Abstract:

In order to define cyto-genetic characteristics, fertile and genetic difference between two chromosome mutated lines of Sorghum-Sudangrass hybrid (SRSCD-01 and SBSCD-02), pollen fertility rate, seed setting rate, chromosome pairing configuration and SSR fingerprints were analyzed using loose spike Sorghum×red shell Sudangrass F₁ and loose spike Sorghum×black shell Sudangrass F₁ as control. The two mutated lines of SRSCD-01 and SBSCD-02 were tetraploid (2n=4x=40) with 40 PMCM I chromosomes. The chromosome pairing configurations of tested two lines were 19.93Ⅱ+0.04Ⅰand 19.93Ⅱ+10.06Ⅰrespectively, which showed a regular pairing behavior. The pollen fertility rates were 92.18% and 91.85% and the seed setting rates were 72.16% and 73.43%, respectively, which was similar to that of its diploid hybrid F₁. Three SSR primer pairs, STWAX-2, S184 and ZCT339, which could amplify clear and stable bands, were screened to analyze the genome DNA of tested materials. A total of 44 SSR loci were obtained with 39 polymorphic loci and the polymorphic rate was 88.64%. Four tested materials can be distinguished from each other depending on the SSR fingerprints amplified by each primer pair, which provides a molecular basis for identifying the tetraploid lines of Sorghum-Sudangrass hybrid, registering new cultivar and protecting intellectual property.

Key words: Sorghum-Sudangrass hybrid, Mutated lines, Chromosome configuration, Fertility, SSR analysis

摘要：

为明确2个高丹草（Sorghum-Sudangrass hybrid）染色体诱变株系SRSCD-01和SBSCD-02的细胞遗传学特征、育性表现及DNA水平上的遗传差异，以二倍体散穗高粱（Sorghum vulgare）×红壳苏丹草、散穗高粱×黑壳苏丹草2个杂交组合F₁为对照，对其花粉可育率、结实率、染色体配对构型及SSR指纹特征进行了分析。结果表明：2个变异株系SRSCD-01和SBSCD-02的PMCMⅠ染色体数目均为40，为四倍体（2n=4x=40），配对构型分别为19.93Ⅱ+0.04Ⅰ和19.93Ⅱ+10.06Ⅰ，染色体配对行为规则。其花粉可育率分别为92.18%和91.85%，结实率分别为72.16%和73.43%，与其二倍体杂种F₁相近。试验筛选出条带清晰稳定的3对SSR引物STWAX-2，S184和ZCT339，对4个供试材料基因组DNA进行PCR扩增共得到44个SSR位点，多态性位点39个，多态性百分率高达88.64%。每对引物扩增的SSR指纹图均可以清晰地将4个供试材料区别开来，这为高丹草四倍体株系鉴定及下一步新品种育成登记和知识产权保护利用提供了分子依据。

关键词: 高丹草, 变异株系, 染色体构型, 育性, SSR分析