Genotypic Variation in Vesicular-Arbuscular My-Corrhizal Dependence of the Pejibaye Palm

Two experiments were undertaken to determine the degree of mycorrhizal dependency of pejibaye (Bactris gasipaes, Palmae) seedling progenies from two Amazonian (Pampa Hermosa; Putumayo) and one Central American (Guatuso) land races. Plants were grown in subsurface samples of either an Oxisol (the Amazonian progenies) or an Ultisol, with or without inoculation with the vesicular-arbuscular mycorrhizae fungus (VAMF) Glomus aggregatum, at three concentrations of soil solution phosphorous (P). VAMF inoculation enhanced leaf phosphorus (P) concentration and dry matter accumulation at the intermediate soil P concentration in all progenies. Dry matter accumulation was enhanced by 17%, 54%, and 64% in the Pampa Hermosa, Putumayo, and Guatuso progenies, respectively. They are therefore classified as being marginally (Pampa Hermosa) or highly dependent. This infra-specific genetic variation with respect to mycorrhizal dependency merits further study for possible exploitation in plant improvement for sustainable agriculture. © 1995, Taylor & Francis Group, LLC. All rights reserved