Improvement And Application Of 'Potato Yu No.2'

'Potato Yu No.2',novel precociously variety with desirable resistance and commercial quality,was released based on some cultivars such as 'Zhengshu No.2'.'Zhengshu No.3','Zhengshu No.4',and 'Zhengshu No.5' by Zhengzhou vegetable research institute.The cultivar coupled with agronomically desirable traits (short dormancy,high resistance to some diseases,good yield,and suitability to international consumers) was suitable to plant in monoculture or intercropping in one-and two-growing season areas in open field,plastic film mulching,plastic tunnel and greenhouse.Selected 'plateau No.7' as a female parent and an accession 'Zheng 762-93' as male parent,the cultivar was improved by crossing and selection for some generations. The mature period covers around 65 d from seedling appearance to harvest,lasts dormant at least 45 d.The yield is about 30 000-60 000kg/hm~2,22 500-37 500 kg/hm~2 in spring and autumn,respectively.More than 90%tubers with oval-shape, smooth yellow skin and pulp,shallow bud are orderly large to meet a first class standard exported.The content of dry matter,starch,reducing sugar,gross protein, vitamin C,is about 20.35%,14.66%,0.177%,2.25%,13.62mg/100g,respectively, the cultivar is used as both processing and fresh food.It is resistant to many kinds of viruses,diseases,and vermin.With more 11.2%yield than the control 'Zhengshu No.4','potato Yu No.2' has been applied in Henan,Anhui,Jiangsu,Fujian,Hebei,Shangdong,Shangxi,Jilin, Hubei,Heilongjiang provinces and so on,and become one of main cultivars, accounting for 40%in total production area,in Henan province.