{"id":{"repo_id":"wku-diss","oai_identifier":"oai:digitalcommons.wku.edu:theses-1992"},"canonical_url":"https://search.dev.ndltd.org/etd/wku-diss/oai:digitalcommons.wku.edu:theses-1992","repository":{"repo_id":"wku-diss","name":"Western Kentucky University","base_url":"https://digitalcommons.wku.edu/do/oai/"},"display":{"title":"Chlorophyll Levels and Leaf Chlorplast Ultrastructure as Ecotypic Characters in Xanthium Strumarium L.","abstract":"The major objective of the work was to clarify some of the adaptive mechanisms that a common widespread species would show as a possible requirement for survival in its natural habitats. Analysis of various populations of Xanthium (cocklebur) indicated differences in chlorophyll levels and leaf chloroplasts ultrastructure between populations. The study also revealed some insight into intrapopulational variation in dark requirements for flowering of selected populations. In addition, caloric values of dried leaf material of cocklebur were analyzed for interpopulational differences. It was evident that higher chlorophyll levels are correlated with increase in latitude of origin and a corresponding decrease in growing season. The limited examination of leaf ultrastructure indicated the manner in which the higher chlorophyll levels are contained. Caloric values of leaf material showed lower total productivity in Texas populations. Variations found in the flowering response of the Tennessee population also gave evidence of the need for further study of plants from that area in relation to correlating that particular population with the other populations in the study.","abstract_html":"The major objective of the work was to clarify some of the adaptive mechanisms that a common widespread species would show as a possible requirement for survival in its natural habitats. Analysis of various populations of Xanthium (cocklebur) indicated differences in chlorophyll levels and leaf chloroplasts ultrastructure between populations. The study also revealed some insight into intrapopulational variation in dark requirements for flowering of selected populations. In addition, caloric values of dried leaf material of cocklebur were analyzed for interpopulational differences. It was evident that higher chlorophyll levels are correlated with increase in latitude of origin and a corresponding decrease in growing season. The limited examination of leaf ultrastructure indicated the manner in which the higher chlorophyll levels are contained. Caloric values of leaf material showed lower total productivity in Texas populations. Variations found in the flowering response of the Tennessee population also gave evidence of the need for further study of plants from that area in relation to correlating that particular population with the other populations in the study.","abstract_has_math":false,"creators":["Abdulrahman, Farag"],"institution":null,"degree_name":"Master of Science","degree_level":null,"degree_discipline":"Department of Biology","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1973,"date_issued":"1973-12-01T08:00:00Z","date_published":"1973-12-01T08:00:00Z","updated_at":"2026-07-24T06:08:02Z","subjects":["Medical Sciences"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalcommons.wku.edu/theses/989","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Abdulrahman, Farag"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Department of Biology"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Medical Sciences"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalcommons.wku.edu/theses/989"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The major objective of the work was to clarify some of the adaptive mechanisms that a common widespread species would show as a possible requirement for survival in its natural habitats. Analysis of various populations of Xanthium (cocklebur) indicated differences in chlorophyll levels and leaf chloroplasts ultrastructure between populations. The study also revealed some insight into intrapopulational variation in dark requirements for flowering of selected populations. In addition, caloric values of dried leaf material of cocklebur were analyzed for interpopulational differences. It was evident that higher chlorophyll levels are correlated with increase in latitude of origin and a corresponding decrease in growing season. The limited examination of leaf ultrastructure indicated the manner in which the higher chlorophyll levels are contained. Caloric values of leaf material showed lower total productivity in Texas populations. Variations found in the flowering response of the Tennessee population also gave evidence of the need for further study of plants from that area in relation to correlating that particular population with the other populations in the study."]},{"key":"dc:title","label":"Title","values":["Chlorophyll Levels and Leaf Chlorplast Ultrastructure as Ecotypic Characters in Xanthium Strumarium L."]}]}],"canonical_facts":{"dc:creator":["Abdulrahman, Farag"],"dc:description.abstract":["The major objective of the work was to clarify some of the adaptive mechanisms that a common widespread species would show as a possible requirement for survival in its natural habitats. Analysis of various populations of Xanthium (cocklebur) indicated differences in chlorophyll levels and leaf chloroplasts ultrastructure between populations. The study also revealed some insight into intrapopulational variation in dark requirements for flowering of selected populations. In addition, caloric values of dried leaf material of cocklebur were analyzed for interpopulational differences. It was evident that higher chlorophyll levels are correlated with increase in latitude of origin and a corresponding decrease in growing season. The limited examination of leaf ultrastructure indicated the manner in which the higher chlorophyll levels are contained. Caloric values of leaf material showed lower total productivity in Texas populations. Variations found in the flowering response of the Tennessee population also gave evidence of the need for further study of plants from that area in relation to correlating that particular population with the other populations in the study."],"dc:identifier":["https://digitalcommons.wku.edu/theses/989"],"dc:subject":["Medical Sciences"],"dc:title":["Chlorophyll Levels and Leaf Chlorplast Ultrastructure as Ecotypic Characters in Xanthium Strumarium L."],"dc:type":["Thesis"],"thesis:degree_discipline":["Department of Biology"],"thesis:degree_name":["Master of Science"]},"updated_at":"2026-07-24T06:08:02Z"}