An Ultrastructural and Stereological Analysis of Pollen Grains of Hyoscyamus niger During Normal Ontogeny and Induced Embryogenic Development
1984; Wiley; Volume: 71; Issue: 4 Linguagem: Inglês
10.2307/2443324
ISSN1537-2197
Autores Tópico(s)Chromosomal and Genetic Variations
ResumoAmerican Journal of BotanyVolume 71, Issue 4 p. 490-504 Article AN ULTRASTRUCTURAL AND STEREOLOGICAL ANALYSIS OF POLLEN GRAINS OF HYOSCYAMUS NIGER DURING NORMAL ONTOGENY AND INDUCED EMBRYOGENIC DEVELOPMENT Thomas L. Reynolds, Thomas L. Reynolds Department of Botany, The Ohio State University, Columbus, Ohio, 43210 Department of Biology, The University of North Carolina, Charlotte, North Carolina, 28223Present address: Department of Biology, The University of North Carolina, Charlotte, NC 28223.Search for more papers by this author Thomas L. Reynolds, Thomas L. Reynolds Department of Botany, The Ohio State University, Columbus, Ohio, 43210 Department of Biology, The University of North Carolina, Charlotte, North Carolina, 28223Present address: Department of Biology, The University of North Carolina, Charlotte, NC 28223.Search for more papers by this author First published: 01 April 1984 https://doi.org/10.1002/j.1537-2197.1984.tb12534.xCitations: 12 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Abstract Selected nuclear and cytoplasmic changes of pollen grains of Hyoscyamus niger during normal gametophytic development and embryogenic development, induced by anther culture, were analyzed and compared ultrastructurally using stereological methods. Potentially embryogenic, uninucleate pollen could be identified within 6 hr of culture by an increased ratio of the volume density of the nucleolar granular zone to the volume density of the fibrillar zone and an increased ratio of dispersed to condensed chromatin in the nucleoplasm. Nonembryogenic pollen in vitro and in vivo possessed prominent nucleolar fibrillar zones and low ratios of dispersed to condensed chromatin. These differences may reflect changes in nuclear activity in potentially embryogenic pollen grains during early stages of culture. Following the first haploid mitosis, in potentially embryogenic pollen the generative cell maintained its large granular nucleolus and high ratio of dispersed to condensed chromatin through its first division to form a proembryoid. The volume fraction of the cytoplasm occupied by mitochondria and plastids and the area fraction occupied by RER and Golgi cisternae differed in the generative cells of potentially embryogenic and nonembryogenic pollen. Those changes only detected in generative cells of potentially embryogenic pollen include: increased area and complexity of cytoplasmic membranes, increased mitochondrial volume, and the presence of plastids at all stages of development. These results support the idea that embryogenic induction of H. niger takes place at the uninucleate stage of development and that subsequent nuclear and cytoplasmic changes are essential for continued sporophytic development. Citing Literature Volume71, Issue4April 1984Pages 490-504 RelatedInformation
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