温度、光强及氮磷比对断枝铜藻幼苗生长的影响

Effects of temperature,light intensity and ratio of nitrogen to phosphorus on growth of seedlings in sea weed Sargassum horneri

为了优化断枝铜藻Sargassum horneri幼苗生长的室内培养条件,试验分别截取5、2 cm铜藻为材料,在培养箱中培养20 d,通过改变温度(10、15、20、25℃)、光照强度(4500、8900、11000 lx)和营养盐配比(NH4NO3∶Na2HPO4=5∶1、8∶1、10∶1、16∶1,质量比)等条件,以及在不同培养时间点测量幼苗的生长情况,寻找有利于其生长的最佳培养条件。结果表明:培养10、20 d时,温度对5 cm组铜藻幼苗长度、质量特定生长率及2 cm组长度特定生长率均有极显著性影响(P<0.01),试验期间温度20℃时,5、2 cm组幼苗平均特定生长率最大且2 cm组生长率显著大于其他温度组(P<0.05);光强仅对2 cm组幼苗培养10 d时的质量特定生长率有极显著性影响(P<0.01),试验期间低光强组(4500 lx)幼苗质量特定生长率显著小于高光强组(11000 lx)(P<0.05);本试验条件下,营养盐配比对幼苗生长无显著性影响(P>0.05)。研究表明,断枝铜藻幼苗生长适宜水温为15~25℃,最适水温20℃,适宜光强为8900~11000 lx,且低培养密度(2 cm)有利于铜藻幼苗生长,本研究结果可为漂浮铜藻幼苗生长提供基础技术数据。

Juvenile sea weed Sargassum horneri of some 5 cm and 2 cm long side branches with blades of 10-13 and 6-8,respectively,were cultured in an incubator at temperatures of 10,15,20℃,and 25℃,light intensity of 4500 lx,8900 lx,and 11000 lx and ratios of nitrogen to phosphorus(NH4NO3∶Na2HPO4=5∶1,8∶1,10∶1,and 16∶1)for 20 days to investigate effects of temperature,light intensity and ratio of nitrogen to phosphorus on growth of the sea weed seedlings and to search for optimization of the culture conditions of sea weed seedlings.The results showed that there was significant effect of water temperature on specific growth rate(SGR)in body length and body weight of 5 cm long seedlings and SGR in body length of 2 cm long seedlings in 10 and 20 day culture(P<0.01),with the maximal SGR in 5 cm and 2 cm long seedlings,and significant higher SGR in 2 cm long seedlings than that in seedlings in other groups(P<0.50).There was very significant effect of only light intensity on SGR in body weight of 2 cm long seedlings(P<0.01),with significant higher SGR at lower light intensity(4500 lx)than that in higher light intensity(11000 lx)(P<0.50).It was found that there was no significant effect of ratio of nitrogen to phosphorus on the seedling growth(P>0.05).The findings indicated that the best growth was observed under the conditions of water temperature of 20℃(15-25℃),light intensity from 8900 lx to 11000 lx,and low density of 2 cm seedlings,which provides basic data for seedlings culture of sea weed Sargassum horneri..