Arbuscular Mycorrhizal Fungi spores diversity and AMF infection in some medicinal plants of District Charsadda KPK

An investigation has been made about the Arbuscular Mycorrhizal Fungi (AMF) spore population and root colonization in 20 medicinal plants selected and collected from district Charsadda at early winter and summer seasons during session 2014-2015. The spore density of AMF ranged from 80 spores per 100gm, and root colonization from 20-80%. The lowest spore density was recorded in Cestrum nocturnum, Ficus carica, Aquilaria agallocha and the highest spore density was recorded in Sedum dendroideum, Cannabis sativa, Triticum aestivum, and Mentha longifolia, Withania somnifera while absent in Brassica campestris, Amaranthus viridis. The spore density of AMF and root colonization by these fungi varied from species to species, season to season, and also affected by host plant growth stages (vegetative-fruiting).AM fungi association was more observed at fruiting stage and low at vegetative and flowering phases of host. The most dominant species of AMF were Glomus followed by Sclerocystis and Acaulospora species.


Introduction
Mycorrhiza is a symbiotic relationship between a fungus and the roots of higher plants [1].''Mycorrhiza, is a mutualistic association between fungi and higher plants, has been documented extensively, but much less is known about the development of Arbuscular Mycorrhizal (AM) fungi'' [2].
AM Fungi is a diverse group of associations which are formed by the co-evolution between fungi and plants and benefits to both partners [3].The term of mycorrhiza describes symbiotic associations between plants and fungi, these associations are assumed to play an important role in the land colonization by plants due to the ability of the symbiotic organisms in acquiring nutrients unavailable to non-mycorrhizal individuals [4].The AMF inoculated plants will improve plant health by enhancing nutrient status, yield and also by promoting the host plants against the pathogens.It is therefore, essential to know the specificity of AMF host pathogen combination for beneficial purpose [5].''Mycorrhizal fungi are mostly widespread since they can be found in the roots of most plant species, these characteristics make mycorrhizal fungi a potential powerful tool to be used in actions towards a sustainable management of the environment''

AMF spores isolation and its quantification
The spores of AM fungi were isolated by ''Wet Sieving and Decanting Technique'' demonstrated by [15].

Identification of AMF spores
The identification of these fungi was done by following the manual of [16] and was also compared with reference species description demonstrated by INVAM (International culture collection of vesicular arbuscular mycorrhizal fungi, 2014).For the characterization of AM fungi, various characteristics of spores such as spore morphology, shape, colour and size were studied.

Root colonization
All the 18 mycorrhizal species show hyphal presence in roots (Table 1) and more than 80
percent of these plants show presence of either hyphae and Arbuscules or hyphae and vesicles or all the three structures individually.Twenty two samples of roots and soil were collected from various parts of district Charsadda, Which is belongs to 16 different families.Our results agree with those of [24], who also reported the occurrence of Mycorrhiza in some members of the family Labiatae species ranged from 55-70% Colonized.Nineteen of the studied plant species formed AMF associations 40-80 percent.AMF mycelium was less 20-30 percent found in the root systems of Ficus carica which is belong to family Moraceae, Aquilaria agallocha belongs to family Thymelaeaceae, Dioscorea rotundata belongs to family Dioscoreaceae, Cymbopogon (lemon grass) belongs to family Poaceae.That is generally accepted as conventionally AMF less host Brassica campestris belongs to family Brassicaceae, which have no any mycorrhizal infection.These results also agree with the results of [25].

Table 1 . Selected plants belong to different families at various host growth stages
Each sample was taken in triplicate and data represented as mean spore density/100gm soil.The total number of spores obtained by wet sieving was referred to as Spore density.
[15]Total no. of root segments investigated Isolation and quantification of spores AMF spores from the 100gm roots zone soil were isolated using wet sieving and decanting method[15].The rhizospheric soil for a particular plant was obtained from different spots, pooled and then mixed to take representative soil sample.