Breeding of Quanshu No.9,a new high quality sweetpotato with multiple disease-resistances and a high starch content

Breeding and main characteristics of Quanshu No.9,a new sweetpotato variety,are preliminarily presented in this report in order to provide references for its potential production and breeding applications.Quanshu No.9 was bred from the female parent,Quanshu 268,by open-pollination by Quanzhou Institute of Agricultural Science in 2003.Its innovative and successful breeding method of using middle-materials as parents of composite hybridization through single cross,group cross or open-pollination was effective for sweetpotato breeding.Trials at multiple-spots in different years showed that Quanshu No.9 had a high yield,and its dry root and starch were especially high and stable.The annual yield of the dry root was between 8.50 and 14.93 t·hm-2,being 104.20% to 152.30% of those of the reference varieties.The annual yield of starch was between 5.62 and 9.85 t.hm-2,being 107.91 to 155.36% of those of the reference varieties.The annual yield of starch was between 6.43 and 9.85 t·hm-2,being 109.75% to 155.36% of those of the reference varieties.The dry matter and starch contents of the fresh root was about 30.05% and 20.5%,respectively,i.e.,3.5%-4.0% higher than those of the reference varieties.The edible and sensory quality of the sweetpotatoes was better than that of Jinshang 57,and equivalent to that of Nanshu 88.Its external appearance was better than the reference varieties’.This variety was resistant to fusarium wilt,bacterial wilt,black spot,and stem nematode.And,among other superior characteristics,it had desirable storage performance and germinating ability.Quanshu No.9 was suitable for either fresh-eating or starch-processing.It was examined and approved by the Crop Variety Approval Committee of Fujian Province.Its acreage in Fujian was about 3000 hm2 in 2009,and the prospect for large production appeared to be bright in Southern and Middle China,as well as,the Lower Reaches of Yangtze River.