Respon Imun Humoral Pada Larva Helicoverpa armigera hubner (Lepidoptera: Noctuidae) Pasca Infeksi HaNPV (Helicoverpa armigera Nuclear Polyhedrosis Virus) dan Keturunannya

Abstract: NPV  is  one  of  the  biological  insecticides  that  kill  the  target  by  infecting  their  cells  including hemocytes.  Hemocytes  play  a  key  role  on  defense  mechanism  against  pathogens  like  NPV.  This  defense mechanism may cause the insect to become more tolerant as well as to chemical insecticides. The tolerances of  insect  to  NPV  could  be  induced  by  humoral  immune  system  (HIS).  The  HIS  can  be  recorded  by  watch prophenoloxidase (PPO) activity or the presence of antibacterial compound (AC). Based on that assumption, this research was conducted to observe the alteration of  PPO and AC due to sublethal infection of HaNPV (Helicoverpa  armigera  nuclear  polyhedrosis  viruses)  on  Helicoverpa  armigera  larvae  and  their  offspring. PPO  was  detected  as  PO  and  measured  spectrometrically  on  microplate-reader.  Protein  concentration  was measured based on the color which appears due to protein-CBG (PO and Bradford reagent) bond at 570 nm. Protein  concentration  was  calibrated  with  BSA.  The  occurrence  of  antibacterial  activity  was  tested  using modified  Hoffman  method.  Inhibition  zones  were  used  to  measure  the  antibacterial  activity  from  E.  coli (Gram  negative)  and  B.  cereus  (Gram  positive).  Immune  responses  were  observed  on  the  fifth  instar Helicoverpa  armigera  after  24  hpi  by  HaNPV  (NPV-P)  and  their  offspring  (NPV-F1  and  NPV-F2).  Also, immune response on control larvae (K-P) were monitored and their filial (K-F1 and K-F2). The titer of PO enzyme  were  not  significantly  different  for  each  generation.  There  was  no  inhibition  zone  on  antibacterial activity test in every generation on NPV-P and K-P larvae. 
Keywords:  Helicoverpa  armigera,  HaMNPV,  humoral  immune  system,  prophenoloxidase  (PPO), antibacterial activity
Penulis: Nani Kurnia
Kode Jurnal: jpbiologidd110293

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Jp Biologi dd 2011