EMS诱变西瓜突变体库的构建及表型分析

采用1.0%诱变剂甲基磺酸乙酯(EMS)处理西瓜品系W1-17种子9h,然后对M1和M2代群体单株在叶、花、茎、育性、分支习性等方面进行表型变异观察,同时选取M2代典型变异株系,利用23对西瓜SSR引物进行分析鉴定,构建西瓜突变体库。结果表明:(1)EMS诱变使M1代幼苗形态呈现出叶畸形、叶褶皱、部分黄化、花畸形、雄花不散粉、卷须畸形、矮小、生长缓慢、不育等特异性状,获得由1 252个单株组成的西瓜突变体M1群体,群体总变异频率为18.33%。(2)M2代共筛选到205个突变植株,40种表型变异,表现在子叶性状(黄化、扭曲不对称、折叠等)、叶和茎性状(叶黄化、变小、裂刻变深,茎变细,节间变短,分支少等)、花性状(花变大,花色变浅,两性花,花瓣皱缩、部分退化、数目突变,柱头畸形,雄蕊不成熟等)和其他性状(生长缓慢、不育等)等方面,总的表型突变率达到了19.59%。(3)针对M2代10个典型变异植株,通过SSR引物分析发现有9份材料在DNA水平上有变异。本研究初步构建了含有120个M1代家系及1 051株M2代植株、40种表型变异的西瓜突变体库。

Construction of EMS Mutagenesis Watermelon Mutant Library and Phenotypic Analysis

The watermelon strain W1 17 was treated with ethylmethanesulfonate (EMS) at 1.0% for 9 h, and phenotypic variation of M₁ and M₂,including the leaf, flower, stalk, fertility and branching habits etc, were studied. The typical mutant lines of M₂ were selected simultaneously, and 23 watermelon SSR primers were used for analysis and identification, and the mutant library of watermelon was constructed finally. The results showed that: (1) the M₁ seedlings mutagenized showed differently morphological characteristics such as leaf deformity, leaf folds, partial yellowing, floral abnormality, male flowers do not loose powder, tendril deformity, short stature, slow growth and infertility, ect. The M₁ population of watermelon mutant was composed of 1 252 individual plants, the total mutation frequency was 18.33%.(2) 205 M₂ mutant plants were screened, and 40 phenotypic variations were found in cotyledon traits (yellowing, asymmetric twist, fold etc.), leaf and stem traits (leaf yellowing, smaller, cracked deep, thin stems, internodes shorter, less branched and so on), floral traits (flowers become larger, lighter color, bisexual flowers, petals shrinkage, partial degradation, the number of mutations, stigma deformities, stamens immature) ,and other traits (slow growth, infertility, etc.), the total phenotypic mutation rate reached 19.59%. (3) For the 10 representative mutant plants of M₂ generation, 9 samples were found to be mutated at the DNA level by SSR primer analysis. In this study, a mutant library of watermelon containing 120 M₁ generation lines and 1051 M₂ generation plants and 40 phenotypic variations was constructed.