为探究1 a年生木榄[Bruguiera gymnorhiza(L.)Lam.]苗木对光照适应能力,采用光照强度模拟控制试验对木榄苗木进行处理,经20%,40%,60%,80%,100%光照强度处理后,测定木榄苗木株高、基径、叶绿素总含量、净光合速率、丙二醛含量、脯氨酸含量、超氧化物歧化酶活性,通过相关性和主成分分析木榄苗木受光照影响情况。结果表明:1)60%光照强度环境木榄苗木株高生长最快,100%光照强度环境木榄苗木基径生长最快;2)在遮阴环境下,叶绿素总含量随光照强度增大而减少,但净光合速率随光照强度增大,表现为先增大再减少,且60%光照强度与80%,100%光照强度叶绿素总含量、净光合速率没有显著差异;3)60%光照强度环境下,木榄丙二醛含量、脯氨酸含量均显著低于20%光照强度环境,但超氧化物歧化酶活性显著高于20%光照强度环境;4)60%光照强度环境下,净光合速率、丙二醛含量、脯氨酸含量与100%光照强度相比均无显著差异,但超氧化物歧化酶活性显著高于100%光照强度环境;5)通过相关性和主成分分析发现,60%光照强度环境木榄苗木生长最佳。因此,1 a生木榄苗木对60%光照强度环境适应性较其他光照环境强,100%光照强度对1 a生木榄苗木具有一定光抑制作用,而20%和40%光照强度却不能满足1 a生木榄苗木对光照的需求。研究结果可为木榄苗木在生态修复过程中适当的进行遮阴处理提供数值参考。

This study was conducted to investigate the light adaptability of 1-year-old Bruguiera gymnorhiza(L.)Lam.seedlings.The seedlings of Bruguiera gymnorrhiza were treated by light intensity simulation control experiment.The indices of plant height,basal diameter,Chl(a+b)content,Pn,MDA content,PRO content and SOD activity were measured after 20%,40%,60%,80% and 100% light intensity treatments.The effects of light on Bruguiera gymnorrhiza seedlings were analyzed by correlation and principal component analysis.The results showed,1)60% light intensity environment of Bruguiera gymnorrhiza seedling height growth fastest,100% light intensity environment of Bruguiera gymnorrhiza seedling base diameter growth fastest.2)The total chlorophyll content decreased with the increase of light intensity,but the net photosynthetic rate increased first and then decreased with the increase of light intensity.There was no significant difference in total chlorophyll content and net photosynthetic rate between 60% light intensity and 80% and 100% light intensity.3)Under 60% light intensity environment,the malondialdehyde content and proline content of Bruguiera gymnorrhiza were significantly lower than those under 20% light intensity environment,but the superoxide dismutase activity was significantly higher than that under 20% light intensity environment.4)There was no significant difference in net photosynthetic rate,malondialdehyde content and proline content between 60% light intensity and 100% light intensity,but the activity of superoxide dismutase was significantly higher than that of 100% light intensity.5)Through correlation and principal component analysis,it was found that 60% light intensity environment was the best for the growth of Bruguiera gymnorrhiza seedlings.Therefore,the adaptability of 1-year-old seedlings to 60% light intensity was stronger than that of other light environments.The results showed that 100% light intensity had a certain light inhibition effect on 1 a Bruguiera gymnorrhiza seedlings,while 20% and 40% light intensity could not meet the needs of 1 a Bruguiera gymnorrhiza seedlings for light.The results provide a numerical reference for the appropriate shading treatment of Bruguiera gymnorrhiza seedlings in the process of ecological restoration.