HEMOGLOBIN (ERYTHROGEN(TM))-ENHANCED MITOTIC DIVISION AND PLANT-REGENERATION FROM CULTURED RICE PROTOPLASTS (ORYZA-SATIVA L.)

Supplementation of culture medium with hemoglobin solution (Erythrogen (TM)) promoted mitotic division, cell colony formation, and plant rege neration from rice (Oryza sativa L. cv. Taipei 309) protoplasts. The m ean (+/- s.e.m., n = 5) final protoplast plating efficiency (FPE) at 2 8 days following exposure to 1:50 (v:v) Erythrogen(TM) (0.55 +/- 0.06% ) was significantly greater (P < 0.01) than in untreated controls (0.2 6 +/- 0.02%). A similar, but less pronounced effect (P < 0.01) also oc curred with 1:100 (v:v) (PE 0.53 +/- 0.04%) and 1:500 (v:v) (PE 0.46 /- 0.05%) Erythrogen(TM), respectively. In contrast, there was no corr esponding increase in plating efficiency with Erythrogen(TM) at 1:1,00 0 (v:v). These beneficial effects were sustained throughout culture. T his leads to a 44% increase (P < 0.01) in protoplast-derived calli pro ducing shoots compared to controls. Cytological analyses confirmed the diploid status of plants regenerated from Erythrogen(TM)-treated and control protoplasts. (C) 1997 Elsevier Science Inc.