Abstract: The cDNA encoding the 326 amino acids of a Class I
basic chitinase gene from Leucaena leucocephala de Wit (KB3,
Genbank accession: AAM49597) was cloned under the control of
CaMV35S promoter in pCAMBIA 1300 and transferred to
Koshihikari. Calli of Koshihikari rice was transformed with
agrobacterium with this construct expressing the chitinase and β-
glucouronidase (GUS). The frequencies of calli 90 % has been
obtained from rice seedlings cultured on NB medium. The high
regeneration frequencies, 74% was obtained from calli cultured on
regeneration medium containing 4 mg/l BAP, and 7 g/l phytagel at
25°C. Various factors were studied in order to establish a procedure
for the transformation of Koshihikari Agrobacterium tumefaciens.
Supplementation of 50 mM acetosyringone to the medium during
coculivation was important to enhance the frequency to transient
transformation. The 4 week-old scutellum-derived calli were
excellent starting materials. Selection medium based on NB medium
supplement with 40 mg/l hygromycin and 400 mg/l cefotaxime were
an optimized medium for selection of transformed rice calli. The
percentage of transformation 70 was obtained. Recombinant calli and
regenerated rice plants were checked the expression of chitinase and
gus by PCR, northern blot gel, southern blot gel, and gus assay.
Chitinase and gus were expressed in all parts of recombinant rice.
The rice line expressing the KB3 chiitnase was more resistant to the
blast fungus Fusarium monoliforme than control line.
Abstract: The biological activity of A. pullulans isolates against
species of the genus Fusarium, bacteria of the genus Azotobacter and
pseudomonads colonizing wheat kernels was evaluated. A field
experiment was carried out in 2009-2011, in north-eastern Poland.
Winter wheat (cv. Bogatka) plants were sprayed with a cell
suspension of A. pullulans at a density of 106 - 108 per cm3 water at
the stem elongation stage and the heading stage. Untreated plants
served as control. The abundance of epiphytic yeasts, bacteria of the
genus Azotobacter, pseudomonads and Fusarium pathogens on wheat
grain was estimated at harvest and after six months’ storage. The
average size of yeast communities was significantly greater on wheat
kernels treated with a cell suspension of A. pullulans, compared with
control samples. In 2010-2011, biological control reduced the
abundance of some species of the genus Fusarium.
Abstract: The microbiological and physicochemical
characteristics of wetland soils in Eket Local Government Area were
studied between May 2001 and June 2003. Total heterotrophic
bacterial counts (THBC), total fungal counts (TFC), and total
actinomycetes counts (TAC) were determined from soil samples
taken from four locations at two depths in the wet and dry seasons.
Microbial isolates were characterized and identified. Particle size and
chemical parameters were also determined using standard methods.
THBC ranged from 5.2 (+0.17) x106 to 1.7 (+0.18) x107 cfu/g and
from 2.4 (+0.02) x106 to 1.4 (+0.04) x107cfu/g in the wet and dry
seasons, respectively. TFC ranged from 1.8 (+0.03) x106 to 6.6 (+
0.18) x106 cfu/g and from 1.0 (+0.04) x106 to 4.2 (+ 0.01) x106 cfu/g
in the wet and dry seasons, respectively .TAC ranged from 1.2
(+0.53) x106 to 6.0 (+0.05) x106 cfu/g and from 0.6 (+0.01) x106 to
3.2 (+ 0.12) x106 cfu/g in the wet and dry season, respectively.
Acinetobacter, Alcaligenes, Arthrobacter, Bacillus, Beijerinckja,
Enterobacter, Micrococcus, Flavobacterium, Serratia, Enterococcus,
and Pseudomonas species were predominant bacteria while
Aspergillus, Fusarium, Mucor, Penicillium, and Rhizopus were the
dominant fungal genera isolated. Streptomyces and Norcadia were
the actinomycetes genera isolated. The particle size analysis showed
high sand fraction but low silt and clay. The pH and % organic
matter were generally acidic and low, respectively at all locations.
Calcium dominated the exchangeable bases with low electrical
conductivity and micronutrients. These results provide the baseline
data of Eket wetland soils for its management for sustainable
agriculture.