木薯根尖染色体的观察技术

目的]探索制作木薯二倍体根尖压片技术,为多倍体的鉴定提供参考。方法]以木薯品种华南124的根尖为试材,在恒温水浴中用1 mol/L HCl溶液处理,进行细胞解离,并进行11~15 min的时间梯度试验以寻找最佳解离时间。通过木薯根尖染色体的解离观察试验,探讨了木薯根尖染色体(二倍体)的观察方法。结果]木薯根尖的最佳取材时间在雨后或头天浇水第2天上午9∶00~10∶00。解离时间梯度试验表明,解离13 min可达到木薯的最佳解离效果。通过比较4种染色试剂(I-IK染液、改良苯酚品红、番红染液和醋酸洋红)的染色效果选出的最佳试剂为改良苯酚品红。结论]该研究为木薯多倍体的直接鉴定提供了新方法。

Observation Technology of Root Tip Chromosome in Cassava

Objective]The research aimed to explore the root tip squash technique of diploid cassava and provide references for the identification of the polyploid.Method]With root tips of cassava variety Huanan 124 as tested materials,they were treated with 1 mol/L HCl in water bath at constant temperature to conduct cell dissociation and time gradient test for 11～15 min so as to seek for the optimum dissociation time.The observation methods of root tip chromosome(diploid) in cassava were discussed through the dissociation and observation experiment on root tip chromosome in cassava.Result]The optimum sampling time for cassava root tips was at 9:00～10:00 a.m.on the day after a rainy or watering day.The time gradient experiment of dissociation showed that the optimum dissociation effect of cassava could be got while dissociating for 13 min.The optimum reagent,which was selected out through comparing the staining effects of 4 staining reagents(I-IK coloration solution,improved phenol fuchsin,safranine staining solution and aceto carmine),was improved phenol fuchsin.Conclusion]The research provided a new method for the direct identification of polyploid cassava.