| Gracilaria salicornia is a kind of red algae that can be adapted to high temperature and it has a significant economic value.The seaweed field formed by Gracilaria salicornia can provide a variety of functions such as improving water quality,providing habitat for animals and so on.But it is being degenerated even disappeared because of the pollution of environment.With the development of manufacturing industry on rubber,it is necessary to develop the cultivation of Gracilaria salicornia massively,which can provide sufficient raw materials for rubber industry,and also repair the ecological environment.Up to now,there are no relevant research reports on studying the growing environment of Graciaria salicornia and how to cultivate it artificially.This paper is the supplement of that.The main points are the study of the growth and the biochemical components on Graciaria salicornia indoors.Then,the investigation about how to cultivate it artificially is carried out during the time between April,2015 and September,2016.The results are as follows:First,By studying the effects of temperature,light intensity,and salinity on the growth of Gracilaria salicornia,and on constriction of photosynthetic pigment,soluble protein,superoxide dismutase and malondialdehyde,it can be concluded that the suitable growth temperature for Graciaria salicornia is 24-32℃.The optimum growth temperature is 28℃.And the suitable growth light intensity is 3000-9000 lx.The optimum growth light intensity is 6000 lx.The suitable salinity is 20-35,and the optimum salinity is 30.Under the condition of appropriate environment,the algae have higher RGR.Meanwhile,the content of soluble protein(SP)is higher.But MDA is lower and the environmental stress is smaller.What’s more,the activity of SOD is higher than that of oxidative stress.Second,through the experiment that how Nitrogen concentration,Nitrogen and Nitrogen-phosphorus ratio had effects on the growth of Gracilaria salicornia,and on constriction of photosynthetic pigment,soluble protein,superoxide dismutase and malondialdehyde,the results concluded that the total inorganic nitrogen concentration is suitable for Gracilaria to grow well in the range of 156-260μmol/L,and the optimum is208μmol/L.In this range,the algae can maintain a fairly rapid growth rate.The suitable scope of nitrogen and phosphorus ratio is 5-10:1,the optimum ratio is 10:1.Compared with the condition of low nitrogen and phosphorus,the growth status,physiological andbiochemical aspects are more higher.Three kinds of inorganic nitrogen that,NO3--N,NH4+-N and NO2--N,are suitable for Gracilaria salicornia to grow.The ratio is1:8:4 or 4:8:1.More with this in seawater environment,it can grow better.Third,it is found that the algae grow faster from March to September than other months in natural sea area.And the biomass is the largest in May,June and July.In breeding season during June and October,Gracilaria salicornia propagate by vegetative propagation and spore reproduction.After October,as the temperature decreases,the growth slows down.Only a few Gracilaria salicornia can be found in natural sea area in December,January and February.Last,the experiment on how to cultivate Gracilaria salicornia artificially was carried out,in the near sea area of Guangdong province in May,2015,where three methods were adopted.The survival rates of three different cultivation methods were 76%,81% and 68%respectively.And the method of clipping seedlings on ropes is the best.The effect is remarkable.It is the ideal choice to build artificial algae field with Gracilaria salicornia for it’s easier and faster to grow quickly,especially,it can protect and repair the coastal ecological environment. |
PDF Full Text Request