GENOTYPIC VARIATION IN VESICULAR-ARBUSCULAR MYCORRHIZAL DEPENDENCE OFTHE 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 eithe r an Oxisol (the Amazonian progenies) or an Ultisol, with or without i noculation with the vesicular-arbuscular mycorrhizae fungus (VAMF) Glo mus aggregatum, at three concentrations of soil solution phosphorous ( P). VAMF inoculation enhanced leaf phosphorus (P) concentration and dr y matter accumulation at the intermediate soil P concentration in all progenies. Dry matter accumulation was enhanced by 17%, 54%, and 64% i n the Pampa Hermosa, Putumayo, and Guatuso progenies, respectively. Th ey are therefore classified as being marginally (Pampa Hermosa) or hig hly dependent. This infra-specific genetic variation with respect to m ycorrhizal dependency merits further study for possible exploitation i n plant improvement for sustainable agriculture.