Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-04T18:19:36.460Z Has data issue: false hasContentIssue false

Regulation of arbuscular mycorrhizal development by plant host and fungus species in alfalfa

Published online by Cambridge University Press:  01 January 1998

D. D. DOUDS, Jr.
Affiliation:
USDA-ARS ERRC, 600 E. Mermaid Lane, Wyndmoor, PA 19038 USA
L. GALVEZ
Affiliation:
USDA-ARS ERRC, 600 E. Mermaid Lane, Wyndmoor, PA 19038 USA
G. BÉCARD
Affiliation:
Laboratoire de Mycologie Végétale, Univ. Paul Sabatier, Bât. 4R1, 118 Route de Narbonne, 31062 Toulouse, France
Y. KAPULNIK
Affiliation:
Institute of Field and Garden Crops, P.O. Box 6 Bet Dagan, 50250, Israel
Get access

Abstract

Two cvs of alfalfa (Medicago sativa L.), Gilboa and Moapa 69, were inoculated in glasshouse pots with three arbuscular mycorrhizal (AM) fungi to investigate the efficacy of mycorrhizas with respect to the extent of colonization and sporulation. Paspalum notatum Flugge also was inoculated to describe fungal parameters on a routine pot culture host. Percentage root length of P. notatum colonized by Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe, Glomus intraradices Schenck & Smith, and Gigaspora margarita Becker & Hall increased from 10 to 21 wk, and all fungi sporulated during that period. In alfalfa, only colonization by G. intraradices increased over that time period, and it was the only fungus to sporulate in association with alfalfa at 10 wk. Glomus mosseae did not sporulate after 16–21 wk despite having colonized 30–35% of the root length of both alfalfa cvs. In vitro experiments in which Ri T-DNA-transformed roots of alfalfa were inoculated with AM fungi showed normal mycorrhizal formation by G. intraradices and a hypersensitivity-like response to Gi. margarita. Colonized cells became necrotic, and HPLC analysis indicated increased concentrations of phenolics and isoflavonoids in these root segments. These data strongly support the existence of a degree of specificity between AM fungi and host that might rely on specific biochemical regulatory processes initiated in the host as a result of the attempts at colonization by the fungus.

Type
Research Article
Copyright
Trustees of the New Phytologist 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)