利用萤光染色跟踪水份在润麦时进入小麦颗粒的路径

本文映示了小麦润麦过程中水分在小麦颗粒中扩散的路径．通过将杜伦麦、软麦在含有萤光试剂的溶液中浸泡12,24,48h之后，萤光切片图像显示出色剂．首先是通过麦胚进入麦粒，再由珠心层传送到麦粒的另一端，同时由糊粉层进入到胚乳．色剂沿背部一侧传送要比腹沟一侧快．皮部吸水速度快，而种皮有抵制水份进入胚乳的作用．从微观观测看出，细胞壁(膜)的三维网状结构形成了水份传送的渠道．色剂在细胞壁里的运动是毛细作用，而在胚乳细胞内的运动则是渗透作用．色剂在细胞壁里的运动要快于在胚乳细胞内的运动．色剂在杜伦麦(硬麦)及软麦里的运动模式是相同的，但是色剂进入软麦的速度要比进入杜伦麦快．

THE USE OF FLUORESCEIN DYE TO STUDY THE MOVEMENT OF WATER INTO WHEAT KERNELS

The dispersion of fluorescein dye in water was investigated during the tempering process in wheat kernedls.Durum and soft wheat kernels were immersed in fluorescein (free acid crystalline) solution(1%,pH7.54) for 12,24 and 48 hours.The fluorescein pattern showed that the dye solution entered the grain primarily through the distal end or germ,then progressed toward the proximal end.Dye accumulations on the dorsal side of the kernels suggest either a faster rate of penetration or greater accumulation in these areas.The apoplast including microcapillary spaces in the cell wall serve as water distribution channels.The movement pattern of the fluorescein was similar for both durum and soft wheat.However,the rate of penetration or degree of accumulation appeared to be greater in the soft wheat.This dye technique is simple,fast,and does not require complicated skills.It may be used to study dye water distribution within other cereal grains.