摘要
观察茶树叶片在萎凋过程的微形态特征,探究白茶萎凋过程中茶树叶片微形态的动态变化规律。使用冷场发射扫描电镜,对5个萎凋时间(0、12、24、36、48 h)处理的福鼎大白茶叶片进行微形态特征观察,对茶树叶片的表面纹饰、气孔、茸毛特征性状进行统计并分析。在萎凋过程中,茶树叶片蜡质纹饰初始为波浪状,随萎凋时间增加,纹饰逐渐变成皱脊状;茸毛纹饰皆为长条形;气孔形状皆为长卵形,具异性气孔(腺鳞)。在萎凋过程中,外气孔长、外气孔宽、内气孔长、内气孔宽和气孔器大小均先增大后减小;气孔密度(286.44±20.41)~(423.78±35.14)个·mm^(-2),先减小后增大,呈正相关;茸毛密度(6.89±0.96)~(15.25±1.87)根·mm^(-2),随萎凋时间增加逐渐增大,呈正相关。白茶萎凋过程中茶树叶片不同微形态性状呈现不同的动态变化规律。蜡质纹饰逐渐皱缩成脊;内外气孔长宽和气孔器大小先增大后减小,气孔密度先减小后增大,茸毛密度持续增大,且都与萎凋时间呈二项式相关;而气孔开度、茸毛直径、茸毛长度、茸毛纹饰无显著变化。
Micromorphological characteristics of tea leaves during withering were examined to decipher the dynamic changes taken place in the process of white tea.Under a cold field emission scanning electron microscope,the morphological characteristics of the epidermal ornamentations,stomata,and trichomes of the leaves of Camellia sinensis cv.Fudingdabaicha at 5 withering stages were examined.During withering,the initial wavy appearance of the epidermal ornamentations gradually turned into wrinkled ridges as the process progressed.Whereas the trichome ornamentations remained in the shape of long strips and the stomata long ovate with heterosexual stomata(gland scales)throughout.Meanwhile,the length and width of outer and inner stomata as well as the stomatal size increased at first but declined afterward;the stomatal density rose from 286.44±20.41·mm^(-2) to 423.78±35.14·mm^(-2) positively correlating with the withering time;and the trichome density also increased from 6.89±0.96·mm^(-2) to 15.25±1.187·mm^(-2) with time.On the other hand,no significant changes in the stomatal opening,the diameter,and the length or pattern of the trichomes were observed throughout the entire process.
作者
刘财国
于文涛
樊晓静
王泽涵
陈晓君
蔡春平
叶乃兴
LIU Cai-guo;YU Wen-tao;FAN Xiao-jing;WANG Ze-han;CHEN Xiao-jun;CAI Chun-ping;YE Nai-xing(College of Horticulture,Fujian Agriculture and Forestry University,Fuzhou Fujian 350002,China;Fujian Key Laboratory for Technology Research of Inspection and Quarantine,Technology Centre of Fuzhou Customs District PR China Fuzhou,Fujian 350001 China)
出处
《茶叶学报》
2021年第2期73-77,共5页
Acta Tea Sinica
基金
福建农林大学茶产业链科技创新与服务体系建设项目(2020-01)
海关总署科研项目(2020HK187)。
关键词
白茶
萎凋
叶片
微形态
扫描电镜
white tea
withering
leaf blade
micromorphology
SEM
