野生长穗桑种质资源云7的多倍体诱导和鉴定

Polyploidy Induction and Identification of Wild Germplasm Resource Yun 7 of Morus wittiorum Hand-Mazz

以野生长穗桑(Morus wittiorum Hand-Mazz)多倍体(2n=7x=49)种质资源云7组培苗的不定芽为材料,用不同浓度秋水仙碱处理一定时间后进行组织培养,观察、鉴定萌发多倍体植株的染色体加倍的效果。不定芽经2 g/L秋水仙碱溶液(以二甲基亚砜作为渗透剂)浸泡2.5 d后,其死亡率为53.76%。以此接近半致死率的诱导条件诱导供试桑树不定芽的染色体加倍,并对其组培苗的腋芽持续多代分离筛选,经过染色体计数观察与流式细胞技术鉴定其倍性,最终得到2株稳定的十四倍体(2n=14x=98)长穂桑植株。诱变植株移栽至室外环境后生长状态良好,由此实现了对野生长穂桑种质资源染色体的人工加倍。

The adventitious buds of wild germplasm resource Yun 7（ polyploidy,2n = 7x = 49） of Morus wittiorum HandMazz were used as experimental material and the effects of concentration as well as treatment time of colchicine on chromosome doubling were investigated. The results indicated that after the adventitious buds were treated with 2 g/L colchicine using dimethyl sulfoxide as penetrant for 2. 5 d,the mortality of adventitious buds was 53. 76%. This induction condition,which could lead to half lethality,was employed to induce chromosome doubling in mulberry adventitious buds,and then were cultured to form shoots. The axillary buds grown on these shoots were separated and screened consecutively for many generations. Chromosome counting and flow cytometry were used to examine polyploidy of the cultured materials. Finally,two M. wittiorum plantlets with stable 14-ploidy（ 2n = 14 x = 98） were obtained. After transplanting,the mutagenic plantlets grew well in outdoor environment,demonstrating that the artificial induction of chromosome doubling in wild germplasm resource of M. wittiorum is successful.