中国农业科学 ›› 2026, Vol. 59 ›› Issue (8): 1748-1759.doi: 10.3864/j.issn.0578-1752.2026.08.011

• 园艺 • 上一篇    下一篇

‘温州蜜柑+桃叶橙’胞质杂种果实增大的生理基础及相关基因发掘

管书萍1(), 李可1(), 解凯东1, 段耀园1, 王婷婷1, 周志虎2, 伍小萌1, 郭文武1,*()   

  1. 1 华中农业大学园艺林学学院/果蔬园艺作物种质创新与利用全国重点实验室, 武汉 430070
    2 秭归县屈原镇农业农村服务中心, 湖北秭归 443600
  • 收稿日期:2025-11-19 接受日期:2026-01-14 出版日期:2026-04-16 发布日期:2026-04-21
  • 通信作者:
    郭文武,E-mail:
  • 联系方式: 管书萍,E-mail:gsp954@126.com。李可,E-mail:3157659021@qq.com。管书萍和李可为同等贡献作者。
  • 基金资助:
    国家自然科学基金联合基金重点项目(U23A20203); 湖北省支持种业高质量发展资金(HBZY2023B00501); 湖北省技术创新计划(2024BBB085); 湖北省技术创新计划(2025BBB009); 国家柑橘产业技术体系(CARS-26)

Physiological Mechanism and Relevant Gene Identification for Fruit Enlargement in Satsuma mandarin+Taoye sweet orange Somatic Cybrid

GUAN ShuPing1(), LI Ke1(), XIE KaiDong1, DUAN YaoYuan1, WANG TingTing1, ZHOU ZhiHu2, WU XiaoMeng1, GUO WenWu1,*()   

  1. 1 College of Horticulture & Forestry Sciences, Huazhong Agricultural University/National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Wuhan 430070
    2 Agricultural and Rural Service Center of Qu Yuan Town, Zigui County, Zigui 443600, Hubei
  • Received:2025-11-19 Accepted:2026-01-14 Published:2026-04-16 Online:2026-04-21

摘要:

【目的】以原生质体融合技术创制的‘温州蜜柑+桃叶橙’胞质杂种(G1+TYC)及其叶肉亲本桃叶橙(TYC)为材料,探究G1+TYC果实增大的生理原因并鉴定关键基因,为柑橘果实大小的分子机理研究提供理论依据。【方法】以G1+TYC和TYC不同发育时期的子房或果肉为材料,通过对不同发育时期(包括成熟期)果实大小、果实糖酸与内源激素含量测定,以及转录组分析,明确G1+TYC果实增大的生理原因,并挖掘控制果实大小的关键基因。【结果】果实大小动态监测结果显示,G1+TYC果实横径和纵径分别于花后75和105 d时显著大于TYC,差异持续至果实成熟(花后240 d)。以2022年数据为例,花后240 d时,G1+TYC的果实横径、纵径分别为79.14和66.75 mm,而同期TYC的果实横径、纵径仅为56.02和53.20 mm,直观反映G1+TYC果实相较于TYC显著增大。G1+TYC成熟果实单果质量、囊瓣宽度、单汁胞重量和面积显著大于TYC,表明汁胞体积增大引起囊瓣宽度增加,是导致G1+TYC体积增大的原因。糖酸含量测定表明,花后90—240 d,G1+TYC果肉中果糖、葡萄糖、蔗糖含量均显著高于TYC,而柠檬酸和总酸含量则显著低于TYC,奎宁酸和苹果酸含量差异无明显规律。内源激素含量测定表明,花后30—60 d,G1+TYC果肉中吲哚-3-乙酸(IAA)含量显著高于TYC,赤霉酸(GA3)含量仅在花后0 d显著高于桃叶橙,玉米素(ZT)含量两年间重复性差,脱落酸(ABA)含量在花后90 d迅速增加,且G1+TYC果肉ABA含量在花后180 d显著高于TYC。结合转录组数据和GO功能富集分析,筛选出5个与IAA代谢相关的基因,在G1+TYC和TYC花后30—60 d果肉中差异表达,可能是决定G1+TYC果实增大的关键候选基因。【结论】明确了汁胞体积增大和果实发育早期果肉中IAA含量升高与G1+TYC果实增大密切相关,基于转录组分析发掘了G1+TYC果实增大相关候选基因。

关键词: 柑橘, 胞质杂种, 果实大小, 内源激素, 转录组

Abstract:

【Objective】Using the somatic cybrid Satsuma mandarin + Taoye sweet orange (G1+TYC), generated by protoplast fusion, and its mesophyll parent Taoye sweet orange (TYC) as materials, this study aimed to elucidate the physiological mechanism underlying fruit enlargement in G1+TYC and to identify candidate genes associated with the increased fruit size observed in this somatic cybrid.【Method】Ovaries and pulp tissues of G1+TYC and TYC at different developmental stages were used as materials. Dynamic monitoring of fruit size traits, determination of sugar and acid contents, and measurement of endogenous hormone levels were performed across various fruit developmental stages including the mature stage. Combined with transcriptome and bioinformatics analysis, this study was conducted to clarify the physiological causes of fruit enlargement in G1+TYC and to identify key candidate genes controlling fruit size.【Result】Dynamic monitoring of fruit development in three consecutive years showed that the transverse diameter of G1+TYC fruits was significantly larger than that of TYC starting from 75 days after flower (DAF), and the longitudinal diameter exhibited a significant superiority from 105 DAF onwards, with these differences persisting until 240 DAF. Taking the 2022 data as an example, the transverse and longitudinal diameters of the fruits from G1+TYC reached 79.14 and 66.75 mm at 240 DAF, respectively, while those from TYC were only 56.02 and 53.20 mm during the same period. This directly reflects the significant enlargement of fruit diameter of G1+TYC compared with TYC. The mature fruits of G1+TYC also had significantly higher fruit weight, segment width, single juice sac weight and area than TYC, indicating that the enlargement of juice sac volume contributed to the increase in segment width, thereby promoting the overall fruit size expansion of G1+TYC. Sugar and acid content determination revealed that the contents of fructose, glucose and sucrose in G1+TYC pulp were significantly higher than those in TYC during 90-240 DAF, whereas the contents of citric acid and total acids were significantly lower in G1+TYC. In terms of other organic acids, the difference in quinic acid and malic acid content between the two genotypes showed no obvious regularity. Endogenous hormone analysis demonstrated that the IAA content in G1+TYC pulp was significantly higher than that in TYC during 30-60 DAF. The GA3 content of G1+TYC was significantly higher only at 0 DAF, while the ZT content showed poor repeatability across the two years of measurement. The ABA content increased rapidly after 90 DAF, and the ABA content in G1+TYC pulp was significantly higher than that in TYC at 180 DAF. Combined with transcriptome sequencing and GO enrichment analysis, five genes related to IAA metabolism were identified to be differentially expressed between G1+TYC and TYC during 30-60 DAF, which might serve as key candidate genes determining the fruit enlargement of G1+TYC.【Conclusion】This study revealed that enlargement of juice sac volume and elevated IAA content in pulp at early stage of fruit development were closely associated with fruit enlargement of G1+TYC. Moreover, candidate genes related to fruit enlargement in G1+TYC were identified based on transcriptome analysis, providing valuable genetic resources for citrus fruit size regulating mechanism research and further genetic improvement.

Key words: Citrus, cybrid, fruit size, endogenous hormones, transcriptome