[1] 范双喜, 李光晨. 园艺植物栽培学[M]. 北京: 中国农业大学出版社, 2008: 1−2.

FAN Shuangxi, LI Guangchen. Horticultural Plant Cultivation [M]. Beijing: China Agricultural University Press, 2008: 1 − 2.
[2] 石江鹏, 张春芬, 李芙蓉, 等. 园艺植物小孢子培养技术研究进展[J]. 山西农业科学, 2017, 45(4): 669 − 673.

SHI Jiangpeng, ZHANG Chunfen, LI Furong, et al. Research progress on microspore culture technology of horticultural plants [J]. Shanxi Agricultural Sciences, 2017, 45(4): 669 − 673.
[3] OPARKA K J. What is phloem unloading? [J]. Plant Physiology, 1990, 94(2): 393 − 396.
[4] DINANT S. Phloem, transport between organs and long-distance signaling [J]. Comptes Rendus Biologies, 2008, 331(5): 334 − 346.
[5] AMSBURY S, BENITEZ-ALFONSO Y. Tightening the pores to unload the phloem [J]. Nature Plants, 2019, 5(6): 561 − 562.
[6] 张凌云, 张大鹏. 光合同化物韧皮部卸载途径和机制[J]. 植物生理学通讯, 2003, 39(4): 399 − 403.

ZHANG Lingyun, ZHANG Dapeng. Unloading pathway and mechanism of photosynthate phloem [J]. Plant Physiology Communications, 2003, 39(4): 399 − 403.
[7] MILNE R J, GROF C P L, PATRICK J W. Mechanisms of phloem unloading: shaped by cellular pathways, their conductances and sink function [J]. Current Opinion in Plant Biology, 2018, 43: 8 − 15.
[8] 吴楚, 朱能斌. 植物中糖转运途径、糖转运蛋白及其生理功能[J]. 湖北农学院学报, 2004, 24(4): 294 − 301.

WU Chu, ZHU Nengbin. Sugar transport pathways, sugar transporters and their physiological functions in plants [J]. Journal of Hubei Agricultural University, 2004, 24(4): 294 − 301.
[9] RUAN Yongling. Sucrose metabolism: gateway to diverse carbon use and sugar signaling [J]. Annual Review of Plant Biology, 2004, 65: 33 − 67.
[10] HU Liping, SUN Huihui, LI Ruifu, et al. Phloem unloading follows an extensive apoplasmic pathway in cucumber (Cucumis sativus L. ) fruit from anthesis to marketable maturing stage [J]. Plant Cell and Environment, 2011, 34(11): 1835 − 1848.
[11] REN Yi, SUN Honghe, ZONG Mei, et al. Localization shift of a sugar transporter contributes to phloem unloading in sweet watermelons [J]. New Phytologist, 2020, 227(6): 1858 − 1871.
[12] LOESCHER W H. Physiology and metabolism of sugar alcohols in higher plants [J]. Physiologia Plantarum, 1987, 70(3): 553 − 557.
[13] PATRICK J W, OFLER C E. Post-sieve element transport of photoassimilates in sink regions [J]. Joural of Experimental Botany, 1996, 47: 1165 − 1177.
[14] 岳胜钱, 栗燕, 杨秋生. 植物光合同化物韧皮部卸载途径研究进展[J]. 河南农业科学, 2016, 45(4): 1 − 6.

YUE Shengqian, LI Yan, YANG Qiusheng. Research progress of photosynthate phloem unloading pathway in plants [J]. Journal of Henan Agricultural Sciences, 2016, 45(4): 1 − 6.
[15] 聂佩显, 李晨, 高艳, 等. 光合同化物韧皮部卸载途径的研究进展[J]. 植物生理学报, 2019, 55(6): 697 − 702.

NIE Peixian, LI Chen, GAO Yan, et al. Research progress in photosynthate phloem unloading pathway [J]. Chinese Journal of Plant Physiology, 2019, 55(6): 697 − 702.
[16] MA Si, LI Yaxin, LI Xin, et al. Phloem unloading strategies and mechanisms in crop fruits [J]. Journal of Plant Growth Regulation, 2019, 38: 494 − 500.
[17] YAN Dawei, YADAV S R, PATERLINI A, et al. Sphingolipid biosynthesis modulates plasmodesmal ultrastructure and phloem unloading [J]. Nature Plants, 2019, 5(9): 1023 − 1023.
[18] YAN Dawei, LIU Yao. Diverse regulation of plasmodesmal architecture facilitates adaptation to phloem translocation [J]. Journal of Experimental Botany, 2020, 71(9): 2505 − 2512.
[19] LEE J Y, MARGARET F. Plasmodesmata in phloem: different gateways for different cargoes [J]. Current Opinion in Plant Biology, 2018, 43: 119 − 124.
[20] BOTHA C E J, MURUGAN N. Changes in structure and dimension of plasmodesmata in the phloem loading pathway in Tecoma capensis (Bignoniaceae)-locating the polymer trap [J]. South African Journal of Botany, 2021, 140: 76 − 86.
[21] MA Si, SUN Lulu, SUI Xiaolei, et al. Phloem loading in cucumber: combined symplastic and apoplastic strategies [J]. The Plant Journal, 2019, 98: 391 − 404.
[22] WEI Xiaoyang, NGUYEN S T, COLLING D A, et al. Sucrose regulates wall ingrowth deposition in phloem parenchyma transfer cells in Arabidopsis via affecting phloem loading activity [J]. Journal of Experimental Botany, 2020, 71: 4690 − 4702.
[23] ZHANG Xiaoyan, WANG Xiuling, WANG Xiaofang, et al. A shift of phloem unloading from symplasmic to apoplasmic pathway is involved in developmental onset of ripening in grape berry [J]. Plant Physiology, 2006, 142(1): 220 − 232.
[24] WU Yun, REN Ziming, GAO Cong, et al. Change in sucrose cleavage pattern and rapid starch accumulation govern lily shoot-to-bulblet transition in vitro [J/OL]. Frontiers in Plant Science, 2021, 11: 564713[2023-07-20]. doi: 10.3389/fpls.2020.564713.
[25] 张懿, 张大兵, 刘曼. 植物体内糖分子的长距离运输及其分子机制[J]. 植物学报, 2015, 50(1): 107 − 121.

ZHANG Yi, ZHANG Dabing, LIU Man. Long-distance transport of sugar molecules in plants and its molecular mechanism [J]. Botany Gazette, 2015, 50(1): 107 − 121.
[26] 刘林. ‘富有’柿果实韧皮部胞间连丝研究[J]. 果树学报, 2012, 29(5): 872 − 876.

LIU Lin. Study on plasmodesmata of phloem of Diospyros kaki cv. ‘Fuyu’ fruit [J]. Journal of Fruit Science, 2012, 29(5): 872 − 876.
[27] ZHANG Chunmei, BIAN Yuan, HOU Sihao, et al. Sugar transport played a moreimportant role than sugar biosynthesis in fruit sugar accumulation during Chinese jujube domestication [J]. Planta, 2018, 248(5): 1187 − 1199.
[28] 侯思皓, 边媛, 牛辉陵, 等. 枣和酸枣果实韧皮部糖分卸载途径及其积累研究[J]. 果树学报, 2017, 34(12): 1580 − 1589.

HOU Sihao, BIAN Yuan, NIU Huiling, et al. Study on sugar unloading pathway and accumulation in phloem of jujube and jujube fruit [J]. Journal of Fruit Science, 2017, 34(12): 1580 − 1589.
[29] ZHEN Qiaoling, FANG Zhengting, PENG Qian, et al. Developing gene-tagged molecular markers for evaluation of genetic association of apple SWEET genes with fruit sugar accumulation [J/OL]. Horticulture Research, 2018, 5(1): 14[2023-07-20]. doi: 10.1038/s41438-018-0024-3.
[30] 聂佩显. 同化物在枣果实韧皮部卸载的细胞学路径[D]. 泰安: 山东农业大学, 2009.

NIE Peixian. Cytological Pathway of Assimilate Offloading in Phloem of Jujube Fruit [D]. Tai’an: Shandong Agricultural University, 2009.
[31] WRIGHT K M, OPARKA K J. Physicochemical properties alone do not predict the movement and compartmentation of fluorescent xenobiotics [J]. Journal of Experimental Botany, 1994, 45(1): 35 − 44.
[32] 吴国良. 核桃果实韧皮部卸载的细胞学路径[D]. 北京: 中国农业大学, 2004.

WU Guoliang. Cytological Pathway of Phloem Unloading in Walnut Fruit [D]. Beijing: China Agricultural University, 2004.
[33] 宁代锋. 杨树光合同化物卸载的细胞学路径及其生理生化机制[D]. 南京: 南京林业大学, 2008.

NING Daifeng. Cytological Pathway and Physiological and Biochemical Mechanism of Offloading of Poplar [D]. Nanjing: Nanjing Forestry University, 2008.
[34] 岳胜钱. 牡丹光合同化物韧皮部转运的细胞学路径[D]. 郑州: 河南农业大学, 2016.

YUE Shengqian. Cytological Pathway of Phloem Transport of Paeonia suffruticosa [D]. Zhengzhou: Henan Agricultural University, 2016.
[35] 任陈希. CFDA示踪黄梁木碳水化合物的运输通道[D]. 广州: 华南农业大学, 2017.

REN Chenxi. CFDA Tracing of Carbohydrate Transport Channels of Neolamarckia cadamba [D]. Guangzhou: South China Agricultural University, 2017.
[36] CHEN Cheng, YUAN Yulin, ZHANG Chen, et al. Sucrose phloem unloading follows an apoplastic pathway with high sucrose synthase in Actinidia fruit [J]. Plant Science, 2017, 255: 40 − 50.
[37] LI C L, FANG K F, LEI H, et al. Phloem unloading follows an extensive apoplastic pathway in developing strawberry fruit [J]. Journal of Horticultural Science &Biotechnology, 2012, 87(5): 470 − 477.
[38] ZHANG Huping, WU Juyou, TAO Shutian, et al. Evidence for apoplasmic phloem unloading in pear fruit [J]. Plant Molecular Biology Reporter, 2014, 32(4): 931 − 939.
[39] 张凌云. 苹果果实韧皮部质外体卸载的证据[D]. 北京: 中国农业大学, 2003.

ZHANG Lingyun. Evidence of Extracellular Unloading in Phloem of Apple Fruit [D]. Beijing: China Agricultural University, 2003.
[40] WANG Tengduan, ZHANG Huifen, WU Zichen, et al. Sugar uptake in the aril of litchi fruit depends on the apoplasmic post-phloem transport and the activity of proton pumps and the putative transporter LcSUT4 [J]. Plant and Cell Physiology, 2015, 56(2): 377 − 387.
[41] REN Ziming, XU Yunchen, LVY Xuesi, et al. Early sucrose degradation and the dominant sucrose cleavage pattern influence Lycoris sprengeri bulblet regeneration in vitro [J/OL]. International Journal of Molecular Sciences, 2021, 22(21): 11890[2023-07-20]. doi: 10.3390/ijms222111890
[42] WERNER D, GERLIT N, STADLE R. A dual switch in phloem unloading during ovule development in Arabidopsis [J]. Protoplasma, 2011, 248(1): 225 − 235.
[43] MEHDI R, LAMM C E, ANJANAPPA R B. Symplasmic phloem unloading and radial post-phloem transport via vascular rays in tuberous roots of Manihot esculenta [J]. Journal of Experimental Botany, 2019, 70(20): 5559 − 5573.
[44] XIA Guohai, ZHANG Dapeng. Intercellular symplastic connection and isolation of the unloading zone in flesh of the developing grape berry [J]. Acta Botanica Sinica, 2000, 42(9): 898 − 904.
[45] KNOBLAUCH M, VENDRELL M, de LEAU E, et al. Multispectral phloem-mobile probes: properties and applications [J]. Plant Physiology, 2015, 167(4): 1211 − 1220.
[46] 张鹤华, 李艳芳, 聂佩显, 等. 蓝莓果实同化物韧皮部卸载路径与糖代谢酶活性[J]. 林业科学, 2017, 53(3): 40 − 48.

ZHANG Hehua, LI Yanfang, NIE Peixian, et al. Assimilation phloem unloading path and enzyme activity of sugar metabolism in blueberry fruit [J]. Scientia Silvae Sinicae, 2017, 53(3): 40 − 48.
[47] WU Guoliang, ZHANG Xiaoyan, ZHANG Lingyun, et al. Phloem unloading in developing walnut fruit is symplasmic in the seed pericarp and apoplasmic in the fleshy pericarp [J]. Plant Cell Physiology, 2004, 45(10): 1461 − 1470.
[48] 冯俊淳. 慈竹笋的蔗糖卸载途径及糖代谢和运输相关基因表达分析[D]. 绵阳: 西南科技大学, 2020.

FENG Junchun. Analysis of Sucrose Offloading Pathway and Expression of Genes Related to Glucose Metabolism and Transport of Bamboo Shoots of Bambusa emeiensis [D]. Mianyang: Southwest University of Science and Technology, 2020.
[49] NIE Peixian, WANG Xiaoyi, HU Liping, et al. The predominance of the apoplasmic phloem-unloading pathway is interrupted by a symplasmic pathway during Chinese jujube fruit development [J]. Plant and Cell Physiology, 2010, 51(6): 1007 − 1018.
[50] VIOLA R, ROBERTS A G, HAUPT S, et al. Tuberization in potato involves a switch from apoplastic to symplastic phloem unloading [J]. Plant Cell, 2021, 13(2): 385 − 398.
[51] PANIAGUA C, SINANAJ B, BENITEZ-ALFONSO Y. Plasmodesmata and their role in the regulation of phloem unloading during fruit development [J/OL]. Current Opinion in Plant Biology, 2021, 64: 102145[2023-07-20]. doi: 10.1016/j.pbi.2021.102145.
[52] 张宏平, 张晋元, 吴国良. 扁桃果实超微结构和组织结构观察[J]. 中国南方果树, 2017, 46(3): 116 − 119.

ZHANG Hongping, ZHANG Jinyuan, WU Guoliang. Observation on ultrastructure and tissue structure of almond fruit [J]. Fruit Trees of Southern China, 2017, 46(3): 116 − 119.
[53] 张宏平, 张晋元, 吴国良, 等. 扁桃种皮组织结构和超微结构观察[J]. 江西农业大学学报, 2018, 40(1): 72 − 77.

ZHANG Hongping, ZHANG Jinyuan, WU Guoliang, et al. Tissue structure and ultrastructure observation of almond seed coat [J]. Journal of Jiangxi Agricultural University, 2018, 40(1): 72 − 77.
[54] ZHANG Lingyun, PENG Yiben, SANDRINE P T, et al. Evidence for apoplasmic phloem unloading in developing apple fruit [J]. Plant Physiology, 2004, 135(1): 574 − 586.
[55] 张宏平, 张晋元, 刘玉香, 等. 桃果实组织结构和超微结构细胞学研究[J]. 北方园艺, 2018(1): 29 − 34.

ZHANG Hongping, ZHANG Jinyuan, LIU Yuxiang, et al. Study on tissue structure and ultrastructural cytology of peach fruit [J]. Northern Horticulture, 2018(1): 29 − 34.
[56] 李春丽, 侯柄竹, 张晓燕, 等. 无花果果实韧皮部卸载路径由共质体向质外体途径转变[J]. 科学通报, 2016, 61(8): 835 − 843.

LI Chunli, HOU Bingzhu, ZHANG Xiaoyan, et al. Phloem unloading path of fig fruit changes from symplast to exoplasmic pathway [J]. Chinese Science Bulletin, 2016, 61(8): 835 − 843.
[57] 章英才, 海源, 黄月, 等. 灵武长枣果实同化物韧皮部卸载和运输途径研究[J]. 西北植物学报, 2020, 40(12): 2054 − 2064.

ZHANG Yingcai, HAI Yuan, HUANG Yue, et al. Study on unloading and transportation route of assimilate phloem in Ziziphus jujuba‘Lingwuchangzao’fruit [J]. Acta Botanica Boreali-Occidental Sinica, 2020, 40(12): 2054 − 2064.
[58] 陶珊珊, 章英才, 王静, 等. 枣果实同化物韧皮部卸载和运输途径研究[J]. 电子显微学报, 2022, 41(2): 171 − 180.

TAO Shanshan, ZHANG Yingcai, WANG Jing, et al. Study on unloading and transport pathway of assimilates phloem in Jujube fruit [J]. Journal of Chinese Electron Microscopy Society, 2022, 41(2): 171 − 180.
[59] 黄月, 章英才, 苏伟东, 等. 灵武长枣果实维管束韧皮部及周围细胞的超微结构特征[J]. 广西植物, 2021, 41(1): 133 − 143.

HUANG Yue, ZHANG Yingcai, SU Weidong, et al. Ultrastructural characteristics of vascular bundle phloem and surrounding cells in the fruit of Ziziphus jujuba cv. ‘Lingwuchangzao’ [J]. Guangxi Botanical Science, 2021, 41(1): 133 − 143.
[60] 车佳俐. 蔓越橘果实同化物卸载路径及糖转运蛋白SWEET基因的表达分析研究[D]. 长春: 吉林农业大学, 2022.

CHE Jiali. Analysis of Assimilate Unloading Pathway and Expression of Sugar Transporter SWEET Gene in Cranberry Fruit [D]. Changchun: Jilin Agricultural University, 2022.
[61] 赵阳阳, 郭雨潇, 孙永江, 等. 文冠果果实韧皮部及其周围薄壁细胞的超微结构观察及功能分析[J]. 西北植物学报, 2019, 39(9): 1581 − 1588.

ZHAO Yangyang, GUO Yuxiao, SUN Yongjiang, et al. Ultrastructural observation and functional analysis of phloem and surrounding parenchyma cells of Xanthoceras sorbifolium fruit [J]. Acta Botanica Boreali-Occidental Sinica, 2019, 39(9): 1581 − 1588.
[62] GIFFORD R M, THORNE J H, HITE W D. Crop productivity and photoassimilate partitioning [J]. Science, 1984, 225(4664): 801 − 808.
[63] SCHMALSTIG J G, COSGROVE D J. Coupling of solute transport and cell expansion in pea stems [J]. Plant Physiology, 1900, 94(4): 1625 − 1633.
[64] ALONI B, WYSE R E, GRIFFITH S. Sucrose transport and phloem unloading in stem of Vicia faba: possible involvement of a sucrose carrier and osmotic regulation [J]. Plant Physiology, 1986, 81(2): 482 − 486.
[65] LI Yaxin, LIU Huan, YAO Xuehui, et al. Hexose transporter CsSWEET7a in cucumber mediates phloem unloading in companion cells for fruit development [J]. Plant Physiology, 2021, 186(1): 640 − 654.
[66] RUAN Yongling, PATRICK J W. The cellular pathway of postphloem sugar transport in developing tomato fruit [J]. Planta, 1995, 196(3): 434 − 444.
[67] GODT D, ROITSCH T. The developmental and organ specific expression of sucrose cleaving enzymes in sugar beet suggests a transition between apoplasmic and symplasmic phloem unloading in the tap roots [J]. Plant Physiology and Biochemistry, 2006, 44(11/12): 656 − 665.
[68] SCHMALSTIG J G, GEIGER D R. Phloem unloading in developing leaves of sugar beet: Ⅰ. Evidence for pathway through the symplast [J]. Plant Physiology, 1985, 79(1): 237 − 241.
[69] SCHMALSTIG J G, GEIGER D R. Phloem unloading in developing leaves of sugar beet: Ⅱ. Termination of phloem unloading [J]. Plant Physiology, 1987, 83(1): 49 − 52.
[70] DENG Lin, LI Pengcheng, CHU Caihua, et al. Symplasmic phloem unloading and post-phloem transport during bamboo internode elongation [J]. Tree Physiology, 2020, 40(3): 391 − 412.
[71] 刘毅, 邓琳, 李鹏程, 等. 竹子快速生长过程中糖分代谢与运输机制研究[J]. 世界竹藤通讯, 2022, 20(4): 104 − 108.

LIU Yi, DENG Lin, LI Pengcheng, et al. Study on sugar metabolism and transport mechanism of bamboo during rapid growth [J]. World Bamboo and Rattan Communication, 2022, 20(4): 104 − 108.
[72] GAFFAL K P, FRIEDRICHS G J, EL-GAMMA S. Ultrastructural evidence for a dual function of the phloem and programmed cell death in the floral nectary of Digitalis purpurea [J]. Annals of Botany, 2007, 99(4): 593 − 607.
[73] ESCHRICH W. Phloem unloading in aerial roots of Monstera deliciosa [J]. Planta, 1983, 157(6): 540 − 547.
[74] WANG Xiaoyi, YOU Hali, YUAN Yihang, et al. The cellular pathway and enzymatic activity for phloem-unloading transition in developing Camellia oleifera Abel. fruit [J/OL]. Acta Physiologiae Plantarum, 2018, 40(2): 23[2023-07-20]. dio: 10.1007/s11738-017-2598-z.
[75] ZHOU Jing, DU Bingshuai, CHEN Yuqing, et al. Integrative physiological and transcriptomic analysis reveals the transition mechanism of sugar phloem unloading route in Camellia oleifera fruit [J/OL]. International Journal of Molecular Sciences, 2022, 23(9): 4590[2023-07-20]. doi: 10.3390/ijms23094590.