N. P. GENCHEV and E. M. GENCHEVA
Plant Protection Institute, EG - 2232 Kostinbrod, Bulgaria
GENCHEV, N. P. and E. M. GENCHEVA, 2006. Inheritance of radiation induced sterility in males of the Oriental fruit moth, Grapholitha molesta Busck., (Lepidoptera: Tortricidae). Bulg. J. Agric. Sci, 12: 489-499
Results of studies on the inheritance of radiation induced sterility in males of Grapholitha molesta Busck. are reported. The partially sterilizing effect of gamma radiation on irradiated as pupae male parents is characterized with moderate increase in parallel with the dose increase. The adult emergence from irradiated pupae, longevity of moths and sex ratio were not affected by the applied radiation doses. Female moths are more radiosensitive than males. The highest level of inherited sterility in males of F1 generation was established after irradiation of their parents with dosage of 125 Gy. However, some decrease of this effect was observed in the variants with doses of 175 Gy and 200 Gy. The transmission of inherited sterility from F1 males to their F2 descendants is a slighter, but still perceptable process. The highest levels of inherited sterility were registered in the variants with dosages of 125 Gy and 150 Gy, but somewhat reduced effect was recorded for doses of 100,175 and 200 Gy.Progeny of F1 and F2 males OFM manifested sex ratios significantly skewed in favor of male moths. As it seems, these sex ratio shifts are results of a dose-dependent process.