24-表油菜素内酯和盐度对浒苔生长和生理活性的影响

为探讨低温条件下外源植物激素和盐度变化对浒苔光合生理的影响,本文选取浒苔为供试材料,研究24-表油菜素内酯和盐度对其生长、光合色素、叶绿素荧光参数、抗氧化活性和可溶性蛋白含量的影响.结果表明: 与正常盐度(近岸海水盐度为25)相比,浒苔的生长在盐度10处理下显著增加,增幅为45.9%,但在盐度5处理下显著降低.盐度5处理的浒苔比其他盐度处理具有较高的Chl a和可溶性蛋白.24-表油菜素内酯(0.2 mg·L^-1)的加入显著抑制了浒苔的生长,尤其在盐度25处理下,浒苔呈现负增长的趋势,并大量释放孢子(配子),有效光化学效率、超氧化物歧化酶酶活性和可溶性糖含量明显降低,但可溶性蛋白含量显著增加.即在温度15 ℃条件下,可通过适当降低盐度促进浒苔的生长;在盐度25条件下,可通过添加24-表油菜素内酯促进孢子(配子)释放,为浒苔的大规模养殖提供原材料.

Combined effects of 24-epibrassinolide and salinity on the growth and physiological perfor-mance of Ulva prolifera

In order to study the combined effects of brassinosteroids and salinity on the growth and physiological performance of Ulva prolifera under low temperature condition, we investigated the growth, chlorophyll content, chlorophyll fluorescence parameters, soluble protein and carbohydrate contents in this algae, which was grown under three salinity in the presence or absence of 24-epibrassinolide. The results showed that, compared to control salinity (25) treatment, the growth rate of U. prolifera was enhanced by 45.9% under the moderate hyposaline condition (10), but decreased under low salinity (5) treatment, which showed high contents of chlorophyll and soluble protein. However, the presence of EBR (0.2 mg·L^-1) significantly reduced the growth of U. prolifera, especially under the control salinity (25) treatment, under which the fresh mass decreased and more spores were released. Additionally, the effective quantum yield (F_v′/F_m′), the activity of SOD and the content of soluble carbohydrate also decreased, but the soluble protein content increased under the control salinity treatment in the presence of EBR. In conclusion, moderatehypo-saline condition could be used to enhance the growth of U. prolifera at 15 ℃, and under normal salinity (25), the EBR could be used to promote the release of spores and produce more materials for mass production of U. prolifera.