Variations in response of determinate common bean (Phaseolus vulgaris L.) genotypes to arbuscular mycorrhizal fungi (AMF) inoculation

Abstract

This study evaluated seedling traits (shoot/root length, fresh and dry weights of shoots/roots, number of leaves, shoot diameter), phosphorus (P) content, mycorrhizal colonization (MC), and relative mycorrhizal dependency (RMD) of 21 common bean genotypes inoculated by 4 different arbuscular mycorrhizal fungi (AMF) [Glomus intraradices (Gi), Glomus mosseae (Gm), Gigaspora margarita (Gim), and commercial AMF (cAMF)] in a growth chamber under controlled growing conditions. With the exception of shoot diameter, inoculated plants had better seedling traits than noninoculated plants. P content of shoot was also higher in inoculated plants than in noninoculated plants. Of the 20 genotypes and Nadide cv. examined, 5 responded positively and 3 responded negatively to inoculation with all AMF types. Great variations in RMD and MC were observed, with the highest RMD and MC in the T120 (69.54%) and T71 (81.09%) genotypes and the lowest in the V77 (1.26%) and V78 (31.42%) genotypes. Positive correlations were found between RMD and seedling traits, with the exception of shoot length as well as root length, P content, and colonization. MC was significantly correlated only with P content.