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柑桔类珠心胚现象对研究其进化和种质保存方面有着重要意义，但是给其有性杂交育种工作造成相当大的麻烦：它不仅使杂交后代难于区分合子苗和珠心苗，而且会使合子胚发育中途天折。解决的途径是适时分离合子胚进行单独培养。为此，本工作于柑桔胚胎发育的不同时期取样、固定、观察，研究其合子胚发育规律，确定珠心胚侵入胚囊的时期。结果表明：一般情况下，授粉后３０ｄ，合于处于单细胞状态（Ｆｉｇ．１Ａ）；授粉后４０ｄ；合子开始分裂（Ｆｉｇ．１Ｂ）；授粉后４５ｄ，合子胚形成８－１６个细胞，珠心胚开始分裂（Ｆｉｇ．１Ｃ）；授粉后５０ｄ，合子形成球形胚，珠心胚尚未侵入胚囊（Ｆｉｇ．１Ｄ＆Ｅ）；授粉后５５ｄ，合子胚为球形胚或早心形胚，开始有少数珠心胚侵入胚囊（Ｆｉｇ．１Ｄ＆Ｅ）；授粉后６０ｄ，合子胚为心形胚（Ｆｉｇ．１Ｇ）。授粉后８０ｄ，合子胚为晚心形，珠心胚巨大量侵入并迅速发育（Ｆｉｇ．１Ｈ）。杂交的组合对合子，胚珠及果实发育均有一定影响，主要取决于杂交亲本。与种间杂交相比，属间杂交其合子分裂较迟，合子胚发育较慢，珠心胚侵入时期也较迟（Ｔａｂｌｅｌ，Ｆｉｇ．２）。这种发育速度的差异，引起所产生的合子胚的大小（Ｔａｂｌｅ２）珠心胚侵率（Ｔａｂ
The phenomenon of citrus parenchyma plays an important role in studying its evolution and preservation of germplasm, but it causes considerable troubles for its sexual hybrid breeding. It not only makes it difficult for hybrid offspring to distinguish Zygotic and Mucuna seedlings, Zygotic embryonic development half-way day off. The solution is the timely separation of zygotic embryos cultured separately. Therefore, this work sampled, fixed, observed and studied the development of zygotic embryos in different stages of the development of citrus embryos, and determined the period of infancy of embryo sacs. The results showed that: in general, 30 days after pollination, the cells were in a single cell state (Fig.1A); 40 days after pollination, the zygotes started to divide (Fig.1B); 45 days after pollination, zygotic embryos formed 8-16 cells, At 50 days after pollination, the zygotes formed spherical embryos, and the bead heart had not invaded into the embryo sac (Fig.1D & E). At 55 days after pollination, zygotic embryos were either globose or early-shaped embryos, Beads embryos invade into the embryo sac (Fig.1D & E); 60 days after pollination, zygotic embryos are heart-shaped embryos (Fig.1G). At 80 days after pollination, the zygotic embryo was late-heart-shaped, and a large amount of bead-shaped embryos invaded and rapidly developed (Fig.1H). Hybrid combinations have some influence on the zygotic, ovule and fruit development, depending on the hybrid parents. Compared with interspecific hybridization, the interspecific hybridization led to the later splitting of the zygotes, the slower development of zygotic embryos, and later inoculation of the karyochi embryos (Table 1, Fig. 2). The difference in the rate of development, the size of the resulting zygotic embryo (Table 2)