桃是原产于我国的果树种类之一，种植面积和产量近年来稳居世界第一位[1-2]，产业化栽培在我国落叶果树中居第三位，也是我国最古老的栽培果树之一，其栽培史在4000年以上。我国桃种质资源丰富，经过长期的栽培演化，以及桃育种工作者的选育研究，新中国成立以来育成不同用途的桃新品种600 多个[1]。21 世纪是河北科技师范学院桃育种团队在2000年选育的耐贮运晚熟桃，经济性状优良[3]，尤以果个大、色泽艳、含糖量高、晚熟、耐贮等突出优点，在河北南部、山西临猗、山东蒙阴、重庆潼南等地广泛栽培，但因其抗寒性较差，限制了该品种在石家庄以北地区的推广栽培。为保持21 世纪桃的优良性状，解决抗寒性差的问题，于2003年开始，以21世纪品种为亲本，开展品种改良工作，历经17 a（年），育成抗寒性较强的优质桃新品种世纪之星。
1 选育过程
2003年春季选择亲本进行人工杂交，以21世纪和久脆（原大久保实生后代‘35号’）[4]分别为父母本进行正反杂交，将获得的杂交种子在冬季进行沙藏。2004 年3 月在温室内营养钵播种获得实生苗389株，其中正交261株，反交128株，定植于河北科技师范学院桃育种基地（昌黎县），2008年全部实生树进入结果期。2010年1月份我国北部遭遇了几十年不遇的低温，昌黎县出现-21.1 ℃低温，实生树自然淘汰194 株，基地内36 株21 世纪无一幸存，对存活的195 株抗寒力良好的实生树，根据育种目标对其果实性状[5]进行连续观察记载和选择，获得初选优系‘J3-1’。2010—2013 年进行高接，2015 年开始陆续在保定、秦皇岛、北京、唐山等地进行多点试验和品种比较试验。2021 年1 月昌黎县再次出现了-21 ℃低温，该优系未发生冻害。表明果实优良性状稳定，适应性良好。2021 年4 月通过了河北省林木品种委员会审定，命名为世纪之星（图1），良种编号：冀S-SV-AP-005-2020。
2 主要性状
2.1 植物学特征
树势中庸，树姿开张，树干光滑，灰褐色，老树树皮有横向裂纹。新梢光滑，分枝较多，青绿或红褐色。各类果枝均能结果，以中长果枝为主。叶片宽披针形，叶缘锯齿粗大，叶柄短，6～8 mm，柄基有圆形腺体2～4个；叶色深绿，叶面平整，花芽肥大呈圆锥形，花梗极短，萼筒内壁橙黄色，花朵为蔷薇型，花瓣卵圆形，花瓣粉红色，有雄蕊20枚，花柱1枚。有花粉。
2.2 果实经济性状
果实圆形、端正，两侧对称，果顶微凸，缝合线深，平均单果质量350 g，最大单果质量589.2 g；果实底色黄白，果面着鲜红色，着色度80%；果肉白色，近成熟时呈现红色，黏核，不溶质，硬度8.9 kg·cm-2；汁液中多，风味甜，具香气，可溶性固形物含量16.0%，较耐贮运，在常温下可贮藏10～15 d，在低温下可贮藏30～40 d（表1）。
表1 世纪之星与父母本的比较
Table 1 Typical characteristics of Shijizhixing and its parents
2.3 物候期
世纪之星属于晚熟品种，在秦皇岛地区，一般4月18日左右开花，盛花期4月下旬，花期持续7～8 d，果实8月下旬至9月上旬成熟，果实发育期125 d，适宜采摘期7～10 d，11月上旬落叶。
3 栽培技术要点
适宜沙壤土栽植；株行距（2～3）m×（5～6）m 为宜；适宜的树形为开心形、Y字形；自花结实，无需配置授粉树；幼树开张角度以30°～45°为宜；结果以后，冬季修剪采用长枝修剪法；重点去除直立旺枝。果实成熟前一个月控制水分供应；因其花芽量较大，在花果管理中，按20 cm间距留花留果；无特殊病虫害。
4 综合评价
世纪之星桃主要用于鲜食兼加工（制罐）。其成熟期正好在大量中熟品种采收之后，补充空档，具有很好的市场前景。自然存贮5 d后汁液增多，风味甘甜，香气浓，适于鲜食。同时，其果肉白色，核附近红色素少，又为黏核，故也可用于加工。
参考文献References：
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Breeding report of a new high-quality peach cultivar Shijizhixing
SONG Liqin1,WANG Licheng2,WANG Haijing1,LIU Junming2,LI Qingquan2,LIU Jianzhen1,WU Junkai1,XIAO Xiao1,YU Fengming1,ZHANG Libin1*
(1College of Horticultural Science and Technology,Hebei Normal University of Science and Technology/Hebei Key Laboratory of Horticultural Germplasm Excavation and Innovative Utilization,Qinhuangdao 066004,Hebei,China;2Department of Forestry of Mancheng,Baoding 072150,Hebei,China)
Abstract: Shijizhixing is a new high-quality and late-ripening peach variety derived from a cross between 21 Century and Jiucui in 2003 at experimental field.The male parent,21 Century is a late-ripening variety with good storability,high total soluble solids and good coloration,but its poor cold resistance limits its cultivation area.The female parent Jiucui has a good storability and is cold resistant.Both of them were bred by the peach breeding team of Hebei Normal University of Science&Technology.The cross-pollination was performed in 2003,and the hybrid seeds were collected and sown in the same year.389 seedlings were planted at experimental field in Hebei Normal University of Science &Technology,and the seedlings fruited in 2008.In the early January of 2010,the northern part of China experienced an extreme low temperature,which dropped to 21.1 degrees below zero in Changli county.Thirty-six 21 Century trees planted in the same experimental field were frozen to death,and 194 of the seedling trees were eliminated.J3-1 was selected from the survived seedling trees for its strong cold resistance and good fruit characters.From 2010 to 2020,the continuous observation was performed in Baoding,Qinhuangdao,Tangshan (Hebei province) and Beijing.In the early January of 2021,J3-1 experienced a freezing stress with the lowest temperature reached 21 degrees below zero in Changli county.The flower buds of all peach varieties except J3-1 were damaged by freezing.In a word,the fruit characters of J3-1 were consistent in the past 10 years.J3-1 has passed the examination and approval of Hebei Forest Tree Variety Committee,and was named Shijizhixing in April,2021.The trees of Shijizhixing are moderately vigorous and open in canopy,with a smooth and gray-brown trunk,bark of which has transverse cracks in the old trees.All types of fruit branches can bear fruit.The leaves are broadly lanceolate with a short petiole.The flower buds are plump and conical in shape with extremely short pedicels about 6-8 mm.The spherical fruit is bilaterally symmetry with an average weight about 350 g.The maximum single fruit weight can be up to 589.2 g.From 2018 to 2020,the output of Shijizhixing in Department of Forestry of Mancheng was 2242 kg per 666.7 m2,2236 kg per 666.7 m2,2110 kg per 666.7 m2,respectively.The base color of fruit is yellowish white with 75% bright red peel.Its flesh is white,also partly red when ripe.The fruit hardness is 8.9 kg·cm-2.The fruit is of good taste with aromatic flavor,and the soluble solids content is 16.0%.It has a good tolerance to cold and storability.The fruit growth period is 125 d.The fruit ripens from late August to early September in Qinhuangdao and Tangshan,Hebei Province.Shijizhixing trees perform well in neutral sandy soils with good moisture and fertilizer holding ability.The spacing recommended is(2-3)m×(4-5)m with opencentered training or Y-type training.The opening angle of sapling should be 30°-45°,and water supply should be controlled one month before fruit ripening.The stamens could produce viable pollen and doesnt need a pollinating tree.The trees have no special diseases and insects or pests.
Key words: Peach;New cultivar;Shijizhixing
中图分类号：S662.1
文献标志码：A
文章编号：1009-9980(2022)08-1511-03
DOI:10.13925/j.cnki.gsxb.20220049
收稿日期：2022-02-14
接受日期：2022-03-19
基金项目：河北省科技厅项目（14226301D-6）；河北省农业农村厅项目（HBCT2018100203）；热杂果现代种业科技创新团队(21326310D)
作者简介：宋立琴，女，助理研究员，硕士，主要从事桃遗传育种研究。Tel：0335-8069851，E-mail：yyylx9311@163.com
*通信作者Author for correspondence.Tel：13603232069，E-mail：13603232069@163.com
