Fine structure of the root nodules of Dryas drummondii Richards (Rosaceae)

• Published in: Canadian Journal of Botany
• Main Author: Newcomb, William
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1981
• Subjects: Plant Science; Mountain avens
• Online Access: http://dx.doi.org/10.1139/b81-300; http://www.nrcresearchpress.com/doi/pdf/10.1139/b81-300

The root nodules of Dryas drummondii (common name: mountain avens; Family Rosaceae) possess numerous nodule lobes devoid of nodule roots and thus they exhibit the Alnus-type of nodule morphology. Each nodule lobe possesses a nodule meristem, infected cortical cells, and a central vascular cylinder. The endophyte is prokaryotic and has two forms: septate hyphae, 0.3–0.6 μm in diameter, and nonseptate vesicles, ca. 2 μm in diameter; thus, the endophyte appears to be an actinomycete similar to those of other Frankia-induced nodules. A polysaccharide capsule surrounds both forms of the endophyte and contains numerous electron-dense inclusions near the hyphae in host cells containing both forms of the endophyte.