单胚清见橘橙×椪柑产生高比例多胚种子及多胚有性的分子检测  

High Ratio of Polyembryonic Seeds in Monoembryony Kiyomi×Ponkan and Molecular Evidences against Asexual Origins for Polyembryonies

作　　者：洪棋斌[1] 李喜庆[1] 江东[1] 陈竹生[1] 向素琼[1] 龚桂芝[1] 叶庆亮[1] 

机构地区：[1]中国农业科学院柑橘研究所,重庆400712

出　　处：《中国农业科学》2003年第7期829-833,共5页Scientia Agricultura Sinica

基　　金："十五"国家攻关资助项目 (2 0 0 2BA5 15B0 9)

摘　　要：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。Polyembryony is a serious handicap in citrus breeding. To obtain zygotic off-springs, monoembryonic seed parents were usually used in breeding programs. Kiyomi, a superior monoembryonic variety, was used as seed parent in 7 cross combinations. When male parents were Chandler pummelo and Tarocco blood orange, only monoembryonic seeds were observed; When Washington sanguine, Lixing orange and Bingtang orange were used, no more than 7.2% of polyembryonic seeds were observed; While male parents were Ponkan varieties nucellar line No.3 and Ota pnokan, high ratio of polyembryonic seeds was observed. The ratio of polyembryonic seeds was steadily at about 30% in two consecutive year and was significantly different from other results reported. Polyembryonic seeds were observed in monoembryonic varieties some times, but normally their ratios were no more than 7% usually. Polyembryonic-seedlings were got by separating the multi-embryonies in seeds of Kiyomi × Nucellar line No. 3 and then used in RAPD analysis. Identical bands of male parent and/or different bands from seed parent were found in most of the polyembryonic-seedlings and it can be sure that these seedlings were of zygotic origins. Some pairs of polyembryonic-seedlings have identical bands in all tested primers and may be the results of zygotic embryony divisions. Different bands were also found in other pairs of polyembryonic-seedlings and this may indicate multi-egg fertilization or other source of variation.

关 键 词：单胚清 橘橙 椪柑 比例 多胚种子 多胚有性 分子检测 育种 珠心胚 母本配制 杂交试验 

分 类 号：S666[农业科学—果树学]