SYMBIOTIC RELATIONSHIP OF AM FUNGI WITH ROOT OF PHYLLANTHUS AMARUS IN WESTERN GHATS, OF TAMIL NADU

The mutually association between a fungus and root of a higher plants are called as Mycorrhiza, when the fungal hyphae live on root surface is called Ectomycorrhiza and when penetrate the root and grows inside the root tissue is called Endomycorrhiza. The different type of Arbuscular Mycorrhizal fungi (AMF) were evaluated for the symbiotic relationship with Phyllanthus amarus in Western Ghats. Glomus fasciculatum, Gigospora margarita, etc., are isolated in the forest rhizosphere soil. In the presence of AMF in root tissues generally had greater plant height, biomass, stem diameter, number of leaves and phosphorus content where rich in amount compared to other plant species.


INTRODUCTION
Mycorrhiza is the most dominant organism among the many microbial community of the rhizosphere. It has been known to form a symbiotic relationship with the fine roots of plants [1] while enhancing plant capabilities to absorb nutrients [2]. The importance of mycorrhiza has been acknowledged in the fields of agriculture forestry and other hand use [3]. AMF are soil fungi colonizing most of the plant roots and forming an association called Endomycorrhiza. More than 90% of plant and 80% of plant families in all terrestrial environment from the association [4] with these obligate fungi belonging to the group Glomeromycota [5]. These fungi are known to improve the nutritional status of host, particularly that of phosphorous and there by enhance their growth, development and yield [6,7].
The current day emphasis is on sustainable agriculture, which uses less of chemical inputs like fertilizer and pesticides having adverse effect on the soil health, fertility and environment. The mycorrhiza plays an important role in sustainable agriculture [7]. The taxon Phyllanthus has about eight herbaceous species represented in South India, of which grown in TamilNadu. Phyllanthus amarus is a medicinal plant with numerous medicinal properties. It is a small herbal plant grow up to 60-75 cm in the tropical and sub tropical rain fed crop. Every part of Phyllanthus amarus has medicinal use and is used for treating anti-viral, hepatitis, jaundice, gonorrhea, frequent menstruation, skin sores, swelling, itchiness, and diabetes. The whole plant (root, stem, leaf area) is used in Ayurvedic formulations [8].
The objective of the study reveal that the status and diversity of AMF on medicinal plants of Phyllanthus species.

Study area
The study area of the Western Ghats, which lies between 10˚13' to 10˚33' N in latitude and 76˚ 49' and 77˚ 21' E. The vegetation of this region, harbor may endemic species and is a unique ecological tract rich in biodiversity.

Experimental Soil
The physicochemical characteristics of the exprimental soil used for experiment were tested in Department Soil Science testing laboratories at Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India.

Rhizosphere Effect [9]
The quantitative rhizosphere effect of the plants was calculated using the formula: R/S=

Arbuscular Mycorrhizal Inoculation
AM fungal spores were isolated from the forest soil, following the wet sieving and decanting method [10]. The spores were identified by using the manual written by Schenck and Perez [11]. The Genera of Acaulospora, Gigaspora, Glomus, Scutellospora and Sclerocystis were isolated from 100g rhizosphere soil samples. Ten kg of the experimental soil was collected from forest and filled in each pot after sterilization. The AM fungal spore inoculum was added (10g/each pot).

Establishment of test plant and greenhouse experiments
The studies were conducted under greenhouse conditions with temperature ranges from 28-31˚C. AM fungal treatments were given on a layer below the germinated randomized. All the pots are maintained greenhouse condition.

Mycorrhizal Status
Results were processed using Phillips et al.
[12] technique to study the percent of root colonization.

Phosphorus Content
The phosphorus content in the shoots was determined by the vanado-molybdate phosphoric acid yellow color method outlined by Jackson [13].

RESULTS AND DISCUSSION
The   In this study highest mycorrhizal percent colonization was observed in plants treated with Glomus species. Highest number of mycorrhizal spores was found in root zone soil. Least number of spores occurred in the uninoculated root zone of plants [14]. Host preference among AM fungi has been reported by earlier workers [15]. The plant biomass (shoot+root) was enhanced due to Glomus species inoculation with the Allium cepa L. (Figure 1 and 2) has been reported in aromatic plants like Palmarosa, Eucalyptus, Bergamot mint and Sweet basil.