东乡野生稻渐渗系基因组结构变化及多样性分析

摘要

[Objective] The aim of the study was to make research on genomic struc- ture variation and variety analysis of Dongxiang wild rice. [Method] Introgression groups of BC1F6 were based on donor of Oryza rufipogon Griff. and receptor of O. sativa sp. indica Kate. Strains of 239 in the group were analyzed on Polymor- phism with the help of 25 couples of SSR primers distributed in 12 pairs of chromo- somes. [Result] Gene fragments of O. rufipogon Griff. were found penetrated in the 25 microsatellite sites and most of the groups kept the parents of Xieqinzao B or DNA sequence of O. rufipogon Griff. The average rate of recurrent homozygous bands was 78.13% in the ILs, but the highest was 94.98% （amplified by primer RM131） and the lowest was 60.25% （RM171）. The average rate of donor homozy- gous bands was 13.37%, but the highest was 32.64% （RM171） and the lowest was 2.93% （RM1095）. There were numerous heterozygous sites in the population and the average heterozygosis rate was 5.62%, while the highest was 10.04%（RM401）. Moreover, we found some parental fragments were lost and some novel fragments were not detected in either parent in BC1F6 population. The average rate of lost bands was 2.88%, while the highest was 13.39% （RM311） and the lowest was 0 （RM401）. The average rate of new bands was 1%. The average of Nei＇s gene di- versity （He） and Shannon＇s Information index （I） were 0.276 and 0.457 respectively in high generation of introgression lines. [Conclusion] The study demonstrated that distant hybridization led to extensive genetic and epigenetic variations in high gener- ation of introgression lines, which expanded the base of genetic variation and laid an important foundation for rice improvement and germplasm innovation.%[目的】研究东乡野生稻渐渗系基因组结构变化及对其进行多样性分析。[方法]以东乡野生稻（O．rufipogonGriff．，供体）和栽培稻协青早B（O．sativasp．indicaKato．，受体）构建的Bc，R渐渗群体为研究材料，利用筛选出的分布在12对染色体上的25对SSR引物对群体中的239个株系进行多态性分析。[结果]适25个微卫星位点都有东乡野生稻DNA片段不同程度的渗入，群体均大部分保留亲本协青早B或东乡野生稻的DNA序列。渐渗系基因组中平均受体纯合条带百分率为78．13％，最高达94．98％（引物为RM131），最低为60．25％（引物为RM171）。平均供体纯合条带百分率为13．37％，最高达32．64％（引物为RM171），最低为2．93％（RM1095）。群体中还存在一些杂合位点，平均杂合率为5．62％，最高达10．04％（引物为RM401）。此外，BC1F6渐渗群体中发现有双亲条带的丢失和一些双亲所没有的新条带出现，其中平均亲本条带丢失率为2．88％，最高达13．39％（引物为RM311），最低为0（引物为RM401），平均新带率为1％。高世代渐渗群体平均Mi’s基因多样性（胁）和平均Shannon’s信息多样性指数（Jr）分别为O．276和0．457。[结论]通过远缘杂交渐渗系发生了广泛遗传与表观遗传变异，扩大了遗传变异基础，为水稻品种改良与种质创新奠定了重要基础。