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Journal of Microbiology and Biotechnology Research

Scholars Research Library J. Microbiol. Biotech. Res., 2012, 2 (1):212-222

(http://scholarsresearchlibrary.com/archive.html) ISSN : 2231 –3168 CODEN (USA) : JMBRB4

Arbuscular mycorrhiza and dark septate fungal associations in medicinal and aromatic plants of Guwahati Bidyut B. Sharma1 and D.K Jha2 1

Department of Environmental Science, Gauhati University, Assam, India Microbial Ecology Laboratory, Department of Botany, Gauhati University, Assam, India ______________________________________________________________________________ 2

ABSTRACT The present work was done with the aim of generating baseline data on arbuscular mycorrhizal (AM) and dark septate endophytic (DSE) associations in medicinal and aromatic plants of Guwahati. During the present study, a total number of 20 species of medicinal and aromatic plants were studied. All the plant species were found to have AM associations. However, out of 20 species only 12 plant species harbored DSE colonization. DSE colonization has been recorded in 10 plant species which has not been reported earlier from the present study area. Twelve plant species were colonized by both AM and DSE fungi. Physico-chemical parameters of the rhizosphere soil samples were also analyzed statistically and tested for its correlation and variation against percentage of AM and DSE root colonization and also mycorrhizal spore count. Keywords: Fungi, Arbuscular mycorrhiza (AM), Dark septate endophyte (DSE), Medicinal and Aromatic plants (MAPs), colonization, spore, Guwahati. ______________________________________________________________________________ INTRODUCTION Mycorrhiza is a symbiotic association between plant and fungus localized in roots or root–like structures and is responsible for nutrient transfer, involving synchronized plant-fungus development and regulating ecosystem functioning [1]. This association occurs in most of the angiosperms, all gymnosperms, pteridophytes and some bryophytes. It improves the survival, nutrient acquisition, reproduction and growth of the component organisms [2]. The arbuscular mycorrhizal association is the most common and widely occurring mycorrhizal associations. These mycorrhizas are agriculturally important and have great economic significance. They also protect the host’s roots against soil borne pathogens and promote plant growth performance [3].

212 Available online at www.scholarsresearchlibrary.com

Sharma and Jha J. Microbiol. Biotech. Res., 2012, 2 (1):212-222 _____________________________________________________________________________ Recent attention has been drawn by a ubiquitous group of miscellaneous fungi known as the Dark Septate Fungi (DSE). DSE are commonly found as root colonizers in a broad range of plants in the temperate and tropical habitats. They are characterized by melanized hypahe and microsclerotia [4]. Although the ecological role of DSE is currently unresolved, yet new research findings prove that DSE can promote growth under stressed environment [5- 7]. There are around 35,000 to 70,000 medicinal and aromatic plants used in various systems of medicine throughout the world [8 and 4]. Cultivation of medicinal and aromatic plants is being currently carried out in large scale to meet the ever-increasing demand for herbal drugs and cosmetics. However, the amount of bioactive compounds and aromatic oils extracted from largescale operations is small compared to the amount of raw material used. In this regard, AM fungi can play an important role. Arbuscular mycorrhizal fungi not only improve the nutritional status, growth and development of plants, provide protection against root pathogens and resistance to drought and salinity but also increase the concentration of active ingredients and secondary metabolites in host plant roots [9- 13]. Currently emphasis is being given on exploitation of the useful and appropriate soil microorganisms present in the rhizosphere of medicinal plants [14]. Arbuscular mycorrhizas are reported to be widespread in medicinal and aromatic plants [15 – 18]. Works related to mycorrhizal association in medicinal and aromatic plants in different parts of the world are meager [4, 15, 16, 17 and 18]. So far, different authors have reported 1350 species of plants used in ethno-medicinal preparations from Northeast India. However, there exists very little information on the arbuscular mycorrhizal and dark septate endophytic association in medicinal and aromatic plants in Northeast India. With this view we studied the status of AM distribution and DSE colonization in selected commonly occurring medicinal and aromatic plants in Guwahati. MATERIALS AND METHODS 1.1 Description of the Study Area: The present study was carried out at two locations i.e. Kamakhya Hill and Gauhati University (GU) campus, Guwahati, Assam. Guwahati city bounded by 26° 8’- 26° 11’ N latitude and 91° 39’ – 91° 41’ E longitude. Physiographically, the Kamakhya hill area consists of low lying and strips of broken hills. The altitudinal range varies from 50 meter to 340 meter. The soil is mainly red soil with sandy deposits. The G.U campus is comprised of hillocks, streams, beels, swamps and cultivable lands having mainly alluvial and marshy soil. Guwahati area has a typical monsoon type of climate. The area receives sufficient rainfall throughout the year, average annual rainfall being 161.19 cm. The area has a cool and foggy winter, a moderately cool spring and a faintly hot and humid summer. The rainfall in the city is not uniform and the rainy season extends from March to October.


Sharma and Jha J. Microbiol. Biotech. Res., 2012, 2 (1):212-222 _____________________________________________________________________________ The vegetation in the Kamakhya hill is mainly mixed deciduous type with occasional presence of evergreen trees. In G.U campus the vegetation consist of aquatic plants and weeds in the wetlands, agricultural crops in the open fields and mixed deciduous type in the hillocks. Sample Collection: Root and soil samples were collected from the rhizosphere of 20 medicinal and aromatic plants belonging to 20 genera in 15 families. The samples were collected from February to May of 2008, from Kamakhya Hill and Gauhati University Campus. Random sampling procedure was followed for sampling. Ten to fifteen separate roots (10-15 cm length) from each plant were collected. Only young roots were collected for the assessment. They were mixed and a composite sample was made. Approximately 100gm of the rhizosphere soil was collected. The soil samples were brought to the laboratory in sterile containers. Before analysis, the samples were spread out thinly on paper for drying in air in shade. The big lumps were broken down; plant roots, pebbles, and other undesirable matters were removed. After the soil became completely dry, it was sieved through a 320 mm sieve. The samples were preserved in clean polythene bags for further analysis. Collected root samples were washed and either stained within 24hrs or preserved in FAA (formalin: glacial acetic acid: 70% ethanol:: 5:5:90) until they were processed. 1.2 Soil Physico-chemical Characteristics: The pH of the soil sample was determined by using digital pH meter in soil water suspension of 1:5(w/v). Percentage soil moisture content, soil temperature, total nitrogen, available phosphorus, exchangeable potassium and percentage soil carbon were estimated following the techniques as described by [19]. 1.4 Estimation of root colonization and endogonaceous spore population: The extent of root colonization by the arbuscular mycorrhizal and dark septate endophytic fungi was estimated following the procedures adopted by [4]. Percentage root colonization was calculated by the following formulae – % Colonization =

Number of segments colonized x 100 Total number of segments studied

Mycorrhizal spores in the rhizosphere soil samples were isolated by following the wet sieving and decanting technique of [20]. RESULTS A total number of 42 species of medicinal and aromatic plants were identified from the study area (Table 1). Local names and the medicinal properties of the plants were collected from available literatures and from the local people having traditional knowledge of herbal medicines. Out of these 20 commonly occurring and traditionally used plant species were selected for mycorrhizal study (Table-2). Incidence of AM and DSE associations:

All the 20 plant species examined during the present study were found to be colonized by arbuscular mycorrhizal fungi (Table- 2). DSE association was recorded only in 12 species out of the 20 medicinal and aromatic plants examined (Table-2). The plant species where DSE 214 Available online at www.scholarsresearchlibrary.com

Sharma and Jha J. Microbiol. Biotech. Res., 2012, 2 (1):212-222 _____________________________________________________________________________ colonization was observed were Amaranthus spinosus, Calotropis procera, Centella asiatica, Chenopodium album, Coriandrum sativum, Cyperus rotundus, Leucas plukenitii, Mikenia micrantha, Murraya koenigii, Panicum sp., Solanum indicum and Swertia chirayita. While AM fungal association was found in all the plant families studied, DSE colonization was found only in the following 9 families out of 15 families studied (Table-2). The extent of AM association ranged between 52.17% (Swertia chirayita) to 92.30% (Achyranthus aspera) (Table- 2). Arbuscular mycorrhizas were characterized by the presence of both intercellular and intracellular hyphae, arbuscules and vesicles. Intracellular hyphal coil was, however, seen only in Leucas plukenitii (Fig: 7). The extent of DSE colonization ranged between 30.43% (Swertia chirayita) to 58.30% (Coriandrum sativum). DSE were frequently characterized by narrow and septate hyphae. They commonly occurred on the root surface and were found running parallel to the long axis of the roots. Individual hyphae sometimes grew along the grooves between adjacent epidermal cells and colonized the roots intercellularly. The DSE hyphae usually branched perpendicularly. Microsclerotia were observed in the root segments of Coriandrum sativum, Amaranthus spinosus (Fig: 4) and Mikenia micrantha (Table-2). Physico-chemical properties of Rhizosphere soil samples: The results of chemical analysis of rhizosphere soil samples are presented in Table-3. The percentage of Carbon in the soil samples ranged from 1.87 % to 4.12 %, the highest being in Amaranthus spinosus and the lowest in Adhatoda vasica. The percentages of total Nitrogen in the soil samples ranged from 0.104 % to 0.35 %. The amount of available Phosphorus ranged between 0.024mg/g of soil to 0.057mg/g of soil sample. The concentration of exchangeable Potassium in the soil samples was low and ranged from 0.07mg/g to 0.72 mg/g of soil. However, it was below detection limit in soil samples collected from rhizosphere of Adhatoda vasica and Commelina benghalensis. The soil pH varied from 5.37 to 7.61.The soil temperature ranged from 27.5°C to 30.4°C while the soil moisture content varied from 18.26 % to 38.3 %. Population of arbuscular mycorrhizal spores: Population of mycorrhizal spore in the rhizosphere soil samples differed significantly amongst the plants. Highest numbers of mycorrhizal spores were isolated from the rhizosphere soil of Datura metel and Commelina benghalensis and lowest from Leucas plukenitii (Table-4). DISCUSSION AM associations were present in the roots of all the medicinal and aromatic plants examined. The occurrence of DSE, however, was observed only in 60% of the total plant species studied. AM associations were found in species belonging to the following families: Acanthaceae, Asclepidaceae, Amaranthaceae, Asteraceae, Caesalpinaceae, Chenopodiaceae, Commelinaceae, Cyperaceae, Labiatae, Nyctaginaceae, Poaceae, Rutaceae, Solanaceae, Umbellifereae, and Verbanaceae. Amongst these, Amaranthaceae was earlier presumed to be non-mycorrhizal family [21]. Recently Muthukumar et al (2006) [4] had also reported AM colonization in Amaranthaceae family and the result of the present study supports their findings. However, the 215 Available online at www.scholarsresearchlibrary.com

Sharma and Jha J. Microbiol. Biotech. Res., 2012, 2 (1):212-222 _____________________________________________________________________________ observation of AM colonization in Achyranthus aspera, Commelina benghalensis, Cyperus rotundus, Murraya koenigii (Fig: 1) and Lantana camara are in contradiction to the findings of Muthukumar et al (2006) [4]. Among the plant species harboring DSE association in the present study, only Cyperus rotundus (Cyperaceae) was earlier known to harbor DSE associations [22,4]. Again, DSE association was also recorded in Panicum sp., Swertia chirayita, Centella asiatica, Murraya koenigii, Solanum indicum, Coriandrum sativum (Fig: 6 and 8), Chenopodium album (Fig: 5), Calotropis procera, Leucas plukenitii, Mikenia micrantha during the present investigation. The occurrence of DSE associations in these plant species were not reported earlier form the present study area. Colonization of roots by both DSE and AM fungi corroborates with the reports of Jumpponen and Trappe (1998) and Muthukumar et al (2006) [22, 4]. Simultaneous occurrence of DSE and AM fungi was observed in case of Centella asiatica and Leucas plukenitii (Fig: 2 and 3). Such type of dual colonization by both AM fungi and DSE reflects the dynamic nature of the rootcolonizing fungal community [4]. Yu et al (2001) and Barrow (2003) [23, 24] also reported penetration of the vascular bundle by AM fungi as well as DSE. The occurrence of both Arum type and Paris type of AM morphology was observed among the plant species examined in this study. Both Arum type and Paris type of AM fungi have been reported to occur in medicinal and aromatic plants [4]. Percentage of root colonization by AM and DSE fungi and the number of mycorrhizal spores was greatly affected by the soil pH, temperature and moisture. The percentage of AM root colonization and DSE root colonization showed negative statistically insignificant correlation with soil pH. The study revealed that more alkaline the soil less was the percentage root colonization. This supports the fact that fungi are acid tolerant. However, the soil spore population showed positive correlation with soil pH. These correlations were, however, statistically insignificant. The percentage of AM colonization showed positive but insignificant correlation with soil temperature. The root colonization by DSE fungi and spore population were negatively correlated with soil temperature. Soil temperature appeared to exert some influence on arbuscular mycorrhizal spore distribution, both quantitatively and qualitatively. Both the percentage of AM root colonization and spore count had a negative correlation with soil moisture. The DSE root colonization, however, was found to have a positive but statistically insignificant correlation with soil moisture. Such variations observed can be attributed to the complex interactions of different environmental factors in different ecosystems and the ecological adaptability of mycorrhiza. As far as chemical parameters of soil are concerned, in case of many plants the percentage of root colonization by AM fungi and DSE was significantly higher even with lower availability of carbon, phosphorus, nitrogen or potassium. This corroborates with the findings of Newsham (1999) and Jumpponen (2001) [5, 7].


Sharma and Jha J. Microbiol. Biotech. Res., 2012, 2 (1):212-222 ______________________________________________________________________________ Table 1: List of some medicinal and aromatic plants commonly found at the study sites PLANT SPECIES Abrus precatorius Acalypha indica Achryanthus aspera Adhatoda vasica Ageratum conyzoides Alstonia scholaris Amaranthus spinosus Andrographis paniculata Argemone maxicana Asperagus racemosus Azadirachta indica Boerhaavia diffusa Calotropis procera Cannabis sativa Cassia fistula Cassia tora Catharanthus roseus Centella asiatica Chenopodium album Cissampelos pariera Costus speciosus Coriandrum sativum Croton tiglium Cyperus rotunuds Datura metel Dioscorea alata Eupatorium odoratum Elephantopus scaber Hedyotis corymbosa Jatropa curcus Kyllinga brevifolia Lantana camara Leucus plukenitii Mikenia micrantha Mirabilis jalapa Murraya koenigii Ocimum sanctum Panicum sp. Swertia chirayita Solanum indicum Terminalia arjuna Vernonia cinerea

FAMILY Papilionaceae Euphorbiaceae Amaranthaceae Acanthaceae Asteraceae Apocynaceae Amaranthaceae Acanthaceae Papaveraceae Liliaceae Meliaceae Nyctaginaceae Asclepidaceae Cannabidaceae Caesalpinaceae Caesalpinaceae Apocyanaceae Umbellifereae Chenopodiaceae Menispermaceae Costaceae Umbellifereae Euphorbiaceae Cyperaceae Solanaceae Dioscoriaceae Asteraceae Asteraceae Rubiaceae Euphorbiaceae Cypearceae Verbanaceae Labiatae Asteraceae Nyctaginaceae Rutaceae Labiatae Poaceae --Solanaceae Combretaceae Asteraceae

LOCAL NAMES Latumoni Bishhori Ubtisodh/Upamarg Bhahak tita Gondhao Bon Chatiana Kota Khutara Kalmegh Sialkata Satamul Neem Punarnaba Akanda Bhang Sonaru Soru Medelua Nayantara Manimuni Jilmil saak Tabuki lota Jom Lakhuti Dhania Koni Beeh Motha Dhatura Kham alu Germani Bon Hatikhoj Bon jaluk Bhotora Keya bon Goo phool Doroon Usannalata Godhuli gopal Narasingha Tulsi --Sirota Tita bhekuri Arjun --

MEDICINAL INDICATION Mammal poison Chronic Bronchitis Purgative Chronic Bronchitis Blood coagulant Astringent, Anti-helminthic -Fabrifuge , Tonic Laxative Diuretic Hypoglycaemic, anti-microbial Astringent Cardio tonic Narcotic,sedative Cathertic Cathertic, anti-helminthic Cytotoxic, anti-hypertensive Anti-dysenteric Stomach diseases Diuretic, fabrifuge Cortico-steroid Stomach problems Purgative Anti-inflamatory Anti-spasmodic, mydiatric Anti-fertility Blood coagulant Fever, stomach pain Fever, liver problems Wound dressing Urinary problems Anti-malarial, stimulant Sinusities Against insect bites --Anti-gastritis Anti-pyretic --Anti-helminthic Gastro-enteric problems Heart stimulant Piles disease

Table 2: Arbuscular mycorrhiza (AM) and Dark Septate Endophyte (DSE) Association in Medicinal and Aromatic Plants Serial No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Plant Species Panicum sp. Ocimum sanctum (Tulsi) Lantana camara (Goo phool) Cyperus rotundus (Motha) Swertia chirayita (Sirota) Centella asiatica(Manimuni) Murraya koenizii(Narasingha) Datura metel (Dhatura) Adhatoda vasica (Bahok tita) Solanum indicum(Tita bhekuri) Coriandrum sativum(Dhania) Chenopodium album(Jilmil saak) Cassia tora(Soru medelua) Amaranthus spinosus(Kota khutura) Commelina benghalensis(Kanasimalu)

AM Colonization (in %) RLH 19.44 25.84 26.18 16.60 21.70 40.70 45.16 16.42 23.4 14.83 41.60 21.17 24.68 26.16 19.17

RLA 31.88 38.31 29.30 29.10 4.30 14.80 3.22 26.19 15.82 53.42 8.30 40.47 28.34 40.37 14.63

RLV 27.33 19.30 13.89 37.50 26.08 22.2 32.25 25.19 29.86 10.19 50.0 12.34 18.27 12.79 29.31

RLC 75.08 83.46 69.52 83.20 52.17 66.60 77.40 68.81 69.25 73.94 66.60 73.65 71.30 79.33 63.91

DSE Colonization (in %) Microsclerotia Total 31.63

50.39 30.43 48.14 45.16

10.0

35.30 58.30 41.59

11.1

40.89


Sharma and Jha J. Microbiol. Biotech. Res., 2012, 2 (1):212-222 ______________________________________________________________________________ 16 17 18 19 20

Achyranthus aspera(Upamarg/Ubtisodh) Calotropis procera(Akanda) Leucas plukenitii Mirabilis jalapa(Godhuli gopal) Mikenia micrantha(Usannalata)

46.15 17.32 21.17 26.18 34.64

15.38 19.34 40.47 29.30 8.60

30.76 14.27 12.34 13.89 55.68

92.30 66.25 73.65 62.8 65.60

42.58 31.63 7.6

38.38

RLH- root length with hyphae/hyphal coils; RLA- root length with arbuscules; RLV- root length with vesicles; RLCtotal root colonization


Sharma and Jha J. Microbiol. Biotech. Res., 2012, 2 (1):212-222 ______________________________________________________________________________


Sharma and Jha J. Microbiol. Biotech. Res., 2012, 2 (1):212-222 ______________________________________________________________________________ Table 3: Physico-Chemical Characteristics of Soil Collected From the Rhizosphere of Different Medicinal and Aromatic Plants Serial No.

Plant Species

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Panicum sp. Ocimum sanctum (Tulsi) Lantana camara (Goo phool) Cyperus rotundus (Motha) Swertia chirayita(Sirota) Centella asiatica(Manimuni) Murrya koenzii(Narasingha) Datura metel (Dhatura) Adhatoda vasica (Bahok tita) Solanum indicum(Tita bhekuri) Coriandrum sativum(Dhania) Chenopodium album(Jilmil saak) Cassia tora(Soru medelua) Amaranthus spinosus(Kota khutura) Commelina benghalensis(Kanasimalu) Achyranthus aspera(Upamarg/ Ubtisodh) Calotropis procera(Akanda) Leucas plukenitii(Doroon) Mirabilis jalapa(Godhuli gopal) Mikenia micrantha(Usannalata)

Temperature (In oC ) 29.2 28.40 29.0 28.0 28.0 27.8 27.5 27.50 28.20 29.10 29.50 30.40 29.0 29.50 30.40 30.4 30.0 30.4 29.8 30.2

Moisture (In %) 19.47 28.20 19.34 21.8 32.11 37.91 27.24 22.17 18.26 36.12 38.0 38.3 32.74 34.15 27.44 26.08 27.09 37.6 32.20 32.26

pH 7.20 6.79 5.37 5.73 7.13 6.80 6.14 7.24 6.40 6.74 6.71 6.81 6.20 5.92 6.82 6.32 7.61 7.21 6.97 5.49

C (in %) 2.3 3.7 2.17 2.32 2.4 2.67 3.81 2.90 1.87 3.22 3.18 2.72 3.78 4.12 2.22 2.63 2.30 2.87 3.41 2.72

Total Nitrogen (in %) .109 0.32 0.14 0.24 0.21 0.23 0.33 0.24 0.16 0.27 0.23 0.13 0.32 0.35 0.104 0.226 0.21 0.34 0.136 0.18

P (mg/g) 0.047 0.029 0.051 0.030 0.043 0.034 0.041 0.056 0.033 0.027 0.024 0.036 0.057 0.042 0.047 0.036 0.038 0.053 0.039 0.042

K (mg/g) 0.50 0.26 0.61 0.12 0.72 0.53 0.60 0.41 BDL 0.45 0.63 0.35 0.57 0.62 BDL 0.26 0.37 0.48 0.23 0.07

KH- Kamakhya hill; GU- Gauhati University campus; BDL – below detectable limit Table-4: Number of Spores Isolated from Rhizosphere Soil of Each Plant Species Serial No.

Plant Species

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Panicum sp. Ocimum sanctum (Tulsi) Lantana camara (Goo phool) Cyperus rotundus (Motha) Swertia chirayita (Sirota) Centella asiatica (Manimuni) Murraya koenigii (Narasingha) Datura metel (Dhatura) Adhatoda vasica (Bahok tita) Solanum indicum (Tita bhekuri) Coriandrum sativum (Dhania) Chenopodium album (Jilmil saak) Cassia tora (Soru medelua) Amaranthus spinosus (Kota khutura) Commelina benghalensis (Kanasimalu) Achyranthus aspera (Upamarg) Calotropis procera (Akanda) Leucas plukenitii (Doroon) Mirabilis jalapa (Godhuli gopal) Mikenia micrantha (Usannalata)

No. Of Spores Isolated ( per 10gm of soil sample) 3 5 6 8 10 7 5 11 9 7 5 7 3 7 11 3 7 2 6 3

CONCLUSION During the present investigation, a total number of 42 medicinal and aromatic plant species were identified from the study area. From the results of the present study it can be concluded that there is a high incidence of arbuscular mycorrhiza (AM) and dark septate endophytic (DSE) fungal associations in the medicinal and aromatic plants of the study area. All the plant species studied were colonized by AM fungi, while DSE colonized 60% of the plant species. AM fungal colonization was recorded in 15 plant families and DSE colonization only in 9 families. These 220 Available online at www.scholarsresearchlibrary.com

Sharma and Jha J. Microbiol. Biotech. Res., 2012, 2 (1):212-222 ______________________________________________________________________________ include the Amaranthaceae family, which was earlier presumed to be non-mycorrhizal. In addition, in the present investigation DSE association was recorded in Panicum sp., Swertia chirayita, Centella asiatica, Murraya koenigii, Solanum indicum, Coriandrum sativum, Chenopodium album, Calotropis procera, Leucas plukenitii, and Mikenia micrantha that were not recorded earlier. The occurrence of both Arum type and Paris type of AM morphology was observed in the medicinal and aromatic plants of the study area. Dual colonization of roots by AM and DSE fungi in Centella asiatica and Leucas plukenitii indicates the dynamic nature of root colonizing fungal community. Since large numbers of medicinal and aromatic plants are present in Northeast India, extensive research works are required to create a database of mycorrhizal species colonizing these plants and to determine their efficiency in promoting growth and increasing the concentration of bioactive compounds and aromatic oils. Acknowledgements The authors would like to acknowledge the Department of Environmental Science and the Department of Botany of Gauhati University for providing the authors the requisite laboratory facilities to carry out the research work. REFERENCES [1] Brundrett, M. Biol. Rev, 2004, 79, pp.473-495. [2] Smith SE, Read DJ (eds). Mycorrhizal symbiosis. Academic, San Diego, CA, 1997. [3] Kung'u, J.B. Effect of vesicular-arbuscular mycorrhiza (VAM) inoculation on growth performance of Senna spectabilis. In: Managing Nutrient Cycles to Sustain Soil Fertility in SubSaharan Africa (Ed. A.Bationo), 2004, Academy Science Publishers, Nairobi, Kenya. [4] Muthukumar, T., Senthilkumar, M., Rajangam, M and Udaiyan, K. Mycorrhiza, 2006, 17: 11-24 [5] Newsham, K. K.. New Phytol., 1999, 144:517–524 [6] Barrow, J.R., Osuna, P. Nutt. J. Arid Environ., 2002, 51:449–459 [7] Jumpponen, A. Mycorrhiza., 2001, 11:207–211 [8] Farnsworth, N.R., Soejarto, D.D. Global importance of medicinal plants. In: Akerele O, Heywood V, Synge H (eds) The conservation of medicinal plants. Cambridge University Press, Cambridge, UK, 1991, pp 25–51 [9]Jeffries, P. Use of mycorrhizae in agriculture, CRC Critical Review of Biotechnology, 1987, 5: 319-357 [10] Chiramel T., Bagyaraj, D.J., Patil, C.S.P. J. Agri. Tech., 2006, 2(2): 221-228 [11] Vierheilig, G.H., Bennett, R., Kiddle, G., Kaldorf, M., Ludwigmuller, J. New Phytol., 2000,146: 343–352. [12] Devi, M.C., Reddy, M.N. Plant Growth Regul., 2002, 37:151–156 [13] Yao, M.K., Desilets, H., Charles, M.T., Boulanger, R., Tweddell, R.J. Mycorrhiza., 2003, 13:333–336 [14] Sen., A.N. Harnessing of soil microorganisms for the benefit of medicinal plants. In: Gautam PL, Raina L, Srivastava U, Rayachaudhuri SP, Singh BB (eds) Prospects of medicinal plants. Indian Society of Plant Genetic Resources, New Delhi, 1998, pp 275– 280 [15] Udea T, Husoe T, Kubo S, Nakawashi I (1992). Trans. Mycol. Soc. Japan., 33:77–86 221 Available online at www.scholarsresearchlibrary.com

Sharma and Jha J. Microbiol. Biotech. Res., 2012, 2 (1):212-222 _____________________________________________________________________________ [16] Muthukumar, T., Udaiyan, K. J. Mycol. Plant Pathol., 2001. 31:180–184 [17] Khade, S.W., Bukhari, M.J., Jaiswal, V., Gaonkar, U.C., Rodeigues, B.F. J. Econ. Taxon. Bot., 2002, 26:571–578 [18] Bukhari, M.J., Khade, S.W., Jaiswal, V., Gaonkar, U.C., Rodrigues, B.F. Plant Arch., 2003, 3:167–174 [19] Saxena, M. M. Analysis of Water, Soil and Air. 1st edn, 1987, Agro Botanical Publisher, India. [20] Gerdemann, J.W., Nicolson, T.H. Trans. Br. Mycol. Soc., 1963, 46:235–244 [21] Tester, M., Smith, S.E., Smith, F.A. Can. J. Bot., 1987, 65:419–431 [22] Jumpponen, A., Trappe, J.M. New Phytol., 1998, 140:295–310 [23] Yu, T., Nassuth, A., Peterson, R.L. Can. J. Microbiol., 2001, 47:741–753 [24] Barrow, J.R. Mycorrhiza, 2003, 13:239–247
