甜叶菊同源四倍体离体诱导及鉴定

In vitro Induction and Identification of Autotetraploid Stevia rebaudiana Bertoni

用不同浓度秋水仙素溶液处理甜叶菊不定芽,诱导同源四倍体,并进行解剖学、染色体鉴定和流式细胞仪鉴定倍性。结果表明:(1)用0.20%的秋水仙素溶液浸泡甜叶菊不定芽12h,同源四倍体诱导率最高,可达32.14%。(2)同源四倍体植株与二倍体(对照)相比,其气孔、叶片等均表现巨大性,且叶片变厚、叶色浓绿、叶片皱缩。(3)对照植株染色体2n=2x=22,四倍体植株染色体2n=4x=44;流式细胞仪倍性鉴定结果显示,对照DNA相对含量为100,四倍体DNA相对含量为200。(4)该研究共鉴定出48株甜叶菊同源四倍体植株,为进行倍性植株的诱导奠定了技术基础,为进一步开展甜叶菊同源四倍体新品种的选育提供了实验材料。

Autotetraploid plants of Stevia rebaudiana Bertoni were induced by immersing buds with different concentrations of colchicines solution,then autotetraploid plants were confirmed based on morphological characters, stomatal analysis, chromosome determination and flow cytometry analysis. The results of this study showed that buds immersed in 0.20% eolehieine solution for 12 h prior to culture induced as high as 32. 14% autotetraploid plants. The stomatal size of autotetraploid plants was larger than that in diploid plants; Autotetraploid plants possessed larger, thicker and deeper green leaves, and distorted ap- pearances in comparison with diploid plants; The chromosome numbers of diploid cells was 2n：2x= 22 ,an- totetraploid cells was 2n= 4x=44;The relative DNA content of diploid was 100,antotetraploid was 200 by flow cytometry analysis to determine their ploidy. A total of 48 lines of autotetraploid plantlets were successfully induced by coiehieine. This technique for in vitro induction of autotetraploid Stevia could provid technical basis for the induction of ploidy plants,and provid experimental material for the further research of new varieties of autotetraoloid breeding orograms.