影响华柑4号椪柑果实大小的因子研究  

Study on factors affecting fruit development of seedless ponkan cultivar Huagan No.4

作　　者：刘承浪 李港秋 李顺心 魏冉冉 路妍 程超 唐政 刘保艳 叶俊丽[1] 柴利军[1] 邓秀新[1] 谢宗周[1] LIU Chenglang;LI Gangqiu;LI Shunxin;WEI Ranran;LU Yan;CHENG Chao;TANG Zheng;LIU Baoyan;YE Junli;CHAI Lijun;DENG Xiuxin;XIE Zongzhou(National Key Laboratory for Germplasm Innovation&Utilization of Horticultural Crops/College of Horticulture and Forestry Sciences,Huazhong Agricultural University,Wuhan 430070,Hubei,China;Institute of Tropical and Subtropical Cash Crops,Yunnan Academy of Agricultural Sciences,Baoshan 678000,Yunnan,China;Changjiang Survey,Planning Design and Research Co.,Ltd,Wuhan 430010,Hubei,China)

机构地区：[1]果蔬园艺作物种质创新与利用全国重点实验室·华中农业大学园艺林学学院,武汉430070 [2]云南省农业科学院热带亚热带经济作物研究所,云南保山678000 [3]长江勘测规划设计研究有限责任公司,武汉430010

出　　处：《果树学报》2025年第4期721-731,共11页Journal of Fruit Science

基　　金：国家现代农业(柑橘)产业技术体系(CARS-26);长江勘测规划设计研究有限责任公司自主创新项目(CX2021Z52)。

摘　　要：【目的】探究影响无核椪柑果实大小的关键因子,为生产优质大果椪柑提供理论依据。【方法】以无核椪柑华柑4号(HG4,后同)和有核椪柑华柑2号(HG2,后同)为试材,通过观察果实生长发育动态、测定植物内源激素含量及分析转录组数据等手段来明确HG4果实发育的影响因子。【结果】与HG2相比,HG4果实偏小且发育迟缓,发育早期其内源激素IAA、GA_(3)、Zeatin含量偏低。通过对比HG2和HG4的两个发育时期的果实转录组数据,鉴定出参与细胞发育等生物过程的173个差异表达基因。其中HG4生长素合成通路上YUC的同源基因(CmYUC10、CmYUC11)、赤霉素合成通路上GA20ox的同源基因(CmGA20ox1、CmGA20ox5)和细胞分裂素合成通路上的基因CmIPT2表达水平整体相较于HG2更低,该表达趋势与内源激素含量测定的结果相符。此外,统计分析表明HG4结果母枝粗度在1.56~3.49 mm,与果实横径呈正相关;位于树上部的果实中,横径>70 mm的大果占比高达40%,而生长在下部的果实中,横径>70 mm的大果仅有4%。【结论】HG4果实发育早期激素代谢通路基因低表达影响其内源激素含量,可能限制了果实细胞分裂和细胞扩张,同时发现HG4结果母枝粗度和结果高度也是影响其果实大小的重要因素。【Objective】Ponkan(Citrus reticulata Blanco.)is one of the main Mandarins cultivars in China.Huagan No.4 is a new seedless cultivar selected from a bud sport of Jing’an ponkan,with improved fruit quality.However,the cultivar has the problems of low fruiting rate and slow fruit development,limiting its industrial deployment.Therefore,it is important to clarify the key factors affecting the fruit size of seedless ponkan for high-quality production.【Methods】Huagan No.4(HG4)and Huagan No.2(HG2)were used as test materials.The paraffin section was used for observing the fruit development,sequencing transcriptome was performed to detect the difference of the gene expression between the two varieties.【Results】The observation of the equatorial surface of young fruits from 5 to 45(DAF)revealed that the number of cell layers in the white pericarp of HG4 was more than HG2 on 5 DAF,but consistently less than HG2 from 15 to 45 DAF.The morphology of HG4 and HG2 was also observed during the cell division stage,and the white pericarp cell density of both continued to decrease from 5 to 45 DAF.The cell density of HG4 was consistently larger than HG2 from 15 to 45 DAF,and the significant difference was found on 35 DAF.The fruit transverse longitudinal diameters were measured at 30 day intervals starting on 80 DAF and it were found to be consistently and significantly smaller in HG4 than HG2.The plant endogenous hormone IAA,GA_(3) and Zeatin contents in young fruits of HG2 and HG4 showed an overall increase followed by a decrease from 15 days before flowering(DBF)to 45 DAF.The IAA contents of HG4 and HG2 were 117.08 ng·g-1 and 290.21 ng·g-1,respectively,on 45 DAF,the different was significant.The GA_(3) content of HG2 peaked at 2.27 ng·g-1 on 25 DAF,while the GA_(3) content of HG4 was only 0.90 ng·g-1,with significant differences.The GA_(3) and Zeatin contents of HG2 were higher than those of HG4 on 25 and 45 DAF.The differentially expressed genes were screened using the Citrus clementina genome with the criteria of

关 键 词：柑橘 无核椪柑 内源激素 果实发育 基因表达分析 

分 类 号：S666[农业科学—果树学]