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多胚现象是柑橘研究及育种实践中一个重要问题。为了避开珠心胚的干扰 ,育种实践中常采用单胚材料作母本。清见橘橙是柑橘杂交育种中一个比较优良的单胚材料 ,以其为母本配制了 7个杂交组合。当父本为强德勒柚和塔罗科血橙时 ,只产生单胚种子 ;父本为脐血橙梨形橙和冰糖橙时 ,产生较低比例的多胚种子 ,为 3.5 %～7.2 %;而以新生系 3号柑和太田柑为父本时 ,则产生高比例的多胚种子 ,达 2 8.4%～ 44 .2 %。通过连续 2年杂交试验 ,发现清见×柑产生高比例多胚种子现象比较稳定。此现象与前人研究的结论有明显不同 ,前人多认为单胚柑橘一般只产生单胚种子 ,即使有时也产生多胚种子 ,但其比例较低 ,一般不超过 7%。为此 ,笔者对清见×新3号柑的多胚种子进行了分胚培养 ,获得多胚苗 ,并取部分幼苗叶片进行RAPD分析。分析发现多数多胚苗具有父本的特征带或具有与母本明显不同的带型 ,肯定为有性后代 ;而且这些多胚苗大部分在遗传上非常一致 ,可能为同一受精卵分裂而来 ,但也发现所检测的部分多胚苗之间还存在差异谱带 ,可能为多卵受精发育而来 ,或在同一受精卵分离后出现了明显的变异。
The phenomenon of polyembryon is an important issue in citrus research and breeding practice. In order to avoid the interference of bead embryos, single embryo materials are often used as the female parent in breeding practice. Clear orange tangerine citrus cross breeding is a relatively good single embryo materials, as its female parent prepared seven hybrid combinations. When the male parent was strong de Le Pomelo and Tarot Blood Orange, only single embryo seeds were produced; when the male parent was cord blood orange peach orange and rock candy orange, a lower proportion of polyembryonic seeds was produced, which was 3.5% -7.2 %. However, the high proportion of polyembryonic seeds was found in the parents of Pseudosiphon kaempferi No.3 and Pterocarpus citri reticulata, reaching 8.42 ~ 44.2%. Through two consecutive years of hybridization test, it was found that the high ratio of polyembryonic seeds produced by Qingjian × Ponkan was relatively stable. This phenomenon is obviously different from the conclusion of previous studies. Many people in the past thought that single embryo citrus generally only produced single embryo seeds, even though it sometimes produced multiple germ seeds, but its proportion was relatively low, usually less than 7%. To this end, the author of the clear see × new No. 3 polygonatum seed embryos were divided embryos were cultured to obtain polyembryonic seedlings, and take part of the seedlings leaves for RAPD analysis. Analysis found that most of the polyembryonic seedlings have the male parent characteristic band or with a significant difference with the female genus, certainly sexual offspring; and most of these polyembryonic seedlings are genetically very consistent, probably from the same fertilized eggs split , But also found that some polyembryonic seedlings detected there are differences between the band may be derived from the development of fertilized eggs, or after the same fertilized egg separation showed significant variation.