Leaf water and carbohydrate status of VA mycorrhizal rose exposed to drought stress

Abstract

Shoot water relations and carbohydrate levels were compared for droughted nonmycorrhizal and vesicular-arbuscular (VA) mycorrhizal Rosa hybrida L. cv 'Samantha' plants grown with high and low phosphorus fertilization. Leaf diffusive conductance (gi) of plants colonized by Glomus intraradices Schenk and Smith and Glomus deserticola Trappe, Bloss and Menge were 2 × and 1.5× greater, respectively, than in nonmycorrhizal plants. Regardless of P fertilization, leaf osmotic and bulk water potentials were 0.5 to 1.1 MPa higher in mycorrhizal than in nonmycorrhizal plants. Leaf starch, chlorophyll and water contents while fructose, glucose and total soluble carbohydrates were lower. Level of P fertilization had no effect on water relations or soluble carbohydrate content of nonmycorrhizal roses. The water status of droughted rose was impoved more by G. intraradices than by G. deserticola. © 1987 Martinus Nijhoff Publishers.