广藿香抗青枯病离体筛选技术的研究

Study on in vitro selection of Pogostemon cablin resistant to bacterial wilt

以广藿香叶片及带节茎为材料，研究青枯菌粗毒素不同制备方法、青枯菌不同培养时间及不同菌液浓度对外植体离体再生的影响。结果表明：过滤灭菌法制备的青枯菌粗毒素致毒性比湿热灭菌法处理更强，外植体成活率明显降低；以培养12h的青枯菌粗毒素对外植体有较大的致毒性，外植体变褐死亡现象较突出，培养30d后，叶片及带节茎出芽率分别为10．33％及36．11％；浓度在1．41×10^8cfu／ml以上的菌液粗毒素对外植体有明显的毒害作用，大多外植体枯黑死亡，出芽率较低，同时在该浓度时，大多数无根苗难以生根，植株基部变黑，叶片变黄，生长不良。确定了青枯菌粗毒素对广藿香不同离体培养阶段的致毒性，建立了以青枯菌粗毒素为选择压力的广藿香离体筛选体系。

The leaf segments and nodular stem segments from Pogosternon cablin were cultured in vitro. The factors connected with the in vitro selection, such as the different antiseptic methods of R. solanacearum crude toxins,the cultural time and the concentrations of R. solanacearum were studied. The results showed that：The survival rate of explants on the media with R. solanacearum crude toxin sterilized from filters is lower, which showed the toxicity of the crude toxin sterilized from filter was stronger than that of crude toxin sterilized in hot and damp. The explants on the media with the crude toxin from cultured 12 h bacteria were prominently browning and dead. And after 30 d,the shoot formation rate of leaf segments and nodular stem segments were 10. 33 % and 36. 11 % respectively. Crude toxin from bacteria concentration above 1.41 × 10^8 cfu/ml could inhibit the regeneration of explants obviously, with high death rate and low shoot formation rate. And also,the root formation of the shoots from the explants was difficult at that concentration of crude toxin. The R. solanacearum crude toxin had toxicity to the explants and could inhibit the plant regeneration of P. cablin. The system of in vitro selection of P. cablin resistant to bacterial wilt was established