|
Efficiency of plant
growth-promoting rhizobacteria (PGPR) for the enhancement of
rice growth
M.
Ashrafuzzaman1,2*, Farid Akhtar Hossen1,
M. Razi Ismail2, Md. Anamul Hoque3, M.
Zahurul Islam4, S.M. Shahidullah2 and
Sariah Meon2
1Department
of Crop Botany, Bangladesh Agricultural University,
Mymensingh, Bangladesh.
2Institute
of Tropical Agriculture, Universiti Putra Malaysia, 43400
Serdang, Selangor, Malaysia.
3Department
of Soil Science, Bangladesh Agricultural University,
Mymensingh, Bangladesh.
4Division
of Soil Science, Bangladesh Institute of Nuclear
Agriculture, Mymensingh, Bangladesh..
*Corresponding author. E-mail:
drashraf2007@yahoo.com.
Accepted
23 January, 2009 |
|
Plant growth-promoting rhizobacteria (PGPR) are beneficial
bacteria that colonize plant roots and enhance
plant growth by a wide variety of mechanisms. The
use of PGPR is steadily increasing in agriculture
and offers an attractive way to replace chemical
fertilizers, pesticides, and supplements. Here, we have
isolated and characterized the PGPR from the rhizosphere
soil of rice field for the enhancement of growth of rice.
Rhizosphere soils were collected from different areas of
Mymensingh in Bangladesh. Ten isolates of bacteria,
designated as PGB1, PGB2, PGB3, PGB4, PGB5, PGT1, PGT2,
PGT3, PGG1 and PGG2, were successfully isolated and
characterized. Subsequently, to investigate the effects of
PGPR isolates on the growth of rice, a pot culture
experiment was conducted. Prior to seeds grown in plastic
pots, seeds were treated with PGPR isolates and seedlings
were harvested after 21 days of inoculation. Isolates PGB4,
PGT1, PGT2, PGT3, PGG1 and PGG2 induced the production of
indole acetic acid (IAA), whereas only PGT3 isolate was able
to solubilize phosphorus. Most of isolates resulted in a
significant increase in plant height, root length, and dry
matter production of shoot and root of rice seedlings.
Furthermore, PGPR isolates remarkably increased seed
germination of rice. Among the ten isolates, PGB4 and PGG2
were found almost equally better in all aspects such as dry
matter production, plant height and root length of rice, and
IAA production. Isolate PGT3 was also found to be promising
in IAA production having an additional property of phosphate
solubilization. The present study, therefore, suggests that
the use of PGPR isolates PGB4, PGG2 and PGT3 as inoculant
biofertilizers might be beneficial for rice cultivation as
they enhanced growth of rice, and induced IAA production and
phosphorus solubilization.
Key
words:
IAA, PGPR, phosphorus solubilization, rice growth, seed
germination. |
