. Response of different alfalfa (Medicago sativa L.) genotypes on arbuscular mycorrhizal (AM) fungi and studies on the propagation of AM fungi. Master Thesis, Lanzhou University,Lanzhou. 1-76 (in Chinese)

Chen YL

, 2007. Mycorrhizology. Science Press, Beijing. 1-447(in Chinese)

Gehring CA

, 2012. Disrupting mycorrhizal mutualisms: a potential mechanism by which exotic tamarisk outcompetes native cottonwoods. Ecological Applications, 22(2):532-549

The disruption of mutualisms between plants and mycorrhizal fungi is a potentially powerful mechanism by which invasives can negatively impact native species, yet our understanding of this mechanism's role in exotic species invasion is still in its infancy. Here, we provide several lines of evidence indicating that invasive tamarisk (Tamarix sp.) negatively affects native cottonwoods (Populus fremontii) by disrupting their associations with arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) fungi. At a field site in the early stages of tamarisk invasion, cottonwoods with tamarisk neighbors had reduced EM colonization and altered EM fungal community composition relative to cottonwoods with native neighbors, leading to reductions in EM propagule abundance in the soil beneath tamarisk. Similarly. AM colonization of cottonwoods was reduced with a tamarisk neighbor, but there were no significant changes in AM fungal spore communities or propagule abundance. Root colonization by nonmycorrhizal fungi, including potential pathogens, was higher in cottonwoods with tamarisk neighbors. A greenhouse experiment in which AM and EM inoculation and plant neighbor were manipulated in a fully factorial design showed that cottonwoods benefited from mycorrhizas, especially EM, in terms of shoot biomass when grown with a conspecific, but shoot biomass was similar to that of nonmycorrhizal controls when cottonwoods were grown with a tamarisk neighbor. These results are partially explained by a reduction in EM but not AM colonization of cottonwoods by a tamarisk neighbor. Tamarisk neighbors negatively affected cottonwood specific leaf area, but not chlorophyll content, in the field. To pinpoint a mechanism for these changes, we measured soil chemistry in the field and the growth response of an EM fungus (Hebeloma crustuliniforme) to salt-amended media in the laboratory. Tamarisk increased both NO3- concentrations and electrical conductivity 2.5-fold beneath neighboring cottonwoods in the field. Salt-amended media did not affect the growth of H. crustuliniforme. Our findings demonstrate that a nonnative species, even in the early stages of invasion, can negatively affect a native species by disrupting its mycorrhizal symbioses. Some of these changes in mycorrhizal fungal communities may remain as legacy effects of invasives, even after their removal, and should be considered in management and restoration efforts.

Rillig MC

Holben WE

, 2005. Neighboring plant influences on arbuscular mycorrhizal fungal community composition as assessed by t-rflp analysis. Plant and Soil, 271(1-2):83-90

Controls on root colonization by arbuscular mycorrhizal fungi (AMF) include host nutrient status, identity of symbionts and soil physico-chemical properties. Here we show, in the field, that the subset of the AMF community colonizing the roots of a common grass species, Dactylis glomerata, was strongly controlled by neighboring roots of a different plant species, Centaurea maculosa, an invasive forb, thus adding a biological spatial component to controls on root colonization. Using an AMF-specific, 18s rDNA-based terminal restriction fragment length polymorphism (T-RFLP) analysis method, significant differences were found between AMF community fingerprints of samples derived from roots of grasses with (GCm) and without (G0) neighboring C. maculosa. There were also significant differences between samples derived from C. maculosa roots (Cmac) and both GCm and G0 roots. Sample ordination indicated three generally distinct groups consisting of Cmac, GCm and G0, with GCm samples being of intermediate distance between G0and Cmac. Our results indicate that, with the presence of C. maculosa, AMF communities of D. glomerata shift to reflect community composition associated with C. maculosa roots. These results highlight the importance of complex spatial distributions of AMF communities at the scale of a root system. An additional dimension to our study is that C. maculosa is an aggressively invasive plant in the intermountain West. Viewed in this light, these results suggest that pervasive influences of this plant on AMF communities, specifically in roots of its competitors, may represent a mechanism contributing to its invasive success. However, further work is clearly required to determine the extent to which AMF genotypic alteration by neighboring plants influences competitive relationships.

Radford IJ

Orlovich DA

, 2009. Do alterations of arbuscular mycorrhizal fungal communities change interactions between an invader Hieracium lepidulum and two co-occurring species? A glasshouse study. Australasian Mycologist, 28:29-35

Bever JD

Maron JL

, 2009. Evidence for the evolution of reduced mycorrhizal dependence during plant invasion. Ecology, 90(4):1055-1062

Introduced species inevitably experience novel selection pressures in their new environments as a result of changes in mutualist and antagonist relationships. While most previous work has examined how escape from specialist enemies has influenced herbivore or pathogen resistance of exotic species, post-introduction shifts in exotic dependence on mutualists have not been considered. In a common environment, we compared dependence on AM fungi of North American and European populations of Hypericum perforatum (St. John's Wort), a forb native to Europe. Introduced North American populations responded less to inoculation with AM fungi than did European populations. Root architecture was strongly correlated with mycorrhizal response, and introduced populations had finer root architecture than native populations. Finally, introduced populations exhibited decreased root and increased reproductive allocation relative to European populations, consistent with a transition to a weedier life history; however, biomass allocation patterns were uncorrelated with mycorrhizal response. These findings are the first demonstration of a genetically based reduction of mycorrhizal dependence and shift in root architecture in an introduced species.

Hartnett DC

Wilson GWT

, 1999. Interacting influence of mycorrhizal symbiosis and competition on plant diversity in tallgrass prairie. Oecologia (Berlin), 121(4):574-582

In tallgrass prairie, plant species interactions regulated by their associated mycorrhizal fungi may be important forces that influence species coexistence and community structure; however, the mechanisms and magnitude of these interactions remain unknown. The objective of this study was to determine how interspecific competition, mycorrhizal symbiosis, and their interactions influence plant community structure. We conducted a factorial experiment, which incorporated manipulations of abundance of dominant competitors, Andropogon gerardii and Sorghastrum nutans, and suppression of mycorrhizal symbiosis using the fungicide benomyl under two fire regimes (annual and 4-year burn intervals). Removal of the two dominant C4 grass species altered the community structure, increased plant species richness, diversity, and evenness, and increased abundance of subdominant graminoid and forb species. Suppression of mycorrhizal fungi resulted in smaller shifts in community structure, although plant species richness and diversity increased. Responses of individual plant species were associated with their degree of mycorrhizal responsiveness: highly mycorrhizal responsive species decreased in abundance and less mycorrhizal responsive species increased in abundance. The combination of dominant-grass removal and mycorrhizal suppression treatments interacted to increase synergistically the abundance of several species, indicating that both processes influence species interactions and community organization in tallgrass prairie. These results provide evidence that mycorrhizal fungi affect plant communities indirectly by influencing the pattern and strength of plant competitive interactions. Burning strongly influenced the outcome of these interactions, which suggests that plant species diversity in tallgrass prairie is influenced by a complex array of interacting processes, including both competition and mycorrhizal symbiosis.

Bever JD

, 2009. Mycorrhizal densities decline in association with nonnative plants and contribute to plant invasion. Ecology, 90(2):399-407

Belowground interactions between herbaceous native species and nonnative species is a poorly understood but emerging area of interest to invasive-species researchers. Positive feedback dynamics are commonly observed in many invaded systems and have been suspected in California grasslands, where native plants associate strongly with soil mutualists such as arbuscular mycorrhizal fungi. In response to disturbance, invading nonnative plants proliferate, and to the degree these species associate weakly with soil mutualists, we would expect mutualist efficacy to degrade over time. Degraded mutualist efficacy would negatively impact mutualist-dependent native species or their recruitment following a disturbance. We investigated the feedback dynamics of soil conditioned both with native and nonnative herbaceous communities of southern California grasslands to test this degraded mutualist hypothesis. Using a mesocosm approach, we inoculated each community with live soil originating from a remnant native grassland and varied the plant communities (i.e., native or nonnative) along a plant-species-richness gradient. After one year, we then used this conditioned soil for reciprocal feedback tests on a native and nonnative indicator species. We show that a native herbaceous forb (Gnaphalium californicum) grows best in soil conditioned by a diverse mix of other native species that includes G. californicum but is inhibited by soil conditioned by a diverse mix of nonnative species. We also show that an invasive, nonnative herbaceous forb (Carduus pycnocephalus) exhibits strong growth in soil lacking arbuscular mycorrhizal fungi and in soil conditioned by a diverse mix of nonnative species that include C. pycnocephalus, and that it is inhibited by the same soil that best promotes the native, G. californicum. Separate bioassays for mycorrhizal density show a reduction of arbuscular mycorrhizal fungi in the nonnative-conditioned soil relative to the native-conditioned soil, which suggests that nonnative species do not promote the growth of mycorrhizal fungi in the same way that native species do. The growth patterns resulting from the vegetative history of these distinct soil communities provide evidence of a biotic feedback mechanism that may account for the maintenance of persistent communities of nonnative (and often invasive) plants ubiquitous throughout California grasslands.

Guo JY

Wang DH

, 2002. Alien invasive species in China: their damages and management strategies. Biodiversity Science, 10(1):119-125 (in Chinese)

The impacts and invasion method of alien invasive species (AIS), and prevention and management of biological invasion are discussed. Biological invasion is becoming one of the most important factors threatening biodiversity and stability of various ecological systems in China. The impacts of these biological invasions are becoming a more serious problems with development and increase of global trade, transportation, international travel and ecological tourism. Harmful AIS often leads to irreversible species extinction, and results in substantial economic losses within managed and natural ecosystems, including agriculture, forestry, fishery and animal production. Newly invading weeds, insect pests and plant diseases frequently result in large scale outbreaks and persistent use of chemical pesticides. Successful invasion and spread of some major insect pests and weeds in China were caused by man made factors. These include decision mistakes and unintentional introduction of some plants, such as water hyacinth and alligator weed as pig food, irresponsible introduction actions taken by individual/group without any ecological concerns, and lack of rapid response mechanism for eradicating potentially AIS as soon as they appear. China is an agricultural country. Any biological invasion will be a "big bomb" for our agriculture and inevitably result in ecological and economic losses in specific ecosystem and specific geographic regions. Prevention of biological invasion is an important aspect for safeguarding the state′s ecological safety. Development and researches should focus on building the state capacity, research capacity, and management capacity for addressing AIS problem. Based on the urgent situation of AIS in China, priority for research and action plans concentrate on: developing methods to identify the origin and pathways of invasive population; understanding the biological and ecological bases of AIS; developing environmentally friendly methods for control of AIS; developing environmental impact assessment and risk analysis methods for AIS; and developing methods for the recovery of habitats after control of AIS.

Jin J

Xu MN

Liu XB

, 2006. Effects of plant, soil and soil management on soil microbial community diversity. Chinese Journal of Ecology, 25(5):550-556 (in Chinese)

Soil microbe is an important component of soil ecosystem,and its community diversity in different habitats is the hotspot of recent soil ecological study.This paper summarized the research advances in the effects of plant,soil,and soil management on the diversity of soil microbial community. Soil microbial community diversity varied with plant community diversity,plant species and genotypes,and plant growth stages and its root zone.The effects of soil on soil microbial community diversity were related to soil texture and its organic matter content.There was an interaction between soil and plant on the diversity of soil microbial community.Soil microbial community diversity was also strongly affected by soil management.Long-term monoculture and applying chemical fertilizers or pesticides decreased the diversity,while applying organic manure or non-tillage increased the diversity and was good for maintaining the functions of soil ecosystem.

Shen XJ

Fang WP

Jin KY

Zhu SJ

, 2007. The effects of cotton root exudates on growth and development of Verticillium dahliae. Cotton Science, 19(4):286-290 (in Chinese)

A greenhouse experiment was conducted to assess the adverse impact of transgenic cotton on ecosystem and environment via effect of transgenic Bt+CpTI cotton root exudates on growth and antioxidant activity of conventional parental cotton. Results showed elevated reductive and oxidative species activities in the leaves of conventional parental cotton seedlings treated with varying concentrations of transgenic cotton root exudates. Compared to control, 14.9% to 39.9% increase in catalase, 8.8% to 114% increase in for peroxidase, 21.3% to 59.7% increase in phenylalanine ammonia-lyase and 5.8 to 19.5 fold in ascorbate specific peroxidase was observed. However, biomass and height of conventional cotton seedlings were not affected by any concentration of transgenic cotton root exudates. These results suggested that cultivation of transgenic Bt+CpTI cotton plants poses little risk to conventional parental cotton based on their root interactions.

Qiang S

, 2011. China’s invasive alien species. Science Press, Beijing. 1-684(in Chinese)

Liu WX

Gui FR

Liu WZ

Wan FH

Zhang LL

, 2012. Invasion of exotic Ageratina adenophora Sprengel. alters soil physical and chemical characteristics and arbuscular mycorrhizal fungus community. Acta Ecologica Sinica, 32(22):7027-7035 (in Chinese)

Li Q

Chen FX

Xu HY

, Inderjit,

Wan FH

, 2017. Arbuscular mycorrhizal fungi facilitate growth and competitive ability of an exotic species Flaveria bidentis. Soil Biology & Biochemistry, 115(2017):275-284

New herbicides based on natural products are claimed to address weed resistance and environmental concerns related to synthetic herbicides. In our previous studies, certain volatile organic compounds (VOCs) produced by Ulex europaeus and Cytisus scoparius were argued to be responsible for the phytotoxicity of both shrub species. Interactions among VOCs were hypothesized to explain the inconsistency between the effects of the identified pure compounds and those naturally emitted from fresh plant material. In this work, eugenol, verbenone, terpinen-4-ol, α-terpineol, and linalool were assayed as binary mixtures of Amaranthus retroflexus and Digitaria sanguinalis. Powerful synergistic inhibitory effects were revealed for germination and early growth. Only 3.1 ppm of verbenone was enough to inhibit A. retroflexus germination when paired to other VOCs. Eugenol was capable of exacerbating the effects of terpinen-4-ol on A. retroflexus, even though it was innocuous when acting alone at 12.5 ppm. The verbenone and linalool pair produced very significant synergistic effects in terms of D. sanguinalis germination. The synergistic effects were predominantly irreversible for D. sanguinalis, since seeds exposed to paired VOCs were unable to recover their germination capacity after removing the phytotoxins or produced damaged seedlings. Both shrub species have been revealed as sources of natural herbicide molecules, with promising synergistic modes of action that deserve to be studied in depth.

Li Q

Yerger EH

Chen X

Shi Q

Wan FH

, 2018. AM fungi facilitate the competitive growth of two invasive plant species, Ambrosia artemisiifolia and Bidens pilosa. Mycorrhiza, 28(8):703-715

Invasive species often cause enormous economic and ecological damage, and this is especially true for invasive plants in the Asteraceae family. Arbuscular mycorrhizal fungi (AMF) play an important role in the successful invasion by exotic plant species because of their ability to promote growth and influence interspecific competition. However, few studies have evaluated the effects of invasive Asteraceae species on AMF diversity and how feedback mechanisms during competition with native species subsequently affect the accumulation of nutrient resources. Two exotic Asteraceae, Ambrosia artemisiifolia and Bidens pilosa, were monitored during competition with a native grass species, Setaria viridis, which is being replaced by these exotic species in natural areas around the study site. From these species continuously maintained in a field plot for 5 years, we collected the rhizosphere soil and cloned and identified soil AMF. Furthermore, AM fungal spores were isolated from rhizosphere soil of the two invasive species and used as inoculum in greenhouse experiments, to compare growth and nutrient accumulation during competition. The results indicate that although the AMF diversity in the rhizosphere soil of A. artemisiifolia and B. pilosa differed, the three most abundant species (Septoglomus viscosum, Septoglomus constrictum, Glomus perpusillum) were identical. The addition of AMF inoculum changed the competition between the plants, increasing the competitive ability of the invasives and decreasing that of the native. The results show a similar AMF community composition between A. artemisiifolia and B. pilosa, increased AMF root colonization of the invasive species during competition, AMF-enhanced N accumulation, and AMF-facilitated competitive growth of the invasive species.

Yin YL

Li YP

Xu Y

Chen SL

Ye XL

, 2010. Relationship between root exudates of grafted eggplants and Verticillium wilt resistance and their components identification. Acta Ecologica Sinica, 30(11):3073-3079 (in Chinese)

黄奔立, 许云东, 伍烨, 张顺琦, 陈学好 , 2007. 两个不同抗性黄瓜品种和云南黑籽南瓜根系分泌物对黄瓜枯萎病发生的影响. 应用生态学报, 18(3):559-563

研究了黄瓜品种津研4号（感枯萎病）、津春4号（抗枯萎病）和云南黑籽南瓜根系分泌物对津研4号黄瓜枯萎病发生的影响及其原因.结果表明:感病品种根系分泌物处理的黄瓜枯萎病发病早，接种后第15天病株率显著高于对照，至第20天时病株率与对照相近；而抗病品种根系分泌物处理的病株率一直显著小于对照.感病品种根系分泌物浇灌的植株株高、鲜质量降低，根系活力下降、电导度（伤害度）增加，而抗病品种和云南黑籽南瓜根系分泌物处理对植株影响较小.感病品种根系分泌物促进了黄瓜枯萎病菌的生长，而抗病品种和云南黑籽南瓜根系分泌物则抑制了病菌生长.

胡文武, 辛国荣, 郭健桦, 彭雪 , 2015. 广州地区7种菊科入侵植物丛枝菌根侵染和根围土壤孢子密度的生境差异性分析. 热带亚热带植物学报, 23(2):183-190

为了解广州地区7 种菊科(Compositae)入侵植物与丛枝菌根真菌(Arbuscular mycorrhizal fungi, AMF)的互作共生关系,调查了这7 种菊科入侵植物在4 种生境中的AMF 侵染和根际土壤孢子密度,并分析土壤因子对AMF 的影响。结果表明, 7 种入侵植物根内均受到AMF 侵染,根际土壤中均检测到AMF 孢子;AMF 侵染在宿主间差异显著,生境间的差异不显著;孢子密度在生境和宿主间的差异均显著,人工绿地、农田果园的AMF 孢子密度均显著高于森林周边和滨海地带。相关性分析表明,农田果园生境的根际土壤孢子密度与土壤有机质含量呈显著负相关关系;森林周边生境的AMF 总侵染率与土壤全氮呈极显著正相关关系;人工绿地的AMF 总侵染率与土壤速效氮含量呈显著负相关关系;滨海地带的AMF 总侵染率与土壤有效磷含量呈显著负相关关系。这些对理解菊科植物入侵机理具有非常重要的作用。

李媛媛 , 2013. 不同紫花苜蓿基因型对AM真菌的响应以及AM真菌扩繁的研究. 兰州大学硕士论文,兰州. 1-76

刘润进, 陈应龙 , 2007. 菌根学. 北京: 科学出版社. 1-447

万方浩, 郭建英, 王德辉 , 2002. 中国外来入侵生物的危害与管理对策. 生物多样性, 10(1):119-125

本文探讨了外来入侵生物的概念及其在我国的危害状况、入侵原因，提出了外来入侵生物的预防及管理对策。随着国际贸易往来和旅游业的发展，生物入侵在我国不断加剧，正在成为威胁我国生物多样性与生态环境的重要因素之一。外来入侵种的生态代价是造成本地物种多样性不可弥补的消失以及物种的灭绝，其经济代价是农林牧渔业产量与质量的惨重损失与高额的防治费用。生物入侵在我国大部分是由于人为因素引起的。这些因素包括：缺乏对引进种的利益与风险进行评估、淡薄的生态意识与不顾生态后果的经济利益驱使下的盲目引进、缺乏严格的科学监管体系或监管不力、缺乏全面检疫的体系与机制。外来入侵生物的综合性与系统性研究已成为当今我国生态环境保护、农业生产和经济可持续发展的重大研究领域。我国对外来入侵生物的预防与管理应着重于国家能力、研究能力、监测与管理能力三大体系的建设上。根据我国国情和目前的紧急现状应制定出优先行动计划。对特定外来种的入侵生物学基础研究、特定生态系统或地理区域入侵种现状及影响的关键评估研究、特定外来入侵生物对生态环境影响的风险评估体系及经济损失的模式研究、发展控制外来有害生物的环保型技术与方法研究、外来生物受控制后生态系统的恢复与栖息生境的复原技术与方法等,均是目前亟待研究的课题。

王光华, 金剑, 徐美娜, 刘晓冰 , 2006. 植物、土壤及土壤管理对土壤微生物群落结构的影响. 生态学杂志, 25(5):550-556

土壤微生物是土壤生态系统的重要组成部分，对土壤微生物群落结构多样性的研究是近年来土壤生态学研究的热点。本文综述了有关植物、土壤类型以及土壤管理措施对土壤微生物群落结构影响的最新研究结果，指出植物的作用因植物群落结构多样性、植物种类、同种植物不同的基因型，甚至同一植物不同根的区域而异；而土壤的作用与土壤质地和有机质含量等因素有关；植物和土壤类型在对土壤微生物群落结构影响上的作用存在互作关系。不同的土壤管理措施对土壤微生物群落结构影响较大，长期连作、大量的外援化学物质的应用降低了土壤微生物的多样性；而施用有机肥、免耕可以增加土壤微生物群落结构多样性，有利于维持土壤生态系统的功能。

吴玉香, 沈晓佳, 房卫平, 金奎英, 祝水金 , 2007. 陆地棉根系分泌物对黄萎病菌生长发育的影响闭. 棉花学报, 19(4):286-290

徐海根, 强胜 , 2011. 中国外来入侵生物. 北京: 科学出版社. 1-684

于文清, 刘万学, 桂富荣, 刘文志, 万方浩, 张利莉 , 2012. 外来植物紫茎泽兰入侵对土壤理化性质及丛枝菌根真菌(AMF)群落的影响. 生态学报, 32(22):7027-7035

为了揭示外来植物紫茎泽兰入侵对入侵地土壤丛枝菌根真菌(AMF)群落及相关肥力的影响,比较测定了紫茎泽兰不同入侵程度土壤理化性质、AMF侵染率及AMF群落的差异。结果表明,紫茎泽兰入侵降低了土壤pH,使土壤中有机碳、全氮和速效钾含量分别增加83.0%,106.9%和111.0%;尽管对全磷含量没有显著影响,但有机磷含量呈升高的趋势,而速效磷呈降低的趋势。紫茎泽兰入侵降低了本地植物的AMF侵染率;随着入侵程度的加深,土壤中以膨胀无梗囊霉(Acauospora dilatata)为优势种的AMF群落结构逐渐转变为以近明球囊霉(Glomus claroideum )为优势种的结构,紫茎泽兰可在其根周选择培育近明球囊霉,而对其它AMF种,特别是对膨胀无梗囊霉则存在抑制作用;基于各AMF种多度的聚类分析表明,形成紫茎泽兰单优群落土壤中各AMF种多度与未入侵的本地植物群落及入侵程度较轻的紫茎泽兰与本地植物群落之间存在明显分歧。综合分析推断认为,紫茎法兰入侵改变了入侵地土壤理化性状,抑制AMF对土著植物的侵染,改变AMF群落,并在其根周选择培育近明球囊霉,这可能是紫茎泽兰入侵及扩张的重要途径之一。

周宝利, 尹玉玲, 李云鹏, 徐妍, 陈绍莉, 叶雪凌 , 2010. 嫁接茄根系分泌物与抗黄萎病的关系及其组分分析. 生态学报, 30(11):3073-3079

探讨了嫁接对茄子土传病害黄萎病抗性的影响，采用浸根法收集茄子根系分泌物，并利用气-质联用技术检测了根系分泌物的组分和含量，测定了茄子根系分泌物及其模拟化感物质对黄萎菌菌丝生长的化感作用，分析嫁接后茄子根系分泌物的组成差异，探讨了嫁接茄抗病性与其根系分泌物成分的关系。结果表明：嫁接使茄子发病率显著降低。土壤黄萎菌数量随发育时期的推进而显著低于自根茄。嫁接茄根系分泌物对黄萎菌菌丝生长有一定的抑制作用。GC-MS检测结果显示，嫁接换根使茄子根系分泌物的组成成分发生一定的改变，嫁接根系分泌物中检测到了烃类、酯类、醇类、酚类、酮类、苯类和胺类物质，其中苯、醇和胺类在ZG中未检测到。但嫁接茄也缺少自根茄中检测到的炔类和菲啶。酚类公认的化感物质含量表现出自根茄大于嫁接茄。模拟物质对黄萎菌菌丝生长的影响表明：邻苯二甲酸二丁酯表现出在0.05-0.5 mmol?L-1浓度范围随浓度增加抑制作用增强，后随浓度增加抑制作用有所减弱。而豆蔻酸和棕榈酸均表现出随浓度增加先促进后抑制黄萎菌菌丝的生长。

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