Breeding and Application of Restorer Guanghui 1002 with Weak Photoperiod Sensitivity and Bacterial Blight Resistance in Hybrid Rice

Abstract

It is of significance to develop and promote late-maturing rice varieties with weak sensitivity to photoperiod for bringing the potential of light and temperature resources into full play at the late growing stage, and enhancing the yield and the grain quality of rice in the late cropping season in South China. By using both traditional breeding and molecular marker-assisted selection to pyramid Xa7, the dominant and wide-spectrum resistant gene of bacterial blight, LP1(LH1)and LP2 (LH2), the complementary gene inducing photoperiod sensitivity, a late-maturing restorer line Guanghui 1002 (R1002) with bacterial blight resistance and the characteristic of weak sensitivity to photoperiod induced by gene interaction. And seven late-maturing high yielding hybrid rice varieties, such as Jifengyou 1002 and Taiyou 1002 derived from the restorer line R1002, were developed and approved for commercial production at national level or provincial level. Among them, Jifengyou 1002 not only had high and stable yield, but also had strong diseases and lodging resistance and wide adaptability. It was recognized by the Ministry of Agriculture and Rural Affairs as a Super Rice variety and the leading agricultural variety in Guangdong Province, and has been the weakly photoperiod-sensitive variety with the largest annual planting area for 5 consecutive years in South China. Taiyou 1002 had fine grain quality, and won the gold prize in the third national taste evaluation of high-quality rice varieties. It also has been widely grown in South China, and became a leading variety in Guangdong Province. Based on the characteristics of the R1002-derived hybrid rice varieties, the high-yield seed production techniques in Guangdong and Hainan were worked out, and a record of 4.59-4.97 t/hm2 of seed production was created for Jifengyou 1002 in Hainan. Strategies for breeding hybrid rice varieties with bacterial blight resistance and enhancing the efficiency of breeding restorer lines with photoperiod sensitivity and longer growth duration were discussed