EFFECT OF BACTERIAL BIOPRIMING ON SEED GERMINATION AND SEEDLING GROWTH OF MULBERRY AND THEIR ANTAGONISM TO RHIZOCTONIA BATATICOLA.

Fluorescent Pseudontonas and Bacillus are considered to be the most promising group of Plant Growth Promoting Rhizobacteria (PGPR), which are also involved in biocontrol of many plant diseases. In view of exploring potential of these microorganisms as mulberry growth promoters and disease control agents, effect of biopriming with nine strains of fluorescent Pseudontonas (Pf-1 to Pf-9) and Bacillus subtilis (Bs) on the seed germination and seedling growth of mulberry was studied. Significantly (P<0.05) higher germination (99.02%) was found when the seeds were bioprimed with B. subtilis followed by Pseudontonas fluorescence (97.50%) strain Pf-9 and Pf-2. However, the vigour index was found higher (368.6) due to biopriming with Pf-4. Compared with control, the mean total length of the seedling was found higher (11.48%) when the seeds were bioprimed with strain Pf-2 in the in vitro germination study. Similarly, study using strile soil showed higher shoot length due to biopriming with Pf-2 and Bs. These strains showed increase in mean total length 12.58% and 3.89% respectively over the control. Antagonistic effect of various plant growth promoting rhizobacteria to Rhizoctonia bataticola a root rot causing fungus showed significantly (P<0.05) less radial growth towards all the bacteria compared with the control (39.88 mm). The radial growth of R. bataticola was least in presence of Bs, Pf-2, Pf-4 and Pf-6 (11-13 mm). The study suggests exploration of effective native antagonistic PGPR for mulberry growth as well as for root rot disease control. [ABSTRACT FROM AUTHOR]