Breeding and Utilization of Fine Quality Japonica CMS Line Aizhixiang A in Rice

Aizhixiang A, developed by testcrossing Aizhixiang (a Japanese japonica rice variety with fine quality and good disease resistance) to Liuqianxin A (a BT-type japonica CMS line) and backcrossing successively with Aizhixiang, is an early-maturing medium japonica CMS line. It is characteristic of fine grain quality, strong disease resistance, desirable agronomic characters, complete male sterility and good combining ability. It was technically identified in August, 2002 and certified in January, 2003 by Jiangsu Crop Variety Release Committee. Crossing it to a new restorer line MR18, the new japonica hybrid rice combination Xiangyou 18 (Aizhixiang A/MR18) has been developed. Certified by Jiangsu Crop Variety Release Committee in January 2003, Xiangyou 18 shows a good grain quality, a high-yielding ability and a good disease resistance in various trials and experimental productions.