FURTHER-STUDIES ON THE INFLUENCE OF MYCORRHIZAE ON GROWTH AND DEVELOPMENT OF MICROPROPAGATED AVOCADO PLANTS

The acclimatization phase during micropropagation of avocado (Persea americana Mill) raises problems concerning the survival and development of plantlets ex vitro. Comparison of potting mixes showed that survival of plantlets was highest in a soil - sand substratum and was increased by inoculation with Glomus sp in a peat - perlite mix. Mycorrhizal infection by Glomus sp during the acclimatization process also improved development of micropropagated avocado plants growing in these 2 substrata. Inoculation with other AM fungi showed that Glomus deserticola, and to a lesser extent Glomus mosseae, improved plant development in the soil - sand mix. Mycorrhiza formation, therefore, appears to play a key role in favouring ex vitro development of micropropagated plants of avocado.