Micropropagation of Avocado cv. Fuerte by Embryo Culture Techniques

Abstract

Embryo rescue is an in vitro technique that has been used to save the hybrid products of fertilization especially when they might be degenerated. A protocol for in vitro Zygotic embryo age micro propagation of Avocado (Persea americana, Mill) cv. Fuertes Was development during two successive seasons (2011 and 2012) in the tissue culture laboratory, Horticulture Department, Faculty of
Agriculture, Ain Shams University, Shoubra El-Khima, Egypt. The effect of sterilization with Clorox, embryo age from full bloom, medium type and sucrose concentration were investigated during establishment stage. The effect of medium types (MS&B5), Cytokinin type (Kinetin & BAP) and Subcultures number in multiplication stage were study. The effect of auxin type (IBA and NAA) at different concentration (0.5, 1.0,2.0 and 4.0 mg/L treatment in rooting stage. Different medium combinations (Sand: Prelate: Vermiculite) with different ratio (by volume) were tested during acclimatization stage. The obtained results showed that, sterilization the avocado embryos with Clorox at 30% gave the lowest Contamination and highest survival percentages. Culture of embryos after 180 and 210 days from Full bloom gave the highest germination percentage on MS&B5 media containing either 30 or 45 g/L Sucrose of avocado embryos. While, embryos cultured after 180 and 210 days from full bloom on MS medium Supplemented with 30 g/L sucrose are the most suitable for germination percentage and average shoot length. During multiplication stage, MS medium recorded the highest
average shoot length as compared with B5 medium. In addition BAP at different concentrations surpassed Kinetin in on creasing number of proliferated shoots/explants. Also, Kinetin surpassed BAP in increased average shoot length. The second subculture gave number of proliferated shoots/explants. IBA at 2-0 mg/L to the culture medium increased in vitro rooting percentage, number of roots and root length of avocado Cv. Fuerte. Medium mixtures of sand: peat: vermiculite at (1: 2: 1 by volume) recorded the highest survival percentage during acclimatization stage. Sterilization the avocado embryos with Clorox at 30% gave the lowest Contamination and highest survival percentages. Culture of embryos after 180 and 210 days from Full bloom gave the highest germination percentage on
MS&B5 media containing either 30 or 45 g/L Sucrose, respectively, without significant differences between them of avocado embryos to rescue of sexual zygote of avocado varieties.