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Accueil du site → Doctorat → États-Unis → 1980 → EFFECTS OF VESICULAR-ARBUSCULAR MYCORRHIZAE ON PLANTS GROWING UNDER SALT STRESS

University of Illinois at Urbana-Champaign (1980)

EFFECTS OF VESICULAR-ARBUSCULAR MYCORRHIZAE ON PLANTS GROWING UNDER SALT STRESS

HIRREL, MARC CHARLES

Titre : EFFECTS OF VESICULAR-ARBUSCULAR MYCORRHIZAE ON PLANTS GROWING UNDER SALT STRESS

Auteur : HIRREL, MARC CHARLES

Université de soutenance : University of Illinois at Urbana-Champaign

Grade : Doctor of Philosophy (PhD) 1980

Résumé
Under salt (NaCl) stress, onions (Allium cepa) and bell peppers (Capsicum annuum) inoculated with either Glomus fasciculatus or Gigaspora margarita grew larger than the nonmycorrhizal controls. To determine if improved phosphate (P) nutrition supplied by the mycorrhizal endophytes was the factor most responsible for enhancing growth under saline conditions inoculated bell peppers were compared to uninoculated controls supplemented with P fertilizer. Leaf P concentrations were 1.5x greater G. fasciculatus inoculated and uninoculated P fertilized treatments than in G. margarita inoculated treatments and 2x greater than the unfertilized low P treatments. The increased P level of the leaves was accompanied by a 2.5 to 4 fold increase in chloride (Cl) concentrations ; however, Na levels did not increase with increasing P. Increased P nutrition of a plant may convey tolerance to high Cl levels ; such that, under saline conditions bell peppers inoculated with G. fasciculatus gain the additional P required to tolerate salt stress better than plants inoculated with G. margarita or nonmycorrhizal low P plants. Since G. margarita provided bell peppers with less tolerance to salt than did G. fasciculatus, the germination of azygospores of G. margarita was compared among 6 concentrations of NaNO(,3), Na(,2)SO(,4), NaCl, KCl and CaCl(,2). Percentage germination was reduced more in the presence of Cl than in the presence of Na. Germination in Na(,2)SO(,4) was often more than 2x greater than in NaNO(,3) at equivalent Na levels ; however, when adjusted for osmotic potential (unequal Na levels) germination in Na(,2)SO(,4) was similar to that in NaNO(,3). Thus osmotic potential does play a role in reducing germination of G. margarita ; however, it appears to be secondary to the effect of Cl.

Mots clés : Biological sciences, Plant pathology

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Présentation : ProQuest

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