Dissertation Research: Ultrastructural Investigations of Fossil Gymnosperm Pollen and its Bearing on the Origins of Angiosperms

拟议的研究将涉及对以下方面的批判性评价： 花粉，主要利用透射和扫描电子 显微镜下，从那些裸子植物组建议密切 与被子植物有关，可能是其祖先。 只有很少的数据已经报告了花粉从 拟调查的裸子植物。 一个小 数据库目前存在分散裸子植物 花粉以及可能与被子植物有亲缘关系的花粉。 然而，拟议的研究将主要讨论 来自不同裸子植物群的花粉粒。 如此狭窄的焦点，采用电子显微镜技术， 允许积累关于以下方面的重要数据： 特殊的花粉特征，并提供了机会， 进行系统发育分析使用更多的字符从 具体分类群的问题，以及解决许多 有关原位花粉的相关和机制问题。 要求提供资金以支付学生的旅费 对两个选定的国内古植物收藏品的调查 裸子植物和一个外国收集，以收集在 原位标本进行调查。

The proposed research will involve the critical evaluation of pollen, primarily using transmission and scanning electron microscopy, from those gymnosperm groups suggested as closely related to angiosperms and implicated as possible ancestors. Only a paucity of data has been reported on pollen from the gymnospermous plants proposed to be investigated. A small database is currently in existence for dispersed gymnosperm pollen as well as pollen with possible angiosperm affinities. The proposed study, however, will principally address the nature of in site pollen grains from the various gymnosperm groups. Such a narrow focus, employing electron microscopic techniques, allows for the accumulations of significant data regarding specific pollen characters and provides the opportunity to perform phylogenetic analyses using many more characters from the specific taxa in question as well as to address numerous correlative and mechanistic queries concerning in situ pollen. Funds are requested to defray the costs of travel by the student investigator to two selected domestic paleobotanical collections of gymnosperms and one foreign collection in order to collect in situ specimens for investigation.