| Abstract: | Polyembryony is a serious handicap in citrus breeding. To obtain zygotic off-springs, monoem-bryonic seed parents were usually used in breeding programs. Kiyomi, a superior monoembryonic tangor, wasused as seed parent in 7 cross combinations. When pollen parents was Chandler pummelo or Tarocco blood or-ange, only monoembryonic seeds were observed. However, when Washington Sanguine, Li-xing orange andBing-tang orange were used as pollen parents, no more than 7.2 % of polyembryonic seeds were observed. In-terestingly, while male parents were Nucellar3 Ponkan and Oota Ponkan, high ratio of polyembryonic seedswas observed. The ratio of polyembryonic seeds was steadily at about 30 % in two consecutive years and was ob-viously different from other results reported. Polyembronic seeds were observed in monoembryonic varietiessometimes, but normally their ratios were no more than 7 %. Polyembryonic-seedlings were got by separatingthe multi-embryos in seeds of Kiyomi × Nucellar3 Ponkan and then their leaves were used in RAPD analysis.Identical bands of male parent and/or different bands from seed parent were found in most of the polyembry-onic-seedlings and so it can be sure that these seedlings were of zygotic origin. Some pairs of polyembryonic-seedlings have identical bands in all tested primers and may be resulted from zygotic embryo divisions. Differ-ent bands were found in other pairs of polyembryonic-seedlings also and this may indicate multi-egg fertiliza-tion or other source of variation. |
