为明确四倍体杂交冰草新品系SZB-01和SZB-02的细胞学及DNA分子水平的遗传特征,采用卡宝品红染色制片法和SSR分子标记技术,对SZB-01和SZB-02与亲本蒙古冰草、航道冰草及其正、反交杂种F1的花粉母细胞减数分裂的染色体配对行为、花粉育性、结实性及DNA指纹特征进行了比较分析。结果表明,SZB-01和SZB-02的PMCMⅠ染色体构型均为2n=4x=28=14Ⅱ,配对行为规则,且环状二价体占优势,染色体遗传稳定;SZB-01和SZB-02的花粉可育率分别为83.39%和85.30%,自然结实率分别为67.54%和69.98%,育性较好;筛选出11对多态性好的SSR引物,通过PCR扩增建立了SZB-01与SZB-02的DNA指纹图,6个供试材料间的遗传距离(GD)变幅为0.3506-0.7541,以GD值0.45为基准可将其分为4类。
In order to investigate the cytology and the genetic difference of the new strains SZB-01 and SZB-02 of tetraploid hybrid wheatgrass, chromosome pairing behavior at PMCM I , pollen fertility rate, seed setting rate and feature of DNA fingerprint of two new strains of tetraploid hybrid wheatgrass and Agropyron mongolicum. Keng, Agropyron cristatum cv. Fairway, inverse and obverse cross hybrids F1 were studied with carbol fuchsin staining and SSR molecular marker. The main results showed that the chromosome pairing configuration of two new lines SZB-01 and SZB-02 were 2n =4x=28=14 II at PMCM I , and the chromosome pairing behavior was regular. The genetic behavior of chromosome was stable, and most of bivalents were cyclic bivalents. The SZB-01 and SZB-02 had a high fertility of 83.39% and 85.30%, respectively. And the seed setting rate of them was also high, up to 67. 54% and SZB-02 69. 98%, respectively. Eleven polymorphic SSR primer pairs had been screened and used for PCR amplification. The amplified polymorphic markers were used to establish DNA fingerprint of two new lines SZB-01 and SZB-02 of tetraploid hybrid wheatgrass. The genetic distance (GD) of six tested materials was ranged from 0. 3506 to 0. 7541. Using the GD value of 0.45 as a threshold, the six tested materials could be clustered into four groups.