Objective:To study the effects of different concentrations of NaN3 and methotrexate on the survival,cluster bud differentiation and rooting of immature embryo callus in rice(Oryza sativa L.).Methods:The immature embryo callus of high-quality rice variety Runzhuxiangzhan was used as explants.The calli of rice immature embryos were treated with 1,2,3,4 mmol/L NaN3 for 8 min,and they were inoculated into the callus growth medium containing 0.001,0.005,0.010,0.050 g/L of methotrexate respectively.The growth status of callus was observed,the browning rate and survival rate of callus were calculated,and then the differentiation rate and rooting rate of callus were calculated.Results:The lethal concentration of methotrexate in rice callus was 0.05 g/L.Methotrexate was an important factor affecting the survival of immature embryo callus in rice,followed by NaN3,and then for their interaction.The difference between treatments was significant.With the increase of the concentration of NaN3 and methotrexate,the callus of rice changed from white to light yellow and brown,the browning rate increased gradually,and the survival rate of callus decreased gradually.A1,A2,A3 and B1,B2,B3 treatment combinations,young embryos of rice callus were white or light yellow,brown rate was 6.67％-50.00％,the survival rate was 23.33％-96.67％.The browning rate was 86.67％-100.00％and the survival rate was 0.00％-6.67％in the combination of A4 and B1,B2,B3,B4.The combination of B4 and A1,A2,A3,A4,the callus browning was more,the browning rate was 66.67％-100.00％,and the survival rate was 0.00％-16.67％.With the increase of the concentration of NaN3 and methotrexate,the rate of cluster bud differentiation of rice callus decreased gradually,and there was significant difference among the treatments.Among them,A4B2 and A2B2 had the highest rate of differentiation,A4B2 had partial differentiation,but the lower,the rate of differentiation was only 5.56％,A4B4 and A4B3 could not differentiate into buds.The rooting rate of clustered buds was 100.00％after culture,with no statistical difference.Conclusion:The survival rate of NaN3-treated callus cultured in 0.05 g/L methotrexate was 0.00％-6.67％,compared with the control decreased by 90.00％-96.67％and 5.56％of the surviving callus could differentiate into cluster buds and take root.The combination of A4B2(0.05 g/L methotrexate and 2 mmol/L NaN3)was the combination to induce the mutation survival,bud differentiation and rooting of rice immature embryos callus.It laid a certain theoretical and practical foundation for rice herbicide resistance breeding in the future.
维普
万方数据