秋水仙素诱导水稻幼穗愈伤组织创制同源四倍体种质的研究

Research on creating autotetraploid rice using colchicum to induce the panicle callus of diploid rice

以普通二倍体水稻亲本为材料,用秋水仙素进行水稻的多倍体化诱导,创制同源四倍体水稻三系亲本材料并对其进行鉴定。结果表明在MS+2,4 D 1.0 mg/L+KT0.2 mg/L+IAA0.2 mg/L和500 mg/L的秋水仙素处理下,水稻愈伤组织染色体加倍效果最好,平均加倍频率可达25.26%。其中,材料CDR22和IR26诱导较易成功,加倍频率分别达到75%和26.5%;相对材料94109 1.3%加倍频率和冈46B 10.8%加倍频率,诱导率差异极显著。对水稻四倍体材料进行形态学鉴定结果表明,与二倍体水稻对照相比四倍体材料在穗长和千粒重两方面极显著提高,种子的长度和宽度也显著增加。对花粉育性鉴定,确认水稻四倍体不育系材料仍为不育,保持系材料自交和杂交可育,恢复系材料自交和杂交可育。对四倍体材料进行细胞形态、染色体数目等方面进行细胞学鉴定,经核型分析表明水稻四倍体材料具有48条染色体,是二倍体水稻的两倍。水稻四倍体材料根尖分生组织细胞与二倍体的根尖分生组织细胞相比,细胞体积、细胞核和核仁显著增大。四倍体三系材料在细胞有丝分裂中期均可规则排列在赤道板,并能均等地移向两极;后期观察中没有发现染色体分离滞后现象,分裂末期细胞能够形成大小相对均一的子细胞。

Colchicine was used to induce diploid rice to create autotetraploid three-line materials. The polyploidization was based on the colchicine-induced callus tissue culture, and the different colchicine concentrations and culture mediums to induce tetraploid plants were experimented. It was confirmed that the optimal concentration for inducement was 500 mg/L, the average induce rate was 25.26 %. Among all the materials, CDR22 and IR26 had higher induced rater in contrary, 94109 and Gang46B had lower induced rate and the difference was significant. Autotetraploid materials was identified of both morphological and cytological, compared plant height, length of pollen sterility, and other major agronomic traits with a diploid rice as the control plant, identified that the autotetraploid materials had very significant advantages in ear length and thousand-grain weight, as well as the size of the seeds. Cytology identification included observation of the cell morphology, the number of chromosomes, and karyotype analysis on the autotetraploid materials confirmed that their chromosome number was 48, twice of the diploid rice. Mitoses in the three lines were common： chromosomes arrayed normally in metaphase and separated balanced into the two poles, chromosome moved without lagging in anaphase and daughter cells normally formed in telophase except one. It has been proved that tetraploid rice has normal meiosis as their diploid relatives, which usually including series of sub-phases as interphase, prophase Ⅰ （five subphases）, prophase Ⅱ , metaphase Ⅰ , Ⅱ , anaphase Ⅰ , Ⅱ and telophase Ⅰ , Ⅱ.