Bacillus thuringiensis var. tenebrionis' in Leptinotarsa decemlineata (Say.) (Coleoptera: Chrysomelidae) larvalarının ortabarsağına etki sürecinin histolojik yöntemlerle belirlenmesi
Küçük Resim Yok
Tarih
2006
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmada, gram pozitif bir bakteri olan Bacillus thuringiensis var. tenebrionis' in protein yapıdaki kristal formlarda olan insektisit etkili ö-endotoksinin etki mekanizması detaylandırılmaya çalışılmıştır. Patates böceği Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae)'nın son dönem larvalarına uygulanan bakterinin sindirim sisteminde oluşturduğu etkiler orta barsak hücreleri üzerinde izlenmiştir. Son döneme yeni geçmiş bir grup larva bakteri ırkının ticari formülasyonu Novodor FC ile önerilen dozda muamele edilmiş patates yaprakları ile beslenirken diğer grup kontrol bireylerini elde etmek amacıyla saf su uygulanmış yapraklarla beslenmiştir. Fiksasyonlar uygulamayı takip eden 12 saatlik dönemde 2 saatlik, sonraki 12 saatlik dönemde 6 saatlik periyotlarda yapılmıştır. Sonraki 24 saatte de fiksasyon süreleri 12 saate yükseltilmiştir. Fikse edilen örneklerden histolojik yöntemlerle hazırlanan preparatlardan izlenen sonuçlara göre bakterinin etkisi beslenmenin başlangıcını takip eden 2. saatin sonunda oluşmaya başlamıştır. 4. ve 6. saatler sonunda daha net görülebilen etki, izleyen 8, 10 ile 12. saatler de giderek yaygınlaşmış ve şiddetlenmiştir.Özellikle beslenmenin başlangıcından 12 saat sonra ve izleyen saatlerde ortabarsak hücrelerinde ve mikrovilar alandaki etkinin en üst seviyeye ulaştığı gözlemlenmiştir.
The steps in mode of action of S-endotoxin with insecticidal efficacy produced by gram-positive bacteria Bacillus thuringiensis var. tenebrionis were described in details. Influences of the bacteria applied on last instars larvae of Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) were observed on brush border membrane of midgut. A group of the fresh last instars larvae were fed with treated leaves by Novodor FC, commercial bacteria formulation, with recommended doses while other groups were being fed with treated leaves by distillated water. Fixations were done with two hours intervals at the first twelve hours after treatment. At following twelve hours fixations periods increased to six hours intervals and twelve hours intervals at following another twenty four hours. Effects of bacteria were evaluated from slides prepared by histological methods from the fixated samples. According to the results, first symptoms of effects of bacterial toxin on microvillus were observed after two hours from the beginning of feeding. Effects were becoming widespread and stronger at the end of four and six hours. In the samples taken following hours, effects were increased gradually and especially significant damages were detected on brush border membrane and midgut cells after twelve hours.
The steps in mode of action of S-endotoxin with insecticidal efficacy produced by gram-positive bacteria Bacillus thuringiensis var. tenebrionis were described in details. Influences of the bacteria applied on last instars larvae of Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) were observed on brush border membrane of midgut. A group of the fresh last instars larvae were fed with treated leaves by Novodor FC, commercial bacteria formulation, with recommended doses while other groups were being fed with treated leaves by distillated water. Fixations were done with two hours intervals at the first twelve hours after treatment. At following twelve hours fixations periods increased to six hours intervals and twelve hours intervals at following another twenty four hours. Effects of bacteria were evaluated from slides prepared by histological methods from the fixated samples. According to the results, first symptoms of effects of bacterial toxin on microvillus were observed after two hours from the beginning of feeding. Effects were becoming widespread and stronger at the end of four and six hours. In the samples taken following hours, effects were increased gradually and especially significant damages were detected on brush border membrane and midgut cells after twelve hours.
Açıklama
Anahtar Kelimeler
Biyoloji
Kaynak
Türkiye Entomoloji Dergisi
WoS Q Değeri
Scopus Q Değeri
Cilt
30
Sayı
2
