Abstract

The production of double haploids through androgenesis is used by breeders to produce homozygous lines in a single generation. Androgenesis can be achieved by isolated microspore culture, which, however, allows the production of green haploids with a very low efficiency. In order to improve the overall green haploid regeneration in durum wheat, we compare the efficiency of eight different pre-treatments. These pre-treatments were: cold pretreatment for 5 weeks, 0.3M mannitol for 12 days at 4°C; 0.3M mannitol for 7 days at 4°C; 0.7M mannitol for 5 days at 4°C; PEG₄₀₀₀ 1.5% for 5 days at 4°C; PEG₄₀₀₀ 1% for 15 days at 4°C; PEG₄₀₀₀ 1% for 10 days at 4°C and control without pretreatment. The cold treatment for 5 weeks (4°C) is the most efficient and was used to test the androgenetic ability by microspore culture method of three Tunisian durum wheat cultivars (Razzek, Khiar and Azizi).This pretreatment improves significantly the embryogenesis induction and green plants regeneration with green/albina ratio ≈ 2for the cultivar “Khiar”. The PEG₄₀₀₀ 1% for 10 days seems promising pretreatment and this is important to perform new experiments to advance their response.

Key words: Isolated microspore culture, double haploid, durum wheat, pre-treatment.