In vitro rescue and regeneration of zygotic embryos of avocado (Persea americana Mill.)cv. Hass.

A protocol for in vitro zygotic embryo rescue and regeneration of avocado (Persea americana Mill)cv. Hass was developed. The results showed that the best germination percentage (100 per cent)was achieved with embryos cultured after 180 and 210 days from full bloom. Insignificant difference was noticed between MS B5 medium on germination percentage. However, MS medium recorded higher average shoot length compared with B5. However, during multiplication stage, MS medium recorded the highest significant number of proliferated shoots/explant and shoot length of avocado cv. Hass. The highest shoot length was noticed with MS medium. The highest significant number of proliferated shoots/explant was observed with BA at 2 mg/l. The greatest number of proliferated shoots/explant was achieved on MS medium supplemented with BA at 2 mg/l during the 5th subculture (2.6)and MS with BA at 1 mg during the 2nd subculture without significant difference between them. While, the best rooting percentage was recorded with IBA at 2.0 mg/l (49.6 per cent). The highest significant survival percentages (48.4 per cent)was achieved on mixture of sand, peat and vermiculite at ratio 1:1:1.