【摘要】 以同源四倍体青花菜为试材,进行了游离小孢子培养的胚胎诱导条件及胚胎发育途径的研究。结果表明:基因型是影响四倍体青花菜小孢子胚胎诱导率的重要因子,基因型A36的出胚率最高,达到28.5个·蕾-1;热激胁迫(32.5℃)诱导小孢子从配子体发育途径向胚胎发生途径转换,其小孢子胚胎发育途径为典型的单核期小孢子经对称分裂产生胚胎的途径(B途径);4℃低温预处理1d或2d结合32.5℃热激1 d后,对称分裂和多细胞团增加,供试基因型小孢子出胚率显著提高。本研究将有助于游离小孢子胚胎发生机理的研究,以及其他芸薹属小孢子胚胎体系的建立及优化。更多还原

【Abstract】 Microspores culture and embryogenesis of autotetraploid broccoli were studied. The genotype was the most important factor on the induction rate of microspore-derived embryos,and the highest embryo yield reached 28. 5embryos per bud. Under heat stress treatment( 32. 5℃),in vitro microspores could be induced and switched their gametophytic development to embryogenesis. There were two patterns in the first mitosis of microspore: one was asymmetrical division,and the other was symmetrical division. Then two identical or similar size cells were formed the symmetrical division,and divided repeatedly to form embryo( named B pathway). The combination of cold temperature at 4℃ for 1 or 2 days and heat shock( 32. 5℃) for 1 day significantly enhanced the first symmetric divide microspores and multinuclear structures, and finally improved microspore embryogenesis efficiency. Our results will help understanding of the mechanism of embryogenesis in vitro,and also for the construction of microspore culture system for other Brassica hybrids.更多还原