渗透胁迫对大花萱草EMS离体诱变系统的影响

针对提高EMS(甲基磺酸乙酯)对大花萱草愈伤组织突变体率的方法开展的研究。采用了预选择的高渗透固体培养基(甘露醇36g/L+山梨醇36g/L+蔗糖50g/L)。在0.1%EMS半致死剂量诱变前对大花萱草带芽愈伤组织进行不同时间的渗透胁迫预处理。研究渗透胁迫对大花萱草EMS诱变效应的影响。通过对渗透胁迫和EMS诱变后愈伤组织的生长量、成活率、分化率和成苗率等生长状态的观察统计,以及细胞质膜透性和SOD、POD、CAT酶等生理生化指标的测定,得出：渗透胁迫预处理对EMS诱变效应存在一定的影响。渗透胁迫加强了EMS对愈伤组织的伤害作用,表现在细胞质膜透性和SOD、CAT酶活性的升高以及POD活性的降低。处理时间在30min-60min时,胁迫对愈伤组织分化成苗的能力未造成显著影响,但是可提高突变体率6.34%-9.27%。处理时间达90min时,对愈伤组织造成致死伤害。结论：在0.1%EMS半致死剂量诱变大花萱草愈伤组织前,用高渗透固体培养基(甘露醇36g/L+山梨醇36g/L+蔗糖50g/L)进行30min-60min的胁迫预处理可以有效提高突变体率6.34%-9.27%。渗透胁迫时间的长短与突变率提高的幅度没有规律性。

Osmotic Stress: Effects on in vitro Mutagenesis System of EMS in Hemerocallis hybrida

The study is to improve the rate of EMS mutants of Hemerocallis hybrida. The pre selected highly permeable solid medium(mannitol 36g/L+ sorbitol 36g/L+ sucrose 50g/L) was used in the experiment. The callus of Hemerocallis hybrida was treated with osmotic stress at different time span and then induced by 0.1%EMS semi lethal dose. The effect of osmotic stress on the mutagenic effect of EMS was studied. The growth state, survival rate, differentiation rate and seedling growth rate of callus after osmotic stress and EMS mutation were observed and statistically analyzed. And cell membrane permeability and SOD, POD, CAT enzymes were determined. Results：Osmotic stress pretreatment has some effects on EMS mutagenic effect. Osmotic stress enhanced the damage of EMS to callus. The cell membrane permeability and the activity of SOD and CAT enzymes increased, and the activity of POD decreased. Osmotic stress 30min-60min had no significant effect on the ability of callus differentiation,but increase the mutant rate 6.34%-9.27%. Osmotic stress induced lethal damage to callus in 90min. Conclusion ：Before the 0.1%EMS semi lethal dose induced the callus of Hemerocallis hybridai, a high permeable solid medium (mannitol 36g/L+ sorbitol 36g/L+ sucrose 50g/L) was used for 30min-60min stress pretreatment to improve the mutant rate of 6.34%-9.27%.There is no regularity in the duration of osmotic stress and the rate of increase in mutation rate.