摘要
【目的】研究外源褪黑素对高温胁迫下枇杷果皮细胞结构的影响,探讨外源褪黑素缓解高温胁迫对枇杷果实日灼发生的影响,为防控技术研发提供依据。【方法】以4个浓度外源褪黑素喷施新白8号果实,观察比较40℃高温胁迫处理60 min内果实日灼发生差异,筛选最佳外源褪黑素浓度;进一步观察比较喷施清水(对照)和最佳浓度外源褪黑素在40℃高温胁迫处理0、10、30 min时,果皮显微结构与超微结构的差异变化。【结果】高温胁迫30 min时,150μmol·L^(-1)外源褪黑素处理的果实开始出现日灼病斑,比喷施清水(对照)果实日灼病斑出现时间延迟20 min,且日灼症状最轻、病果率及病害等级最低,是最佳浓度。显微和超微结构观察结果表明,高温胁迫处理10 min时,清水处理的枇杷果皮细胞角质层、表皮层、亚表皮层厚度均减小,角质层部分褶皱,表皮细胞部分断裂、变形,亚表皮层细胞变为长椭圆形或纺锤形、细胞壁厚度增加了63.46%;150μmol·L^(-1)外源褪黑素处理的果皮角质层平整、薄厚均匀,细胞形状基本不变,亚表皮细胞壁厚度增加了42.60%;高温胁迫处理30 min时,清水处理的果皮细胞角质层变薄、褶皱明显且数量变多,表皮细胞严重变形,亚表皮细胞呈不规则形、出现较大空腔、细胞壁厚度增加了84.62%,150μmol·L^(-1)外源褪黑素处理的果皮细胞角质层个别区域变薄、褶皱变形,少数表皮细胞破裂,亚表皮层少数空腔、细胞壁厚度增加了65.74%。【结论】喷施浓度为150μmol·L^(-1)外源褪黑素可降低枇杷果实日灼病果率及病害等级,延缓枇杷果实日灼的发生,缓解高温胁迫对果皮组织结构的伤害。
【Objective】This study examined the effects of exogenous melatonin on the appearance quality and cellular structure of loquat fruit after sunburn in order to provide reference for the development of technology to prevent sunburn in loquat.【Methods】Fruit of Xinbai 8 were used as the experimental material.Exogenous melatonin was sprayed at concentrations of 50,100,150,and 200μmol·L^(-1),and spraying clean water as the control.4 hours after spraying,a high temperature stress at 40℃was applied.Sun burning symptoms in loquat fruit were recorded after 0-60 minutes of high temperature stress,and the incidence and degree of sunburn were statistically analyzed to screen for the optimal concentration of exogenous melatonin and to determine the time when exogenous melatonin treatment delayed the occurrence of fruit sunburn symptoms.Paraffin sections and scanning electron microscopy were used to observe and compare the microstructural and ultrastructural changes of fruit peels under high temperature stress at 0,10,and 30 minutes after exogenous melatonin treatments.【Results】Under high temperature stress,loquat fruit was severely sunburnt,with an incidence rate of more than 35%.The rate of grade 0 sunburn was only 63.33%,and the rate of gradeⅠsunburn was 36.67%.Melatonin treatment within 50-200μmol·L^(-1) delayed the occurrence of fruit sunburn.Among them,melatonin at 150μmol·L^(-1) showed the latest sunburn occurrence,the lightest symptoms,the lowest incidence rate.Compared with the control,exogenous melatonin treatment significantly reduced the incidence by 66.8%.The rate of grade 0 sunburn fruit treated with 150μmol·L^(-1) melatonin was the highest,at 87.80%,and the rate of gradeⅠsunburnt fruit was the lowest,both significantly lower than other concentration treatments and the control.After 10 min of heat stress at 40℃,the control showed small brown spots on the sunny side and sunburn symptoms,while the melatonin treated groups did not show any sunburn symptoms.After 30 minutes,the sunburn area i
作者
高雨薇
邓朝军
许奇志
李浩伟
项于倩
马翠兰
蒋际谋
GAO Yuwei;DENG Chaojun;XU Qizhi;LI Haowei;XIANG Yuqian;MACuilan;JIANG Jimou(College of Horticulture,Fujian A&F University,Fuzhou 350002,Fujian,China;Institute of Fruit Trees,Fujian Academy of Agricultural Sciences/Fujian Longan Loquat Breeding Engineering Technology Research Center,Fuzhou 350013,Fujian,China)
出处
《果树学报》
CAS
CSCD
北大核心
2024年第7期1387-1400,共14页
Journal of Fruit Science
基金
“5511”协同创新工程(KXXYJBG0003)
福建省农业科学院科技创新团队(CXTD2021004-1)
中央引导地方科技发展专项(2021L3022)
福建农林大学创新训练项目(3215201062)。
关键词
枇杷
褪黑素
日灼
果皮
解剖结构
Loquat
Melatonin
Loquat
Sunburn
Peel
Anatomical structure
