高温胁迫对高温筛选后海带配子体存活率和生理的影响

Effects of High Temperature Stress on Survival and Physiology of Kelp Laminaria japonica Gametophytes Screened by High Temperature

试验以经过高温筛选存活的海带配子体奔牛(Bn-23-b-2d,Bn-23-b-8d)和对照组配子体奔牛(Bn)为试验材料,在23℃分别处理4、8d和12d,进行了耐高温能力的验证。试验结果表明,3种材料的存活率随处理时间的延长均呈下降趋势,且3种材料的耐高温能力与之前的试验结果一致,依次为Bn-23-b-8d>Bn-23-b-2d>对照组Bn。同时,在高温处理的不同时间点(4、8、12、16d),对3种配子体的叶绿素a、脯氨酸、丙二醛及可溶性糖含量进行了检测,其中,对照组配子体叶绿素a含量随处理时间延长一直下降,而Bn-23-b-2d与Bn-23-b-8d有一定上升后下降;脯氨酸含量在高温胁迫下迅速积累,其中Bn-23-b-8d前期抵抗高温能力最强,抗高温时间最长;对照组Bn丙二醛和可溶性糖含量变化最明显,受到的高温胁迫强度最大。这4种生理指标的变化可以反映配子体的耐高温能力,与存活率验证得到的结果相符。该研究结果显示,高温筛选后其存活率和生理指标的变化能够反映其耐高温能力,为后期耐高温品种的选育奠定了基础。

In this experiment,the gametophytes（Bn-23-b-2d,Bn-23-b-8d）screened by high temperature stress and Bn in control groups were used to verify the resistant ability to high temperature under 23℃for4d,8dand 12 d.The results showed that the gametophytes of Bn-23-b-2d,Bn-23-b-8d,and Bn had decrease in the survival rate with the elapse,with the order as Bn-23-b-8d 〉Bn-23-b-2d〉Bn.Meanwhile,the physiological indicators including the contents of chlorophyll-a,proline（Pro）,malondialdehyde（MDA）and soluble sugar were determined in the gametophytes of Bn-23-b-2d,Bn-23-b-8d,and Bn exposed to 23 ℃for 4d,8d,12 dand 16d,respectively.It was found that the chlorophyll-acontent was declined in the Bn with the extension of time,but increased initially and then dropped down in Bn-23-b-2d and Bn-23-b-8d.The Bn-23-b-2dand Bn-23-b-8d had rapidly accumulated Pro content under high temperature,the maximal resistance capability to high temperature in the Bn-23-b-8d.The most obvious changes in MDA and soluble sugar contents were observed in the control group Bn.The high temperature tolerance capability of gametophyte was reflected in variations in physiological indicators,which was consistent with the survival.The findings reflect the high temperature resistant ability of the kelp gametophytes screened by high temperature,and provide the foundation with breeding of high temperature resistant varieties.