Comparative anatomy of roots and mycorrhizae of common Ontario trees

Abstract

BRUNDRETT, M., MURASE, G., and KENDRICK, B. 1990. Comparative anatomy of roots and mycorrhizae of common Ontario trees. Can. J. Bot. 68: 551-578.The structure of roots and mycorrhizae of trees belonging to 20 important Ontario tree genera were examined. During this study efficient methods for examining root anatomy were developed, and tree root information was compiled. The ultimate lateral roots of most species examined were consistently mycorrhizal, and many species had heterorhizic root systems with separate long and short lateral roots. Tree roots displayed enough structural diversity in features such as thickened, lignified, or suberized walls, and secondary metabolite-containing cells to allow identification of genera. The roots of trees belonged to four major anatomical groups as a result of the major differences between angiosperm and gymnosperm roots, and between those with ectomycorrhizal (ECM) or vesicular-arbuscular mycorrhizal (VAM) associations. (i) Members of the Pinaceae had structurally similar heterorhizic roots that had ECM with a cortical Hartig net. (ii) Thuja (Cupressaceae) had distinctive nonheterorhizic roots with phi thickenings and VAM. (iii) Angiosperms with ECM belonged to diverse families, but all had similar heterorhizic root systems with ECM short roots that had an epidermal Hartig net and a narrow cortex of thick-walled cells. (iv) Most angiosperms with VAM had nonheterorhizic roots, and this group had the greatest diversity of root structural features. Possible structural and defensive roles of root features and potential influences of these features on mycorrhizal formation are considered.BRUNDRETT, M., MURASE, G., et KENDRICK, B. 1990. Comparative anatomy of roots and mycorrhizae of common Ontario trees. Can. J. Bot. 68 : 551-578. Les auteurs ont examink les structures des racines et des mycorhizes d'arbres appartenant a 20 genres d'arbres importants en Ontario. A I'occasion de cette Ctude, des mCthodes efficaces pour Ctudier l'anatomie racinaire ainsi que des informations sur les racines des arbres ont CtC dkfinies. Les racines laterales ultimes de la plupart des espices examinCes Ctaient normalement mycorhizCes et plusieurs espices montrent des systkmes racinaires hCtCrorhiziques oh on retrouve des racines longues et des racines 1atCrales courtes. Les racines montrent suffisamment de diversit6 structurale dans leurs caractCristiques telles que les parois cellulaires Cpaissies lignifiCes ou subCrifiCes et dans le contenu cellulaire en mktabolites secondaires pour permettre l'identification, du moins au niveau des genres. Les racines des arbres appartiennent 2 quatre groupes anatomiques majeurs; ainsi, les differences principales se retrouvent entre les racines des angiospermes et des gymnospermes aussi bien qu'entre les racines ectomycorhizCes (ECM) et endomycorhizienne a vCsicule et arbuscule (VAM). (i) Les membres des Pinaceae ont des racines hCtCrorhiziques de structure similaire, avec ECM et rCseau de Hartig cortical. (ii) Le genre Thuja (Cupressaceae) montre des racines ty...

Atlas of woody plant roots: morphology and anatomy with special emphasis on fine roots

“…2.4.1a), which normally does not form resin ducts in secondary xylem, was easily recognized by the presence of a central resin duct. A central resin duct was also observed by Brundrett et al (1990) in Abies balsamifera. The primary xylem in A. alba can be 2-4 arch (Kutschera & Lichtenegger 2002).…”

Diversity and classification of mycorrhizal associations

“…However, ECM with some degree of intracellular hyphal penetration may occur in a wider range of situations than is generally acknowledged (e.g. Brundrett, Murase & Kendrick, 1990). The differences between ECM and ectendomycorrhizal associations are very unclear, because they do not involve separate plant lineages, and some of the fungi involved are poorly known.…”

Dynamics of heterorhizic root systems: protoxylem groups within the fine‐root system of Chamaecyparis obtusa

“…However, primitive coniferous forests are important plantation forests, representing up to 40% of the total forest area in Japan. The heterorhizy of primitive gymnosperms, compared with other tree groups, is almost unidentifiable by morphological traits alone (Brundrett et al ., 1990).…”