夏季池塘养殖脆江蓠的生长与光合特性

The Growth and Photosynthetic Performance in Sea Weed Gracilaria chouae in a Pond in Summer

在夏季的虾蟹混养池塘的水深20cm、50cm和80cm处养殖脆江蓠,测定其生长、光合作用以及藻体光合色素含量。并在实验室测定不同光照度和温度对脆江蓠生长的影响。试验结果表明,脆江蓠的日相对生长率随着水深增加逐渐降低,在离水面20cm处日相对生长率为11.7%,水深50cm处为9.7%,而在80cm处降至7.1%,最大光合作用速率也随深度增加而降低。光照和温度对脆江蓠的日相对生长速率均有显著影响,而光照的作用更为显著。在26℃、14 000lx光照度下,脆江蓠的日相对生长率为22.9%,而在2200lx光照度下,日相对生长率仅有4.9%。光照度显著影响脆江蓠的光合色素含量,叶绿素a随着水深增加而增加,而藻红蛋白则随着水深增加而减少。在北方海水池塘通过控制养殖水层等措施,养殖脆江蓠具有可行性。

The effects of water depth （20 cm ,50 cm and 80 cm） on growth rate ,photosynthesis and photosynthetic pigments contents were studied in sea weed Gracilaria chouae cultured in shrimp and crab polyculture ponds during summer ,and the effects of light intensity and temperature on grow th of the sea weed were also studied in a laboratory .The results showed that daily relative growth rate （RGR） of the sea weed was found to be decreased gradually with increase in water depth ,with daily RGR of 11 .7% at water depth of 20 cm ,9 .7% at 50 cm and 7 .1% at 80 cm .The maximum net photosynthetic rate was also reduced with increase in water depth .The indoor experiment results showed that the light and temperature had significant effects on RGR of the sea weed ,light playing more significant role than temperature .The daily RGR of 22 .9% was observed in the sea weed under light intensity of 14 000 lx ,while only daily RGR of 4 .9% was found under light intensity of 2200 lx .Light intensity also affected photosynthetic pigment contents significantly ,increase in chlorophyll a with increasing water depth ,and decrease in phycoerythrin with increase in water depth ,indicating that the pigmentation rearrangement is physiological adaptation of G .chouae to light intensity .