A Diploid Female Gametophyte of Sphaerocarpos
نویسندگان
چکیده
منابع مشابه
Wall Projections in the Sporophyte and Gametophyte of Sphaerocarpos
The nutrition of the sporophyte in Sphaerocarpos and liverworts in general has long been controversial . It has not yet been determined whether the chloroplasts in the sporophyte capsule do, in fact, photosynthesize or whether the carbohydrates stored as starch are translocated to the sporophyte from the gametophyte which is known to be photosynthetic and to which the sporophyte remains attache...
متن کاملFemale gametophyte development.
Early in their evolution, plants acquired a life cycle that alternates between a multicellular haploid organism, the gametophyte, and a multicellular diploid organism, the sporophyte. Angiosperms have both female and male gametophytes. The female gametophyte is critical to many steps of the angiosperm reproductive process, including pollen tube guidance, fertilization, the induction of seed dev...
متن کاملPollen tube guidance by the female gametophyte.
In flowering plants, pollen grains germinate on the pistil and send pollen tubes down the transmitting tract toward ovules. Previous genetic studies suggested that the ovule is responsible for long-range pollen tube guidance during the last phase of a pollen tube's journey to the female gametes. It was not possible, however, to unambiguously identify the signaling cells within an ovule: the hap...
متن کاملFemale gametophyte-controlled pollen tube guidance.
During the evolution of flowering plants, their sperm cells have lost mobility and are transported from the stigma to the female gametophyte via the pollen tube to achieve double fertilization. Pollen tube growth and guidance is largely governed by the maternal sporophytic tissues of the stigma, style and ovule. However, the last phase of the pollen tube path is under female gametophyte control...
متن کاملMale and female gametophyte development in Achillea tenuifolia (Asteraceae)
The anther, pollen and ovule development in Achillea tenuifolia were studied with a bright field microscopy. Results showed that the anther is of tetrasporangiate type and the anther wall is composed by four layers: an epidermis, an endothecium, one middle layer and a tapetum layer. Tapetum is of secretory type and its cells showed polyploidy. Pollen tetrads were tetrahedral, microspores were v...
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ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 1934
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.20.3.147