黑核桃(Juglans nigra L.),又称美国东部黑核桃,原产北美洲,属胡桃科核桃属黑核桃种,是温带落叶阔叶林区代表性的多用途树种。该树种具有较高的经济价值,是果材兼用型硬木材树种之一,坚果外壳的硬度远超普通核桃,工业上可用于铝、铅合金等金属制品的天然抛光材料;核仁富含不饱和脂肪酸及蛋白质,风味浓郁独特,营养丰富,具有较高的食品加工价值。该树种的木材结构紧实,强度高,且纹理细腻富光泽,广泛应用于高档家具的制造[1-3]。
BH08 黑核桃优良选育品系,景观与工艺价值较高。果实外形圆润饱满,壳面有密集的大小不均突起且有较明显的棱状,经打磨后可呈现独特的艺术质感,成为手串、念珠等文玩饰品的优选原料;同时,树姿挺拔、叶幕浓密,兼具防风固沙与园林造景功能,是生态修复与园林绿化协同发展的理想树种。
1 选育过程
1993年新疆林业科学院首次从美国内布拉斯加州引进东部黑核桃种子,在新疆林业科学院树木园进行育苗、定植,第4年开花结实,生长适应性良好,完成引种适应性周期。2000年从河南省洛宁县国家级黑核桃良种繁育示范基地引进6个品系1年生嫁接苗,分别定植在南疆—新疆林科院佳木试验站和北疆—新疆林科院玛纳斯试验站,表现出良好的适应性。2016 年通过了新疆林木品种审定委员会审定,命名为新疆黑核桃(良种编号为新S-SF-JN-010-2016)。BH08黑核桃是新疆黑核桃审定良种的家系苗中选育出的坚果小、外形饱满、圆润、质地坚硬、纹路美观、适宜做手串和念珠等饰品、园林绿化的优良品种。2024年通过了新疆维吾尔自治区林木品种审定委员会审定(编号:新R-SSO-JN-006-2024)。
利用8对多态性显著的SSR引物,对4份黑核桃材料进行SSR 分子标记鉴定。结果表明,4 份材料在扩增图谱中BH08 黑核桃与对照(第4 泳道)呈现显著差异(图1)。该分子鉴定结果为黑核桃品种鉴别及种质资源保护提供了科学依据。
2 主要性状
2.1 坚果经济性状
BH08 黑核桃果实形态特征显著,果壳厚实,外形饱满近圆形,果柄长度约4 cm;干果三径测量值为:纵径22.06 mm、横径20.74 mm、侧径19.57 mm;果实基部与顶部均具明显隆起,壳面有密集的大小不均突起且有较明显的棱状;单果平均质量为13.50 g,壳厚2.62 mm、果仁质量3.7 g,出仁率为16.96%(图2)。该品系兼具致密坚硬的壳质特征与独特的立体纹饰。
2.2 植物学特征
该品种树势生长强健,结果以后树姿半开张,树冠圆形,盛果期树高11.63 m,冠幅(东西×南北)5.30 m×6.20 m。奇数羽状复叶,叶片13~23枚,叶柄处簇生黄褐色茸毛,小叶对生,叶基部偏斜,叶缘锯齿状,叶较窄,叶色较深,叶脉较深,2 年生枝中基部为隐芽。该雌雄同株异花,属雌先型(图3)。以中果枝(5~15 cm)结果为主,嫁接后第3年开花结果,第4年花枝率为22%,结果枝率为16.9%。
2.3 生物学特性
2.3.1 物候期 引种于新疆阿克苏地区的黑核桃BH08表现出良好的生态适应性,其生长周期符合当地气候特征。据统计,该品种通常在4 月中旬开始萌芽,4月下旬新叶逐渐展开,呈现出清晰的绿色冠层。5 月初进入营养生长期,枝条顶端分生组织形成新梢,5月中旬雌雄花序同步进入开花期。夏季,在阿克苏充足光热资源充足、天山融水灌溉条件下,果实继续生长发育。9月中下旬种仁完成油脂积累和物质转化,木质化程度达到成熟标准。10月中下旬进入霜冻期,低温导致落叶和休眠。BH08 在该地区已形成稳定的物候期,具有环境适应性与栽培潜力。
2.3.2 抗逆性评价 多年观测结果表明黑核桃BH08 具备多重抗逆特性:(1)抗旱性:深根系及生理耐旱机制,在新疆适宜种植条件下,年灌溉仅需3次(展叶前一次、高生长速生前期一次,入冬前封冻水一次)即可维持正常生长;(2)耐盐碱:可耐受pH ≤8.5 的碱性土壤环境,盆栽试验显示幼苗耐盐阈值为0.48%;(3)抗寒性:休眠期树体具备超强低温耐受性,绝对低温达-35 ℃。
3 栽植技术要点
BH08 适宜在天山北坡、伊犁河谷和塔里木盆地平原绿洲区种植。种植需满足以下条件:立地要求为地下水位低于1.5 m、土层厚度≥50 cm 的微碱性壤砂土或壤土(pH ≤8.0)。造林技术要点包括:播种育苗宜在秋季土壤冻前1 周实施,保留外种皮直接播种;裸根定植时优先选用1~2 年生一级实生苗;栽植密度以3 m×3 m 或3 m×4 m 的株行距配置为佳。嫁接改良推荐以新疆黑核桃做砧木,在春季采用枝接法或夏季实施芽接法嫁接BH08黑核桃优良单株,该组合模式可使嫁接成活率超过90%。嫁接后需落实接穗除萌、水肥调控及中耕除草等技术措施。病虫害防治应注意防控核桃黑斑蚜、枣大球蚧、腐烂病与枝枯病等危害,用3~5°Bé石硫合剂在萌芽前进行全园喷施防控。
4 综合评价
黑核桃新品种BH08 是从新疆黑核桃良种家系中选育的优质品种,具有优异性状和显著特点。其坚果小、果壳圆润饱满、壳质致密坚硬、纹理美观,抗逆境能力强,可作为园林绿化的种质资源推广应用。新品种BH08树干直立、枝繁叶茂,具有防风固沙与园林造景功能,还是园林绿化的理想树种。
参考文献References:
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Breeding of a new black walnut variety BH08
TAN Juan1,WANG Junwu2#,XU Siyuan3,SONG Fenghui3,HU Haifang3*
(1College of Horticulture and Forestry, Tarim University, Alar 843300, Xinjiang, China;2Xinjiang Uygur Autonomous Region Forestry Key Project Quality Management Station, Urumqi 830000, Xinjiang, China;3Xinjiang Uygur Autonomous Region Forestry Academy,Urumqi 830000,Xinjiang,China)
Abstract:BH08 black walnut is a new variety selected from Xinjiang black walnut. In 1993, Xinjiang Academy of Forestry Sciences introduced eastern black walnut seeds from Nebraska, USA for the first time.The seedlings blossomed and fruited in the 4th year,displaying good growth adaptability.In 2000,we introduced 6 strains of one-year grafted seedlings from the national black walnut breeding demonstration orchard in Luoning County,Henan Province,which were planted in the southern and the northern experimental stations of Xinjiang Academy of Forestry Sciences, and showed good demonstration results. In 2016, a variety introduced from the United States was approved by the Xinjiang Forest Tree Variety Approval Committee and named Xinjiang Black Walnut(S-SF-JN-010-2016).BH08 Black Walnut proved to be an ideal cultivar for landscaping. The nuts are small, full and rounded in appearance,with hard texture, beautiful surface lines, can be used for processing into craft jewellery development.The fruit has a pedicle about 4 cm in length,a longitudinal diameter of 22.06 mm,a transverse diameter of 20.74 mm, and a lateral diameter of 19.57 mm. The fruit base and top are protruding, and the fruit surface has dense uneven-sized protrusions and many obvious ribbing. The average weight of fruit is 13.5 g; the thickness of the shell 2.62 mm; the weight of the kernel 3.7 g; and the kernel recovery 16.96%. SSR molecular marker analysis confirmed that its genetic background is unique, significantly different from the other lines.BH08 has good ecological adaptability in Aksu region of Xinjiang and stable phenological period, with drought and salinity tolerance (pH ≤8.5, salt tolerance threshold 0.48%)and cold resistance(-35 ℃).The fruit matures in late September.This variety is monoecious with separate male and female flowers, and is of the female-first type. After grafting, it bears fruit in the third year. It is recommended to plant the variety in slightly alkaline sandy loam or loamy soil (pH ≤8.0)with a water table of less than 1.5 m and a soil thickness of ≥50 cm.Direct sowing of seeds with outer seed coat 1 week is carried out before soil freezing in autumn. Bare root planting is preferred when the seedlings are 1-2 years old,at a planting density of 3 m×3 m or 3 m×4 m.It is recommended to use Xinjiang black walnut as rootstock. Whip grafting of BH08 is applied in spring, while budding used for summer. Such a graft combination enables a survival rate of above 90%.After grafting, it is necessary to strengthen the scion growth by removing sprouts from the stock and well management of water,fertilizer and weeds. Pest control should be strengthened. It can be widely used in the protection forests of agricultural areas and urban gardens in the oasis areas of the north slopes of Tianshan Мountain,the Ili River Valley and the plains of the Tarim Basin.
Key words:Black walnut;New variety;BH08;Landscape greening application
中图分类号:S664.1
文献标志码:A
文章编号:1009-9980(2025)09-2221-04
DOI:10.13925/j.cnki.gsxb.20250180
收稿日期:2025-04-07
接受日期:2025-04-17
基金项目:2022 年度南疆重点产业创新发展支撑计划项目(2022DB022);2024 年中央引导地方科技发展专项资金项目(ZYYD2024CG02);新疆维吾尔自治区重点研发计划项目(2024B02017)
作者简介:谭娟,女,在读硕士研究生,研究方向果树种质资源与品种选育。E-mail:2431678832@qq.com。#为共同第一作者。
*通信作者Author for correspondence. E-mail:huhaifang1109@sina.com