RESPONSE OF WHEAT TO THE INOCULATION OF ARBUSCULAR MYCORRHIZAL FUNGI IN SALT AFFECTED SOIL

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1 Sarhad J. Agric. Vol.25, No.2, 2009 RESPONSE OF WHEAT TO THE INOCULATION OF ARBUSCULAR MYCORRHIZAL FUNGI IN SALT AFFECTED SOIL M. SHARIF*, M.S. SARIR*, J. BAKHT**, S. SAUD*, ASAD ALI*** and MUSHARAF AHMAD*** * Department of Soil and Environmental Sciences, NWFP Agricultural University, Peshawar, Pakistan ** Department of Agronomy, NWFP Agricultural University, Peshawar, Pakistan *** Department of Plant Pathology, NWFP Agricultural University, Peshawar, Pakistan ABSTRACT Arbuscular Mycorrhizal (AM) fungi have the potential to improve crops yield by enhancing plant nutrient accumulation. An experiment was conducted in pots as two factors completely randomized design under natural conditions to study the scope of inoculating wheat crop (Triticum aestivum L. Bhakhar 2002) with AM fungi alone and in combinations with different organic fertilizers in two different soil series of salt affected soils during Shoots dry matter and grain yield of wheat increased significantly (P < 0.05) with the inoculation of AM fungi alone and in combination with farm yard manure (FYM), poultry manure (PM) and humic acid (HA) over control and Nitrogen-Phosphorus-Potash (N-P-K) treatments. Accumulation of N by wheat shoots increased significantly (P < 0.05) with the inoculation of AM fungi alone and with PM and HA and P increased with FYM, PM and HA when compared with N-P-K treatment. Accumulation of Cu by wheat shoots increased significantly (P < 0.05) over control and N-P-K treatments by the inoculation of AM fungi with PM and HA, Zn and Fe with FYM, PM and HA, while Mn increased by AM fungi in combination with FYM, PM and HA in Shabqadar and with HA in Warsak soil series. Significantly (P < 0.05) increased AM fungal roots infection rate of 44 % and spores numbers of 55 in 20 g soil were recorded in the treatment where AM fungi were inoculated with HA. Results suggest that inoculation of wheat with AM fungi in combination with different organic fertilizers have the capability to increase shoots dry matter and grain yield of wheat in salt affected soils due to the improved mycorrhizal roots infections and plant nutrients accumulations. Key Words: AM Inoculation, Nutrient Accumulation, Root Infection, Salt Affected Soil, Spores Density and Wheat Yield Citation: Sharif, M., M.S. Sarir, J. Bakht, S. Saud and Asad Ali Response of wheat to the inoculation of arbuscular mycorrhizal fungi in salt affected soil. Sarhad J. Agric. 25(2): INTRODUCTION Infection of crop with AM fungi can improve their uptake of nutrients, particularly of phosphorus and increase crop production (Menge et al., 1987 and Young et al., 1988). Mamatha et al., (2002) reported improvement in yield and plant nutrient accumulation with mycorrhiza. Responses of some tropical and subtropical cultures to endomycorrhizal fungi have been reported by Jaizme and Azcon, Plants inoculation of AM fungi with rock phosphate may substantially increase P availability to plants (Khan, 1975; Omer, 1998). There are indications to show that AM fungal associations with plant roots can help plants to overcome water stress by stomata regulation in plants (Kevin and Peterson, 1996 and Robert, 2001). The research on mycorrhiza suffers from dilemma of high expectations, which are often not met by indisputable and consistent results (Allen, 1995). It can not be claimed that there is good balance between promised progress, clear understandings and successful applications, such as the use of AM fungal inocula as a biofertilizer (Miller and Jastrow, 1992). The modest outcome may be related to a widely spread research strategy of simplifying complex field situations by factorial pot experiments and the subsequent transfer back to field conditions (Johnson and Pfleger, 1992). Limited information is available about the incidence of AM fungal status in Pakistan (Saif and Iffat, 1976 and Saif and Parveen, 1977). Hussain and Burni (1993) and Burni and Jabeen (1997) reported mycorrhizal association in a few plant species. Soil salinity is a wide spread problem restricting plant growth and biomass production, especially in arid and semi arid regions (Sanchez, 1998). High salinity restricts water and nutrient uptake by roots, may also cause ionic imbalance and toxicity in plants. Soil salinity significantly reduces absorption of mineral nutrients, especially P

2 M. Sharif et al. Response of wheat to inoculation of Arbuscular mycorrhizal fungi 210 because phosphate ion precipitate with Ca ion in salt stress soil and become unavailable to plants (Elyamany, 1981). The effects and response of plant growth to mycorrhizal fungi varied among plant species. Mycorrhizal fungi have shown positive influence on the composition of mineral nutrients (especially poor mobile element i.e. P) of plants grown under salt stress conditions (Al-Karaki and Clarke, 1998). These fungi improve the efficiency of P fertilizer for plant growth, which may be helpful in mitigating salt stress by overcoming the P binding capacity of soil. Plants uptake of N and some essential micronutrients improve when AM infected plants come out of P stress under saline conditions (Founoune and Dupennois 2002). In case of low P availability, AM infections increase the uptake and transport of P to leaves and result in greater shoot growth through an increased production of photosynthates. Inoculation of AM fungi can increase the salt tolerance of plants and eventually can utilize much of the high saline soil for crop production (Iwan, 1987). Mycorrhizal symbiosis helps in restoration and re-vegetation, particularly in salts affected marginal soils with low available P or where fertilization is done with insoluble phosphates. Mycorrhizal fungi play key role as biological measure to reduce the effect of salts on soil because these fungi increase resistance to some diseases by producing antibiotics and improve plants nutrients accumulation in drought conditions. These fungi have the capability to acidify the alkaline conditions of our soils and thus increase the solubility of relatively insoluble nutrients like P, Zn and Cu. Total salt affected area in Pakistan is 5.8 million hectare out of which 0.53 m ha area is in NWFP (Chaudhry et al., 1978). Wheat production is common in the area with cultivation on 8.4 million ha area in Pakistan and 0.72 million ha area in NWFP having production of 21.3 million tones in Pakistan and 1.1 million tones in NWFP (Agric. Statistics of Pakistan, 2006). This experiment was conducted with the main objective to investigate the response of wheat to the inoculation of AM fungi alone and in combination with different organic fertilizers i.e. Farm Yard Manure (FYM), Poultry Manure (PM) and Humic Acid (HA) in salt affected soil. MATERIALS AND METHODS Pot experiment was conducted in open field under natural conditions to study the scope of inoculating wheat crop with AM fungi alone and in combinations with different organic fertilizers in salt affected soil during Wheat crop was inoculated with AM fungal spores isolated from soil under fresh maize growing crop of the research farm of NWFP Agricultural University, Peshawar. Intensity of roots AM infection, spores density in soil and their effect on shoots dry matter and grain yield of wheat and plant nutrient accumulations were determined. The experiment was carried out as two factors randomized complete design. Basal dose of urea, single super phosphate and potassium sulphate was applied uniformly as kg N, P and K ha -1, respectively. Surface soil samples were collected at 0-15 cm depth from salt affected soils of Shabqadar and Warsak series. Ten kg soil was filled in each plastic pot and arranged in three replications. Eight plants of wheat (Triticum aestivum. L. Bhakhar 2002) were allowed to grow in each pot. p ots were irrigated at field capacity by daily addition of water. The crop was harvested after 135 days of growth. Soil Analysis Soil samples were analyzed for various physical and chemical properties. Soil texture was determined by hydrometer method as described by Koehler et al., (1984), soil ph in 1:5 soil and water suspension was determined with the help of ph meter by the method outlined by McClean, (1982) Soil organic matter content (SOM) was determined with the method of Nelson and Sommer, (1982), total N by Kjeldahl digestion method (Bhargna and Raghupathi, 1993) and AB-DTPA extractable P, Cu, Zn, Fe and Mn by the method of Soltanpour and Schawab (1977). Plants Analysis Plant samples collected from each treatment were oven dried at C till constant weight. The ground plant samples were analyzed for N, P, Cu, Zn, Fe and Mn by wet digestion method (Walsh and Beaton, 1977). Isolation of AM Fungal Spores from Soil Spores of AM fungi were isolated from soil by wet-sieving and decanting techniques as described by Gerdeman and Nicolson (1963) and Brundrett., (1996). Soil was suspended in water and then passed through sieves of different sizes. Spores suspension is then centrifuged with sugar solution and the spores layer was collected in a petri dish from just above the layer of sugar solution through syringe pipe.

3 Sarhad J. Agric. Vol.25, No.2, Identification of AM Fungal Spores Spores isolated from the soil samples were identified according to their morphological characteristics including shape, size, color, distinct wall layer, attached hyphae and surface orientation of spores as described by Schenck and Parez (1990). Estimation of AM Fungal Infection Infection rates by AM fungi in the roots of wheat were determined by staining the mycorrhizal chitin with lactic-trypan blue according to the procedure described by Philips and Hyman (1970) and Koske and Gemma (1989). Small pieces of root samples were placed in 10% KOH at 65 o C in such a way that roots were completely covered with KOH to clear the roots path. Root samples are then washed, cooked in 2N HCl at 65 o C in a water bath and stained with 0.1% trypan blue. Spores and hyphae turned blue due to their chitin content. Root pieces were then observed with magnification of 40x under the microscope. The presence of vesicles, arbuscules or hyphae (minimum or maximum) were measured by the techniques described by Giovannetti and Mosse (1980). Statistical Analysis Statistical analysis of data regarding various plants parameters, soil nutrients concentration and their accumulation by plants was done by two factorial Completely Randomized Design according to the procedures given by Steel and Torrie (1980) using MSTATC package. Combined means of the two soil series were evaluated when no significant interactions were found between the two soil series. RESULTS AND DISCUSSION Soil physical and chemical characteristics, shoots dry matter and grain yield of wheat, nutrient concentrations and their plants accumulations are presented in various Tables. To separate the effect of dilution or concentrations caused by variation in wheat shoot yield (Jarrell and Beverly, 1981; Barber, 1984), tissue nutrients concentrations were multiplied by shoot dry matter yield and converted to total amount of nutrient accumulated by plants ha -1. Physical and Chemical Characteristics of Salt Affected Soils under Investigation Data regarding physical and chemical characteristics of the soil series under investigation are presented in Table I. Efficiency of AM fungi is affected greatly by various factors and therefore it is of interest to determine the physical and chemical characteristics of soils for their proper management. Composite samples of the soils under investigations collected before fertilizers application were analyzed for various physical and chemical properties. Texture of soil was silt loam, ph in 1:5 soil and water suspension was 8.8 and 8.6, E.Ce was 11.0 and 8.2 ds m -1. Soil organic matter contents were 1.3 and 1.0 % and lime contents ranged as 11.1 and 10.3 %. Total N concentration was 0.19 and 0.12 % and AB-DTPA extractable P concentration in soil was 6.6 and 6.2 mg kg -1. Soil Fe contents were recorded as 1.09 and 0.12, Cu 4.25 and 3.09, Zn 0.85 and 0.55 and Mn as 6.11 and 5.88 mg kg -1 soil in Shabqadar and Warsak soil series, respectively. Table I Physical and chemical characteristics of salts affected soils under investigation Properties Unit S 1 S 2 Textural Class - Silt loam Silt loam ph (1: 5) E.Ce (1:5) ds m Lime % Organic matter Total nitrogen AB-DTPA-Extractable P mg kg Fe Cu Zn Mn S 1 = Shabqadar soil series S 2 = Warsak soil series

4 M. Sharif et al. Response of wheat to inoculation of Arbuscular mycorrhizal fungi 212 Shoot Dry Matter and Grain Yield of Wheat Table II shows shoot dry matter and grain yield of wheat as affected by the inoculation of AM fungi alone and in combinations with different organic fertilizers. Shoot dry matter yield of wheat increased significantly (P < 0.05) with the inoculation of AM fungi alone and in combination with FYM, PM and HA over control and over the treatments of N, P and K alone and in combination with FYM and PM. There were no significant difference among the treatments of NPK alone and in combination with FYM, PM and HA with no AM fungal inoculation. Grain yield of wheat increased significantly (P < 0.05) with the inoculation of AM fungi alone and in combination with FYM, PM and HA over the treatment of N, P and K applied alone in salt affected soil. Maximum and 34% increased wheat grain yield of 1393 kg ha -1 was recorded with the inoculation of AM fungi with PM when compared with the treatment of PM applied without AM inoculation. Table II. Shoot dry matter and grain yield of wheat as affected by the inoculation of AM fungi Treatments Shoot dry matter yield Wheat grain yield (kg ha -1 ) (kg ha -1 ) Control d* e* N-P-K cd de N-P-K + FYM c cd N-P-K + PM c bc N-P-K + HA bc c N-P-K + AMF b ab N-P-K+ FYM+PM a a N-P-K + FYM+AMF a a N-P-K + PM +AMF a a N-P-K + HA + AMF a b Plant N and P Accumulation Data regarding N and P accumulation by wheat shoot as affected by the inoculation of AM fungi alone and in combinations with different organic fertilizers are given in Table III. Accumulation of N by wheat shoot increased significantly (P < 0.05) over all other treatments with the inoculation of AM fungi alone and in combination with FYM and HA in salts affected soil. Plants P accumulation increased significantly (P <0.05) with the inoculation of AM fungi alone and in combination with FYM, PM and HA over control and treatments of N, P and K, FYM, PM and HA applied without the inoculation of AM fungi. Maximum plants P accumulation of 3.5 kg ha -1 was recorded in the treatment of AM fungal inoculation with HA followed by the treatment of AM fungal inoculation with FYM. Table III. Accumulation of N and P by wheat shoots as affected by the inoculation of AM fungi Treatments Nitrogen Phosphorus (kg ha -1 ) Control dc* e* N-P-K c e N-P-K + FYM bc de N-P-K + PM bc de N-P-K + HA bc cd N-P-K + AMF ab bc N-P-K+ FYM+PM bc b N-P-K + FYM+AMF ab b N-P-K + PM +AMF b b N-P-K + HA + AMF a a *Means with different letter (s) in columns are significantly different at P < 0.05 N-P-K = kg ha -1, respectively Farm yard manure (FYM) = 20 t ha -1 Poultry manure (PM) = 20 t ha -1 Lignitic coal derived humic acid (HA) = 1 kg ha -1 Arbuscular Mycorrhizal fungi (AMF)= 80 spores pot -1 S 1 = Shabqadar soil series S 2 = Warsak soil series

5 Sarhad J. Agric. Vol.25, No.2, Accumulations of Cu and Zn by Wheat Shoot Data in Table IV indicate that accumulation of Cu by wheat shoot increased significantly (P < 0.05) over control and N, P and K treatments by the addition of FYM, PM and HA with and without inoculation of AM fungi in Shabqadar and Warsak series of salts affected soil. Accumulation of Zn by wheat shoot in salt affected soils increased significantly (P < 0.05) by combined inoculation of AM fungi with FYM, PM and HA. Maximum Zn accumulation by wheat shoot was recorded in the treatment of HA application with the inoculation of AM fungi. Table IV. Accumulation of Cu and Zn by wheat shoots as affected by the Inoculation of AM fungi Treatments Cu Zn (kg ha -1 ) Control e* d* e* N-P-K d cd d N-P-K + FYM bc c d N-P-K + PM ab c d N-P-K + HA c bc d N-P-K + AMF c bc c N-P-K+ FYM+PM bc ab b N-P-K + FYM+AMF b b b N-P-K + PM +AMF a b a N-P-K + HA + AMF a a b Accumulations of Mn and Fe by Wheat Shoot Data in Table V indicate that Mn accumulation by wheat shoot in Shabqadar series of salt affected soil increased significantly (P < 0.05) over N, P and K treatments in the treatments of FYM + PM and by the inoculation of AM fungi in combination with FYM, PM and HA, while in Warsak soil series, the treatment of AM inoculation with HA showed significant (P < 0.05) increase over the treatment of N, P and K. In shabqadar series of salts affected soil, accumulation of Fe by wheat shoot increased significantly (P < 0.05) over control and N, P and K treatments in the treatments of FYM plus PM and by the inoculation of AM fungi with FYM, PM and HA. Maximum and significantly (P < 0.05) increased Fe accumulation by wheat shoot was noted by the inoculation of AM fungi with PM followed by the treatment of AM fungal inoculation with FYM. In warsak soil series, Fe accumulation by wheat shoot increased significantly (P < 0.05) over N, P and K treatment by the inoculation of AM fungi alone and in combination with PM, FYM and HA. Table V. Accumulation of Mn and Fe by wheat shoot as affected by the inoculation of AM fungi Treatments Mn Fe kg ha -1 (kg ha -1 ) Control 0.23 e* 0.18 d* d* 0.2 d* 0.25 N-P-K 1.62 de 0.33 cd c 0.4 d 0.11 N-P-K + FYM 2.90 d 0.45 cd c 0.7 cd 1.40 N-P-K + PM 2.18 d 0.60 bcd c 0.4 d 1.20 N-P-K + HA 2.07 d 0.87 bc bc 0.8 cd 1.60 N-P-K + AMF 2.95 d 1.46 c bc 1..5 c 2.20 N-P-K+ FYM+PM 3.27 c 1.40 bc b 1.8 c 2.70 N-P-K + FYM+AMF 3.94 c 1.69 bc ab 2.3 b 3.10 N-P-K + PM +AMF 4.51 b 1.98 bc a 3.5 a 4.10 N-P-K + HA + AMF 5.01 a 3.04 a ab 4.2 a 4.00 * Means with different letter (s) in columns are significantly different at P < 0.05 N-P-K = kg ha -1, respectively Farm yard manure (FYM) = 20 t ha -1 Poultry manure (PM) = 20 t ha -1 Lignitic coal derived humic acid (HA) = 1 kg ha -1 Arbuscular Mycorrhizal fungi (AMF)= 80 spores pot -1 S 1 = Shabqadar soil series S 2 = Warsak soil series

6 M. Sharif et al. Response of wheat to inoculation of Arbuscular mycorrhizal fungi 214 Roots Infection Intensity and Spores Concentration of AM Fungi in Wheat Data regarding AM fungal roots infection intensity and spores concentration in wheat as affected by the inoculation of AM fungi alone and in combinations with different organic fertilizers are presented in Table VI. It was observed that infection rate of wheat roots by AM fungi increased significantly (P < 0.05) over control and N, P and K treatments by the inoculation of AM fungi alone and in combination with FYM, PM and HA of salt affected soil. Maximum root infection rate of 44 % was recorded in the treatment of AM fungal inoculation with HA. Spores concentrations of different size, shape and color were observed in different numbers under binocular microscope. Spores concentrations of AM fungi showed similar trend like the root infection intensity. Significantly (P < 0.05) increased spores numbers of 55 in 20 g soil were recorded by the inoculation of AM fungi with HA. Spores of Glomus fasciculatum were found in abundance in all soil samples where as spores of G. intraradices G. mosseae, G. aggregatum, Acaulospora mellea and Sclerocystis were also identified in the soil samples but in lower densities. Table VI. Treatments AM fungal root infection intensity and spores concentration in wheat as affected by the inoculation of AM fungi AM infection rate AM spores concentration (%) (/20 g soil) Control e* e* N-P-K d d N-P-K + FYM d d N-P-K + PM d de N-P-K + HA d c N-P-K + AMF b ab N-P-K+ FYM+PM c bc N-P-K + FYM+AMF b b N-P-K + PM +AMF c bc N-P-K + HA + AMF a a * Means with different letter (s) in columns are significantly different at P < 0.05 N-P-K = kg ha -1, respectively Farm yard manure (FYM) = 20 t ha -1 Poultry manure (PM) = 20 t ha -1 Lignitic coal derived humic acid (HA) = 1 kg ha -1 Arbuscular Mycorrhizal fungi (AMF)= 80 spores pot -1 S 1 = Shabqadar soil series S 2 = Warsak soil series Inoculation of wheat crop with AM fungi alone and in combination with different organic fertilizers improved shoots dry matter and grains yield of wheat and plants nutrients accumulations. Infection rates in wheat roots and spores concentrations in soil were also increased with the inoculation of AM fungi with different organic fertilizers. Hamel (1996) concluded that AM fungal symbiosis is recognized for its multiple positive effects on plant growth and for its contribution toward improving and maintenance of soil quality. The enhancement in soil organic matter content might be associated with the increased roots dry weight in these treatments. Addition of organic materials along with N, P and K improve the soil organic matter status (Subramanian and Kumaraswamy 1989) and decreases soil ph slightly due to the release of H + ions during nitrification process of fertilizers (Akram, 1978). Jadhav and Patil (1996) reported that inoculation of plants with AM fungi has potential to increase shoot dry weight and crops grains yield along with improved N, P and K accumulation by plants. It was further concluded that AM fungi can be established in previously undisturbed and un-sterilized soil to the benefits of crops. Arihara and Karasawa (2000) found that inoculation of wheat, maize, potato and rape with AM fungi alone and in combination with different organic fertilizers in the previous season promoted roots AM infection of succeeding crops, which in turn enhanced the P uptake, crops growth and grains yield. Millner (1990) investigated that inoculation of AM fungi play a major role in plants P accumulation of most agronomically important crops. Wang et al., (1997) investigated that the infection of host plant with AM fungi markedly increased plants accumulation of P, Cu, Zn and Mn. Ammani et al., (1994) examined roots of 21 grass species and concluded that these species formed multiple AM associations with 30 to 70% root infection rates. Generally, spores density in all soil samples collected from various locations of NWFP seemed to be dominated by the species of Glomus fasciculatum but it still requires further confirmation by crop inoculation, re-

7 Sarhad J. Agric. Vol.25, No.2, isolation and re-identification. Indigenous AM fungal communities generally contain several fungal species. Normally 5 15 species may be found in agro-ecosystems. The spatial distribution of AM fungal species can vary and even when the number is the same at two different soil sites, the species composition of the fungal population can be completely different (Sieverding, 1989). The spores of AM fungi are very distinctive. They range in diameter from 10 µm for Glomus tenue to more than 1000 µm for some Scutellospora species. The spores can vary in color from hyaline (clear) to black and in surface texture from smooth to highly ornamented. Glomus forms spores on the ends of hyphae, Acaulospora forms spores laterally from the neck of a swollen hyphal terminus, and Entrophospora forms spores within the neck of the hyphal terminus CONCLUSION It could be concluded from the results of this experiment that AM fungi may play role as biological measure to reduce the effect of salts on soil as inoculation of wheat with AM fungi in combination with different organic fertilizers have the potential to increase shoot dry matter and grains yield of wheat crop in salt affected soils due to the improved mycorrhizal roots infection rates and plants nutrients accumulation. Further research work is needed to investigate AM colonization across different land-use types. The problems of mass production of inoculums for field crops, improving the possible and efficient interactions existing among crops and fungal partners for economically feasible and sustainable crop production are needed to be focused in future research of this area. ACKNOWLEDGEMENT The authors would like to acknowledge Agricultural Linkage Programme (ALP) of Pakistan Agricultural Research Council (PARC) Islamabad for financial support of this study. REFERENCES Agric. Statistics of Pakistan Govt. of Pakistan, Ministry of Food, Agric. and Livestock Div. (Econ wing) Islamabad, Pakistan. Akram, M Effect of organic and inorganic fertilizers applied to maize crop. M. Sc (Hons) thesis. Deptt. Soil Sci. Univ. Agric. Faisalabad, Pakistan. Al Karaki, G.N. and R.B. Clarke Growth, mineral acquisition and water use by mycorrhiza when grown under water stress. J. Plant Nutr. 21: Allen, E.B., M.F. Allen, D.J. Helm, J.M. Trappe and E. Rincon Patterns and regulation of mycorrhizal plant and fungal diversity. Plant & Soil. 170: Ammani, K., K. Venkateswarlu and A.S. Rao AM fungi in grasses; their occurrence, identity and development. Deptt. of Bot. Nagarjuna Univ. India. 44 (3): Arihara, J. and T. Karasawa Effect of previous crops on AM fungal formation and growth of succeeding maize. Soil Sci. & Plant Nut. 46 (1): Barber, S. A Soil nutrient bioavailability. A mechanistic Approach. Wiley, New York. Bhargna, B.S. and M.B. Raghupathi Analysis of plant material. In Tandon H.L.S. (Ed). Methods of analysis of soils, plants, waters and fertilizers. Fertilizers Dev. and Consulting Org. New Delhi. pp Brundrett, C.M Mycorrhiza in natural ecosystems. Adv. Ecol. Res. 21: Burni, T. and T. Jabeen AM fungi in Concephalum. Pak. J. Plant Sci. 2: Chaudhry, M.B., M.A. Mian and M. Rafiq Nature and magnitude of salinity and drainage problems in Pakistan. Pak. J. Forestry. 28 (2): Diaz, G. and M. Honrubia Development of mycorrhizal colonization and effect of fertilization and inoculation. Deptt. of Biology Vegetal (Botanica), Campus Murcia, Spain. 13(4): Elyamany, A.H Wirkung von Mykorrhiza und Baumwolle im Abhangigkeit von NaCl im Boden. Ph.D. Dissert. Instt. for Crop Prod. Goettingen Univ. Germany. pp Founoune, H. and R. Dupennois Influence of the dual arbuscular ecto and endo mycorrhizal symbiosis on the growth of Acacia holoserieca in glass house conditions. Ann. Sci. 59: Gerdeman, J.W. and T.H. Nicolson Spores of mycorrhiza, Endogone species extracted from soil by wet sieving and decanting. Mycol. Soc. 46(2): Giovannetti, M. and B. Mosse Evaluation of techniques for measuring vesicular arbuscular mycorrhizal infection in roots. New Phytol. 84: Hammel, C Prospects and problems pertaining to the management of AM fungi in agriculture. McGill Univ. Canada. 60 (2-3): Hussain, A. and T. Burni AM association in Paspalum paspalides. Scientific Khyber, 2: Iwan, H.O Mycorrhiza of halophytic grasses in alvard desert of Oregan. USDA, Forest Service Pacific North West Res. Station Cavallis, Oregan. pp

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