土壤原生生物多样性及其生态功能研究进展
收稿日期: 2022-06-28
录用日期: 2022-08-30
网络出版日期: 2022-11-11
基金资助
第二次青藏高原综合科学考察项目(2019QZKK0306);第二次青藏高原综合科学考察项目(2019QZKK0308)
Research progress on the biodiversity and ecological function of soil protists
Received date: 2022-06-28
Accepted date: 2022-08-30
Online published: 2022-11-11
原生生物广泛分布在土壤和不同生境中, 其数量庞大、种类繁多, 在生态系统物质循环和能量流动以及维持土壤和植物健康中起着举足轻重的作用。与土壤其他生物类群相比, 原生生物分类体系和生态类型复杂, 分类鉴定困难且分子检测技术不够成熟, 目前对原生生物的认识相对不足。本文对当前原生生物的相关研究进展进行了总结和梳理, 系统阐述了原生生物的分类系统和营养功能群特征、土壤原生生物的多样性分布特征及影响因子, 重点介绍了原生生物群落在参与土壤养分循环、维持土壤和植物健康等中的功能作用, 并对未来的研究方向与应用前景进行了展望。对土壤原生生物的研究有助于我们深入认识土壤生物多样性资源, 并进行保护性地开发和利用, 维护土壤和生态系统健康。
姚保民 , 曾青 , 张丽梅 . 土壤原生生物多样性及其生态功能研究进展[J]. 生物多样性, 2022 , 30(12) : 22353 . DOI: 10.17520/biods.2022353
Background & Aims: Protists are widely distributed in soil and throughout different habitats with high abundance and diversity. They play important roles in nutrient cycling and the energy flow of ecosystems, as well as maintaining soil and plant health. Compared with other microorganisms and fauna in soil, protists have received little attention until recently, and the study on their classification and molecular detection are largely challenged due to their complex taxonomy systems and ecological types.
Progresses: This review systematically summarized and sorted out previous research on soil protists. The research progress on the taxonomic systems of protists, properties of different trophic functional groups, the distribution pattern, and the influencing factors of soil protists were summarized. Then the ecological functions of protistan communities in participating in soil nutrient cycling and maintaining soil health were further highlighted. The main factors that drive the construction of protistan community was clarified, and the prospect and application prospect were further put forward.
Prospects: The future perspectives and research efforts towards taxonomic classification, biodiversity, ecological function, and applications of soil protists need to be explored.
Key words： protists; taxonomic group; ecological functions; food web; soil health
| [1] | Acosta-Mercado D, Lynn DH (2004) Soil ciliate species richness and abundance associated with the rhizosphere of different subtropical plant species. The Journal of Eukaryotic Microbiology, 51, 582-588. |
| [2] | Adl SM, Simpson AGB, Farmer MA, Andersen RA, Anderson OR, Barta JR, Bowser SS, Brugerolle G, Fensome RA, Fredericq S, James TY, Karpov S, Kugrens P, Krug J, Lane CE, Lewis LA, Lodge J, Lynn DH, Mann DG, McCourt RM, Mendoza L, Moestrup O, Mozley-Standridge SE, Nerad TA, Shearer CA, Smirnov AV, Spiegel FW, Taylor MFJR (2005) The new higher level classification of eukaryotes with emphasis on the taxonomy of protists. The Journal of Eukaryotic Microbiology, 52, 399-451. |
| [3] | Amaroli A (2015) The effects of temperature variation on the sensitivity to pesticides: A study on the slime mould Dictyostelium discoideum (Protozoa). Microbial Ecology, 70, 244-254. |
| [4] | Antonelli M, Wetzel CE, Ector L, Teuling AJ, Pfister L (2017) On the potential for terrestrial diatom communities and diatom indices to identify anthropic disturbance in soils. Ecological Indicators, 75, 73-81. |
| [5] | Bamforth SS (1980) Terrestrial protozoa. The Journal of Protozoology, 27, 33-36. |
| [6] | Bates ST, Clemente JC, Flores GE, Walters WA, Parfrey LW, Knight R, Fierer N (2013) Global biogeography of highly diverse protistan communities in soil. The ISME Journal, 7, 652-659. |
| [7] | Beaver JR, Crisman TL (1989) The role of ciliated protozoa in pelagic freshwater ecosystems. Microbial Ecology, 17, 111-136. |
| [8] | Bernasconi SM, Bauder A, Bourdon B, Brunner I, Bünemann E, Chris I, Derungs N, Edwards P, Farinotti D, Frey B, Frossard E, Furrer G, Gierga M, G?ransson H, Gülland K, Hagedorn F, Hajdas I, Hindshaw R, Ivy-Ochs S, Jansa J, Jonas T, Kiczka M, Kretzschmar R, Lemarchand E, Luster J, Magnusson J, Mitchell EAD, Venterink HO, Pl?tze M, Reynolds B, Smittenberg RH, St?hli M, Tamburini F, Tipper ET, Wacker L, Welc M, Wiederhold JG, Zeyer J, Zimmermann S, Zumsteg A (2011) Chemical and biological gradients along the damma glacier soil chronosequence, Switzerland. Vadose Zone Journal, 10, 867-883. |
| [9] | Bonkowski M, Brandt F (2002) Do soil protozoa enhance plant growth by hormonal effects? Soil Biology and Biochemistry, 34, 1709-1715. |
| [10] | Brazelton JN, Pfeufer EE, Sweat TA, Gardener BBM, Coenen C (2008) 2,4-Diacetylphloroglucinol alters plant root development. Molecular Plant-Microbe Interactions, 21, 1349-1358. |
| [11] | Campbell CD, Warren A, Cameron CM, Hope SJ (1997) Direct toxicity assessment of two soils amended with sewage sludge contaminated with heavy metals using a protozoan (Colpoda steinii) bioassay. Chemosphere, 34, 501-514. |
| [12] | Caron DA, Alexander H, Allen AE, Archibald JM, Armbrust EV, Bachy C, Bell CJ, Bharti A, Dyhrman ST, Guida SM, Heidelberg KB, Kaye JZ, Metzner J, Smith SR, Worden AZ (2017) Probing the evolution, ecology and physiology of marine protists using transcriptomics. Nature Reviews Microbiology, 15, 6-20. |
| [13] | Cavender JC, Landolt JC, Romeralo M, Perrigo A, Vadell EM, Stephenson SL (2016) New species of Polysphondylium from Madagascar. Mycologia, 108, 80-109. |
| [14] | Chakraborty S, Waecup JH (1984) Populations of mycophagous and other amoebae in take-all suppressive and non-suppressive soils. Soil Biology and Biochemistry, 16, 197-199. |
| [15] | Chen SF, Xu RL (2003) Advances of the studies on the soil protozoa. Acta Scientiarum Naturalium Universitatis Sunyatseni, 42(z1), 187-194. (in Chinese with English abstract) |
| [15] | [ 陈素芬, 徐润林 (2003) 土壤原生生物的研究进展. 中山大学学报(自然科学版), 42(z1), 187-194.] |
| [16] | Corsaro D, Walochnik J, Venditti D, Steinmann J, Müller KD, Michel R (2014) Microsporidia-like parasites of amoebae belong to the early fungal lineage Rozellomycota. Parasitology Research, 113, 1909-1918. |
| [17] | Delgado-Baquerizo M, Oliverio AM, Brewer TE, Benavent-González A, Eldridge DJ, Bardgett RD, Maestre FT, Singh BK, Fierer N (2018) A global atlas of the dominant bacteria found in soil. Science, 359, 320-325. |
| [18] | Díaz S, Martín-González A,Carlos Gutiérrez J (2006) Evaluation of heavy metal acute toxicity and bioaccumulation in soil ciliated protozoa. Environment International, 32, 711-717. |
| [19] | Dunthorn M, Lipps JH, Dolan JR, Saab MAA, Aescht E, Bachy C, De Cao MSB, Berger H, Bourland WA, Choi JK, Clamp J, Doherty M, Gao F, Gentekaki E, Gong J, Hu X, Huang J, Kamiyama T, Johnson MD, Kammerlander B, Kim SY, Kim YO, La Terza A, Laval-Peuto M, Lipscomb D, Lobban CS, Long hongan, Luporini P, Lynn DH, Macek M, Mansergh RI, Martín-Cereceda M, McManus GG, Montagnes DJS, Ong’ondo GO, Patterson DJ, Pérez-Uz B, Quintela-Alonso P, Safi LSL, Santoferrara LF, Sonntag B, Song WB, Stoeck T, Stoecker DK, Strüder-Kypke MC, Trautmann I, Utz LRP, Vallesi A, Vd’a?ny P, Warren A, Weisse T, Wickham SA, Yi ZZ, Zhang WC, Zhan ZF, Zufall R, Agatha S (2015) Ciliates—Protists with complex morphologies and ambiguous early fossil record. Marine Micropaleontology, 119, 1-6. |
| [20] | Dupont A?C, Griffiths RI, Bell T, Bass D (2016) Differences in soil micro-eukaryotic communities over soil pH gradients are strongly driven by parasites and saprotrophs. Environmental Microbiology, 18, 2010-2024. |
| [21] | Durán P, Thiergart T, Garrido-Oter R, Agler M, Kemen E, Schulze-Lefert P, Hacquard S (2018) Microbial interkingdom interactions in roots promote Arabidopsis survival. Cell, 175, 973-983. |
| [22] | Falkowski PG (2002) The ocean’s invisible forest. Scientific American, 287, 54-61. |
| [23] | Fenchel T, Finaly BJ (1990) Anaerobic free-living protozoa: Growth efficiencies and the structure of anaeorobic communities. FEMS Microbiology Letters, 74, 269-275. |
| [24] | Feng WS, Yang J, Ye ZH, Miao W, Yu YH, Huang MH, Shen YF (2004) Soil protozoa in wetland treatment system of Pb-Zn mine in Fankou. Chinese Journal of Zoology, 39, 2-11. (in Chinese with English abstract) |
| [24] | [ 冯伟松, 杨军, 叶志鸿, 缪炜, 余育和, 黄铭洪, 沈韫芬 (2004) 凡口铅锌矿湿地处理系统的土壤原生动物. 动物学杂志, 39, 2-11.] |
| [25] | Figueroa-Martinez F, Nedelcu AM, Smith DR, Reyes-Prieto A (2015) When the lights go out: The evolutionary fate of free-living colorless green algae. New Phytologist, 206, 972-982. |
| [26] | Foissner W (1998) An updated compilation of world soil ciliates (Protozoa, Ciliophora), with ecological notes, new records, and descriptions of new species. European Journal of Protistology, 34, 195-235. |
| [27] | Gao YC, Zhu WS, Chen WX (2000) Structure of the protozoan community in soil and its ecological functions. Chinese Journal of Ecology, 19, 59-65. (in Chinese with English abstract) |
| [27] | [ 高云超, 朱文珊, 陈文新 (2000) 土壤原生动物群落及其生态功能. 生态学杂志, 19, 59-65.] |
| [28] | Gao Z, Karlsson I, Geisen S, Kowalchuk G, Jousset A (2019) Protists: Puppet masters of the rhizosphere microbiome. Trends in Plant Science, 24, 165-176. |
| [29] | Geisen S, Cornelia BJR (2014) Soil water availability strongly alters the community composition of soil protists. Pedobiologia, 57, 205-213. |
| [30] | Geisen S, Lara E, Mitchell EAD, V?lcker E, Krashevska V (2020) Soil protist life matters! Soil Organisms, 9, 189-196. |
| [31] | Geisen S, Mitchell EAD, Adl S, Bonkowski M, Dunthorn M, Ekelund F, Fernández LD, Jousset A, Krashevska V, Singer D, Spiegel FW, Walochnik J, Lara E (2018) Soil protists: A fertile frontier in soil biology research. FEMS Microbiology Reviews, 42, 293-323. |
| [32] | Geisen S, Mitchell EAD, Wilkinson DM, Adl S, Bonkowski M, Brown MW, Fiore-Donno AM, Heger TJ, Jassey VEJ, Krashevska V, Lahr DJG, Marcisz K, Mulot M, Payne R, Singer D, Anderson OR, Charman DJ, Ekelund F, Griffiths BS, R?nn R, Smirnov A, Bass D, Belbahri L, Berney C, Blandenier Q, Chatzinotas A, Clarholm M, Dunthorn M, Feest A, Fernández LD, Foissner W, Fournier B, Gentekaki E, Hájek M, Helder J, Jousset A, Koller R, Kumar S, La Terza A, Lamentowicz M, Mazei YR, Santos SS, Seppey CVW, Spiegel FW, Walochnik J, Winding A, Lara E (2017) Soil protistology rebooted: 30 fundamental questions to start with. Soil Biology and Biochemistry, 111, 94-103. |
| [33] | Hu H, Li SJ, Wang R, Wu X, Li YJ, Zhao JN, Li G, Xiu WM (2022) Effects of nitrogen fertilization combined with straw incorporation on soil protist community. Acta Pedologica Sinica, doi: 10.11766/trxb202111090520. (in Chinese with English abstract) |
| [33] | [ 胡菏, 李胜君, 王蕊, 吴宪, 李玉洁, 赵建宁, 李刚, 修伟明 (2022) 氮肥配施秸秆对土壤原生生物群落影响. 土壤学报, doi: 10.11766/trxb202111090520.] |
| [34] | Jassey VEJ, Lamentowicz ?, Robroek BJM, G?bka M, Rusińska A, Lamentowicz M (2014) Plant functional diversity drives niche-size-structure of dominant microbial consumers along a poor to extremely rich fen gradient. Journal of Ecology, 102, 1150-1162. |
| [35] | Kemmitt S, Wright D, Goulding K, Jones D (2006) pH regulation of carbon and nitrogen dynamics in two agricultural soils. Soil Biology and Biochemistry, 38, 898-911. |
| [36] | Krashevska V, Sandmann D, Maraun M, Scheu S (2014) Moderate changes in nutrient input alter tropical microbial and protist communities and belowground linkages. The ISME Journal, 8, 1126-1134. |
| [37] | Krome K, Rosenberg K, Dickler C, Kreuzer K, Ludwig-Müller J, Ullrich-Eberius C, Scheu S, Bonkowski M (2010) Soil bacteria and protozoa affect root branching via effects on the auxin and cytokinin balance in plants. Plant and Soil, 328, 191-201. |
| [38] | Kuikman PJ,Van Veen JA (1989) The impact of protozoa on the availability of bacterial nitrogen to plants. Biology and Fertility of Soils, 8, 13-18. |
| [39] | Lara E, Roussel-Delif L, Fournier B, Wilkinson DM, Mitchell EAD (2016) Soil microorganisms behave like macroscopic organisms: Patterns in the global distribution of soil euglyphid testate amoebae. Journal of Biogeography, 43, 520-532. |
| [40] | Ledeganck P (2003) Plant functional group diversity promotes soil protist diversity. Protist, 154, 239-249. |
| [41] | Mitchell DR (2007) The evolution of eukaryotic cilia and flagella as motile and sensory organelles. In: Eukaryotic Membranes and Cytoskeleton: Origins and Evolution (ed. Jékely G), pp.130-140. Springer, New York. |
| [42] | Mitchell EAD (2004) Response of testate amoebae (protozoa) to N and P fertilization in an Arctic wet sedge tundra. Arctic, Antarctic, and Alpine Research, 36, 78-83. |
| [43] | Moon-van der Staay SY, De Wachter R, Vaulot D (2001) Oceanic 18S rDNA sequences from picoplankton reveal unsuspected eukaryotic diversity. Nature, 409, 607-610. |
| [44] | Neuhauser S, Kirchmair M, Bulman S, Bass D (2014) Cross-kingdom host shifts of phytomyxid parasites. BMC Evolutionary Biology, 14, 33. |
| [45] | Ning YZ, Shen YF (1998) Soil protozoa in typical regions of China. II. Ecological study. Acta Zoologica Sinica, 31, 24-29. (in Chinese with English abstract) |
| [45] | [ 宁应之, 沈韫芬 (1998) 中国典型地带土壤原生动物. II. 生态学研究. 动物学报, 31, 24-29.] |
| [46] | Not F, Del Campo J, Balagué V, De Vargas C, Massana R (2009) New insights into the diversity of marine picoeukaryotes. PLoS ONE, 4, e7143. |
| [47] | Oliverio AM, Geisen S, Delgado-Baquerizo M, Maestre FT, Turner BL, Fierer N (2020) The global-scale distributions of soil protists and their contributions to belowground systems. Science Advances, 6, eaax8787. |
| [48] | Opperman MH, Wood M, Harris PJ (1989) Changes in microbial populations following the application of cattle slurry to soil at two temperatures. Soil Biology and Biochemistry, 21, 263-268. |
| [49] | Peng JJ, Oladele O, Song XT, Ju XT, Jia ZJ, Hu HW, Liu XJ, Bei SK, Ge AH, Zhang LM, Gui ZL (2022) Opportunities and approaches for manipulating soil-plant microbiomes for effective crop nitrogen use in agroecosystems. Frontiers of Agricultural Science and Engineering, 9, 333-343. |
| [50] | Saleem M, Fetzer I, Dormann CF, Harms H, Chatzinotas A (2012) Predator richness increases the effect of prey diversity on prey yield. Nature Communications, 3, 1305. |
| [51] | Scherber C, Eisenhauer N, Weisser WW, Schmid B, Voigt W, Fischer M, Schulze ED, Roscher C, Weigelt A, Allan E, Be?ler H, Bonkowski M, Buchmann N, Buscot F, Clement LW, Ebeling A, Engels C, Halle S, Kertscher I, Klein AM, Koller R, K?nig S, Kowalski E, Kummer V, Kuu A, Lange M, Lauterbach D, Middelhoff C, Migunova VD, Milcu A, Müller R, Partsch S, Petermann JS, Renker C, Rottstock T, Sabais A, Scheu S, Schumacher J, Temperton VM, Tscharntke T (2010) Bottom-up effects of plant diversity on multitrophic interactions in a biodiversity experiment. Nature, 468, 553-556. |
| [52] | Schwarz MVJ, Frenzel P (2003) Population dynamics and ecology of ciliates (Protozoa, Ciliophora) in an anoxic rice field soil. Biology and Fertility of Soils, 38, 245-252. |
| [53] | Seppey CVW, Singer D, Dumack K, Fournier B, Belbahri L, Mitchell EAD, Lara E (2017) Distribution patterns of soil microbial eukaryotes suggests widespread algivory by phagotrophic protists as an alternative pathway for nutrient cycling. Soil Biology and Biochemistry, 112, 68-76. |
| [54] | Singh BN (1949) The effect of artificial fertilizers and dung on the members of amoebae in Rothamsted soils. Journal of General Microbiology, 3, 204-210. |
| [55] | Smirnov AV, Chao E, Nassonova ES, Cavalier-Smith T (2011) A revised classification of naked lobose amoebae (Amoebozoa: Lobosa). Protist, 162, 545-570. |
| [56] | Song WB (2007) Protobiology. Qingdao Ocean University Press, Qingdao. (in Chinese) |
| [56] | [ 宋微波 (2007) 原生生物学. 青岛海洋大学出版社, 青岛.] |
| [57] | Stapleton LM, Crout NMJ, S?wstr?m C, Marshall WA, Poulton PR, Tye AM, Laybourn-Parry J (2005) Microbial carbon dynamics in nitrogen amended Arctic tundra soil: Measurement and model testing. Soil Biology and Biochemistry, 37, 2088-2098. |
| [58] | Stefan G, Cornelia B, J?rg R, Michael B (2014) Soil water availability strongly alters the community composition of soil protists. Pedobiologia, 57, 205-213. |
| [59] | Stefanowicz A (2006) The biolog plates technique as a tool in ecological studies of microbial communities. Polish Journal of Environmental Studies, 15, 669-676. |
| [60] | Sun X, Li Q, Yao HF, Liu MQ, Wu DH, Zhu D, Zhu YG (2021) Soil fauna and soil health. Acta Pedologica Sinica, 58, 1073-1083. (in Chinese with English abstract) |
| [60] | [ 孙新, 李琪, 姚海凤, 刘满强, 吴东辉, 朱冬, 朱永官 (2021) 土壤动物与土壤健康. 土壤学报, 58, 1073-1083.] |
| [61] | Sun YX, Lin QM, Zhao XR, Xing LJ, Wang YS (2003) Distribution of four protozoan genera in rhizosphere and non-rhizosphere soil of corn. Chinese Agricultural Sciences, 36, 1399-1402. (in Chinese with English abstract) |
| [61] | [ 孙焱鑫, 林启美, 赵小蓉, 邢礼军, 王幼珊 (2003) 玉米根际与非根际土壤中4种原生动物分布特征. 中国农业科学, 36, 1399-1402.] |
| [62] | Tian JY (2012) Inpact factor of growth and distribution of protozoa. Natural Sciences Journal of Harbin Normal University, 28(4), 61-63, 70. (in Chinese with English abstract) |
| [62] | [ 田佳玉 (2012) 原生动物生长和分布的影响因子. 哈尔滨师范大学自然科学学报, 28(4), 61-63, 70.] |
| [63] | Wei Z, Song YQ, Xiong W, Xu YC, Shen QR (2021) Soil protozoa: Research methods and roles in the biocontrol of soil-borne diseases. Acta Pedologica Sinica, 58, 14-22. (in Chinese with English abstract) |
| [63] | [ 韦中, 宋宇琦, 熊武, 徐阳春, 沈其荣 (2021) 土壤原生动物——研究方法及其在土传病害防控中的作用. 土壤学报, 58, 14-22.] |
| [64] | Woods LE, Cole CV, Elliott RV, Anderson, Coleman DC (1982) Nitrogen transformations in soil as affected by bacterial-microfaunal interactions. Soil Biology and Biochemistry, 14, 93-98. |
| [65] | Wu LW, Zhang Y, Guo X, Ning DL, Zhou XS, Feng JJ, Yuan MM, Liu S, Guo JJ, Gao ZP, Ma J, Kuang JL, Jian SY, Han S, Yang ZF, Ouyang Y, Fu Y, Xiao NJ, Liu XD, Wu LY, Zhou AF, Yang YF, Tiedje JM, Zhou JZ (2022) Reduction of microbial diversity in grassland soil is driven by long- term climate warming. Nature Microbiology, 7, 1054-1062. |
| [66] | Xiong W, Song Y, Yang K, Gu Y, Wei Z, Kowalchuk GA, Xu Y, Jousset A, Shen Q, Geisen S (2020) Rhizosphere protists are key determinants of plant health. Microbiome, 8, 27. |
| [67] | Yang YH, Yao J, Hu S, Qi Y (2000) Effects of agricultural chemicals on DNA sequence diversity of soil microbial community: A study with RAPD marker. Microbial Ecology, 39, 72-79. |
| [68] | Yang ZC, Wang ZH, Zhang ZH (2010) Monitoring of heavy metal pollution by moss-dwelling protozoa communities in a Hg-Tl mineralized area. Acta Scientiae Circumstantiae, 30, 1486-1491. (in Chinese with English abstract) |
| [68] | [ 杨再超, 王智慧, 张朝晖 (2010) 藓类附生原生动物群落对汞铊矿重金属污染的监测. 环境科学学报, 30, 1486-1491.] |
| [69] | Zancan S, Trevisan R, Paoletti MG (2006) Soil algae composition under different agro-ecosystems in North-Eastern Italy. Agriculture, Ecosystems & Environment, 112, 1-12. |
| [70] | Zelles L (1999) Fatty acid patterns of phospholipids and lipopolysaccharides in the characterisation of microbial communities in soil: A review. Biology and Fertility of Soils, 29, 111-129. |
| [71] | Zhao ZB, He JZ, Geisen S, Han LL, Wang JT, Shen JP, Wei WX, Fang YT, Li PP, Zhang LM (2019) Protist communities are more sensitive to nitrogen fertilization than other microorganisms in diverse agricultural soils. Microbiome, 7, 33. |
| [72] | Zhou KX, Xu MQ, Cao H, Ning YZ (2003) Soil protozoa as monitors of the environment. Chinese Journal of Zoology, 38, 80-84. (in Chinese with English abstract) |
| [72] | [ 周可新, 许木启, 曹宏, 宁应之 (2003) 土壤原生动物在环境监测中的应用. 动物学杂志, 38, 80-84.] |
| [73] | Zhu YG, Peng JJ, Wei Z, Shen QR, Zhang FS (2021) Linking the soil microbiome to soil health. Scientia Sinica Vitae, 51, 1-11. (in Chinese with English abstract) |
| [73] | [ 朱永官, 彭静静, 韦中, 沈其荣, 张福锁 (2021) 土壤微生物组与土壤健康. 中国科学: 生命科学, 51, 1-11.] |
| [74] | Zhu YG, Chen BD, Fu W (2022) Research frontiers in soil ecology. Science & Technology Review, 40, 25-31. (in Chinese with English abstract) |
| [74] | [ 朱永官, 陈保冬, 付伟 (2022) 土壤生态学研究前沿. 科技导报, 40, 25-31.] |
/
| 〈 |
|
〉 |
