Root development and structure in seedlings of Ginkgo biloba

Area of Science:

• Plant anatomy
• Gymnosperm development
• Root biology

Background:

• Ginkgo biloba is a unique, ancient gymnosperm with limited documentation on its primary root system development.
• Understanding root morphology is crucial for plant physiology and evolutionary studies.

Purpose of the Study:

• To document the developmental anatomical features of the primary root system in Ginkgo biloba seedlings.
• To provide a detailed account of root structure from the root tip to the cotyledonary node.

Main Methods:

• Seedlings were cultivated in soil, vermiculite, or a mixture.
• Anatomical structures were examined using brightfield, epifluorescence, and confocal microscopy.
• Sections were analyzed at various distances from the root cap to establish a developmental sequence.

Main Results:

• The vascular cylinder typically exhibits a diarch stele, with variations including modified diarchy and triarchy.
• Metaxylem forms a disc between exarch protoxylem poles, with secondary growth occurring on metaxylem flanks.
• Casparian bands in the endodermis and phi cells in the inner cortex develop early, alongside an early-developing exodermis.

Conclusions:

• The seedling root axes of Ginkgo biloba display greater complexity than previously described in scientific literature.
• These findings significantly contribute to the understanding of root anatomy and development in this ancient gymnosperm.