Compatibility of Frankiae spore positive and spore negative inocula with Alnus glutinosa and Alnus incana

Abstract

Growth, nodulation, and nitrogen fixation by Alnus glutinosa (L.) Gaertn. and Alnus incana (L.) Moench inoculated with two Frankia inocula (a spore positive nodule homogenate and a spore negative isolate) were examined. The spore positive inoculum had a very low compatibility with A. glutinosa while a very large compatibility was found with the spore negative strain. Alnus incana had little specificity to the two types of Frankia which allowed the coexistence and the expression of the nitrogen fixation capacity of the two nodule types on the same root system. This result suggests that, despite the competition from indigenous strains, it may be possible to introduce in some areas a highly effective Frankia strain after careful study of the compatibility.

Key Words:

• Alnus
• Frankia
• strain coexistence
• ¹⁵N₂-fixation.