02037naa a2200193 a 450000100080000000500110000800800410001910000170006024500670007726000090014452015290015365000180168265000160170065000180171665300220173465300190175670000190177577300490179416469331995-08-31       1988    bl ---       0--  u    #d1 aLANGE, J. H.  aStudies on citrus pollination using gamma-irrigadiated pollen.  c1988  aStudies have been performed in Citrus motivated by Pandays' theory of induced egg transformation and parthenogenetic development of embryos by pollination with irradiated pollen.  Poncirus trifoliata (a Citrus relative) and shaddock pollen still germinated following 1,0 kGy irradiation and that of Palestine sweet lime following 2,0 kGy irradiation. The pollination study involved cross-pollination of Clementine mandarin using P. trifoliata or Palestine sweet lime pollen; gamma-irradiated at different doses, with or without a second pollination of the same flowers using normal Valencia sweet orange pollen. Using 0,5 or 1,0 kGy-irridiated P. trifoliata pollen, cross-pollination of Clementine, known for its limited parthenocarpic ability, resulted in the production of large numbers of seedless fruits. It was demonstrated that extensive embryo abortion took place after cross-pollination using irradiated pollen but that fertilization and/ or early ovule development stimulated set and growth of fruitlets. Ovule occupation by irradiated pollen largely prevented fertilization by normal pollen. Pollination, using 0,5 or 1,0 kGy- irrigated pollen followed one day later by a second normal pollination is suggested for further studies on possible transformation of hybrids by the first pollen parent. Seed production after pollinating pollen irradiated at high doses in a single pollination, is very low. Embryo culture to save embryos before abortion and to eliminate the second pollination, should receive attention.  aparthenocarpy  apollination  aseed abortion  aGamma-irradiation  aTransformation1 aVINCENT, A. P.  tS. Afr. J. Bot.gv.54, n.3, p.257-264, 1988.