黄瓜果实贮藏过程中某些形态、生化变化及其控制

THE MORPHOLOGICAL AND BIOCHEMICAL CHANGES OF CUCUMBER FRUITS AND THEIR CONTROL DURING POST-HARVESTED STORAGE

黄瓜果实采后贮藏过程中,随着其花端部位的种子的不断发育,中部及茎端逐渐萎缩变糠,花端膨大(称为“大头现象”)。花端胎座组织中蛋白质、DNA、RNA 及干重等都随着时间延长呈增加趋势,而中部组织的上述物质的含量则急剧下降。贮藏20天,中部果皮及胎座组织中 DNase 活性分别增加了5和7倍,RNase 活性增加了5和6倍,这两种酶活性在花端组织中则几无变化。实验发现用 BA+GA,处理果实对于延迟花端膨大及中部萎缩有效,并能显著延缓果实叶绿素含量的降低。未授粉果实在贮藏过程中不出现“大头现象”,其蛋白质等物质的含量在果实各部位几乎以相同的速度降低。

In the storage of pollinated cucumber fruits which were harvested in commercial size,the adaxial and middle parts of fruit become withering,while abaxial part become expanding. The contents of protein,DNA,RNA as well as dry weights in the abaxial placenta of fruit increase with storage time going on,while those in middle part decrease dramatically.Simu- ltaneously,seeds in abaxial part develope rapidly.DNase activities in middle pericarp and placenta increase by 5 and 7 times respectively,RNase activities there go up by 5 and 6 times. The two enzymes change little in abaxial part.Different treatments of fruits with plant growth regulators BA,GA_3 and NAA show that BA+GA_3(20ppm+100ppm)can most obviously delay the speeds of the withering of the middle part and the expanding of abaxial part and the decrease of chlorophyll content.These results may have commercial value in the freshness- retainning and senescence prevention of the cucumber fruits.The non-pollinated fruits have no“abaxial expending”phenomenon during post-harvested storage.The contents of protein etc.decrease almost equally in any part of the fruit.