Study on reproductive barriers in 4x–2x crosses in Dianthus caryophyllus L
Study on reproductive barriers in 4x–2x crosses in Dianthus caryophyllus L
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DOI：
10.1007/s10681-012-0819-5
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发表时间：
2013-02
期刊：
影响因子：
1.9
通讯作者：
Xuhong Zhou;M. Gui;Da-yao Zhao;Min Chen;Suping Ju;She-song Li;Zhe Lu;Xijun Mo;Jihua Wang-
中科院分区：
文献类型：
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作者：
Xuhong Zhou;M. Gui;Da-yao Zhao;Min Chen;Suping Ju;She-song Li;Zhe Lu;Xijun Mo;Jihua Wang-
石竹4x - 2x杂交中存在繁殖障碍。严重导致结实率低，育种效率低。本研究利用荧光显微镜和石蜡切片技术，观察了‘butterfly’（2n= 4x= 60）与可育育种系‘NH10’（2n= 2x= 30）和‘NH14’（2n= 2x= 30）杂交后受精前和受精后的屏障。在‘蝴蝶’בNH10’和‘蝴蝶’בNH14’杂交中，花粉管向上生长至子房。然而，也发现了花粉管的异常，包括螺旋状和尖状花粉管，以及不相容管中胼胝质沉积。杂交品种‘蝴蝶’与‘NH10’授粉后48 h花柱基部花粉管数最高，为67.2±10.8个，而珠孔穿透的胚珠数较低，为19±4.5个。同样，‘butterfly’与‘NH14’杂交，授粉后48 h花柱基部花粉管的直径为51±6.2，授粉后48 h每个子房穿透小珠孔的胚珠数为11±2.4。结果表明，在4x - 2x杂交中，花粉管难以穿透胚珠。此外，还观察到卵精不融合或极核不融合导致胚乳无胚和胚无胚乳。胚胎在不同发育阶段（胚到子叶胚、主球形胚）发生流产，这可能与反向杂交中胚乳发育不足有关。结果表明，这些组合存在受精前屏障和受精后屏障。由于4x - 2x杂交的受精后障碍，胚胎拯救可能有助于获得杂交F1植株。
Reproductive barriers often exist in 4x–2xcrosses inDianthus caryophyllusL. and seriously lead to low seed set and breeding efficiency. In this study, we inspected pre-fertilization and post-fertilization barriers in crosses between ‘butterfly’ (2n= 4x= 60) and the fertile breeding line ‘NH10’ (2n= 2x= 30) and ‘NH14’ (2n= 2x= 30) using fluorescence microscopy and paraffin section. The growth of the pollen tubes up to the ovary was observed in crosses of ‘butterfly’ × ‘NH10’ and ‘butterfly’ × ‘NH14’. However, abnormalities of pollen tube including coiled and spiky and callose deposition in incompatible tubes has also been detected. In the cross ‘butterfly’ and ‘NH10’, the number of pollen tubes at the base of the style reached the highest value, 67.2 ± 10.8 at 48 h after pollination, but the number of ovules with micropylar penetration was low, 19 ± 4.5. Similarly, in the cross between ‘butterfly’ and ‘NH14’, pollen tubes at the base of the style at 48 h after pollination was 51 ± 6.2 and the ovules with penetrated micropyles per ovary at 48 h after pollination was 11 ± 2.4. It indicated the pollen tubes difficultly penetrated into the ovules in 4x–2xcrosses. In addition, it was observed that non-fused of egg and sperm or non-fused polar nucleus resulted in endosperm without embryos, and embryos without endosperm. Embryos aborted at different developmental stages (prembryo to cotyledon embryo, main globular embryo), which might be related to a deficient endosperm development in reciprocal crosses. The results suggested that pre-fertilization and post-fertilization barriers were detected in these combinations. Due to the post-fertilization barriers in 4x–2xcrosses, the embryo rescue might be contributed to obtain hybrid F1 plants.