Not AvailableTraits involved in plant growth promotion
by bacteria are ambiguously decided as phytohormones,
siderophores, HCN, proteases, chitinases, cellulases,
ammonia, exopolysaccharide production and phosphate
solubilization or antagonistic activity. A total of 40 fluorescent Pseudomonas strains were isolated from diverse
soils of various agro-ecosystems of India. Among these 7
strains viz, P1, P10, P13, P18, P21, P28 and P38 were
selected depending on their character of possessing single
or multiple PGPR traits. These isolates individually and in
combination with AM fungi (Glomus fasciculatum and
Glomus aggregatum) were used for treating sorghum seeds.
25 days after sowing, plants were analysed for different
plant growth promoting parameters. It was observed that
strains in presence of mycorrhizae performed well compared to the strains devoid of mycorrhizae. Pseudomonas
sp. P1 possessing GA3, EPS production and ‘P’ solubilization performed well. Pseudomonas sp. P38 which was a
volatile (HCN) producer but a good phosphate solubilizer
did not perform well. Strain P28 with multiple PGPR traits
did not show the expected out come. Results varied when
mycorrhizae was used in combination. P10 and P13
which were good in IAA, GA3, EPS, siderophore and ‘P’
solubilization performed well with mycorrhizae, with an
overall increase in plant biomass, leaf area, total
chlorophyll and mycorrhizal infection compared to other
combinations. Here, strain P1 in combination with
mycorrhizae did not show significant increase in plant
growth compared to P10 and P13. Hence, mere possession
of multiple PGPR traits does not confer fluorescent Pseudomonas strains as PGPR. Further studies have to be carried out in order to evaluate the other traits which may be
involved in plant growth promotionNot Availabl
