低需冷量桃新品种南桂桃1号的选育

Breeding report of a new low-chilling-requiring peach cultivar Nanguitao No. 1

南桂桃1号是以97-42-40为母本、Flordaglo为父本杂交育成的低需冷量桃新品种,需冷量约200 h。该品种果实扁圆形,果顶稍凹陷,平均单果质量233 g,最大单果质量454 g。果面茸毛中等,底色黄白色,3/4以上着红色。果肉白色,半离核,肉质为硬溶质,风味甜,可溶性固形物含量(w,后同)为12.4%,可滴定酸含量为0.24%。在江苏省南京市(经度118°87′、纬度32°03′)7月上中旬果实成熟,广西壮族自治区桂林市(经度109°45′、纬度24°18′)6月中旬成熟、靖西市(经度106°42′、纬度23°13′)5月底至6月初成熟。该品种生长势偏旺,花为蔷薇型,有花粉,自花结实,早果丰产;流胶病抗性中等,春季温度偏低年份有少量缩叶病发生。适宜江苏、广西以及类似气候条件区域种植。

Low temperature is essential for the normal growth and development of deciduous fruit spe-cies like peach.To break dormancy and resume growth,adequate accumulation of low temperatures(chilling requirement,CR)is necessary.Chilling requirement is the major factor to determine the bloom date,and plays a key role in the climatic distribution of plants as well as fruit yield and quality.With the development of peach production in the southern China and forcing culture in the northern China,low chilling requirement varieties with high quality are needed urgently.Nanguitao No.1 is a new low chill-ing peach cultivar with CRs about 200 h.It was derived from the cross between 97-42-40 as a female parent and Flordaglo as the pollen.The cross was made in spring of 2004,and 79 seedlings were trans-planted in the experimental orchard of Jiangsu Academy of Agricultural Sciences with a spacing of four meters between rows and one meter in the rows in late April of 2005.It was initially selected in 2009 for its early blooming,nice fruit shape and good flavor,and then top grafting was applied in Lishui.Af-ter regional adaptability testing at three sites(including Nanjing,Guilin and Jingxi)over eight years from 2012 to 2019,it was finally selected in 2019.The tree is vigorous with a semi-open growth habit.Young branches are amaranth in color.The internode length is long with the average of 2.93 cm.The green leaves are long lliptic-lanceolate,16.93 cm long and 4.50 cm wide.The petiole length is 0.97 cm,with 4-6 reniform glands.The flower is showy with five pink petals.It blooms in late-February to early-March in Nanjing(118°87′E,32°03′N),mid-February in Guilin(109°45′E,24°18′N),and late Janu-ary in Jinxi(106°42′E,23°13′N).The mature period is in early-mid July in Nanjing,mid-June in Gui-lin and by the end of May to early June in Jingxi.The fruit shape is oblate with concave top.The white skin is mostly covered by red blush.The flesh is white,hard melting,juicy,sweet with good quality.Haematochrome staining of pit cavities was found near the stone.The average fruit weight is 233 g and the maximum fruit weight is 454 g.The soluble solids content is 12.4%and the titratable acid content is 0.24%.The semi-free stone is small and nearly round.This cultivar is self-fruitful,and the open pollina-tion fruit rate is very high,reaching about 60%.It has good precocity and high yield potential,and fruit thinning is needed about 25 d after full bloom for good quality.It is moderately resistant to peach gum-mosis,while leaf curl occurrs in warm and damp spring.Long-shoot pruning should be taken to control vigorous growth of young trees.It can be planted in Jiangsu province,Guilin and Jingxi of Guangxi Zhuang Autonomous Region as well as other areas with similar climate and geographical conditions.