Factors affecting maturation of avocado somatic embryos

Abstract

The effect of mineral salts, sucrose, gellan gum, abscisic acid and coconut water on maturation of avocado (Persea americana Mill.) somatic embryos was studied. Use of B5 major salts was essential to obtain white-opaque embryos. Sucrose at 175 mM, gellan gum (6.8 g l−1 ) or coconut water (10–20%) also enhanced the recovery of white-opaque embryos. Abscisic acid slightly enhanced the appearance of white-opaque embryos. White-opaque embryos were further grown on MS, modified B5 medium supplemented with 10% coconut water or Jensen–MS media and they subsequently germinated on M1 medium. Higher germination rates (11.11%) were obtained with embryos that matured on modified B5 medium supplemented with 10% coconut water, although larger embryos developed on MS medium. Thus, embryo size during maturation does not seem to be correlated with germination capacity. Shoots obtained from germinated embryos could be multiplied in the presence of 4.44 M benzylaminopurine and successfully rooted (80% rate) after a 3 days treatment with 4.92 M indole-3-butyric acid. Over 90% of the rooted shoots survived acclimatization.