中文摘要：

玉米成熟胚组织培养过程中发生褐化可影响愈伤组织的诱导、生长和组培过程的进行。实验研究探讨3种防褐剂硝酸银（AgN03）、活性炭和PVP及培养条件对玉米成熟胚愈伤组织诱导和继代过程中褐化控制的作用。结果表明，一定浓度的AgNO3能明显减轻褐化，其中愈伤组织诱导时10．0mg／LAgNO，控制外植体褐化的效果最佳；愈伤组织继代培养时7．0mg／LAgNO3控制较为适宜。2．0g／L活性炭能有效抑制外植体的褐化，高于此浓度会抑制愈伤组织的诱导；继代培养初期在含2．0g／L活性炭的培养基中培养7d，不仅能有效控制褐化，还在一定程度上促进了愈伤组织的生长。愈伤组织诱导时1．0g／LPVP能在有效控制外植体褐化的同时促进愈伤组织的形成。暗培养能显著减轻褐化的发生．有利于愈伤组织的诱导。

英文摘要：

Browning occurring in tissue culture of maize mature embryos restrained the induction and growth of callus and the process of cultivation. Contrast tests of silver nitrate, activated carbon, PVP and culture condition were designed to study their effects on anti-browning during the process of callus induction and subculture of maize mature embryos. The results showed that silver nitrate can control browning obviously, in which treatment of 10.0 mg/L was optimal to prevent browning of explants, and that of 7.0 mg/L was most effective to prevent callus browning. Activated carbon with concentration of 2.0 mg/L eliminated browning effectively, but inhibited callus initiation in exceeding concentration. A seven-day treatment of 2.0 g/L activated carbon after subculture initiation also eliminated browning as well as promoted the growth of callus to some extent. PVP with concentration of 1.0 g/L reduced the browning of explants and promoted callus induction synchronously. In addition, cultured in dark can significantly reduce the incidence of browning, and is conducive to the growth of callus.