Impact of biocontrol Pseudomonas fluorescens CHA0 and its genetically modified (GM) derivatives on penetration of Meloidogyne javanica in mungbean roots

I. A. Siddiqui, S. S. Shaukat


Pseudomonas /luorescens strain CHAO and its genetically modified (GM) derivatives CHAO-Rif/pME3424 and CHA89 caused a significant reduction in penetration rates of Meloidogyne javanica juveniles in mungbean roots. With increasing nematode densities, nematode penetration rates increased. At low population densities of M. javanica (0, 500, 1000 and 2000 J2/pot), all the three strains of P. /luorescens gave significantly reduced nematode penetration rates. At the highest population density of M. javanica (4000 J2/pot), CHAO-Rif/pME3424 was also effective in the repeated experiments while wild type CHAO was effective only in one experiment. CHA89 failed to cause significant reduction in nematode penetration at high nematode densities (2000 and 4000 J2/pot). Whereas strain CHAO/pME3424 consistently reduced shoot weight, strain CHAO had no such effect but CHA89 enhanced shoot growth. Root weight was not markedly altered by any of the strains.

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