000			02990nam a22002297a 4500
003			OSt
005			20220125121026.0
008			130803b xxu||||| |||| 00| 0 eng d
040			_cCPGS
082			_a632.96
100			_aKongbrailatpam Jina Devi _9919
245			_aEvaluation of native fluorescent pseudomonads against wilt pathogens of major vegetables in Meghalaya / _cby Kongbrailatpam Jina Devi
260			_aUmiam ; _bCPGS, CAU _cc2012.
300			_a[26], 82p. : _bill., some col.;
440			_a[Plant Pathology, School of Crop Protection] _9920
501			_aAbstract: Fluorescent pseudomonads are an ecologically important group of rhizobacteria that are well accepted as biocontrol agent and plant growth promoter. Exploitation of such rhizobacteria for management of plant diseases reduces the hazardous effects of chemical to the environment as well as to human health. The present investigation was carried out with an aim to characterize the fluorescent pseudomonads predominant in mid and up hills of Meghalaya and to evaluate the antagonistic potentiality of native fluorescent pseudomonads against wilt pathogens of major vegetables in Meghalaya. A total of 72 rhizospheric soil samples were collected from different crop rhizospheres viz., maize, rice, banana, pea and pigeon pea from Ri-Bhoi (mid-hills) and East Khasi Hills (mid and up-hills) districts of Meghalaya. Fifty fluorescent pseudomonad isolates obtained from 72 collected soil samples were tentatively grouped into 4 categories i.e. Pseudomonas fluorescens bv. I and II; P. putida bv. A and B based on their cultural, morphological and biochemical properties. Isolates were further screened for production of HCN and presence of 2 biosynthetic genes for antibiotics viz., DAPG and pyrrolnitrin by using gene specific primer pairs Phl2a-Phl2b and Prncf-Prncr respectively. HCN production test was found positive for 12 isolates, whereas two and six numbers of isolates were recorded for presence of DAPG and pyrrolnitrin biosynthetic genes respectively. Antagonistic potential of 17 isolates positive for HCN and antibiotic production was tested against major wilt pathogens i.e. Fusarium oxysporum f.sp. pisi (pea) and Ralstonia solanacearum ( brinjal and capsicum) under in vitro conditions. The radial growth of F. oxysporum f.sp. pisi was found to inhibit most (3.23 cm) by isolate MRN 18, whereas isolate PC (17.33 mm and 15.67 mm) followed by USR 9.2 (16.00 mm and 15.00 mm) was found to have the highest inhibition zone against both R. solanacearum isolates from brinjal and capsicum. These two isolates must be further evaluated under in vivo condition for development of ecologically sustainable biocontrol strategy for management of wilt pathogens of vegetables.
502			_aIncludes bibliographical references.
650			_aVegetable _vWilt pathogens _xBiocontrol _9921
650			_aFluorescent pseudomonads _9922
700			_aMajumder, Dipali _eMajor Advisor _9923
942			_2ddc _cTH
999			_c4078 _d4078