Abstract
Triuris hyalina Miers, an unusual achlorophyllous plant, was investigated for subterranean morphology, root anatomy, and mycotrophy. Stems with scale leaves extend subterraneously to a depth of 15 cm. Pairs of adventitious roots develop at the scale leaves and clumps of apparently radiating roots, formed by accumulations of side shoot and scale leaf developments, occur. Roots consist of epidermis, short cell exodermis, three distinct layers of cortex parenchyma, endodermis, and an extremely reduced central cylinder with one or two central tracheidal xylem elements. The fungus associated with T. hyalina roots exhibits thick-walled, 6-9 µm thick, aseptate external hyphae. It penetrates the epidermis by developing appressoria and enters the cortex solely through the short cells of the exodermis. In the cortex cells, the aseptate hyphae start to coil. In the outer cortex layer, hyphae are thin, frequently branched, and most densely coiled. In the middle cortex layer they are thicker and less densely coiled, and mostly appear degenerated to clumps of amorphous fungal material. The inner cortex layer rarely becomes colonized. Vesicles occur in the outer and the middle cortex layers. This mycorrhizal pattern is interpreted as an adaption to attain a sustainable use from the endophyte. It is suggested that the mycorrhiza in Triuris hyalina be interpreted as a type of arbuscular mycorrhiza (AM). Implications for systematics and ecology are discussed.Key words: Triuris, Triuridaceae, root structure, anatomy, arbuscular mycorrhiza, myco-heterotrophy.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.