不同倍性盾叶薯蓣的生理指标和薯蓣皂苷元量的比较研究

目的通过比较盾叶薯蓣Dioscoreazingiberensis人工四倍体植株和普通二倍体植株在抗性相关指标及薯蓣皂苷元量方面的差异,探索药用盾叶薯蓣倍性育种的应用前景。方法以秋水仙素诱导加倍的、经鉴定确认的3个不同株系四倍体盾叶薯蓣为材料,以二倍体原种为对照,采用分光光度法测定叶片超氧化物歧化酶(SOD)、过氧化物酶(PPO)活性以及可溶性糖的量;高锰酸钾滴定法测定过氧化氢酶(CAT)活性;采用HPLC法测定根状茎薯蓣皂苷元的量。结果四倍体植株SOD、PPO、CAT的活性以及可溶性糖的量明显高于二倍体;四倍体植株薯蓣皂苷元的量显著高于二倍体,增加幅度最大为二倍体原种的27%。结论人工四倍体植株薯蓣皂苷元量高,其生理指标也显示较强的抗性基础,可望直接利用或作为进一步培育高产、高薯蓣皂苷元量薯蓣新品种的良好育种材料。

Comparison of physiological index and diosgenin content in different ploidy of Dioscorea zingiberensis

Objective By comparing the physiological index and diosgenin content of rhizome between the artificial tetraploid and the wild type diploid of Dioscorea zingiberensis, it is aimed at revealing the potential utility of polyploid breeding in medicinal D. zingiberensis. Methods Three clones of the natural diploid and the artificially induced tetraploid of D. zingiberensis were used as materials in this study. The content of SOD, PPO, and soluble sugar of leaves was determined by spectrophotometry, CAT content was measured by using the method of KMnO_4 titration. And the diosgenin content in rhizome was analyzed by HPLC. Results The tetraploid plants showed higher level of SOD, PPO, CAT, soluble sugar content in leaves, and diosgenin content in rhizome than those of the diploid origins. The diosgenin content in the three clones of tetraploid plants increased to 27% as compared to wild type. Conclusion Artificially induced tetraploid presents high content of diosgenin and great potential in stress resistance, which would be available in good seed breeding for high yield of diosgenin.