中文摘要：

在含氮量仅为海区的1／100、含磷量仅为海区的1／15的低氮、磷环境下，对人工选育和建立纯系的坛紫菜褐绿色、红棕色品系3代叶状体（F1、F2、F3）的耐受力情况及生长情况进行研究，发现2个品系的藻体均具有极强的耐低氮、磷能力：1）褐绿色藻体在低氮、磷环境下培养21d才停止生长，叶片无成熟现象，仅轻微的腐烂和萎缩．3～4cm长的藻体培养7～9d时的长度日生长量是对照组的4．73倍，鲜重日增重率是对照组的5．29倍；培养18～21d时的长度日生长量为（0．86±0．27）cm，鲜重日增重率为（5．32±0．21）％．褐绿色品系F3代的平均长度比对照组长28．7cm．2）红棕色藻体在相同条件下培养15d后停止生长，叶片无成熟、腐烂和萎缩，3代叶状体在低氮、磷甚至无氮、磷环境下的耐受力和生长状况均比较稳定且有所提高，遗传性状比较稳定．3～4cm长的红棕色藻体在低氮、磷环境下培养7～9d时的长度日生长量是对照组的4．95倍，鲜重日增重率是对照组的3．58倍；培养13～15d时藻体的长度日生长量为（1．92±0．53）cm，鲜重日增重率为（13．61±0．46）％．F3代的平均长度比对照组长23．16cm．3）通过选育可以看出褐绿色品系比较耐低氮、磷，该品系可以较好地解决养殖过程中低氮、磷环境对于紫菜养殖所造成的危害，缓解由于养殖密度过大而造成的病害发生和减产、减收现象．

英文摘要：

This study discussed the tolerance capability and growth under low N and P conditions （N contents was only 1/100 times of the sea area and P contents was only 1/15 times of the sea area） on the three filial generations （ F1 , F2, F3 ） of the breen and the red brown Porphyra haitanensis stains from artificial selection and pure lines, the results showed that both of the two strains had high capability of low N and P resistant： 1 ） The breen blades stopped growing after having been cultured 21 days under low N and P conditions. The blades did not get mature but were slightly rotten and atrophic; the daily length-increased was 4.73 times of the control and the fresh weight-increased was 5.29 times of the control after having been cultured 7 -9 days when the seedling was 3 -4 cm; the daily length-increased was （0. 86 ± 0. 27） cm and the fresh weight-increased was （5.32 ± 0. 21 ） % after having been cultured 18 -21 days; the average length was 28.7 cm longer than the control in the breen strain F3 thallus. 2） The red brown blades stopped growing after having been cultured 15 days under the same condition, there were no maturity, rot and atrophy phenomena. The tolerance capability and growth were relatively stable and the three filial generations thallus improved under low N and P and even without N and P conditions, and genetic characteristics were relatively stable; the daily length-increased was 4. 95 times of the control and the fresh weight-increased was 3.58 times of the con- trol after having been cultured 7--9 days when the seedlings was 3 -4 cm; the daily length-increased was （1.92 ± 0.53） cm and the fresh weight-increased was （13.61 ± 0.46） % after having been cultured 13--15 days; the average length was 23.16 cm longer than the control in the red brown strain F3 thallus. 3） The selective results indicated that the breen strain better resisted low N and P conditons, and could better reduce the harm of Porphya caused by low N and P conditons in the cultural process and allev