FENG  G.

GAI  J. P.

LI  X. L.

ZHANG  J. L.

English

紀要類 (bulletin)Symposium Paperdepartmental bulletin pape

GAI, J. P.

ZHANG, J. L.

FENG, G.

LI, X. L.

Tohoku University Repository (TOUR) / 東北大学機関リポジトリ

Arbuscular Mycorrhizal Fungi Diversity andContribution to Crop Growth in AgriculturalFields著者 GAI  J. P., ZHANG  J. L., FENG  G., LI  X. L.journal orpublication titleJournal of Integrated Field Sciencevolume 7page range 41-45year 2010-03URL http://hdl.handle.net/10097/4883441Symposium PaperArbuscular Mycorrhizal Fungi Diversity and Contribution to Crop Growthin Agricultural FieldsJ. P. GAI,  J. L. ZHANG, G. FENG and X. L. LI*College of Resources and Environmental Sciences, China Agricultural University,Yuanmingyuan West Road 2,  Haidian District, 100193 Beijing, PR China*e-mail: lixl@cau.edu.cnReceived 17 November 2009; accepted 1 February 2010AbstractArbuscular mycorrhizal (AM) fungi are important soil microorganisms in agroecosystems by enhanc-ing host plant survival and growth. In our survey of AM fungi in the rhizosphere of various crop plants in north and north-west China, thirty three AM fungal species representing seven genera were detected and species richness averaged 2.2 per sample. Glomus etunicatum, G. mosseae and G. intraradices were the dominant species. We also obtained 61 pure isolates, of which 11 pure cultures were registered in the Eu-ropean Bank of the Glomales (BEG). Temporal and spatial dynamics of AMF were studied in the high yield maize system and the result showed that arbus-cular colonization, hyphal density, spore density were all reached the maximal at the milk stage of maize (R1 stage). AM fungal community was in a trend of decreasing with increasing soil depth. AMF spe-cies richness was decreased signiﬁ cantly only at the depth of 60-90 cm in maize root zone. To estimate the effect of AM fungi on crop growth in agricultural fields, sweet potato, maize, rice, spring onion, taro, strawberry, pimiento, melon, cucumber, tomato and celery were selected as host plants. After pre-inoc-ulation or supply AM inoculum directly in the ﬁ eld, the yield and quality of the crops could be improved. The fertilizer was averaged saving 21%. Moleculer and isotope method were also tentatively used in our present study to monitor of introduced AM fungi, to discriminate the contribution of introduced AM fungi to the crop growth. 1. Introduction Agriculture is an important economic sector of China. China has to raise agricultural productivity in its limited and shrinking farmland to guarantee food security for its huge and ever-growing population. Sustainable soil nutrient management is of paramount importance.Arbuscular mycorrhizas are formed by a close as-sociation between roots and arbuscular mycorrhizal fungi (AMF), which are ubiquitous in natural and agricultural ecosystems. AMF have long fascinated Chinese agricultural researchers due to their ability to enhance host plant uptake of nutrients, especially phosphorus (P) (Smith and Read 2008). AMF may also be necessary for the long-term sustainability of ecosystems, particularly due to their role in the maintenance of soil structure, and plant community structure and diversity (van der Heijden and Scheu-blin, 2007). We have done some research on AMF investigation, isolation, efﬁ ciency selection and ﬁ eld test. Here, we will focus on the AMF diversity and contribution to crop growth in north China2. Material and methodsThe AMF diversity investigation was conducted in north and north-west China, including Hebei, Bei-jing, Shandong, Liaoning, Qinghai, Gansu, Xinjiang and Tibet. Soil samples were collected from the root zones of 30 staple crop plants. Isolation and identiﬁ -cation was carried out in pot culture and spore mor-phological method.The study on temporal and spatial dynamics of AMF was conducted in high yield maize systems of Quzhou, China. Two nutrients input treatments were included, high input (HP) and optimum input (OP). Root and soil samples were collected at the V6, VT, R1, R6 growth stage. Ten soil cores in a Z-line were taken to a depth of 90 cm. The cores were separated into sections corresponding to 0-30, 30-60 and 60-90 cm soil depth. Then AMF colonization, spore density, JIFS, 7 : 41  45 (2010)42hyphal density and species richness were determined. The percentage of root length colonized was calculat-ed according to the method of Trouvelot et al. (1986). The colonization data for speciﬁ c AM structures are expressed as percentage of root length. Spores and sporocarps were extracted from 100 g air dried sub-samples of each soil sample in triplicate by wet siev-ing followed by ﬂ otation–centrifugation in 50 % su-crose (Dalpé 1993). The ﬁ nest sieve used was 38 µm. AM fungal spores were counted on a grid-patterned dish under a binocular stereomicroscope.The ﬁ eld trial was carried out in Hebei and Beijing. The tested plants included sweet potato, maize, rice, spring onion, taro, strawberry, pimiento, melon, cu-cumber, tomato and celery et al.SAS 8.2 software was used to conduct all statistical analyses. To analyze the inoculation effect of AMF on different crops, one way analysis of variance was used and means were compared by least significant difference (LSD) at the 5% level.3. Results and Discussion3.1 AMF diversity in agricultural fi eldIn order to study AM fungal diversity, representa-tive soil samples were collected from ﬁ elds in which various crop plants were grown in north and north-west China. Isolation and puriﬁ cation of the mycor-rhizal fungi led to the identiﬁ cation of 33 species in seven genera (Table 1). Sixty-one pure isolates and eighteen pure cultures were obtained, of which 11 pure cultures were registered in the European Bank of the Glomales (BEG). They are G. mosseae BEG167, G. etunicatum  BEG168, Glomus clarodieum BEG180, G. etunicatum BEG181, G. constrictum BEG182, G. mosseae BEG189, G. mosseae BEG190, G. mosseae BEG191, G. intraradices BEG192, G. intraradices BEG193 and A. morrowiae BEG194. A germplasm stock was established for storage of the resources in the target area.The results from analysis of the ecological diversity in the ﬁ eld soils showed that the frequency of occur-rence of the genus Glomus was highest and Acaulos-pora was the second most abundant genus. Glomus etunicatum, G. mosseae and G. intraradices were the dominant species and species richness averaged 2.2 per sample. It was consistent with the former survey in arid and semiarid zones of north China (Zhang et al. 1994; Gai et al., 2006). 3.2 Temporal and spatial dynamics of AMF in high yield maize systemThere were no signiﬁ cant differences in the tempo-ral dynamics of root AM colonization between high input (HP) and optimum input treatments (Fig. 1). However, there was some difference among the ar-buscular, vesicular and total colonization trend. It was obviously that arbuscular colonization was highest at R1, while vesicle formation reached maximum at V6. Spore density was in a similar temporal dynamics to arbuscular colonization, which reached maximum at R1, and then decreased. Some AMF acquire nutrients near the roots while Table 1. AM fungus isolated from North ChinaGAI et al.   Genus SpeciesAcaulospora A. lacunosa A. laevis A. mellea A. rugosa A. scrobiculataA. spinosa A. sp.Archaespora Ar. gerdemannii Ar. leptotichaEntrophospora En. sp.Gigaspora Gi. margaritaGlomus G. aggregatum G. caledonium G. claroidem G. clarum G. constrictumG. diaphanum G. etunicatum G geosporum G. intraradices G. macrocarpumG. mosseae G. reticulatum G. rubiforme G. versiforme G. fragarioides G. sprum like G. 'cluster sp' G. sp.Paraglomus Pa. OccultumScutellospora S. calospora S. gilmorei S. pellucida43Arbuscular Mycorrhizal Fungi Diversity and Contribution to Crop Growth in Agricultural FieldsFig. 4. Species richness of AMF at different soil depth categories in HP and OP treatmentsFig. 3. Hyphal density of AMF at different soil depth categories in HP and OP treatmentsFig. 2. Spore density of AMF at different soil depth categories in HP and OP treatmentsFig. 1. Root Colonization Rates in HP and OP treatments. The bar shows the difference error, same as below.44others forage further away and explore different soil volumes (Smith et al., 2000). This can lead to increased productivity through the complementary use of resources. A similar phenomenon has been observed in plants with different rooting depths. Host preference and host range are two functional traits that are potentially very important. The present study showed that spore density were highest in the topsoil (at 0-30 cm) and showed a decreasing trend with in-creasing soil depth at both nutrient treatments (Fig. 2). Hyphal length and species richness (Fig. 3 and Fig. 4) was in a similar trend. Similar results were obtained in studies by Jakobsen and Nielsen (1983) and Rillig and Field (2003). Physical and chemical properties of soil change with depth and inﬂ uence the distribution of soil organisms (Abbott and Robson 1991; Entry et al. 2002). Fungi are especially sensi-tive to low partial pressures of oxygen which prevail at depth (Brady and Weil 1996). AMF are also likely to be scarce where roots are sparse (Anderson et al. 1987).3.3 Effect of AM fungi on staple crop growthThe inoculaton experimental results showed that the yield and quality of the tubers were improved by inoculation with mycorrhizal fungi. The isolates BEG168, GSP4 and BEG141 increased sweet potato tuber yield by 10% (Table 2). Reducing sugar content Treatments FW (g/tuber) Tuber no. per plant Tuber yield (kg/plot) Tuber yield (kg/hm2) Increasing (%)CK 238.9b 4.5a 33.2b 34912b 0BEG141 268.8ab 3.9a 36.6a 38488a 10GSP4 247.8b 4.6a 37.0a 38949a 11BEG168 304.5a 3.9a 36.8a 38739a 11M3 280.0ab 3.6a 33.9b 35686b 2Endo1 267.0ab 3.5a 35.5ab 37370ab 7Table 2. Tuber yield and yield index of different inoculation treatmentsTreatmentsDry percentage(%)Total starch content(%FW)Reducing sugar content(%DW)Total carotenes content(ug/gDW)CK 22.3a 14.9a 15.78b 22.5bBEG141 23.5a 14.5a 16.125ab 28.3aGSP4 24.1a 15.2a 19.93a 22.1bBEG168 23.4a 16.1a 17.11ab 26.9abM3 24.1a 14.8a 16.25ab 22.1bEndo1 22.9a 14.9a 15.30b 23.8abTable 3. Tuber quality index of different inoculation treatmentsTreatmentsPimiento Melon Watermelon Celery Green Chinese Onion (kg/120seedings) (kg/84seedlings) (kg/40seedlings) (kg/20seedlings) (kg/hm2)AM 69.0a 31.45a 384.5a 16.2a 10472aCK 65.5a 28.35b 342.0b 13.7b 12361bIncreasing(%)5.5 10.9 12.4 18.3 15.3Table 4. Yield of horticultural crops of different inoculation treatmentsGAI et al.45and total carotenes were increased in isolates GSP4 and BEG141 by mycorrhizal inoculation (Table 3). Inoculating AMF also increased the yield of some horticulture crops. The increasing rate varied from 5.5% to 18.3% (Table 4).The experiment results indicate great potential of applying mycorrhizal biotechnology in sustainable agriculture in the future.New methods such as quantitative molecular tech-niques were quite important for the investigation on the relative abundance of various AMF types and their impact on ecological processes. Moleculer and isotope method were also tentatively used in our present study to monitor of introduced AM fungi, to discriminate the contribution of introduced AM fungi to the crop growth. It still should be strengthened in the furtue study.Acknowledgments We thank the British Council and the UK Depart-ment for International Development through their De-velopment Partnerships in Higher Education program (Project DelPHE 1.64) and the Special public sector research (Project 200803034) for generous ﬁ nancial support.ReferencesAbbott, L. K. and A. D. Robson (1991) Factors inﬂ u-encing the occurrence of vesicular-arbuscular my-corrhizas. Agric. Ecosyst. Environ., 35: 121-150.Anderson, E. L., P. D. Millner and H. M. Kunishi (1987) Maize root length density and mycorrhizal infection as inﬂ uenced by tillage and soil phospho-rus. J Plant Nutr., 10: 1349-1356.Brady, N. C. and R. R. Weil (1996) Organisms and ecology of the soil. The nature and properties of soil, 11th edn. Prentice-Hall, Upper Saddle River, NJ, pp 328-360.Entry, J. A., P. T. Rygiewicz, L. S. Watrud and P. K. Donnelly (2002) Influence of adverse soil condi-tions on the formation and function of arbuscular mycorrhizas. Adv. Environ. Res., 7: 123-138.Gai, J. P., P. Christie, G. Feng and X. L. Li (2006) Twenty years of research on biodiversity and dis-tribution of arbuscular mycorrhizal fungi in China: a review. Mycorrhiza, 16: 229-239.Jakobsen, I. and N. E. Nielsen (1983) Vesicular-arbuscular mycorrhiza in ﬁ eld-grown crops. I. My-corrhizal infection in cereals and peas at various times and soil depths. New Phytol., 93: 401-413.Rillig, M. C. and C. B. Field (2003) Arbuscular my-crorrhizae respond to plants exposed to elevated atmospheric CO2 as a function of soil depth. Plant Soil. 254: 383-391.Smith, S. E. and D. J. Read (2008) Mycorrhizal Sym-biosis. Academic Press, LondonSmith, F. A., I. Jakobsen and S. E. Smith (2000) Spa-tial differences in acquisition of soil phosphate between two arbuscular mycorrhizal fungi in sym-biosis with Medicago truncatula. New Phytol., 147: 357-366.van der Heijden, M. G. A. and T. R. Scheublin (2007) Functional traits in mycorrhizal ecology: Their use for predicting the impact of arbuscular mycorrhizal fungal communities on plant growth and ecosys-tem functioning. New Phytol., 174: 244-250.Zhang, M. Q., Y. S. Wang, C. Zhang and L. Huang (1994) The ecological distribution characteristics of some genera and species of VAMF in northern China. Acta Mycol. Sinica., 13: 166-172.Arbuscular Mycorrhizal Fungi Diversity and Contribution to Crop Growth in Agricultural Fields

Arbuscular Mycorrhizal Fungi Diversity and Contribution to Crop Growth in Agricultural Fields

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Arbuscular Mycorrhizal Fungi Diversity and Contribution to Crop Growth in Agricultural Fields

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