9
enhancement in the shoot dry weight was about 0.04 g/plant whereas after
21 days it was about 0.17 g/plant.
Furthermore, post-bacterial (Herbaspirillum seropedicae SmR1) inoculation
performance of different wheat genotypes has shown that the roots of different cultivars of wheat viz. CD 119 and 120 responded positively when inoculated with the
strain SmR1 (Neiverth et al. 2014). Increase in the root fresh weight leaf fresh and
dry weight in the CD 119 cultivar by 0.32 g, 1.06 g, and 0.72 g, respectively, was
observed compared to the control within 7 days. Similarly, there has been increase
in cultivar CD 120 by 0.11 g, 0.28 g, and 0.06 g, respectively, from the control. The
productivity of the genotype CD 120 was significantly enhanced after the inoculation of SmR1 in the absence of urea (Neiverth et al. 2014). Ramesh et al. (2014) also
reported improved wheat growth treated with the zinc-solubilizing Bacillus aryabhattai, which included three strains, namely, MDSR7, MDSR11, and MDSR14,
which enhanced plant height by 17 cm, 12 cm, and 22 cm, respectively. Substantial
improvement in the shoot dry weight (2.3 g/plant, 0.6 g/plant, and 2.7 g/plant) was
also observed with MDSR7, MDSR11, and MDSR14 strains, respectively. In the
case of rice, a key staple food, inoculation of the cyanobacterium Calothrix elenkinii improved growth of shoot length by about 12.7 cm and root length by 7.37 cm
compared to the control. Fresh and dry weight of rice plants were also enhanced
about 323.33 mg and 24.67 mg, respectively, in comparison to control, which was
76.67 and 15.10 mg, respectively. The physiological attributes such as chlorophyll
(up to 6.21 μg/g in leaf and 2.66 μg/g in root), IAA production (26.95 μg/g in leaf
and 14.07 μg/g in root), nitrogenase activity (11.11 nmol C 2 H 4 /plant/h), and hydrolytic and defence enzymes were also enhanced (Priya et al. 2015). Among hydrolytic enzymes, chitosanase activity was high in inoculated plants, by 10.7 and
9.0 IU/mg fresh weight in the root and shoot, respectively, compared to the control
(Priya et al. 2015). Overall, cyanobacterial inoculation helped the root system
against any fungal infections and subsequently promoted its growth. Similar observations of enhanced agronomic, physicochemical, enzymatic, and biochemical
parameters were also observed in rice cultivars inoculated with three cyanobacterial
strains (Singh et al. 2011). Inoculation of cyanobacterial strains also enhanced accumulation of phenylpropanoid metabolites, especially phenolic acids and flavonoids
in the rice plants that were correlated with the enhanced antioxidant properties
under stress condition. In another study, five endophytic diazotrophic bacterial
strains (KW7-S22, KW7-S06, SW521-L21, CB-R05, HS-R01) inoculated in rice
enhanced the length of the fresh leaf (39.11, 41.29, 37.99, 50.25, and 43.21 cm,
respectively) and root (21.98, 25.56, 19.41, 33.73, and 28.11 cm, respectively). The
length of dry leaf and root was also enhanced (0.36, 0.39, 0.31, 0.49, and 0.42 cm)
and (0.24, 0.27, 0.18, 0.39, and 0.33 cm, respectively) after treatment of all five
strains (Ji et al. 2014). Inoculation of Bacillus aryabhattai strains MDSR7,
MDSR11, and MDSR14 in soybean enhanced the growth of the plants. Plant height
was enhanced to 38, 32, and 40 cm respectively, in the three strains, as compared to
the control which was about 24 cm. Similarly, the shoot and root dry weight were
enhanced, to 8.8, 7.5, and 9.3 g/plant and 2.5, 2.0, and 2.6 g/plant, respectively following the treatment of three strains.
2.3 Plant Growth-Promoting Traits and Microbial Functions
enhancement in the shoot dry weight was about 0.04 g/plant whereas after
21 days it was about 0.17 g/plant.
Furthermore, post-bacterial (Herbaspirillum seropedicae SmR1) inoculation
performance of different wheat genotypes has shown that the roots of different cultivars of wheat viz. CD 119 and 120 responded positively when inoculated with the
strain SmR1 (Neiverth et al. 2014). Increase in the root fresh weight leaf fresh and
dry weight in the CD 119 cultivar by 0.32 g, 1.06 g, and 0.72 g, respectively, was
observed compared to the control within 7 days. Similarly, there has been increase
in cultivar CD 120 by 0.11 g, 0.28 g, and 0.06 g, respectively, from the control. The
productivity of the genotype CD 120 was significantly enhanced after the inoculation of SmR1 in the absence of urea (Neiverth et al. 2014). Ramesh et al. (2014) also
reported improved wheat growth treated with the zinc-solubilizing Bacillus aryabhattai, which included three strains, namely, MDSR7, MDSR11, and MDSR14,
which enhanced plant height by 17 cm, 12 cm, and 22 cm, respectively. Substantial
improvement in the shoot dry weight (2.3 g/plant, 0.6 g/plant, and 2.7 g/plant) was
also observed with MDSR7, MDSR11, and MDSR14 strains, respectively. In the
case of rice, a key staple food, inoculation of the cyanobacterium Calothrix elenkinii improved growth of shoot length by about 12.7 cm and root length by 7.37 cm
compared to the control. Fresh and dry weight of rice plants were also enhanced
about 323.33 mg and 24.67 mg, respectively, in comparison to control, which was
76.67 and 15.10 mg, respectively. The physiological attributes such as chlorophyll
(up to 6.21 μg/g in leaf and 2.66 μg/g in root), IAA production (26.95 μg/g in leaf
and 14.07 μg/g in root), nitrogenase activity (11.11 nmol C 2 H 4 /plant/h), and hydrolytic and defence enzymes were also enhanced (Priya et al. 2015). Among hydrolytic enzymes, chitosanase activity was high in inoculated plants, by 10.7 and
9.0 IU/mg fresh weight in the root and shoot, respectively, compared to the control
(Priya et al. 2015). Overall, cyanobacterial inoculation helped the root system
against any fungal infections and subsequently promoted its growth. Similar observations of enhanced agronomic, physicochemical, enzymatic, and biochemical
parameters were also observed in rice cultivars inoculated with three cyanobacterial
strains (Singh et al. 2011). Inoculation of cyanobacterial strains also enhanced accumulation of phenylpropanoid metabolites, especially phenolic acids and flavonoids
in the rice plants that were correlated with the enhanced antioxidant properties
under stress condition. In another study, five endophytic diazotrophic bacterial
strains (KW7-S22, KW7-S06, SW521-L21, CB-R05, HS-R01) inoculated in rice
enhanced the length of the fresh leaf (39.11, 41.29, 37.99, 50.25, and 43.21 cm,
respectively) and root (21.98, 25.56, 19.41, 33.73, and 28.11 cm, respectively). The
length of dry leaf and root was also enhanced (0.36, 0.39, 0.31, 0.49, and 0.42 cm)
and (0.24, 0.27, 0.18, 0.39, and 0.33 cm, respectively) after treatment of all five
strains (Ji et al. 2014). Inoculation of Bacillus aryabhattai strains MDSR7,
MDSR11, and MDSR14 in soybean enhanced the growth of the plants. Plant height
was enhanced to 38, 32, and 40 cm respectively, in the three strains, as compared to
the control which was about 24 cm. Similarly, the shoot and root dry weight were
enhanced, to 8.8, 7.5, and 9.3 g/plant and 2.5, 2.0, and 2.6 g/plant, respectively following the treatment of three strains.
2.3 Plant Growth-Promoting Traits and Microbial Functions