Molecular Marker Assisted Breeding of a New <i>Japonica</i> Hybrid Rice

Abstract

The development of Japonica  hybrid rice is of great significance to ensure supply of good quality Japonica  rice and food security in China. Aiming at the problems of late growth period, unstable yield, and the need to improve rice quality and seed production yield of Japonica  hybrid rice, a new Japonica  hybrid rice combination 'Shenyou28' with early maturity, good quality, blast resistance, stable and high yield and easy seed production was developed by using molecular breeding techniques including high-density rice gene chip. 'Shenyou28', bred by Shanghai Academy of Agricultural Sciences, is a three-line Japonica  hybrid rice with 'Shen21A' as sterile line and 'Shenhui26-28' as restorer line. For two-year regional trials from 2018 to 2019, the average output were 10 588.5 kg/hm 2 , which was 11.6% higher than the control variety 'Huayou14'. For the one-year production trial, the output reached 10 473.0 kg/hm 2 , which was 4.8% higher than the control variety 'Huayou14'. 'Shenyou28' has good quality, reaching the second grade of national standard, and has fragrance because it carries fragrance gene badh2-p-5 ’ UTR . It also has good resistance to rice blast and bacterial blight because it aggregates the rice blast resistance genes Pi2 , Pita , Pib , Pi9 , Pi54 , Pikm , Pit , and bacterial blight resistance gene Xa21 . It was approved by the Crop Variety Certification Committee of Shanghai in 2020. The breeding process, variety characteristics and key points of high yield mechanized seed production technology of 'Shenyou28' are introduced in this study.