Mutagenic treatment of microspore-derived embryos of turnip rape (Brassica rapa) to increase oleic acid content

The article presents the results of a study on obtaining mutant doubled haploids of turnip rape. The culture medium for producing embryos in isolated microspore culture was optimized. The optimal medium formula was NLN + 13% S + 0.05 mg/L NAA + 0.05 mg/L BA. Embryos derived from isolated microspore culture were treated with EMS mutagen in three concentrations (4 mM, 8 mM, and 12 mM). Mutant doubled haploid plants and their seeds were obtained. Agronomic evaluation and analysis of fatty acid composition in mutant lines seeds showed that they had valuable traits in terms of seed oil quality and yield. Analysis of the fatty acid composition of the seeds of the obtained mutant doubled haploids showed an increase in the percentage of oleic acid (~11%–12%) in comparison with donor cultivars. Our results showed that mutagenesis of embryos from a culture of isolated microspores has potential for improving the qualitative traits of turnip rape.     

哈萨克斯坦阿尔泰山树木径向生长及其对气候要素的响应

针对哈萨克斯坦阿尔泰山南坡西伯利亚云杉（Picea obovata）和西伯利亚落叶松（Larix sibirica）开展树轮研究,建立树轮年表,计算年平均树轮宽度值和年平均断面积生长量（BAI）,并分析在1988年发生升温突变前后,这2个树种树轮宽度指数变化趋势,及其树木径向生长对气候因子的响应。结果表明：在升温突变前后,2个树种树轮宽度指数变化趋势一致。但是,在升温突变后,其变化趋势均由不显著增加转为显著下降。即树木径向生长减缓;升温突变后,2个树种树木径向生长对降水的响应有所减弱,而对气温的响应有所增强,并且发生了树轮指数和气候因子间相关性“正负转换”的情况。