吉粳503是吉林省农业科学院水稻研究所于1999年以日本高产优质品种奥羽346为母本,以抗逆性强、大穗、少蘖的丰优207为父本杂交,当年冬在海南加代,2000年在所内进行F2代单株选拔,当选单株2000年冬 Jijing 503 is the Institute of Rice Research Institute of Jilin Academy of Agricultural Sciences in 1999 to high-yielding varieties of high-quality Japanese Oku 346 as the female parent to strong resistance, big spike, less tiller abundance you 207 as the male parent hybrid, In 2000, the F2 single plants were selected in the institute, and the single plant was selected as the winter of 2000