不同培养条件对长紫菜叶状体生长及生理响应的研究

Effects of different culture conditions on growth and physiological response of Porphyra dentata thallus

为探索长紫菜在不同培养条件下的生理响应,研究了在不同温度、盐度和光照培养条件长紫菜叶状体的生长及生理响应,主要测定藻体的生长、光合色素、可溶性蛋白和丙二醛(MDA)含量、抗氧化酶活性等生理指标的变化。结果表明,在培养温度为17～20℃时,长紫菜藻体可以保持较高相对生长速率,当温度高于23℃时,其生长明显受到抑制,藻体发红并出现溃烂;长紫菜叶状体在盐度25～35下可以保持较快生长,在低于盐度25的条件下,藻体的光合色素、可溶性蛋白、丙二醛(MDA)的含量以及过氧化物酶(POD)、过氧化氢酶(CAT)活性均产生显著的变化,并观察到藻体变薄、发白、腐烂现象;在光照为3 000～6 000 lx时,藻体生长速率较为稳定,藻体在光照为9 000 lx条件下的叶绿素a含量低,可溶性蛋白和MDA含量以及POD活性都出现显著增高,并观察到发红及溃烂现象。因此,适合长紫菜叶状体生长的温度为17～20℃,盐度为25～35,光照在6 000 lx左右。

Porphyra dentata is one of the main species of natural resources of Porphyra,which has high economic and medicinal value.It is meaningful to develop and increase new Porphyra cultivation by studying the ecological characteristics of P.dentate.In order to understand physiological responses of P.dentate cultured in different conditions,we studied the responses of P.dentate to different temperature,salinity and light intensity by determining the change about growth,photosynthetic pigments contents,soluble protein contents,malondialdehyde（MDA）contents and the peroxidase activity.The experimental results showed that,thallus was able to maintain a high relatively growth rate under 17-20 ℃,when temperature was higher than 23 ℃,the growth of thallus was inhibited,it turned to redness and appeared to fester.At salinity of 25-35,the thallus grew quickly under culture conditions,when culture salinity was lower than 25,the content of photosynthetic pigment,soluble protein,malondialdehyde（MDA）and the activity of peroxidase（POD）and catalase（CAT）of thallus was significantly changed,and thallus became thinner and whitish,its edge displayed decay phenomenon.The thallus had a high growth rate under culture light intensity of 3 000-6 000 lx,when the culture light intensity reached 9 000 lx,content of chlorophyll a of thallus was low,but the content of soluble protein and MDA and the activity of POD were significantly increased,the thallus began to fester after several days’ culture.According to the result,we know that suitable culture conditions for P.dentata thallus are temperature of 17-20 ℃,salinity of 25-35,and light intensity of 6 000 lx.