W&M ScholarWorks Dissertations, Theses, and Masters Projects Theses, Dissertations, & Master Projects 1997 Taxonomic Implications of Sporanglial Ultrastructure Within the Subfamily Melobesioideae Corallinales, Rhodophyta) Bethany Ann Griffin College of William & Mary - Arts & Sciences Follow this and additional works at: https://scholarworks.wm.edu/etd Part of the Systems Biology Commons Recommended Citation Griffin, Bethany Ann, ax"T onomic Implications of Sporanglial Ultrastructure Within the Subfamily Melobesioideae Corallinales, Rhodophyta)" (1997). Dissertations, Theses, and Masters Projects. Paper 1539626098. https://dx.doi.org/doi:10.21220/s2-pnjz-de41 This Thesis is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Dissertations, Theses, and Masters Projects by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. TAXONOMIC IMPLICATIONS OF SPORANGIAL ULTRASTRUCTURE WITHIN THE SUBFAMILY MELOBESIOIDEAE (CORALLINALES, RHODOPHYTA) A Thesis Presented to The Faculty of the Department of Biology The College of William and Mary in Virginia In Partial Fulfillment Of the Requirements for the Degree of Master of Arts By Bethany Ann Griffin 1997 APPROVAL SHEET This thesis is submitted in partial fulfillment of the requirements for the degree of Master of Arts Bethany Ann Griffin Approved, April 1997 Sharon T. Broadwater A ^ Scott I\$artha A. Case DEDICATION To Jon, for giving new meaning to the word supportive. iii TABLE OF CONTENTS Page ACKNOWLEDGEMENTS............................................................................... v LIST OF TABLES AND DIAGRAMS................................................................vi LIST OF FIGURES ..................................................................................vii ABSTRACT...................................................................................................... viii INTRODUCTION..............................................................................................2 MATERIALS AND METHODS....,...................................................................12 RESULTS..........................................................................................................14 DISCUSSION.............. 23 REFERENCES.......................................... 36 TABLES AND DIAGRAMS................................................................................41 KEY TO ABBREVATIONS................................................................................49 FIGURES.......................................................................................................... 50 VITA...................................................................................................................88 iv ACKNOWLEDGMENTS I can not fully express the extant of my appreciation for many at the College of William and Mary, but a thank you is a beginning. Dr. Sharon Broadwater always found the time, not only for the countless drafts of this thesis, but for any question or bought of enthusiasm that came to me along the way, which is perhaps the distinguishable mark of a true mentor. Dr. Joe Scott provided much technical expertise in microscopy, which is only surpassed by the extent of his knowledge in red algal literature. Dr. Martha Case was a wonderful committee member through asking many thought provoking questions and sharing her expertise. Ms. Thomas is literally a “jewel.” I admire both her strong work ethic and amazing attitude about life. Mr. Bill Saunders was always present lending encouragement along the way. And lastly, Ms. Kristy Mays (my algal partner in crime) and Ms. Kathleen Markel, made whatever spare time I had left simply a joy with their amazing friendship. v LIST OF TABLES AND DIAGRAMS Tables Page 1 Coralline Classification according to Johansen and Woelkerling ........................... 41 2 Coralline Classification according to Cabioch and Chamberlain ........................42 3 Summary of Characteristics for Corallinaceae Classification ...................43 4 General Sporangial Developmental Pattern for the Corallinaceae ..........44 5 Variable Sporoganial Development Features in the Melobioldeae ......... 45 Diagrams 1 Formation of Secondary Pit-connections ....................................................... 46 2 Formation of Cell Fusions ................................................................................46 3 Triphasic Life History......................................................................... 47 4 Monomerous Thallus Contruction ..................................................................47 5 18 s Ribosomal Sequence Data according to Baliey and Chapman.... ...............48 LIST OF FIGURES Figures Page 1-2. Light Micrographs of General Thallus Structure ............................................................... 50 3-6. SEM of Lithothamnium phvmatodeum Thallus.................................................................. 52 7-9. SEM of Mesoohvllum lamellatum Thallus...........................................................................54 10-13. SEM of Paraphysis Exterior Structure of Lithothamnium phvmatodeum........................ 56 14-17. SEM of Paraphysis Interior Structure of Lithothamnium phvmatodeum......................... 58 18-20. SEM of Paraphysis Structure Surrounding Sporangium of Mesophvllum lamellatum....60 21-24. TEM of Multi nucleated Paraphysis Cells of Lithothamnium soo...................................... 62 25-28. SEM and TEM of Sporangia.................................................................................................64 29-32. SEM and TEM of Pore Plugs and Related Features ..........................................................66 33-36. TEM of Sporangia and Stalk Cells of Lithothamnium phvmatodeum............................ 68 37-41. TEM of Stage 1 Sporangia of Lithothamniumanti Mesoohvllum ................................70 42-45. TEM of Early Stage 3A bisporangia Lithothamnium phvmatodeum...............................72 46-51. TEM of Early Stage 3A tetrasporangia of Mesoohvllum lamellatum..............................74 52-56. TEM of Late Stage 3A bisporangia Lithothamnium phvmatodeum.................................76 57-61. TEM of Late Stage 3A tetrasporangia of Mesoohvllum lamellatum................................78 62-66. TEM of Stage 3B bisporangia of Lithothamnium phvmatodeum.................................... 80 67-71. TEM of Stage 3B tetrasporangia of Mesoohvllum lamellatum....................................... 82 72-76. TEM of Stage 3C bisporangia of Lithothamnium phvmatodeum................................... 84 77-79. TEM of Stage 30 tejtrasporangia of Mesoohvllum lamellatum............................... 86 ABSTRACT This investigation examined sporangial development in two genera of coralline red algae, Lithothamnium and Mesophvllum, to determine ultrastructural features useful for systematic analysis and to clarify the confusing state of coralline classification at the subfamily level. With this study, a total of four genera and six species have been investigated in the non-geniculate subfamily Melobesioideae. All melobesioidean genera lacked nuclear associated electron- dense material (EDM), the presence of which is typical of all other subfamilies having cells that undergo cell fusion. This lack may reflect other evidence that indicates that the Melobesioideae are more primitive and may have separated prior to EDM establishment. Organelle nuclear associations, vesicle types, and pattern of starch organization were present but variable and unlikely to be useful characters at the subfamily level. This is the first electron microscopic study of paraphyses, a group of interspersed, vegetative cells within conceptacles. Apparent lack of calcification was confirmed, as well as, the presence of elongate semi-degenerated cells. However, this study reports the existence of a second, truncated cell form and the presence of a multinucleate condition in some paraphyses cells. In conjunction with supporting molecular data, this study presently favors the taxonomic scheme of Cabioch & Chamberlain over Johansen & Woelkering, with the possibility that more ultrastructural information will warrant the establishment of a new scheme. TAXONOMIC IMPLICATIONS OF SPORANGIAL ULTRASTRUCTURE WITHIN THE SUBFAMILY MELOBESIOIDEAE (CORALLINALES, RHODOPHYTA) INTRODUCTION This ultrastructural investigation of sporogensis in two genera, Lithothamnium and Mesoohvllum, contributes to the body of knowledge to be utilized in determining a more phylogenetic system of ciassifaction at the subfamily level for the coralline red algae (Corallinales, Rhodophyta). Specific objectives of this research include establishment of a consistent sporangial development pattern for both the Melobesioideae and the Corallinaceae, characterization of paraphyses structure, and determination of the taxonomic usefulness of sporongenesis features to better understand relationships within the Corallinaceae. Whereas taxonomy is the classification of organisms into groups, systematics is a broader discipline whose main goal is to derive correct phylogenetic relationships through the use of information such as taxonomy. Central principles that define systematic investigation include identification, description, and naming of species, with emphasis on synthesizing biological information into a ciassifaction system that reflects the phylogenetic