Insecticidal Bacillus thuringgiensis isolations from lemon growing areas and identification

In this study, bacterial isolations were performed from the samples taken from the lemon orchards (flowers, leaves, shoots, soil, fruit) which are located in three different locations (Çıkacak, Çarkçılı and Elvanlı) of Kargıpınar which is connected to the district of Erdemli, Mersin. Firstly, in morphological and biochemical test, 84 rod and sporulated bacteria were dertermined. Crystalline toxin cry genes were detected in 19 of 84 isolates (H1, H5, H7, H8, H18, H26, H27, H31, H33, H34, H35, H37, H39, H40, H42, H57, H65, H77 and H80). Genetic analyzes were conducted to investigate putative bioinsecticide Bacillus thuringiensis bacterial cells with the crystal toxin gene(s). For this purpose, polymerase chain reactions and agorose gel electrophoretic analyzes were performed by using primers according to the main domains of the insecticide cry genes (Cry1, Cry2, Cry3, Cry4) found in these species, and consequently related DNA band observations were performed. Crystal toxin cry genes were observed in the genomes of 19 isolates, and within them, 6 B. thuringiensis isolates carrying the four cry genes were obtained. According to these results obtained in the thesis research, it can be said that the obtained Bacillus thuringiensis bacterial isolates, due to carrying 4 insecticide genes, have high potential to be used in biological bacterial pest control. The results are important for other biological control studies like in vitro and in vivo bioassay researches and therefore, the bacterial isolates are an important source as a biological control agent, so for other subsequent investigations being conducted. The resulting bacterial isolates may be an important source as the putative biological control agents. Therefore, it is an important data for, specifically bacterial pest control, researches such as the subsequent in vitro and in vivo bioassays and so for further investigations.