Breeding and Properties of Hybrid Rice Yexiangyou 699

  Objective  A disease-resistant, high-quality hybrid rice was bred to meet the market demand and improve the profitability for the farmers.

  Method   Based on the desired gene haplotypes, the high-yield, disease-resistant, strong-restoring and combining Fuhui 699 restorer line was selected as the male parent to cross with the female parents, the 3 sterile Yexiang A lines that are known for their desirable fragrance, high quality, and strong disease-resistance. The resulting F₁ hybrid was examined for the target traits at multi-year and multi-point rice blast resistance tests as well as multi-ecological adaptability and rice quality analyses.

  Result  From 2017 to 2018, the choice hybrid, Yexiangyou 699, was submitted to the regional trial on mid-season rice in Fujian. It displayed an evenly distributed population of acceptable plant type and delivered a two-year averaged growth period of 140.4 d, which was 2.8 d shorter than the reference, II You 3301. The effective panicle number of the cultivar averaged 2.085 million panicles·hm⁻², the plant height 135.4 cm, the seed setting rate 86.89%, and the 1000-grain weight 26.3 g. The average crop yield was 9 404.3 kg·hm⁻², which was 1.50% higher than that of control. The hybrid inherited 7 blast-resistance and two virus-resistance genes from the parents rendering it blast-free in the field and laboratory for 2 years.

  Conclusion  The rates of brown and milled rice of Yexiangyou 699 (now officially identified as Min Approved Rice No. 20200012) were 80.1% and 68.5%, respectively. The grain quality indicators of the hybrid included 0.8% on chalkiness, Grade 1 on transparency, 5.5 on alkali elimination, 86 mm on gelatinized consistency index, 14.0% on amylopectin content, 3^rd grade on the high-quality edible rice set by the Ministry, and high yield and strong disease-resistance in the field. Yexiangyou 699 was recommended as a new breed for cultivation.