麝香石竹玻璃苗与正常苗的生理特性差异

诱导麝香石竹茎段外植体产生不定芽的分化,所得到的正常苗与玻璃苗的生理特性明显有差异。表现在玻璃苗的鲜重、干重、粗纤维和叶绿素含量与正常苗相比显著降低;玻璃苗的可溶性糖含量增加38％,而蔗糖含量下降63%,束缚水含量显著增高,自由水含量明显降低;玻璃苗的淀粉酶总活性也明显升高,碱性和中性区过氧化物酶同工酶活性显著提高而酸性区的同工酶活性有所下降。然而,玻璃苗和正常苗形成时的芽分化频率以及伸长生长量之间无明显区别。结果表明,麝香石竹试管苗的玻璃化可能是在碳水化合物代谢、氮代谢和水分存在状况等发生生理异常的情况下在芽分化启动后的生长过程中发生的,而不是在芽分化启动时已经决定的。

PHYSIOLOGICAL CHARACTERISTIC DIFFERENCES BETWEEN VITREOUS SHOOTS AND NORMAL SHOOTS OF CARNATION

There were a series of physiological characteristic differences betweenvitreous shoots and normal shoots regenerated from the stem explants of carnation(Dianthus caryophyllus L. cv. Salmon Stasalm). As compared with normal shoots,the fresh weight, dry weight, crude fibre and chlorophyll contents of vitreous shootsof carnation lowered obviously; the soluble sugar content of vitreous shoots increa-sed by 38%, and sucrose content decreased by 63%; the bound water content ofvitreous shoots heightened apparently, and the free water content lowered notably;the total amylase activity of vitreous shoots rose markedly, and the peroxidaseisozyme activities in the basic and neutral regions ascended strikingly and those inth acidic region descended. However, there were not obvious differences of buddifferentiation frequencies and shoot growth speeds in the forming of normal shootsand vitreous shoots. The results showed that the vitrification of carnation regenera-ted shoots occurred probably in their growth course after the starting of bud dif-ferentiation, not in the initiation of bud differentiation when they suffered thephysiological disorder of carbohydrate metabolism, nitrogen metabolism, water con-tent conditions and so on.