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为了探索栽培稻与药用野生稻种间杂种体内异源基因组重组引起的DNA甲基化变异规律,及其生物学效应,利用甲基化敏感扩增多态性(MSAP)技术对辽粳944、药用野生稻及其杂种F_1不同发育时期的叶片和小穗基因组DNA甲基化水平和模式的遗传变异特点进行了分析。结果表明,辽粳944、药用野生稻及其杂种F_1的叶片和小穗DNA的甲基化水平表现出相同的变化趋势,即随着生长发育的进行,DNA甲基化水平呈下降趋势,各组织的全甲基化率均显著高于半甲基化率(P=0.000);杂种在分蘖期、减数分裂期及开花期叶片DNA平均总甲基化率、全甲基化率和半甲基化率分别为20.19%,16.06%及4.13%,其甲基化水平高于双亲;而杂种在减数分裂期、小孢子发育期及花粉成熟期小穗DNA平均总甲基化率、全甲基化率和半甲基化率分别为17.38%,13.67%及3.71%,均比辽粳944高,而比药用野生稻低;杂种小穗的半甲基化率显著高于辽粳944(P=0.015)。杂种叶片和小穗DNA的甲基化模式均有5种类型。经过对94个甲基化特异片段的序列分析,有38个片段的序列与已知或假定功能的基因具有同源性。为进一步研究栽培稻与野生稻种间杂种不育机理奠定了基础。
In order to explore the rule of DNA methylation variation caused by heterologous genome recombination in interspecific hybrids of O. sativa and O. sativa, and its biological effects, the genetic polymorphisms of Liaojing 944 , The characteristics of genetic variation of DNA methylation level and patterns of leaves and spikelets of medicinal wild rice and its hybrid F1 at different developmental stages were analyzed. The results showed that the methylation level of DNA in leaves and spikelets of Liaojing 944, medicinal wild rice and hybrid F1 showed the same trend, that is, the DNA methylation level decreased with the growth and development, The methylation rates of all the tissues were significantly higher than those of the half methylated ones (P = 0.000). The average total DNA methylation and total methylation rates of the hybrids during tillering, meiosis and flowering were The methylation rates of the hybrids were 20.19%, 16.06% and 4.13%, respectively, and their methylation levels were higher than those of their parents. The average total methylation rate of spikelet DNA at the stage of meiosis, microspore development and pollen maturity , The full methylation rate and the half methylation rate were 17.38%, 13.67% and 3.71%, respectively, which were higher than that of Liajing 944 and lower than that of medicinal wild rice. The hemomethylation rate of hybrid spikelets was significantly higher Liaojing 944 (P = 0.015). There are five types of methylation patterns in hybrid leaf and spikelet DNA. After the sequence analysis of 94 methylated specific fragments, the sequence of 38 fragments has homology with the known or hypothetical gene. This laid the foundation for further study on the mechanism of interspecific hybrid sterility between cultivated rice and wild rice.