A 100 ml aliquot of a CHM1 culture suspension (1.6 107 cfu
ml1) was drenched into the rhizosphere soil of 2-week-old rice
and cole seedlings, planted in pots (height 15 cm; diameter 20 cm;
volume 3503 cm3). The soil drenched with the same volume of LB
medium served as negative control. Each treatment contained 30
seedlings, and each treatment including control was in triplicate.
After incubation for 2 months under greenhouse conditions, fresh
weights of the seedlings and plant heights of the crops were
measured. The growth promotion effect (GPE, %) was estimated by
the formula:
GPE ð%Þ ¼ ð1 Wa=WbÞ 100
Where Wa is the fresh weight of the seedlings in the control group
and Wb is that in the test group.
The content of chlorophyll was determined according to the
method of Pflugmacher and Steinberg (1998).