the rhizosphere is the area around the root of a plant occupied by a unique population of usefulbacteria known as plant growth promoting rhizobacteria (pgpr). in this study, the isolation andidentification of rhizobacteria from orange (citrus sinensis) orchards using 16s rrna gene, as well asbiological and biochemical assays is reported. analysis of 16s rrna gene was confirmed bybiological and ...

background bacillus thuringiensis is the most successful biological control agent used in agriculture, forestry and mosquito control. however, the insecticidal activity of the b. thuringiensis formulation is not very stable and rapidly loses its biological activity under field conditions, due to the ultraviolet radiation in sunlight. melanin is known to absorb radiation therefore photo protecti...

conclusions bacillus thuringiensis is very sensitive to the interaction of p. fluorescens, however is capable to survive in soil due to its capacity of sporulate. some of the cells in the form of spores germinated and folded slightly and remained in a constant cycle of sporulation and germination. this confirms that b. thuringiensis ips82 can germinate, grow and sporulate in soil. results the a...

We studied the effects of combinations of Bacillus thuringiensis spores and toxins on the mortality of diamondback moth (Plutella xylostella) larvae in leaf residue bioassays. Spores of B. thuringiensis subsp. kurstaki increased the toxicity of crystals of B. thuringiensis subsp. kurstaki to both resistant and susceptible larvae. For B. thuringiensis subsp. kurstaki, resistance ratios were 1,20...

The bacterial strain Bacillus cereus is closely related to Bacillus thuringiensis, although any genetic relationship between the two strains is still in debate. Using rep-PCR genomic fingerprinting, we established the genetic relationships between Brazilian sympatric populations of B. cereus and B. thuringiensis simultaneously collected from two geographically separate sites. We observed the fo...

Levels, genetic traits and stability of resistance to Bacillus thuringiensis of the Bang Bua Tong (BS) population of the diamondback moth Plutella xylostella collected in Thailand were investigated. The BS population exhibited 668 and 66.5-fold resistance to formulations derived from B. thuringiensis subsp. kurstaki (Toarow CT®), and B. thuringiensis subsp. aizawai (XenTari®), respectively. In ...

Bacillus thuringiensis is the most widely applied biological insecticide and is used to manage insects that affect forestry and agriculture and transmit human and animal pathogens. This ubiquitous spore-forming bacterium kills insect larvae largely through the action of insecticidal crystal proteins and is commonly deployed as a direct bacterial spray. Moreover, plants engineered with the cry g...

Among the phytophagous insects which attack crops, the fall armyworm, Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera, Noctuidae) is particularly harmful in the initial growth phase of rice plants. As a potential means of controlling this pest, and considering that the entomopathogen Bacillus thuringiensis Berliner demonstrates toxicity due to synthesis of the Cry protein, the present stu...

In sporulating cultures of Bacillus thuringiensis subsp. yunnanensis HD977, two cell types are observed: cells forming only spores and cells forming only crystals. Curing analysis suggested that the crystal proteins are plasmid encoded. Through plasmid transfer experiments, it was established that a 103-MDa plasmid is involved in the crystal production. Conjugal transfer of this plasmid to Cry-...

J. Econ. Entomol. 86(3): 697-705 (1993) ABSTRACT Eleven populations of diamondback moth, Plutella xylostella (L.), were collected in 1990 from Brassica plants in six states of the United States and in Indonesia and tested for their responses to two formulations of Bacillus thuringiensis subsp. kurstaki (Javelin we and DipeI2X), permethrin, and methomyI. Populations from Florida that had been tr...