Adventive embryogenesis in Citrus
Adventive embryogenesis in Citrus
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DOI：
10.1080/00087114.1983.10797645
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发表时间：
1983
期刊：
影响因子：
2.1
通讯作者：
H. Wilms;J. L. Went;M. Cresti;F. Ciampolini
中科院分区：
文献类型：
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作者：
H. Wilms;J. L. Went;M. Cresti;F. Ciampolini
从超微结构水平研究了不定胚发生的机制。以3个柑橘品种为材料，其中2个为多胚性品种，1个为单胚性品种。柑橘的不定胚是在珠孔半部胚囊附近的珠心组织中发生的，顺便从合点端开始。珠心胚状体由原始细胞分化而来。在多胚性品种中，在开花时就已经存在初始细胞：在单胚性品种中，没有初始细胞。在成熟胚囊阶段，初始细胞具有“分生组织”特征。在分裂之前，它们会形成新的细胞壁，成为类似受精卵的细胞。在这个发育过程中，它们被隔离，它们原来的细胞壁被解体。与此同时，周围的珠心细胞退化和消失，初始细胞嵌入胚乳。
SUMMARYThe mechanism of adventive embryogenesis was studied at ultrastructural level. Three Citrus cultivars were used as material, two poly-embryonic and one mono-embryonic. The adventive embryos in Citrus are initiated in the nucellar tissue adjacent to the embryo sac in the micropylar half and incidentally from the chalazal end. The nucellar embryoids derive from initial cells. Initial cells are present already at the time of flowering in the poly-embryonic cultivars: in the mono-embryonic cultivar initial cells are absent. At the mature embryo sac stage the initial cells have a « meristematic » character. Before division they develop new cell walls and become « zygote-resembling » cells. During this development they are isolated and their original cell walls are disintegrated. Simultaneously the surrounding nucellar cells degenerate and disappear and the initial cells become embedded in the endosperm.