荔枝果皮细胞壁组成与裂果发生关系的研究  

Study on the Relationship Between Cell Wall Components of Pericarp and Fruit Cracking in Litchi

作　　者：葛涵涛 林诗雅 王惠聪[1] GE Hantao;LIN Shiya;WANG Huicong(College of Horticulture,South China Agricultural University,Guangzhou 510642,China)

机构地区：[1]华南农业大学园艺学院,广东广州510642

出　　处：《广东农业科学》2023年第9期117-126,共10页Guangdong Agricultural Sciences

基　　金：国家荔枝龙眼产业技术体系专项(CARS-32-08);广州市科技计划项目(202103000057,202206010023)。

摘　　要：【目的】通过比较裂果易感性不同的荔枝品种细胞壁组分的差异,研究外源喷施生长素类似物2,4-二氯苯氧乙酸(2,4-D)对裂果和果皮细胞壁组分的影响,探讨细胞壁组成与裂果发生的关系。【方法】比较2个易裂果荔枝品种(‘桂味’‘糯米糍’)和2个不易裂果荔枝品种(‘怀枝’‘岭丰糯’)花后75 d的果皮碳水化合物含量变化,并观察花后60~85 d果皮组织结构和木质素分布。利用2,4-D分别对2个果场的‘糯米糍’果穗进行浸泡处理,使用GC-MS测定裂果高发期的果皮可溶性糖含量,分光光度计法测定果皮淀粉和结构性碳水化合物含量,最后通过透射电镜、果皮组织木质素染色观察荔枝果皮组织结构。【结果】易裂果的‘糯米糍’果皮中己糖(果糖、葡萄糖、半乳糖)含量显著低于不易裂果的‘怀枝’和‘岭丰糯’。果胶含量与裂果易感性之间关系复杂,‘糯米糍’果皮果胶含量较低、仅1.7 mg/g,且果大、易裂果;‘桂味’果皮果胶含量高、为4.0 mg/g,果小、也易裂果。2,4-D处理后,前期暂时提高了座果率,但对最终座果率无显著影响;2,4-D处理可导致果皮细胞层数增多,内果皮细胞轮廓变模糊;与对照相比,40 mg/L 2,4-D处理后果皮果胶含量增多、细胞壁增厚、裂果率增加。【结论】裂果易感性不同的荔枝品种果皮中碳水化合物含量存在明显差异,其中果胶在荔枝裂果中可能扮演双重的角色,细胞膨大过程中果胶合成和降解呈动态变化,果胶含量过高则果皮延展性差,果实小易裂果,果胶含量过低则果皮延展性好,果实大但抗裂性低、也易裂果;2,4-D处理对‘糯米糍’最终座果率无影响但显著增加裂果风险。【Objective】By comparing the differences in cell wall components among litchi varieties with different susceptibility to fruit cracking,the study aims to investigate the effects of exogenous application of auxin analogue 2,4-D on the cell wall composition of pericarp and fruit cracking,and to further explore the relationship between the cell wall synthesis metabolism and fruit cracking incidence.【Methods】The changes in carbohydrate contents of two easily cracked litchi varieties(‘Guiwei’and‘Nuomici’)and two not easily-cracked litchi varieties(‘Huaizhi’and‘Lingfengnuo’)after 75 days of flowering were compared,and the tissue structure and lignin distribution of the pericarps at the 60-85 d after flowering were observed.Fruit clusters of‘Nuomici’in two orchards were dipped into auxin analog 2,4-D,and the soluble sugar contents in the pericarps were determined by GC-MS.The starch and structural carbohydrate contents of the samples were detected by using a spectrophotometer.Transmission electron microscopy and lignin staining were used to observe the tissue structure of litchi pericarp.【Result】The contents of hexose including fructose,glucose and galactose in the pericarp of cracking susceptible variety‘Nuomici’were significantly lower than those of low-cracking varieties‘Huaizhi’and‘Lingfengnuo’.A complicate relationship between pectin contents and fruit cracking susceptibility was found.In the pericarp of‘Nuomici’,the pectin content was only around 1.7 mg/g.And the fruit was bigger and susceptible to cracking.While in the cracking susceptible smaller fruit variety‘Guiwei’,the pericarp contained high pectin(4.0 mg/g).2,4-D treatment only temporarily increased the fruit setting rate of litchi in the early stage,but it had no significant impact on the final fruit setting rate.2,4-D treatment could lead to an increase in the number of layers of pericarp cells and the blurring of the contour of inner pericarp cells;Compared with the control,the treatment with 40 mg/L 2,4

关 键 词：荔枝 裂果 果皮 可溶性糖 细胞壁组分 2 4-二氯苯氧乙酸 

分 类 号：S667.1[农业科学—果树学]