毛竹四倍体诱导及初步鉴定

Induction and Preliminary Identification of Tetraploid in Phyllostachys edulis

【目的】植物多倍体品种在表型、营养物质含量及抗逆性等方面都具有十分优良的表现,本研究借鉴多倍体育种这一成功的育种方法,旨在突破毛竹新品种缺乏的瓶颈,获得毛竹新品种多倍体的种质资源。【方法】以经浸泡后的毛竹吸胀种子为材料,用不同浓度的秋水仙素进行不同时间的诱变处理。以种子下胚轴膨大为变异植株的早期鉴定标准,并通过流式细胞仪测定细胞核DNA含量鉴定四倍体毛竹,比较分析二倍体与同源四倍体形态学和生理生化方面的特征。【结果】0.5 g·L^-1的秋水仙素就可以诱导吸胀后的毛竹种子的染色体加倍,其中以0.5 g·L^-1的秋水仙素浸泡72 h以及1 g·L^-1的秋水仙素浸泡24 h效果最佳,二者诱导率都可达5%左右;流式细胞仪测定表明,四倍体毛竹叶片细胞DNA相对含量比二倍体增加1倍;与二倍体相比,四倍体植株叶片下表皮的气孔密度显著降低而气孔大小明显增大(P<0.05);四倍体毛竹株高、叶片长度和宽度显著增加,其光合作用优于二倍体植株。【结论】利用秋水仙素处理毛竹吸胀种子,可以成功诱导出四倍体植株,并且四倍体毛竹与二倍体植株的生理生化特点存在显著差异。

【Objective】Polyploid varieties have very good performance in phenotype,nutrient content and stress resistance.The method of polyploid breeding was used,hoping to overcome the difficulties encountered in current breeding of Phyllostachys edulis,and to create new germplasm resources of polyploid varieties.【Method】The imbibed seeds of P.edulis after soaking were treated with colchicine of different concentrations at different durations for mutation induction.Seed hypocotyl expansion was used as the indicator for early detection of mutation,and then DNA content of these candidates was identified by flow cytometry.The morphological,physiological and biochemical comparisons between diploid and homologous polyploid were performed.【Result】0.5 g·L^-1 colchicine could induce chromosome doubling of bamboo seeds after swelling,and 5%induction rate could be obtained by soaking with 0.5 g·L^-1 colchicine for 72 h and 1 g·L^-1 colchicine for 24 h.The flow cytometry detected that the relative DNA content of tetraploid P.edulis leaves was 2 times of diploid.Compared with diploid,the stomata density of the epidermis of the tetraploid was significantly decreased,the size of the stomata was significantly increased(P<0.05),and the plant height,leaf length and leaf width of the tetraploid bamboo increased significantly,and the photosynthesis of the tetraploid plants was higher.【Conclusion】The treatment of swelled seeds with colchicine can successfully induce tetraploid for P.edulis,and there are significant differences in physiological and biochemical characteristics between the tetraploid and the diploid.