Root Hair Length Determines Beneficial Effect of a Glomus Species on Shoot Growth of Some Pasture Species

• Published in: The New phytologist 1995-10, Vol.131 (2), p.247-254
• Main Authors: Schweiger, P. F., Robson, A. D., Barrow, N. J.
• Format: Article
• Language: English
• Subjects: Agricultural soils; Agronomy. Soil science and plant productions; Biological and medical sciences; Economic plant physiology; Fundamental and applied biological sciences. Psychology; Glomus; Glomus sp; Hyphae; Microbial colonization; mycorrhizal benefit; Parasitism and symbiosis; pasture species; Pastures; Phosphates; Plant growth; Plant physiology and development; Plant roots; Plants; root hair length; Root hairs; Sandy loam soils; Symbiosis; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...)
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.1995.tb05726.x

Differences between plant species in the benefit derived from arbuscular mycorrhizal colonization have often been attributed to differences in physical properties of their roots, especially in root hair development. To test this hypothesis, the growth response to phosphate of five pasture species which differed markedly in the length of their root hairs was measured. Plants in the mycorrhizal treatments were inoculated with a Glomus sp. (isolate WUM 10(1)) while non-mycorrhizal plants received control inoculum. Benefit was described as the relative effectiveness of phosphorus (P) for the mycorrhizal plants compared with non-mycorrhizal plants. The beneficial effect of Glomus sp. was inversely related to root hair length of the host plant but it was not well related to root diameter, root length per plant or root/shoot ratio. It is suggested that root hairs and external hyphae of Glomus sp. act as alternative, similar ways of shortening the distance for the diffusion of phosphate in soils.