Seed source and vesicular-arbuscular mycorrhizal symbiont affects growth of Juglans nigra seedlings.

Seedlings of Juglans nigra from three seed sources were grown in fumigated soil without vesicular-arbuscular mycorrhizal (VAM) fungi or inoculated with Gigaspora margarita, Glomus deserticola or Glomus etunicatum. Vesicular-arbuscular mycorrhizal development varied significantly between fungal symbionts within a black walnut source. Glomus deserticola and G. etunicatum produced the highest levels of root colonization in all sources. Significant differences in seedling shoot and root growth were attributed to root colonization by specific VAM fungi in each black walnut source. Glomus deserticola stimulated seedling leaf area and root weight 26 and 52%, respectively, in one seed source. Seedling leaf N, P and K concentrations were significantly improved by VAM in two seed sources. Juglans nigra seedlings respond favorably to VAM colonization. However, differences between seed sources suggest a strong host-symbiont interaction. [ABSTRACT FROM AUTHOR]