Haemoglobin (Erythrogen™) enhanced microcallus formation from protoplasts of indica rice (Oryza sativa L.)

Abstract

The beneficial effects have been studied of supplementing culture medium with 1:100 -1:500 (v:v) of a commercial haemoglobin solution (Erythrogen™) on the mitotic division of cell suspensionderived protoplasts of Indica rices (Oryza sativa L.). Protoplasts were cultured in liquid medium, at densities of 1.5 × 106 or 2.5 × 106ml-1, on nitrocellulose membranes overlaying a semi-solidified medium layer that was supplemented with both Erythrogen™ and nurse cells of Lolium multifiorum. The mean final plating efficiencies (FPEs) of rice cv. BR26 protoplasts cultured with 1:200 (v:v) Erythrogen™, at 1.5 × 106ml-1 (0.018 ± 0.003%; n = 8) and 2.5 × 106ml-1 (0.016 ± 0.002%; n = 8), were both significantly (P < 0.05) greater than controls lacking Erythrogen™ (0.0058 ± 0.002%; n = 8 and 0.0041 ± 0.001%; n = 8, respectively). Similarly, the mean FPEs of cv. Bini protoplasts cultured with 1:200 (v:v) Erythrogen™ at 1.5 × 106ml-1 (0.012 ± 0.003%; n = 6) and 2.5 × 106ml-1 (0.017 ± 0.001%; n = 6) were also significantly (P < 0.05) greater than their respective controls (0.003 ± 0.001%, n = 6 and 0.002 ±0.001%, n = 6). In contrast, supplementation with 1:100 or 1:500 (v:v) Erythrogen™ did not lead to sustained mitotic division and microcallus formation in both rice cultivars.