在不同世代中APIV水稻的多胚苗频率研究

Studies on frequencies of polyembryonic seedlings of APIV rice in the different generations

在APIV水稻的三个自交世代中 ,其多胚苗频率比较低 ( 4 .67%～ 5 .14 % ) ,在不同世代之间变化并不明显。在由单胚苗植株所产生的自交群体中包括有单胚苗植株和多胚苗植株 ,而在由多胚苗植株所产生的自交群体中也包括有单胚苗植株和多胚苗植株 ,这说明APIV的单胚苗植株与多胚苗植株具有相同的基因型 ,其多胚苗性状是相对稳定的遗传性状 ,要从其中进一步筛选出多胚苗频率更高的单株则比较困难 ,除非在其群体内发生了基因突变或其遗传性状发生了改变。在APIV的杂交世代中 ,由APIV的单胚苗植株与双胚苗植株杂交 ,其后代的多胚苗发生频率无显著差异 ;由APIV与紫血稻杂交 ,其后代的多胚苗发生频率很低( 0 5 8%～ 3 .0 6% ) ,但在各群体内出现了一些多胚苗频率更高的单株 ( 6.2 5 %～ 9.42 % )。根据试验结果 ,我们认为在基因型杂合的群体内对多胚苗性状进行选择会有明显效果 ,而在纯合群体中无选择价值 ;APIV的多胚苗性状是受多基因控制的数量性状 。

The frequency of the polyembryonic seedlings of APIV in the three selfcross generations were lower(4.67%～5.14%) and there was no obvious difference in the different generations. There were the uniembryonic plants and the polyembryonic ones in the selfcross colony produced by a uniembryonic plant, but there were also the two kinds of plants in the selfcross colony reproduced by a polyembryonic plant. The genetic types of the uniembryonic and the polyembryonic plants of APIV are the same. The polyembryonic character is relatively stable in genetics. It is more difficult to find and to breed the plant with the higher frequency of polyembryo in APIV, except the genetic change or the gene mutation. In the cross generations, there was no outstanding difference in the frequencies of the progenies from the crosses of the uniembryonic and the polyembryonic plants of APIV. The frequencies in the progenies of APIV×Purple Blood Rice crosses was very low(0.58%～3.06%),but there were the plants with the higher frequencies(6.25%～9.42%). According to the results, we think that the selection of polyembryonic character in the heterogenetic type colony is very obvious, but no in the pure genetic type colony; that the polyembryonic seedlings of APIV is a kind of quantitative character controlled by the multigenes, and its genetic mechanism is more complicated.