甜瓜突变体库的构建及M_2群体表型变异的研究

Construction of Mutant Library and Research on Phenotypic Variation of M_2 Population in Melon

利用8种不同浓度的甲基磺酸乙酯(EMS),4种不同的浸种时间,处理甜瓜品系"3-2-2"种子,根据M1植株发芽率,筛选出适宜的诱变剂量为浓度1.2%,诱变时间24 h。采用这种方法构建了含有67个M1家系及相应自交M2种子的甜瓜突变体库。对M1群体541个单株的表型变异进行了全生育期初步调查,总的表型变异频率达71.53%。对M2群体603个单株的节间长度、主蔓粗度、叶片长度、叶片宽度、叶柄长度、叶柄粗度共6个表型性状进行形态学调查表明:除节间长度外,其他5个性状和野生型相比均差异显著;不同性状的变异系数不同,叶柄长度的变异系数最大,达15.37%,节间长度的变异系数最小,为7.10%;在M2中,编号为25的家系叶片出现了黄色和绿色的性状分离。

Seeds of the melon strain ‘3-2-2 ＇ were treated by ethyl methane sulfonate （EMS） with 8 different concentrations and 4 different time in this study, and the suitable EMS mutation dosage for seed mutagenesis was determined as a concentration of 1.2% and 24 h by studying the germination rate of M1 plants. By this way,the melon mutant library containing 67 M1 families and their selfing seeds of M2 was constructed. For M1 individuals in the mutant library,phenotypic traits of 541 seedlings at whole growing period were investigated, resulting in total mutant frequency of 71.53%. For M2 individuals in the mutant library,length of internode, diameter of main stem,length of leaf, width of leaf, length of petiole and diameter of petiole of 603 seedlings were investigated. Except length of internode, differences of the other 5 traits were significant compared to the wild type. Variation coefficient of different phenotypic traits were different,the maximum was 15.37% in length of petiole, and the minimum was 7.10% in length of internode. In ME generation,leaf color of No. 25 line appeared segregation of yellow and green.