条斑紫菜叶状体色落症的初步研究

通过海区采样，运用光镜和电镜观察等实验方法，研究了条斑紫菜叶状体色落症，并对患病紫菜加工成的干品进行了初步的品质分析。光镜检查结果表明，患病藻体细胞的液泡很大，色素体萎缩或是挤向细胞边缘，藻体基部死亡细胞较多；电镜下患病藻体细胞的红藻淀粉颗粒增多。品质分析显示，患色落症干紫菜的总糖含量明显高于正常干紫菜，粗蛋白、脂肪、色素和游离氨基酸等指标均比正常干紫菜低，尤其是三种呈味氨基酸（Asp，Glu和Ala）所占比例非常低，由此造成紫菜品质低劣，对紫菜质量的影响较大。对健康藻体和患病藻体进行红外线活体吸收光谱的测定结果也表明，患色落症的藻体色素含量极低。用添加营养盐的海水对患色落症的藻体进行培养，发现6d后藻体色泽均有不同程度的恢复，藻体细胞也逐渐恢复到正常。

Preliminary studies on the discoloration of Porphyra yezoensis thallus

Through sampling thalli from suffered sea area,the discoloration of Porphyra yezoensis was studied by photomicrography and electron microscope technique.And preliminary quality test was conducted on dried laver,Porphyra yezoensis that suffered from discoloration as well.The results of microscope-observation showed that,diseased thalli cells had large vacuoles,their chloroplasts atrophied or crushed to the edge of cell,several cells at the base died,and floridean starch particles manifolded under electron microscope.Quality test showed that total suger contents of faded dried lavers were apparently higher than those in normal dried lavers,while crude protein,fat,photosynthetic pigments and free amino acids in diseased laver were lower than normal dried lavers.Especially,the percentage of three flavour amino acids(Asp,Glu and Ala) in faded lavers was extra low.These influenced the quality of lavers greatly and resulted in inferior quality.The results of the absorption spectrum on the normal thalli and diseased thalli demonstrated again that the content of photosynthetic pigments in thalli that suffered from discoloration is extremely low.When we added nitrogen in seawater to culture the diseased thalli,the color restored more or less and thallus cells returned to normal after 6 days.