Mycorrhizal inoculation in the plant causing increase in growth and production of phytochemicals is well reported, however little information is available related to the effect of mycorrhiza on morphological and biochemical properties of the medicinal plants like Ashwagandha. The present study is an attempt on diversity analysis in Withania somnifera with an aim to ascertain the nature and extent of genetic diversity present among different accessions in presence of mycorrhiza. The major biochemical constituents of Ashwaganda roots are with nolides which are well known for its medicinal properties. Mycorrhizal associations confer benefits like better nutrition acquisition, enhanced growth, defense enhancement and improved abiotic and biotic stress tolerance in plants. The present investigation was undertaken to assess genetic diversity among five different accessions of W. somnifera using morphological and biochemical markers and the effect of mycorrrhizal inoculation on these marker. The present study concluded that presence of mycorrhiza was effective on plant growth and phytochemical constituents more than non-treated plants. Amongst five selected germplasms IC 283662, JA 134, RAS 23, MPAS 6 and MWS 205 of W. somnifera, JA 134 showed best response in pretext of the selected morphological and biochemical features in presence of mycorrhiza.

No abstract

Biological control refers to the potential application of introducing or inhabitant microorganisms to reduce the damage caused by one or more plant pathogens. A continuous interplay between ecosystem and its rhizospheric organisms brings the control of soilborne pathogens which are more diffi cult to manage. Since last two decades, biocontrol has been gaining considerable interest to maintain sustainable agriculture system. Mycorrhizae are among the most primeval, intimate, and vital association which colonize symbiotically through the roots of various vascular, nonvascular, and crop plants. The arbuscular mycorrhizal (AM) fungi develops a complex mutualistic association with host plant roots via various mechanisms. From the initiation of symbiosis till the formation of arbuscules and/or vesicles, a number of changes occur in plant metabolism, plant nutritional status, and plant resistance. The key indicators of AM fungi for an effective defense response are reduction in the infectivity of soilborne pathogens or suppression of pathogen metabolism or increase in plant's tolerance toward pathogen. Proposed grounds for a healthier state of plants associated with AM fungi are attributed to (1) improvement in nutritional status of plants, (2) competition between mycorrhiza and pathogen for nutrition and infection sites, (3) modifi cations in root anatomy and morphology, (4) release of plant root exudates, (5) harboring microbial fl ora antagonistic to root pathogens, and (6) improved localized as well as systemic resistance in plants. The effective and prolonged mycorrhiza-induced resistance involves various phytohormones, secondary metabolites, pathogenrelated proteins, and defense enzymes. Such activation leads to a primed state in plant, which allows quicker and mightier defense response against pathogens. This chapter provides an overview of the underlying mechanisms involved in mycorrhiza-induced disease resistance and priming in plants.

No abstract