Influence of phosphate fertilization on the growth and nutrient status of micropropagated apple infected with endomycorrhizal fungi during the weaning stage

Abstract

Microplants of 2 apple rootstocks (M9, M26) and one cultivar (Golden) were inoculated with VAM fungi during a very early weaning stage of acclimatization following micropropagation and supplied with nutrient solution at different P concentrations. Phosphate fertilization containing a high level of P (40 ppm) had no effect on the growth response of mycorrhizal apple plants. At the lower levels of 8 and 4 ppm P mycorrhizal plants maintained the same growth rate as with 40 ppm P. Phosphate fertilization had no influence on endomycorrhizal infection. No difference was observed in the mineral contents of mycorrhizal and nonmycorrhizal plants, or between plants receiving different levels of P. At the lower fertilization rates of P, endomycorrhizal infection not only improved growth but also homogeneity of Golden and M26 plants. © 1992.