Breeding of New Hybrid Rice Combination Y Liangyou 7 with High Yield and Good Quality by Introducing Yield-increase QTLs of Wild Rice

Y Liangyou 7 or Y58S/R163,is a new two-line medium hybrid rice combination developed by China National Hybrid Rice Research and Development Center(CNHRRDC).R163 is a new CNHRRDC-developed parental line carrying both yld1.1 and yld2.1 QTLs from a Malaysian common wild rice by crossing 9311,a parent of super hybrid rice,as the receptor and recurrent parent,with the Malaysian common wild rice,the donor of the yieldincrease QTLs,and selecting single plants with yield-increase QTLs with the aid of molecular markers to make backcrosses successively.Y58S is a CNHRRDC-developed PTGMS line with a wide adaptability.Y Liangyou 7 is characteristic of good plant type,high-yielding capacity,fine grain quality,strong stress resistance and wide adaptability.In March,2008,it was registered and released to commercial production by Hunan Provincial Crop Variety Appraisal Committee,and in the same year it was ranked as a super rice variety in Hunan Province.The breeding procedure,characteristics and major applied techniques in high-yielding cultivation and hybrid seed production of Y Liangyou 7 were introduced in this paper.