核桃组织培养中外植体褐变多酚氧化酶活性的控制

Study of Polyphenoloxidase Activity on Controlling Browning of Explants in Tissue Culture of Walnut

[目的]研究抑制核桃外植体多酚氧化酶(PPO)活性的方法,得到数学模型来达到精确控制褐变的目的,并且为核桃组织培养过程中控制褐变提供理论依据。[方法]以硫代硫酸钠(Na2S2O3)、硝酸银(AgNO3)、聚乙烯吡咯烷酮(PVP)为PPO活性抑制因子,设定为X1、X2、X3。通过三元二次回归组合设计建立回归方程,并用贡献率法判断三因子对方程的重要性,用降维法分析各单因子与指标之间的关系,了解各因子之间的互作关系。[结果]实测值回归方程为:y=0.162-0.101x1-0.015x2-0.331x3-0.047x1x2+0.091x1x3+0.029x2x3-0.026x12+0.124x22+0.100x32。Na2S2O3、AgNO3、PVP三因子在抑制核桃外植体PPO活性方面,以PVP作用最为突出,其次为Na2S2O3,再次为AgNO3。在不同的码值水平下,各因子间的交互作用有所变化。[结论]核桃组织培养过程中外植体褐变是影响核桃组培成功的一个主要因素。利用三元二次回归组合设计方法来设计试验因子的用量,更能提高试验结果的准确性和科学性。

[Objective]The method of controlling the activity of PPO of walnut explants was studied.Establishing mathematical model provided theoretical basis for controlling browning in tissue culture of walnut.[Method] The inhibitor factors were sodium thiosulphate,silver nitrate and polyvinylpyrrolidone.And three factors were assumed to be X1,X2,X3.The regression equation was defined through the method of triquadratic regression combination design.The devotion rate method was used to estimate the most important factor in controlling the activity of PPO.According to the method of multifactor dimensionality reduction,the relation between all experimental factors and indices were analyzed.[Result]The regression equation was y=0.162-0.101x1-0.015x2-0.331x3-0.047x1x2＋0.091x1x3＋0.029x2x3-0.026x12＋0.124x22＋0.100x32.According to the devotion rate method,the results showed that the ability of inhibiting PPO activity was PVPNa2S2O3AgNO3.In different range of factor level,the relation between all experimental factors was different.[Conclusion]Establishing mathematical model was important in scientific experiments.It could increase efficiency and veracity of experiment.