西北沙区梭梭根系深色有隔内生真菌等微生物时空分布及对根际土壤环境的响应

赵昕,高慧利,龙俊萌,刘燕霞,李夏,贺学礼

菌物学报 ›› 2021, Vol. 40 ›› Issue (10) : 2716-2734.

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菌物学报 ›› 2021, Vol. 40 ›› Issue (10) : 2716-2734. DOI: 10.13346/j.mycosystema.210109 CSTR: 32115.14.j.mycosystema.210109
研究论文

西北沙区梭梭根系深色有隔内生真菌等微生物时空分布及对根际土壤环境的响应

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Spatial and temporal distribution and the response to rhizosphere soil environment of dark septate endophyte and other microorganisms in roots of Haloxylon ammodendron in sand area of Northwest China

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文章历史 +

摘要

为揭示西北沙区不同时空尺度梭梭Haloxylon ammodendron根系深色有隔内生真菌(dark septate endophyte,DSE)分布规律及其环境驱动机制,分别于2019年7月、9月和12月在安西极旱荒漠国家级自然保护区和民勤连古城国家级自然保护区采集根系和土壤样品,根据真菌形态学特征、组织化学等方法,研究了梭梭根系DSE真菌定殖规律、定殖特征及其与土壤环境因子间的相互关系。结果表明,DSE真菌在自然生境梭梭根系广泛定殖,形成具有时空异质性的典型暗色有隔菌丝和微菌核结构。梭梭根系DSE真菌定殖受季节和空间分布影响,其中总定殖率在生长旺季7月最高(85.6%),且菌丝隔间距显著大于9、12月;安西样地菌丝定殖率(71.5%)和总定殖率(85.6%)显著高于民勤样地(40.7%,60.0%),但民勤样地微菌核直径显著高于安西样地。相关性分析表明,DSE定殖率及形态特征受土壤理化性质影响,温度、有效磷是影响DSE真菌定殖率的主要土壤因子,湿度和碱解氮是影响DSE真菌定殖形态的主要土壤因子。相比空白土壤,梭梭根际革兰氏阳性细菌含量、土壤脲酶活性以及安西样地有效磷含量均更高,预示其对荒漠土壤具有改善作用。本研究对梭梭DSE真菌时空分布和影响因素的系统性调查有助于为荒漠化治理和生态恢复提供依据。

Abstract

The distribution pattern and driving factors of dark septate endophyte (DSE) in roots of Haloxylon ammodendron across spatial and temporal scales in Northwest China were investigated. Soil and plant root samples were collected from Anxi Extreme-arid Desert National Nature Reserve and Minqin Liangucheng National Nature Reserve in July, September and December in 2019. Based on morphology and histochemistry assay, the relationship between the colonization characteristics of DSE fungi in the roots of H. ammodendron and soil factors were observed. The investigation showed that DSE fungi colonized extensively in the roots of H. ammodendron in natural desert habitats, forming typical dark and septate hyphae and microsclerotia with spatial and temporal heterogeneity. The DSE colonization pattern of H. ammodendron roots was affected by seasonal and spatial variability, and the total colonization rate was the highest in vigorous growth period in July (85.6%), and the hyphal septum interval was significantly distant in July than in September and December. The hyphal colonization rate (71.5%) and total colonization rate (85.6%) in Anxi were significantly higher than that in Minqin (40.7%, 60.0%), but the microsclerotium diameter was significantly increased in Minqin as compared with that in Anxi. The correlation analysis indicated that DSE colonization rate and morphological characteristics were affected by soil physical and chemical factors. Temperature and available phosphorus of soil were the main factors affecting DSE colonization rate, while humidity and alkali-hydrolyzed nitrogen were the main soil factors affecting DSE colonization characteristics. Compared with the blank soil, the content of Gram positive bacteria, the activity of soil urease and the available phosphorus content (in Anxi sample plots) in the rhizosphere soil of H. ammodendron were significantly higher, indicating that H. ammodendron could improve the desert soil. This study provides helpful reference material for desertification control and ecological restoration in dry areas of Northwest China.

关键词

梭梭 / 深色有隔内生真菌 / 荒漠 / 时空分布 / 环境因子

Key words

Haloxylon ammodendron / dark septate endophyte / desert / spatial and temporal distribution / environmental factors

引用本文

导出引用
赵昕, 高慧利, 龙俊萌, 刘燕霞, 李夏, 贺学礼. 西北沙区梭梭根系深色有隔内生真菌等微生物时空分布及对根际土壤环境的响应[J]. 菌物学报, 2021, 40(10): 2716-2734 https://doi.org/10.13346/j.mycosystema.210109
ZHAO Xin, GAO Hui-Li, LONG Jun-Meng, LIU Yan-Xia, LI Xia, HE Xue-Li. Spatial and temporal distribution and the response to rhizosphere soil environment of dark septate endophyte and other microorganisms in roots of Haloxylon ammodendron in sand area of Northwest China[J]. Mycosystema, 2021, 40(10): 2716-2734 https://doi.org/10.13346/j.mycosystema.210109
丛赤壳科Nectriaceae成立于1865年,模式属为丛赤壳属Nectria (Fr.) Fr.。Rossman et al. (1999)根据形态学特征,将广义的丛赤壳类真菌划分为丛赤壳科和生赤壳科Bionectriaceae。丛赤壳科的主要特征包括子座发达或具基部子座,子囊壳肉质,具丛赤壳型中心体,单生至聚生,表生,近球形、球形、倒梨形至椭圆球形,子囊壳颜色鲜艳,KOH+,LA+,子囊壳表面光滑、具疣状物或毛状物,壳壁厚度通常大于25 μm, 子囊圆柱形至柱棒状, 子囊孢子椭圆形至拟纺锤形, 无分隔至具多个分隔,表面平滑、具条纹、小刺或疣状突起,无色至淡黄褐色(Rossman et al. 1999;庄文颖 2013;Lombard et al. 2015)。目前丛赤壳科已知约55属900余种(Lombard et al. 2015),我国累计报道16属100余种(庄文颖 2013; Zeng & Zhuang 2014, 2015, 2016a, 2016b, 2016c, 2017, 2018, 2019, 2020, 2021a, 2021b; Zeng et al. 2018)。 该科真菌主要分布于温带和热带地区,物种多样性丰富,对农林业发展有重要影响,开展资源调查和系统分类研究,将更新对我国种质资源的认识。

1 材料与方法

研究材料主要采自安徽、河南、湖北、云南和西藏等地的自然保护区和森林公园。采用常规研究方法(Rossman et al. 1999),记录子囊壳在3%氢氧化钾(potassium hydroxide,KOH)水溶液和100%乳酸(lactic acid,LA)溶液中的颜色变化。为观察解剖结构特征,将子囊壳置于冷冻切片机YD-1508A(中国金华)上制作厚度约6-8 μm的切片,在解剖镜Olympus SZX7下选取结构完整的切片用乳酚棉兰染色,显微观察其壳壁结构和附属物特征。挑取单个子囊壳制作压片,经乳酚棉兰染色,显微观察子囊和子囊孢子的形状、大小,孢子的颜色、表面纹饰和分隔情况;采用Zeiss Axioskop 2 plus (哥廷根)光学显微镜配备的Canon G5摄像系统拍照。观察菌株在CMD (cornmeal dextrose agar)、PDA (potato dextrose agar)和SNA (synthetic nutrient-poor agar) (Nirenberg 1976)培养基上25 ℃培养7 d的菌落形态,测量菌落直径。
研究标本存放于中国科学院微生物研究所菌物标本馆(herbarium mycologicum academiae sinicae,HMAS),菌种保藏于微生物研究所真菌学国家重点实验室。参照Wang & Zhuang (2004)的方法提取菌丝DNA,使用引物ITS5/ITS4 (White et al. 1990)和LR0R/LR5 (Rehner & Samuels 1994)扩增ITS和LSU序列,获得序列提交至GenBank,使用BioEdit 7.0.5.3 (Hall 1999)进行序列拼接、比对和编辑,运用BLASTN在NCBI (https://www.ncbi.nlm.nih.gov/)数据库进行检索。
本研究综合形态解剖、培养性状、DNA序列和无性阶段等特征,对各标本进行系统分类鉴定。采用最大简约(maximum parsimony,MP)和贝叶斯(Bayesian inference,BI)方法明确其系统发育位置,选取ITS和LSU序列构建系统发育树。进化树中,最大简约分析支持率(bootstrap proportion,BP)大于50%和贝叶斯分析后验概率(posterior probability,PP)大于90%分别显示在各分支节点上。

2 分类

肯达拉赤壳 图1
Cosmospora khandalensis (Thirum. & Sukapure) Gräfenhan & Seifert [as 'khandalense'], in Gräfenhan, Schroers, Nirenberg & Seifert, Stud. Mycol. 68: 96, 2011. Fig. 1
Cephalosporium khandalense Thirum. & Sukapure, in Sukapure & Thirumalachar, Mycologia 58(3): 359, 1966.
图1 肯达拉赤壳 (HMAS 247850)

A-C:25 ℃培养7 d的菌落形态 (A:PDA;B:CMD;C:SNA);D-L:分生孢子梗和分生孢子. 标尺:D-L=10 μm

Fig. 1 Cosmospora khandalensis (HMAS 247850).

A-C: Colonies after 7 d at 25 °C (A: PDA; B: CMD; C: SNA); D-L: Conidiophores and conidia. Bars: D-L=10 μm.

Full size|PPT slide

在PDA培养基上,25 ℃生长7 d菌落直径22-23 mm,表面絮状,气生菌丝致密,白色,产生黄绿色色素;在CMD培养基上,25 ℃生长7 d菌落直径23-24 mm,表面绒毛状,气生菌丝稀疏,白色,产生黄绿色色素;在SNA培养基上,25 ℃生长7 d菌落直径21-23 mm,表面绒毛状,气生菌丝稀疏,白色,产生淡黄绿色色素。无性阶段acremonium型,分生孢子梗无色,不分枝或简单分枝,产孢细胞为单瓶梗,圆柱形,长34-64 μm,基部宽1.5-2.5 μm,顶部宽1.0-1.5 μm;分生孢子卵圆形至椭圆形,末端钝圆,无分隔,无色,表面平滑,2.5-5×1.5-2 μm,末端具黏性,通常聚集成团。
标本:湖北神农架木城哨卡,枯枝上生,2014 Ⅸ 22,郑焕娣、曾昭清、秦文韬、陈凯 10045,HMAS 247850 (ITS、LSU GenBank登录号:OK103798、OK103806)。
世界分布:中国、印度、日本、阿根廷、巴西。
讨论:湖北菌株分离自枯枝,其菌落形态、分生孢子等特征与Sukapure & Thirumalachar (1966)和Herrera et al. (2015)的描述一致。序列分析显示中国材料与产于印度的模式菌株(CBS 356.65) ITS序列仅相差1 bp (522/523),LSU完全相同(796/796)。
翠绿赤壳 图2
Cosmospora viridescens (C. Booth) Gräfenhan & Seifert, in Gräfenhan, Schroers, Nirenberg & Seifert, Stud. Mycol. 68: 96, 2011. Fig. 2
Nectria viridescens C. Booth, Mycol. Papers 73: 89, 1959.
图2 翠绿赤壳 (HMAS 247851)

A-C:25 ℃培养7 d的菌落形态 (A:PDA;B:CMD;C:SNA);D-L:分生孢子梗和分生孢子. 标尺:D-L=10 μm

Fig. 2 Cosmospora viridescens (HMAS 247851).

A-C: Colonies after 7 d at 25 °C (A: PDA; B: CMD; C: SNA); D-L: Conidiophores and conidia. Bars: D-L=10 μm.

Full size|PPT slide

在PDA培养基上,25 ℃生长7 d菌落直径23-24 mm,表面絮状,气生菌丝致密,白色,产生黄色至黄绿色色素;在CMD培养基上,25 ℃生长7 d菌落直径25-26 mm,表面絮状,气生菌丝较稀疏,白色,产生黄绿色色素;在SNA培养基上,25 ℃生长7 d菌落直径25-27 mm,表面绒毛状,气生菌丝稀疏,白色。无性阶段acremonium型,分生孢子梗无色,不分枝或简单分枝,产孢细胞为单瓶梗,圆柱形,长30-68 μm,基部宽1.8-2.5 μm,顶部宽1.0-1.2 μm;分生孢子椭圆形至杆形,末端钝圆,无分隔,无色,表面平滑,3-5×2-3 μm,末端具黏性,少数聚集成团。
标本:西藏米林南伊沟,Ganoderma sp.上生,2016 Ⅸ 13,郑焕娣、曾昭清、王新存、陈凯、张玉博 10806,HMAS 247851 (ITS、LSU GenBank登录号:OK103799、OK103807)。
世界分布:中国、捷克、丹麦、英国。
讨论:西藏菌株的形态特征与Booth (1959)提供的原始描述一致。Gräfenhan et al. (2011)对其形态相近种进行了详细讨论。我国菌株与捷克菌株(CBS 102430)的ITS和LSU序列分别相差2 bp (518/520)和3 bp (785/788),与来自英国的模式菌株(IMI 73377a)相差5 bp (534/539)和6 bp (782/788),将上述差异视为种内变异。这是该种首次在亚洲发现(Herrera et al. 2015)。
剑孢新赤壳 图3
Neocosmospora protoensiformis Sand.-Den. & Crous, in Sandoval-Denis, Lombard & Crous, Persoonia 43: 156, 2019. Fig. 3
Fusarium protoensiforme (Sand.-Den. & Crous) O’Donnell, Geiser, Kasson & T. Aoki, in Aoki, Geiser, Kasson & O'Donnell, Index Fungorum 440: 3, 2020.
图3 剑孢新赤壳 (HMAS 290889)

A-C:自然基物上的子囊壳;D,E:25 ℃培养7 d的菌落形态 (D:PDA;E:SNA);F:子囊壳纵切面结构;G-I:子囊及子囊孢子;J-L:子囊孢子;M,N:分生孢子梗和小型分生孢子;O:小型分生孢子;P-S:大型分生孢子. 标尺:A-C=1 mm;F=50 μm;G-S=10 μm

Fig. 3 Neocosmospora protoensiformis (HMAS 290889).

A-C: Ascomata on natural substratum; D, E: Colonies after 7 d at 25 °C (D: PDA; E: SNA); F: Median section of an ascoma; G-I: Asci with ascospores; J-L: Ascospores; M, N: Conidiophores and microconidia; O: Microconidia; P-S: Macroconidia. Bars: A-C=1 mm; F=50 μm; G-S=10 μm.

Full size|PPT slide

无子座;子囊壳单生至群生,表生,球形至梨形,表面具疣状物,乳突较小,干后侧面明显凹陷,新鲜时为鲜红色,干后为深红色,在3% KOH水溶液中呈暗红色,100%乳酸溶液中呈黄色,高274-363 μm,直径216-294 μm;疣状物高4-40 μm,细胞球形至近球形,8-22×6-20 μm;壳壁厚20-50 μm,细胞矩胞组织至角胞组织,5.4-15×2.2-8 μm,胞壁厚1.0-1.5 μm;子囊棒状,顶部简单,无顶环,具8个孢子,43-60×5-10 μm;子囊孢子椭圆形,具1个分隔,分隔处稍缢缩,无色,表面平滑,在子囊中斜向单列排列,10-15× 5-8 μm。
在PDA培养基上,25℃培养7 d菌落直径40 mm,气生菌丝致密,白色;在SNA培养基上,25 ℃培养7 d菌落直径45 mm,白色,气生菌丝稀疏;分生孢子梗简单分枝,锥形、近圆柱形至针形,表面光滑,长22-56 μm,基部宽2-3 μm,顶部宽1-1.5 μm;大型分生孢子镰刀形,通常一端带小弯钩,具4-9个分隔,50-85×4-5 μm;小型分生孢子卵圆形、棒状至椭圆形,不弯曲,具0(-1)个分隔,无色,表面平滑,8-17(-20)×3-5 μm,末端具黏性,少数聚集成团。
标本:云南高黎贡山百花岭,枯树皮上生,2017 Ⅸ 15,张意、郑焕娣、王新存、张玉博 11363,HMAS 290889 (ITS、LSU GenBank登录号:OK103800、OK103808)。
世界分布:中国、委内瑞拉。
讨论:该种可在人工培养基上产生子囊壳,与自然基物上的相比,子囊壳和子囊孢子的大小基本一致,子囊稍大(53-105×8-13.8 μm vs. 43-60× 5-10 μm) (Sandoval-Denis et al. 2019),我国菌株与产自委内瑞拉的模式菌株(NRRL 22178)的ITS序列相差5 bp (518/523),LSU序列完全一致(535/535)。本研究将上述差异处理为种内变异。
罗杰森假赤壳 图4
Pseudocosmospora rogersonii C.S. Herrera & P. Chaverri, Mycologia 105(5): 1299, 2013. Fig. 4
图4 罗杰森假赤壳 (HMAS 247852)

A,B:25 ℃培养14 d的菌落形态 (A:PDA;B:SNA);C-I:分生孢子梗和分生孢子;J,K:分生孢子. 标尺:C-K=10 μm

Fig. 4 Pseudocosmospora rogersonii (HMAS 247852).

A, B: Colonies after 14 d at 25 °C (A: PDA; B: SNA); C-I: Conidiophores and conidia; J, K: Conidia. Bars: C-K=10 μm.

Full size|PPT slide

在PDA培养基上,25 ℃生长14 d菌落直径37 mm,具壳状,粉红至米褐色,背面同色;在SNA培养基上,25 ℃生长14 d菌落直径15 mm,气生菌丝极稀疏,淡粉色。无性阶段acremonium型,分生孢子梗简单,不分枝,圆柱形,朝顶部渐细,无色,长28-95 μm,基部宽1.2-1.5 μm,顶部宽0.8-1 μm。分生孢子矩形、椭圆形至杆状,不分隔,无色,表面平滑,2.5-5×1-1.8 μm。
标本:安徽金寨天堂寨,真菌上生,2011 Ⅷ 24,陈双林、庄文颖、曾昭清、郑焕娣7889,HMAS 247852 (ITS、LSU GenBank登录号:OK103796、OK103804)。
世界分布:中国、美国。
讨论:与Herrera et al. (2013)基于美国材料对该种的描述相比,我国安徽菌株的分生孢子略小(2.5-5×1-1.8 μm vs. 2.9-5.5×1.1-2.6 μm),其他特征相同。菌株7889的ITS (520/520)和LSU (764/764)序列与模式菌株BPI 1107121完全一致。该种在我国发现使其分布范围由北美洲扩展至亚洲。
瘤顶赤壳 图5
Tumenectria laetidisca (Rossman) Salgado & Rossman, in Salgado-Salazar, Rossman & Chaverri, Fungal Diversity 80: 451, 2016. Fig. 5
Nectria laetidisca Rossman, Mycol. Pap. 150: 36, 1983.
=Cylindrocarpon bambusicola Matsush., Matsush. Mycol. Mem. 5: 9. 1987.
图5 瘤顶赤壳 (HMAS 290890)

A-C:自然基物上的子囊壳;D,E:25 ℃培养14 d的菌落形态 (D:PDA;E:SNA);F:子囊壳纵切面结构;G-K:分生孢子梗和分生孢子;L:厚垣孢子. 标尺:A-C=1 mm;F=50 μm;G-L=10 μm

Fig. 5 Tumenectria laetidisca (HMAS 290890).

A-C: Ascomata on natural substratum; D, E: Colonies after 14 d at 25 °C (D: PDA; E: SNA); F: Median section of an ascoma; G-K: Conidiophores and conidia; L: Chlamydospores. Bars: A-C=1 mm; F=50 μm; G-L=10 μm.

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无子座;子囊壳单生,表生,球形至近球形,顶部具乳突,高38-75 μm,基部宽50-100 μm,顶部宽30-50 μm,干后不凹陷,新鲜时为鲜红色,干后为深红色,在3% KOH水溶液中呈暗红色,100%乳酸溶液中呈黄色,高225-304 μm,直径206-225 μm;壳壁厚28-48 μm,分2层,外层厚23-41 μm,细胞角胞组织至球胞组织,5-13× 3-8 μm,胞壁厚0.8-1.0 μm;内层厚5-7 μm,细胞矩胞组织,8-15×2.5-3.5 μm,胞壁厚0.6-0.8 μm;子囊和子囊孢子未见。
在PDA培养基上,25 ℃生长14 d菌落直径36 mm,表面絮状,气生菌丝致密,白色,背面产生米黄色至淡黄褐色色素;在SNA培养基上,25 ℃生长14 d菌落直径42 mm,表面绒毛状,气生菌丝稀疏,白色。无性阶段cylindrocarpon型,分生孢子梗无色,产孢细胞圆柱形,18-35×3.5- 5 μm;大型分生孢子圆柱形至纺锤形,中间宽,两端略圆,具3-5个分隔,48-77.1×7.4-10.9 μm;偶见厚垣孢子,球形至近球形,直径5-18 μm,间生或串生。
标本:河南洛阳重渡沟,枯枝上生,2013 Ⅸ 20,郑焕娣、曾昭清、朱兆香8813,HMAS 290890 (ITS、LSU GenBank登录号:OK103797、OK103805)。
世界分布:中国、日本、牙买加。
讨论:该种曾被纳入Nectria,综合形态学特征和分子系统学证据,Salgado-Salazar et al. (2016)以其为模式种建立新属Tumenectria Salgado & Rossman,目前仅包括1个种。河南材料状态不佳,子囊壳数量很少,未观察到子囊和子囊孢子,其无性阶段特征符合Salgado-Salazar et al. (2016)的描述。中国菌株(8813)与日本菌株(CBS 100284)的ITS (478/478)和LSU (797/797)序列完全一致,而与牙买加的模式菌株(CBS 101909)分别相差5 bp (473/478)和0 bp (797/797)。

3 系统发育分析

为了清晰地显示5个中国新记录种的系统发育位置,选择丛赤壳科的7个种14个菌株的ITS和LSU序列,以Stachybotrys chartarum为外群,运用MP和BI方法分别构建系统发育树。结果显示,BI树和MP树的拓扑结构一致,最大简约分析产生的唯一进化树(图6)显示菌株HMAS 247850、247851、290889、247852和290890分别与Cosmospora khandalensisCosmospora viridescensNeocosmospora protoensiformisPseudocosmospora rogersoniiTumenectria laetidisca聚类在一起,从而支持了上述形态学研究的结果。
图6 基于ITS和LSU序列的MP树

粗体显示5个中国新记录种的系统发育位置,MPBP大于50% (左)、BIPP大于90% (右)标注于分支节点上

Fig. 6 Maximum parsimony phylogram reconstructed from the combined sequences of ITS and LSU.

the phylogenetic position of the five Nectriaceae species new to China. MPBP above 50% (left) showing and BIPP above 90% (right) are given respectively.

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基金

国家自然科学基金(31800345)
国家自然科学基金(31770561)
河北省自然科学基金(C2020201043)

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