The phenotypically uniform indica rice variety IR64 was chosen for study of the source and inheritance of within cultivar residual variation using a set of SSR markers.Molecular heterogeneity in IR64 was identified on the short arm of chromosome 2 involving at least five SSR loci spanning nearly 30 cM.The SSR variations originated from the parental lines of IR64(IR5657-33-2 /IR2061-465-1-5-5)and were segregating in the selfed bulk seed stock in a Mendelian manner for more than 20 years.This study was one of few examples to verify successfully that within cultivar variations of SSR in morphologically uniform selfing crops came from its parental lines,which has immediate and commercial applications including test of seed purity,varietal fingerprinting,and curation and propagation of germplasm collections.
通过EMS诱变籼稻品种IR64获得一个稳定遗传的淡褐色斑点叶突变体lbsl1(light brown spotted leaf 1)。在自然条件下,突变体播种后10～14d,叶片上出现淡褐色斑点,随后逐渐扩散至全叶,第1叶至剑叶上均有淡褐色斑,为全生育期性状。斑点性状的表达对株高、生育期、结实率和千粒重等农艺性状具有显著的影响。遗传分析结果表明,该淡褐色斑点叶性状受一个隐性核基因控制。将突变体lbsl1与正常叶色水稻Morobereken杂交构建F2定位群体,利用SSR标记,最终将该淡褐叶基因lbsl1(t)定位在第6染色体短臂上一个约130kb的区段上。定位的结果和发展的群体为该基因的进一步精细定位和克隆奠定了基础。
