【摘要】 继首次报道单胚清见与多胚椪柑杂交产生高比例多胚种子后,在单胚槾橘(Citrus tardiferax Hort.ex Tan)与多胚岩溪晚芦椪柑(Citrus reticulata Blanco)的杂交组合中,又发现高比例多胚种子,其比例一般为30%左右。为探明多胚来源,对多胚进行了分胚组织培养,获得同一种子来源的多胚苗。选取多组多胚苗进行叶形态比较分析。结果表明,同种子来源的多数多胚苗及亲本间叶形指数差异显著,但5胚苗中有3株跟母本相似,难以判断来源。筛选来自9个柑橘不同连锁群上的特异SSR引物对多胚苗进行标记分析,结果显示,多胚苗在多个标记上与母本不同,不可能为无性后代(珠心胚来源),均可能是有性苗;同组多胚苗之间既有部分在全部检查位点完全相同,表明其可能由同一合子胚分裂而来,也有部分在多个检查位点明显不同,可能来源于多卵受精形成的不同合子胚。更多还原

【Abstract】 Following the first report of high ratio polyembryonic seeds in monoembryonic Kiyomi × polyembryonic Ponkan,polyembryonic seeds were found in the cross monoembryonic Manju(Citrus tardiferax Hort.ex Tan) × polyembryonic Yanxiwanlu Ponkan(C.reticulata Blanco) also.The ratio of polyembryonic seeds was about 30% generally.To investigate the origin of polyembryos,the embryos from polyembryonic seeds were cultured in vitro.Polyembryonic seedlings from one seed were selected and analysed by leaf morphology and SSR markers.The result of leaf morphology analysis showed that most of the polyembryonic seedlings were significantly different to both parents and indicated zygotic origins,but three seedlings in the 5 seedlings group were similar to the seed parent and it is difficult to determine their origins.Nine specific SSR markers from different citrus linkage groups were screened and used in SSR analysis.Four or more markers were found to show different band patterns among all polyembronic seedlings and seed parent.And it indicated that all seedlings were most likely to be sexual origins.Some of the polyembronic seedlings from one seed were identical to all tested markers and others were different in more than one marker.And this might indicate their different zygotic embryos origins,splitting of zygotic embryos or fertilization of more than one egg.更多还原