EFFECT OF PLANT GROWTH PROMOTING FUNGAL INOCULANT ON THE GROWTH OF ARACHIS HYPOGEA (L.) AND IT’S ROLE ON THE INDUCTION OF SYSTEMIC RESISTANCE AGAINST RHIZOCTONIA SOLANI

摘要

Beneficial plant microbe interactions in the rhizosphere are primary determinants of plant health andsoil fertility. Plant growth promoting fungi have great effect towards the growth of plant crops. Soil borne pathogenicfungi cause heavy crop losses all over the world. As the use of chemicals for disease control and fertilization causesenvironmental problems, there is a need for alternative control measures. The most important and economicallycultivated plant pea-nut was selected to test the growth promotion by antagonistic microorganisms with or with ourpathogen Rhizoctonia solani. This necessitates a study on Plant Growth Promoting Fungi (PGPF) as adequate workhas gone on rhizobacteria. The present investigation was conducted to study the effect of PGPF on the growth ofArachis hypogea(L.) and its role of induction of systemic resistance against Rhizoctonia solani.Forty fiverhizosphere fungal isolates were obtained from 12 different cultivated field crops and were screened for theirpotential to promote growth in Arachis hypogea(L.). The isolate (Cc2) obtained from Cucumis sativus(L.).Duch.ex.poir was identified as the potential plant growth promoting fungus. The effect of soil inoculation with the selectedisolate Cc2on the gro wth of healthy plants of Arachis hypogea(L.) and those challenged with Rhizoctonia solani wasstudied by pot culture experiment. The overall vegetative growth of plant (Root and Shoot development, Dry matteraccumulation) and reproductive growth (Pod and Seed development) were studied. The fungal inoculants improvedeffectively the growth both in plants challenged and unchallenged with Rhizoctonia solani. The soil inoculation ofCc2has improved the chlorophyll, carotenoid, anthocyanins ,total soluble sugar and protein content compare to theuntreated plants (T0) and plants infected byRhizoctonia solani(T1). The phenol and proline contents were found tobe higher in plants challenged with Rhizoctonia solani.Growth hormone production ability of the selected isolatewas determined. Results revealed that the selected isolate could produce Indole Acetic Acid and Gibberellic Acid.The in vitro study by dual culture method revealed that there was a negative interaction (Antibiosis) between theplant growth promoting fungal inoculant (Cc2) and the pathogen Rhizoctonia solani.It could be concluded that theselected isolate Cc2proved to be a potential fungus in promoting plant growth and yield in Arachis hypogea(L.) andin inducing systemic resistance in Arachis hypogea (L.) against Rhizoctonia solani.Finally Cc2was identified asRhizopussp., in generic level.