玉米籽粒发育过程中胚乳核DNA含量的变化同籽粒性状的关系

The Relationship of DNA Content in Corn Endosperm Nuclei to Kernel Traits during Kernel Development

用双波长(550,488nm)显微分光光度法测定籽粒发育时期不同Su2基因剂量(0-3)玉米杂交种(Mo_(17)×B73)胚乳核的DNA含量.结果表明:单个胚乳核的DNA含量在授粉后第8天是3.0-4.6C,10天以后迅速上升,20-22天达到高峰,为48.9-63.9C,然后下降.年份间DNA含量差异显著(P≤0.05).在籽粒发育过程中,胚乳核DNA含量与籽粒重量和体积显著相关(r=O.7738,0.8369,P≤0.01).胚乳细胞中Su_2基因的数量水平对胚乳核DNA含量没有剂量效应.

A two-wave length (550-488nm)microspectrophotometric method was employed to measure Feulgen Stained corn endosperm nuclei of four isogenetic genotypes (B73×Mo17). The mean DNA content per nucleus in centrally lacated endosperm averaged between 3. 0 and 4. 6C (C = haploid content )at 8 days after pollination (DAP) ,and then dramatically increased after 10 DAP reaching peak levels between 48. 9 and 63. 9C at 20 to 22 DAP,followed by a decrease in old endosperm tissue. The DNA content per nucleus was significantly affected by the environmental differences. DNA content with kernel weight and kernel volume showed significantly pos-sitive correlation during kernel developnent. Dosage effect on DNA content per nucleus in sugary-2 endosperm was not apparent during kernel development.