~(14)C-葡萄糖在椪柑果实粒化枯水过程中的转移和转化

碰柑贮藏中期,囊辦注射~(14)C-葡萄糖后,在枯水果和正常果的果皮和非标记囊辦均出现放射性活度,并以标记囊辦及其对应果皮为中心,向周围递减,这可能是物理扩散的结果。初枯果果皮放射性活度显著低于正常果,而其不溶物的放射性活度和呼吸强度与对照相比均无显著差异;~(14)C-葡萄糖在初枯果果皮之间或囊辦之间的扩散显著比正常果容易。这说明枯水的起因并非果肉营养物向果皮转移,而可能与衰老有关。在枯水发展过程中,全枯果果肉有24.65%的~(14)C-葡萄糖转化为不溶性物质,显著高于正常果的6.41%;中枯果和全枯果的呼吸强度分别为17.18ml/h·kg 和23.64ml/h·kg,显著高于正常果的11.03ml/h·kR。因此,我们认为椪柑在枯水过程中,果肉可溶性营养物消失的主要原因是转化为不溶性物质向果皮转移和呼吸消耗。

THE TRANSFORMATION AND TRANSLOCATION OF ~(14)C-LABELLED GLUCOSE IN THE COURSE OF GRANULATION DEVELOPMENT OF Batangas mandarin FRUITS

In the middle of storage period for Batangas mandarin fruits,the fruits segment was in- jected with ~(14)C-labelled glucose.Radioisotope was found in the rind and non-injected segments of the granulated fruits or normal fruits.The results showed that the radioactivity in the rind of slight-granulated fruits was significantly lower than that in normal fruits.The diffusion of ~(14)C- labelled glucose to the rind or to the segments of slightly granulated fruits was significantly high- er than that of normals.These results indicated that granulation was not caused by the shift of nutritive matter from the juice sac to the rind but likely by its senescence.In the course of gran- ulation development,the radioactivity of insoluble carbohydrate of the juice sac in severely gran- ulated fruits was 24.65% of the total sac radioactivity.However,it was only 6.41% in normal fruits.Although the radioactivity in the rind of granulated fruits was lower than that in normal fraits,it increased faster.The respiratory rate of medium granulated fruit was 17.18 CO_2 ml/ kg·h and that of severely granulated fruit was 23.64 CO_2 ml/kg·h.Both were significantly higher than that of normal fruits(11.03 CO2 mi/kg·h).It was suggested that the sharp loss of soluble nutritive matter in the juice sac of granulated fruits might result from their transforma- tion into insoluble matter,translocation to the rind and respiration consumption.