桔梗胚乳吸器结构研究

对桔梗（PlatycodongrandiflorusA.DC）的胚乳吸器进行了显微结构和超微结构研究，结果如下：1．胚乳的发育属细胞型。8-细胞胚乳时分化出珠孔吸器；16-细胞胚乳时分化出合点吸器。2．吸器细胞的壁存在大量壁内突，彼此交织成网状结构，浓厚的细胞质里有丰富的线粒体、内质网和高尔基体；细胞核及核仁异常增大；吸器细胞与胚乳细胞间存在大量的胞间连丝。3．珠被绒毡层与胚囊壁之间存在二层角质层，共同包围着胚囊，只在胚囊的珠孔端与合点端开口。胚乳吸器的功能是对来自孢子体的营养物质起吸收与转运作用，从而保证胚乳和胚的发育。

STUDIES ON THE STRUCTURE OF ENDOSPERM HAUSTORIA IN PLATYCODON GRANDIFLORUM A.DC

The endosperm haustoria of Platycodon grandiflorum A.DC were studied using themicroscopic techniques at the light and electron microscope levels.The main results areas follows: 1.The development of the endosperm is of the cellular tyep.A micropylarhaustorium is differentiated at eight-celled endosperm stage and a-chalazal haustorium atsixteen-celled endosperm stage.2. A large amount of wall ingrowths interweaved network, dense cytoplasm with abundant mitochondria,ER and dictyosomes, and markedlarge nuclei and nucleoli are found in the haustorial cells connected endosperm cells withnumerous plasmodesmata. 3. Two cuticular layers are observed between the integumentary typetum and embryo sac,which enclose the ernbryo sac from all sides but leave anapture at each pole where a edosperm haustorium is formed. The main role of endospermhaustoria is to absorb and transport nutrients to endosperm from sporophyte during itsdevelopment.