Importance of root length in mycorrhizal colonization of welsh onion

Abstract

Sixteen cultivars of Welsh onion (Allium fistulosum L.) with different root lengths were evaluated for phosphorus (P) uptake and response to arbuscular mycorrhizal inoculation. Allium fistulosum were grown with or without (control) arbuscular mycorrhizal fungus Glomus fasciculatum. Mycorrhizal colonization, root length, shoot dry weight and shoot P concentration were determined 82 d after sowing. All cultivars were highly colonized with G. fasciculatum. Shoot P uptake and shoot dry weight were different among cultivars and increased by the mycorrhizal colonization. Cultivars with short roots were more responsive to the mycorrhizal colonization than those with long roots. This suggests that root length should be considered in mycorrhizal‐plant symbiosis.