【作者】 杨芳；

【导师】 李文红；

【作者基本信息】 广西大学 ， 水产养殖， 2014， 硕士

【摘要】 为了解北部湾细基江蓠繁枝变种自然群体的生长和氮营养特征,本研究采用现场观测方法分别对东兴、北海和深圳海区细基江蓠繁枝变种群体生活海区的水质、藻体生长及其总氮、总磷含量进行了为期一周年和5个月的监测;并以三个海区的江蓠样本为材料,在实验室内进行种类分子鉴定和氮吸收特征试验。研究结果发现:(1)三个海区的江蓠样本形态和解剖学特征均类似细基江蓠繁枝变种。Rubisco基因序列和COI基因序列分析结果发现:三个海区江蓠样本的COI基因序列长度均为632 bp,仅有两个位点差异,深圳和东兴地区的GC含量均为59.7%,北海为59.9%;Rubisco基因序列没有差异,长度和GC含量分别为274 bp,48.9%。与Genbank中的细基江蓠繁枝变种(Gracilaria tenuistipitata var,Genbank:AY673996.1)相关序列比对结果证实:三个地区的江蓠样本为细基江蓠繁枝变种。(2)2013年7月至11月对东兴、北海、深圳三个海区水质监测分析发现:三地的水环境存在显著差异。深圳海区盐度(23-30)、水温(27-31℃)均较东兴的高(P<0.05);北海海区氮营养盐含量(0.645-0.965mg/L)较深圳的高(P<0.05);北海海区盐度、水温、总氮、氨态氮、亚硝酸盐、活性磷均较东兴海区的高(P<0.05)。基于6项化学指标的综合水质评价结果显示:三个海区水质质量良好,综合水质类别介于《GB3097-1997海水水质标准》的Ⅰ-Ⅲ类之间。三个海区水中的氮磷质量比值(N/P)周年变化范围分别为:深圳8.90-14.86,北海7.58-30.71,东兴2.96-20.64。N/P最高值均出现在夏季,仅北海一地水体N/P大于22,最低值均出现在秋季且小于10,说明夏季北海海区营养盐受磷限制,秋季三海区均受氮限制。(3)2013年4月至2014年3月对东兴海区细基江蓠繁枝变种群体生长和海区水质的周年监测分析发现:细基江蓠繁枝变种生长在泥沙底海湾的水域中,呈半悬浮状态,没有固着器;一年四季都能生长,没有有性繁殖现象。藻体密集且纤细,颜色以红褐色为主,月均体长范围为12.56-18.81 cm,月均干重生物量范围为13.54-33 g/m2,藻体的月均长度与干重生物量变化趋势相似,最高值均出现在2013年11月,最低值出现在7-8月,说明11月种群生长和生物量达到最大值。中大长级(20-30cm)藻体在冬春季的出现频数较大,藻体长度最大值(31.6cm)出现在3月。藻体月均含氮量秋初(9月)最高4.02%,春季(4月)最低1.656%;藻体含磷量秋季(10月)最高0.508%,夏初(7月)最低0.275%。东兴海区藻体氮磷含量与藻体N/P、水体N/P呈正显著相关,藻体N/P值夏季(8月)最高11.8,冬春季(4月)最低4.65,周年N/P变化范围为4.65-11.8,为N限制(质量比值小于14),冬末及春季生长速率最快。(4)2013年7月至11月对东兴、北海、深圳三个海区细基江蓠繁枝变种群体生态学调查发现,三个海区的水质、藻体颜色、体长、体重、密度、生物量和藻体含氮磷量存在一定差异。具体如下:北海地区江蓠藻体墨绿色和灰褐色,海藻鲜重范围为0.84-3.87 g,长度5.47-33.6 cm,密度为184株/m2个;深圳地区江蓠海藻鲜重范围为0.51-2.19 g,长度9.1-27.5 cm,密度为305株/m2,藻体颜色以黄褐色和深褐色为主;东兴海区江蓠海藻鲜重范围为0.36-3.05 g,长度7.2-31.6 cm,密度为298株/m2,藻体颜色以红褐色和墨绿色为主。说明北海种群密度最小,但单株藻体长度和重量最大。三地藻体的月平均生物量最大值分别为深圳42 g/m2、北海24 g/m2、东兴33 g/m2,均在11月份出现;最小值分别为深圳16 g/m2、北海8.5 g/m2、东兴13.5 g/m2,出现在8月份左右。说明三地藻体生长基本同步,种群生物量最大值和最小值分别出现在11月和8月,且北海月平均生物量明显低于深圳和东兴地区。三个海区藻体含氮量月均值深圳为2.301-4.134%,北海为3.994-4.631%,东兴为2.198-4.020%,北海藻体含氮量与深圳、东兴的存在显著差异(P<0.05)。三地藻体含氮量最高值均出现在9月份,分别为:深圳4.134%,北海4.631%,东兴4.02%,北海藻体含氮量较深圳、东兴的高。相关性分析表明:藻体含氮量与综合水质级别、水体含氮量呈极显著相关(P<0.01),与温度和水体含磷量呈显著相关(P<0.05),说明海水综合水质、水体氮、磷含量和温度对海藻含氮量影响显著。三海区藻体对无机氮富集能力存在差异。深圳藻体对无机氮富集系数月均值为7.60-22.43,北海为13.10-29.66,东兴为12.16-25.96,说明北海藻体的无机氮富集能力最高,东兴次之,深圳最低。北海和东兴地区细基江蓠繁枝变种对水体无机氮(N)富集系数最高值均出现在秋末(11月份),深圳最高值出现在夏季(7月)。相关性分析表明:北海藻体无机氮富集能力与深圳的存在显著差异(P<0.05),东兴与其余两地差异不显著(P>0.05);藻体对无机氮富集能力与水质及藻体含氮量无显著相关。三个海区藻体内N/P变化趋势与海水N/P相似,最高值均出现在夏季(7-8月份),分别为深圳8.84,北海13.92,东兴11.8,夏季北海藻体N/P较深圳、东兴的高;秋季(10-11月)藻体N/P值最低,分别为深圳6.12,北海6.76,东兴6.23,藻体秋季生长速率较快,藻体受N营养盐限制。(5)在温度22(±1)℃,盐度20(±2)的条件下,以硝态氮和氨态氮为氮源,三个细基江蓠繁枝变种种群藻体在0-160 μmol/L氮浓度(NH4-N,N02-N)范围时藻体对氮营养盐的吸收、藻体NR酶、SOD酶活性和脯氨酸含量变化结果显示:40 μmol/L的供氮水平能使深圳和北海地区细基江蓠繁枝变型处于相对最佳的生理状态,此时深圳、北海地区江蓠藻体对氮的最大吸收速率分别是0.484 μmol/(g·h)、0.396 μmol/(g·h),NR酶、SOD酶活性和脯氨酸含量分别是:深圳63.36 μg/(g·h)、107.99 U/g、27.55 μg/g,北海 69.14 μg/(g·h)、103.32 U/g、30.72 μg/g;20 μmol/L 的供氮水平能使东兴地区细基江蓠繁枝变型处于相对最佳的生理状态,此时江蓠藻体对氮的最大吸收速率是0.245 μmol/(g·h),NR酶、SOD酶活性和脯氨酸含量分别是:62.8μg/(g·h)、120.13 U/g、22.79 μg/g。说明深圳和北海地区细基江蓠繁枝变型种群对高氮营养盐环境的适应能力强于东兴地区种群,运用于高氮海区生态修复的潜力较大。更多还原

【Abstract】 In this study,we monitor Dongxing,Beihei and Shengzheng total three sea areas seven months to understand the growth and nitrogen nutrition characteristics of natural population of G.tenuistipitata var in Beibu Gulf of China.These monitoring indexes contain water quality,algae growth,and total content of nitrogen and phosphorus of these three sea areas.Furthermore,we identified the specie of Gracilaria samples from these three sea areas by DNA barcode,and tested the nitrogen absorption characteristics of these Gracilaria samples.The results of this study are reproduced below.(1)The morphological and anatomical characteristics of Gracilaria samples from these three sea areas are similar to G.tenuistipitata var.Meanwhile,these three Gracilaria samples were identified as G.tenuistipitata var(Genbank:AY673996.1)by DNA barcode.The COI gene of these three gracilaria samples has 632bp and two sites differences between of them,the GC contents of Dongxing,Beihei and Shengzheng total three Gracilaria samples respectively are 59.7%,59.7%,59.9%.The Rubisco genes of these three Gracilaria samples have 274bp and no difference between of them,the GC contents of these Gracilaria samples are 48.9%.(2)July 2013 to November,the water quality monitoring analysis of Dongxing,Beihai and Shenzhen total three sea areas found that there are significant differences between these three regions of the water environment.The salinity(23-30)and temperature(27-31)of Shenzhen sea area are higher than Dongxing see area(P<0.05).The nitrogen nutrient content(0.645-0.965mg/L)of Beihai sea area are higher than Shenzhen see area(P<0.05).The Salinity,water temperature,nitrogen,ammonia nitrogen,nitrite and reactive phosphorus of Beihai sea area are higher than Dongxing see area(P<0.05).Three sea areas of comprehensive water quality evaluation based on six chemical indicators indicated that the comprehensive water quality of these sea areas was good which between class Ⅰ to Ⅲcategories ranging of "GB3097-1997 sea water quality standards".The range of annual variation of mass ratio of nitrogen and phosphorus(N/P)of these three sea areas respectively were 8.90-14.86(Shenzhen),7.58-30.71(Beihai),2.96-20.64(Dongxing).The N/P values of all these sea areas were highest in summer,only Beihai of N/P is greater than 22,the lowest N/P values of all these sea areas were in the fall and less than 10,indicating that Beihai see area was restricted by phosphorus nutrient in the summer and these three see areas were restricted by nitrogen nutrient in the fall.(3)April 2013 to March 2014,the annual monitoring analysis of sea water quality and population growth of G.tenuistipitata var based on Dongxing sea area found that the G.tenuistipitata var grown in bottom sediment of the Gulf waters,a semi-suspension state without holdfast;grow all year round,there is no sexual reproduction.The Gracilaria is concentrated and thin,red-brown,the average monthly Length is 12.56-18.81cm and average dry weight biomass is 13.54-33g/m,the highest values were in November 2013,the lowest value in July-August,indicating that population growth and biomass maximum in November.Large long stage(20-30cm)algae appeared frequency frond in the winter and spring,length max(31.6cm)in March.Nitrogen content of Gracilaria have maximum(4.02%)in September and have minimum(1.656%)in April;phosphorus content have maximum(0.508%)in October and have minimum(0.275%)in July.The nitrogen in Gracilaria associated with the N/P in Gracilaria and water,the values of N/P highest in summer(August)is 11.8,minimum in winter and spring(April)is 4.65,the annual N/P range of 4.65 to 11.8,to limit the N(mass ratio is less than 14),the fastest growth rate in late winter and spring.(4)July 2013 to November,the population ecology survey of G.tenuistipitata var in Dongxing,Beihai and Shenzhen total three see areas found that there are some differences of see water,the algae color,length,weight,density,the amount of biomass and algae of nitrogen and phosphorus-containing between these three sea areas.The results of this study are reproduced below.The G.tenuistipitata var are dark green and gray-brown from Beihai,seaweed fresh weight are 0.84-3.87g every plant,and length are 5.47-33.6cm every plant,density are 184 plants every square one months;The G.tenuistipitata var are brown and dark brown colors from Shenzhen,seaweed fresh weight are 0.51-2.19g every plant,length are 9.1-27.5cm every plant,density are 305 plants every square one months;The G.tenuistipitata var are red-brown algae and dark green color colors from Dongxing,seaweed fresh weight are 0.36-3.05g every plant,length are 7.2-31.6cm every plant,density are 298 plants every square one months;That description Beihai plant population density but the smallest body length and weight of the largest frond.Monthly average biomass maximum of three algae were Shenzhen is 42g/m2,Beihai is 24g/m2,Dongxing is 33g/m,both in November;the minimum Shenzhen is 16g/m2,Beihai is 8.5g/m2,Dongxing is 13.5g/m2,occurs around August;That described The G.tenuistipitata var from three region have the same growth state,population biomass maximum and minimum,respectively,in November and August,and the average monthly biomass from Beihai was significantly lower than in Shenzhen and Dongxing.Nitrogen content of G.tenuistipitata var from Shenzhen in every month are 2.301-4.134%,from Beihai in every month are 3.994-4.631%from Dongxing in every month are 2.198-4.020%,Beihai has a significant difference(P<0.05)with Shenzhen and Dongxing.The nitrogen content of G.tenuistipitata var from three region were highest in September,Shenzhen was 4.134%,Beihai was 4.631%,Dongxing was 4.02%.The nitrogen content of G.tenuistipitata var from Beihai was higher than Shenzhen and Dongxing.Nitrogen content of G.tenuistipitata var had a great significantly correlated(P<0.01),with comprehensive water quality and nitrogen content of water,had a significantly correlated(P<0.05),with salinity and phosphorus content of water.That described a comprehensive water quality water,nitrogen and phosphorus of content and temperature effects on the nitrogen content of the G.tenuistipitata var.There had a different in nitrogen enrichment capability from three reigons,Beihai was best with 13.10-29.66,Dongxing was second with 12.16-25.96,Shenzhen was lowest with 7.60-22.43.Beihai and Dongxing had the highest nitrogen enrichment capability in November,but Shenzhen was in July.Only Shenzhen and Beihai had a significant difference(P<0.05),there were no significant correlation in nitrogen enrichment capability,nitrogen content of algae and water.Nitrogen and phosphorus ratio of G.tenuistipitata var and water were similar,the highest values were in summer(7-8 months),respectively,Shenzhen was 8.84,Beihai was 13.92,Dongxing was 11.8,Beihai was higher than Shenzhen and Dongxing in summer;The lowest values were in autumn(10-11 months),respectively,Shenzhen was 6.12,Beihai was 6.76,Dongxing was 6.23,G.tenuistipitata var had a faster growth rate in autumn,were N nutrient restrictions.(5)We conducted a series of conditional experiments at a temperature of 22(± 1)℃,salinity 20(± 2),using three G.tenuistipitata var populations from Shenzhen,Beihai and Dongxing determine the effects of nutrient supply(NH4-N,NO2-N)about 0-160umol/L on nitrogen uptake,algae NR enzymes,SOD activity and proline content.The results show that the appropiate N concentration for G.tenuistipitata var populations of Shenzhen and Beiha is 40μmol/L,exhibiting maximum uptake rates of 0.484 μmol/(g·h)and 0.396μmol/(g·h)respectively,NR enzymes,SOD activity and proline are:Shenzhen 63.36μg/(g·h),107.99U/g,27.55μg/g,North 69.14μg/(gh),103.32U/g,30.72μg/g;20μmol/L.At the sane time,the appropiate N concentration for G.tenuistipitata var populations of Dongxing is 20umol/L,exhibting maximum uptake rates of 0.245μmol/(g·h),NR enzymes,SOD activity and proline are:62.8μg/(g·h),120.13U/g,22.79μg/g.Our results suggest that G.tenuistipitata var populations of Shenzhen and Beiha are more effecient at addapting to high nitrogen nutrient environment than Dongxing population,so Shenzhen populations and Beiha poulations have greater potential to repair sea area.更多还原