Application of commercial arbuscular endomycorrhizal fungal inoculants to the establishment of micropropagated grapevine rootstock and pineapple plants

Abstract

Commercial inoculants of arbuscular mycorrhizal (AM) fungi were tested on 2 plant species. Micropropagated grapevine plantlets were grown in a greenhouse and inoculated with 2 commercial inoculants applied to the growth substrata. No physical or chemical effect of the sterilized inoculants was observed. Mycorrhizal grapevine plants showed a 3-fold increase in shoot growth as compared to control plants. Almost all root pieces were infected and the percentage of root length showing presence of the mycorrhizal fungus was ≈ 30%. The same inoculants were compared to efficient fungal isolates in micropropagated pineapple plants of 3 varieties grown in a controlled environment chamber with simulated tropical conditions. Plants grew better in acid than in alkaline soil, and Glomus sp (isolate LPA21) was more efficient in acid soil than both commercial inoculants. An increased inoculant dose from 1% to 3% sometimes caused an increase in root infection with increases or decreases in plant growth depending on pineapple variety or type of inoculum used. One inoculant tended to improve growth in alkaline soil, while another was more efficient in acid soil. The implications of the use of these products are discussed. © 1992.