秋水仙素对金达苜蓿染色体加倍效果的影响

Effects of colchicine on chromosome doubling of Medicago sativa L.cv.Jinda

【目的】获得金达苜蓿四倍体的纯合体,为不同倍性苜蓿遗传特性研究及不同倍性间实现基因的流动奠定基础。【方法】以金达苜蓿(Medicago sativa L.cv.Jinda)种子(2n=16)为材料,利用秋水仙素结合组织培养,研究了秋水仙素不同质量浓度(0.02,0.07,0.12mg/mL)、不同处理时间(1,3,7d)对金达苜蓿愈伤组织诱导效果及染色体加倍效果的影响,并从形态学和根尖染色体观察对变异株进行倍性鉴定。【结果】秋水仙素质量浓度和处理时间2个因素对金达苜蓿诱变效果均有一定程度的影响,随着秋水仙素质量浓度的升高、处理时间的延长,愈伤组织的诱导率和分化率均下降,成苗率则规律不明显,其中0.07mg/mL秋水仙素处理3d的诱导效果最好,愈伤组织的诱导率达到60.5%,愈伤组织分化率为33.63%,诱变幼苗成苗率为24.1%。倍性鉴定结果表明,获得的变异植株为四倍体与二倍体的混倍体。【结论】0.07mg/mL秋水仙素处理3d是获得多倍体变异幼苗的最佳条件,获得了四倍体和二倍体的混倍体。

【Objective】This study obtained pure alfalfa tetraploid to provide basis for studying different genetic features of alfalfa and realizing the gene flow between ploidy.【Method】Using colchicine in combination with tissue culturing,the effects of colchicine concentration（0.02,0.07,and 0.12 mg/mL）and treatment time（1,3,and 7 d）on callus induction and chromosome doubling effect of Medicago sativa L.cv.Jinda were studied.The ploidy was also identified from morphology and apical chromosomes.【Result】The concentration of colchicine and treatment time had certain effects on mutation of Medicago sativa L.cv.Jinda.The callus induction rate and regeneration frequency decreased as the increase of concentration of colchicine and treatment time.The treatment of 0.07 mg/mL colchicine for 3 dwas best for polyploidy induction with callus induction rate,regeneration frequency and regeneration rate of 60.5%,33.63% and24.1%,respectively.The ploidy identification showed that the obtained mutant plants were mixoploid.【Conclusion】The treatment with 0.07 mg/mL colchicine for 3 dwas most effective on polyploidy induc-tion,and the mutagenic plant chromosome number was mixoploid including tetraploid and diploid.