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HONG Qi-bin LI Xi-qing JIANG Dong CHEN Zhu-sheng XIANG Su-qiong GONG Gui-zhi YE Qing-liang 《中国农业科学(英文版)》2003,2(5)
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. 相似文献
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高浓度激素喷穗对多胚水稻胚胎发育的影响 总被引：1，自引：0，他引：1
用无融合生殖“固定”水稻杂种优势是水稻遗传和育种中一个十分活跃的研究领域。近年来,我国一些研究,不仅已证实了水稻具有无融合生殖特性,而且获得一批低频率发生的水稻无融合生殖材料(即水稻多胚苗和单性生殖材料等)。但是,已发现的水稻无融合生殖材料最为突出的问题是可用于“固定”杂种优势的无融合生殖方式(即不定胚)的频率太低,通常只有百分之零点儿,难以直接应用。所以,如何提高不定胚的频率成为关键所在。鉴于水稻多胚苗中的不定胚发育与合子胚发育存在竞争关系,通常是后者抑制前者的 相似文献
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Sajjad Hussain Franck Curk Patrick Ollitrault Raphaël Morillon François Luro 《Scientia Horticulturae》2011
All commercial citrus rootstocks are polyembryonic and propagated by seeds. Although these seeds produce uniform plant material most of the time, zygotic or polyploid citrus seedlings may arise. The aim of this study was to understand how zygotic or tetraploid rootstock could affect a citrus rootstock selection field trial. A trifoliate orange selection field trial, which was planted in 1974 and grafted with clementine, was re-investigated with respect to the presence of rootstocks that were not true-to-type. Among the 288 trees investigated, flow cytometry identified 2.4% of rootstocks as tetraploid and SSR markers indicated that 6.6% were zygotic. Yield data showed that the presence of tetraploid rootstock dramatically decreased (by about 45%) clementine fruit production. However, zygosity did not always affect fruit production and a range of effects were observed, from a slight increase in production to a 24% decrease. Exclusion of non-true-to-type genotypes from the production analysis indicated that the best candidate for rootstock was a clone previously ranked in the middle of the 32 rootstocks under evaluation. However, the presence of zygotic rootstock did not appear to cause any significant differences in fruit quality during the first 5 years of the investigation, which suggests that non-true-to-type plants cannot be identified by fruit quality parameters. This study indicates that tetraploid and zygotic rootstocks have a strong impact on citrus fruit production in orchards, and removal of off-type seedlings is required prior to planting in any agronomic trial. 相似文献
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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 总被引：3，自引：1，他引：2
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。 相似文献
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在所观察的７１６份资源中．除个别外，多胚苗出现的频率很低。多胚苗可以分成５种类型：Ⅰ型，单胚有独立的根茎叶。Ⅱ型，单胚之间有共同的根系，但各有独立的子叶、真叶和茎。Ⅲ型，单胚之间有共同的根系和子叶．但没有共同的真叶和茎。Ⅳ型，单胚之间有共同的根系、子叶和部分真叶，但茎基部不联合。Ⅴ型，单胚之间有共同的根系、子叶和部分真叶，且茎基部联合。幼苗子叶数目与出现多胚苗的频率及多胚苗的类型密切相关。 相似文献
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