.

In vitro evaluation of plant growth regulators on tissue

Table 5. Effect of different concentration of partially purified of auxins from Pseudomonas aeruginosa An-1-kul and An-13-

kul on percent of root regeneration from in vitro developed shoots of cabbage ( Brassica oleracea var.capitata )

% root regeneration

Media

Rooting start after

Mean

RM₀

No rooting

RM₁ (0.1mg/l)

12 days

100

RM₁ (0.15mg/l)

13days

RM₁ (0.2mg/l)

12 days

100

RM₁₃ (0.1mg/l)

10 days

RM₁₃ (0.15mg/l)

10 days

RM₁₃ (0.2g/l)

No rooting

on callus formation and shoot regeneration was

Discussion: Available literature showed that it was

shown by partially purified cytokinin from An-1-

the first preliminary study in India regarding the

kul at 2.0mg/l concentration in MS medium (lacking

comparative effect of the plant growth regulators

standard and commercial cytokinin) followed

(cytokinins and auxins) obtained Pseudomonas

by cytokinin from An-13-kul at 1.0 and 1.5 mg/l

strains. Inoculation of soybean callus with PGPR

concentration)(Table3and4).Ourinvestigationhave

strain of P. putida strain G11-32 showed significantly

shown that partially purified cytokinins at different

increased the growth of soybean callus in tissue

concentrations from both the strains An-1-kul and

bioassay in medium without vitamins (Chenway

An-13-kul when added in MS medium (without

and Nelson, 1991). While strain of P. putida G 2-8

commercial cytokinin) induced callus formation and

decreased the callus biomass. The study showed

shoot regeneration in some replications.

that the composition of growth medium affected the

Effect of partial purified auxins from Pseudomonas

callusbiomassformation.Callusbiomasshavelowest

aeruginosa An-1-kul and An-13-kul on root

growth when grown on medium without growth

regeneration in in vitro developed shoots and

regulators and bacterial inoculation had no effect on

development of roots

callus biomass when grown on NAA (naphthalene

acetic acid) and kinetin deficient media. But callus

Root growth promotion is often observed to be the

biomass was heightest when media contain growth

initial or sometimes the sole effect of inoculation with

regulators but no vitamins. Contradictory to these

PGPR (Holl et al., 1988; Chenway et al., 1988). This

result our studies showed positive results on callus

type of bioassay is important for effective screening

formation and initiation of shoot regeneration from

of putative PGPRs and the type of auxins used to

broccoli hypocotyl explants. It may be due to that

mark influence in the percentage of root formation

the partially purified cytokinins form Pseudomonas

(number of rooted shoots). The maximum percent of

aeruginosa strains An-1-kul and An-13-kul have been

root regeneration (100%) in different concentrations

used upto maximum concentration of 2.0mg/l.%

of auxins was recorded in rooting medium RM₁

shoot regeneration of 25% and 10% was observed

having 0.1 mg and 0.2mg/l concentration of partially

in different replications i.e. 3 shoots per 4 explant

purified auxins from An-1-kul. While only 25%

and 6 shoots per 20 explant (3/4 and 6/20 shoots)

root regeneration was observed in rooting media

were observed in two replications of treatment

containing 0.15mg/l and 0.1mg/l concentrations of

with 2.0mg/l of cytokinins from An-1-kul. Similarly

auxins from An-1-kul and An-13-kul after 13 days of

only one replication of treatment with 1.0 mg/l of

incubation, respectively (Table 5).

cytokinins from second strain i.e. An-13-kul showed

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