Evaluation On Fruit Characteristics And Detection On Virus Diseases In Mother Tree Of ’Ruiyang’ & ’Ruixue’

‘Ruiyang ’ and ‘ Ruixue’ ar e two new late-ripening apple cul tiva rs bred by Northwest A&F Unive rsity. To acce lera te the cultivar extension, it is essential to comprehensively study t heir cultivationl charact eristics and virus disease occurre nce in mother tree. In this work, the main fruit char acteristics(including frui t quality, yield, and storage chara cter istics) of the t wo culti vars were surveyed and evaluated comparing with that of their parents and check culti vars including ‘Fuji’, ’Qinguan’, ‘Pink lady’, ‘ Gol den delicious’ and ‘Orin’. Meanwhile,t hree kinds of latent vir uses that apple stem pi tting virus( ASPV), apple stem grooving virus(ASGV), appl e chlorotic leaf spot vi rus(ACLSV), and a kind of viroid that apple scar skin viroid(ASSVd) i n mother tree of ‘Ruiya ng’ and ‘ Ruixue’ were detected by RT-PCR. The main results obtaine d are as follows:1. The s ur vey res ults i n the field show that ‘Ruiyang’ exhibited t he characteristics of easy i nitiation of floral bud with pr ecocious fruit bearing. It has the cultivation characteri stics of hi gh and stable yield. This cultivar can bloom and bear fruit s after grafted on young tree for t wo years. The ability of yielding of dwarf t ree was 2917 Kg per 667m2 in the fifth year, which i s simil ar to ‘Qingua n’ and obvious ly higher than ‘Fuji’. ‘Ruiya ng’ exhibited the following main fruit char acteristics:(1) The fruit is conical, large in si ze. The surface of fruit is smooth and clean. The skin of fruit is strong red color. It c an be easily planted without bagging.(2)Good quality with fine and juicy flesh, crisp texture, ri ch-sweet and sour flavor, close to that of ‘Fuji’, significantly be tte r than that of ‘Qinguan’.(3)The storage ability i s strong, and t he be st e dible period i s about 60 th day after harvest.2. ‘Rui xue’ is a late-ripening yel low apple cultivar. This cultivar can bloom after pl anted or grafted on young tr ee for two years, bear fruits for three ye ars. The ability of yielding of dwarf tree was 2824 Kg pe r 667m2 in the fifth year. The main fruit characteristics of ‘Ruixue’i nclude :(1)The fruit with high pile is cylindr ical, large in size. The surface with no r ust is bright and clean. The appearance quality is obviously better t han that of ‘Golden de lic ious’ and ‘Orin’. The grou nd colo r is yel lowi sh-green and the sun-side is cover ed wit h splashe d red.The skin of baggi ng fruit i s pink col or.(2)The flesh is fine, firm and crisp i n texture, with special aroma, juicy and aromat ic fla vor in good balance of sugar and aci d.( 3)Goodstora bili ty with up to 150 days under room-temperature and the best edible period is about90 t h day after harvest.3. The results of virus detection in mother t ree of ‘ Ruiyang’ and ‘Ruixue’ showed that t he t wo cultivars were both infected by ASG V, ACLSV and ASSV d, were not infected by ASPV.