This paper was based on data collected during the 38th and 39th Chinese National Antarctic Research Expeditions in the Amundsen Sea. The spatiotemporal distribution patterns of length(total length, AT) and sexual matu...This paper was based on data collected during the 38th and 39th Chinese National Antarctic Research Expeditions in the Amundsen Sea. The spatiotemporal distribution patterns of length(total length, AT) and sexual maturity stages of Antarctic krill(Euphausia superba) were examined. The age structure and geographic distribution of cluster groups also were studied. The results reveal significant diurnal variations in the length and maturity stages of Antarctic krill during the morning(MRN) to morning twilight(MTW) period, with mean lengths ranging from 28.92 to 45.87 mm. Two cyclical patterns were observed.Regarding maturity stages, the krill were composed of juveniles, adult males, and adult females in increasing order of proportion,with a notably higher proportion of non-gravid females compared to gravid females, and mainly distributed in evening twilight(ETW) to dawn(DWN), MTW to day(DAY), MRN to MTW, MRN to MTW and night(NIT) to DAY periods, respectively.Significant spatial variations in krill length and maturity stages occur, with a marked regional boundary around 130°W. K-means clustering analysis of krill length identified Group Ⅰ, Group Ⅱ, and Group Ⅲ, with dominant age classes of 3+, 0 and 3+, and 3+to 4+, respectively. Group Ⅱ was widely distributed in the surveyed waters, whereas Group Ⅰ and Group Ⅲ were distributed only in waters west of 130°W. The study area features a significant continental slope, where adults and gravid females were primarily distributed on its slopes and to the south. This spatial pattern also profoundly influenced the distribution of different cluster groups.展开更多
为科学评价南极磷虾这一新兴资源,同时为小型虾的高值化加工利用提供参考,选取体型上相近的南极磷虾与脊尾白虾作为研究对象,通过测定基本营养成分、氨基酸组成和脂肪酸组成分析2种虾的营养学特征,通过测定游离氨基酸与呈味核苷酸,进而...为科学评价南极磷虾这一新兴资源,同时为小型虾的高值化加工利用提供参考,选取体型上相近的南极磷虾与脊尾白虾作为研究对象,通过测定基本营养成分、氨基酸组成和脂肪酸组成分析2种虾的营养学特征,通过测定游离氨基酸与呈味核苷酸,进而计算滋味活性值与味精当量(equivalent umami concentration,EUC)评价其鲜度。结果表明,南极磷虾和脊尾白虾的粗蛋白质量分数具有显著性差异(P<0.05),分别为13.25%和16.41%,粗脂肪质量分数同样差异显著(P<0.05),分别为3.12%和1.10%。2种虾的脂肪酸组成有明显不同,南极磷虾的不饱和脂肪酸含量相对更高。南极磷虾的水解氨基酸总量低于脊尾白虾(P<0.05),但必需氨基酸所占比例更高,更加符合FAO/WHO推荐的蛋白质营养的理想模式。南极磷虾和脊尾白虾均是次黄嘌呤核苷酸和游离谷氨酸对鲜味起主要贡献作用,其EUC分别为11.01 g MSG/100 g和12.98 g MSG/100 g。南极磷虾与脊尾白虾都具有较高的营养价值,且具备理想的鲜味特征,在普通食品、调味品开发方面具有广阔的市场前景。展开更多
Amplified fragment length polymorphism(AFLP)was used to analyze 2 populations: Schima superba Gardn. et Champ. and Castanopsis chinensis Hance. across three different communities representing three succession ...Amplified fragment length polymorphism(AFLP)was used to analyze 2 populations: Schima superba Gardn. et Champ. and Castanopsis chinensis Hance. across three different communities representing three succession stages, in Dinghu Mountain, China. These two were middle succession species in the lower subtropical broad_leaved forest. Four AFLP primer combinations using total 48 individuals of S. superba provided 24, 40, 27 and 27 reliable bands, of which 15, 23, 23 and 16 were polymorphic, respectively. Similarly, total 48 individuals of C. chinensis provided 27, 20, 33 and 39 reliable bands, of which 12, 5, 15 and 13 were polymorphic respectively. These bands were used as presence/absence data to assess the levels of genetic variation and population structure of those species. From average heterozygosity, S. superba possessed higher molecular variation than C. chinensis . Analysis of molecular variance(AMOVA)indicated that most of the genetic variation of S. superba was due to the differences within population(95.99%, P <0.001), with 4.01% ( P <0.001)genetic variation among population. Similarly, AMOVA indicated the most of the genetic variation of C. chinensis was due to the differences within population(75.36%, P <0.001), with 24.64%( P <0.001)genetic variation among communities(24.64%). DCA(Detrended Correspondence Analysis) analysis showed that the individuals of S. superba from the same community did not cluster together, while the individuals of C. chinensis from the same community roughly cluster together. The above results reflected the biological characteristics of the two different species suggesting the significant effect of microenvironment of different community on population differentiation and its relationship of which to forest succession resulted in genetic divergence.展开更多
通过对不同个体水力导度(KL)的研究,揭示水力导度在树木水分利用中的关键作用,可为深入研究森林水分循环提供理论依据.采用热消散探针液流测定系统连续监测广州地区6棵不同大小荷木(Schima superba)样树的液流密度(JS),结合树木的叶片水...通过对不同个体水力导度(KL)的研究,揭示水力导度在树木水分利用中的关键作用,可为深入研究森林水分循环提供理论依据.采用热消散探针液流测定系统连续监测广州地区6棵不同大小荷木(Schima superba)样树的液流密度(JS),结合树木的叶片水势(ΨL)、土壤湿度、树高、边材面积(AS)、冠幅等参数,分析整树水力导度的日变化和干湿季变化,揭示不同大小样树水力导度的变化规律.结果显示:不同胸径大小的6棵样树液流密度差别明显,液流密度最大值未出现在胸径最大的样树中,而是在胸径略小的树木中.通过测定6棵样树的液流密度值可以进一步求算出样树的整树水力导度,总体上讲,6棵树的日均水力导度表现出明显的起伏波动;其中干季水力导度(0.017 g m-2s-1 M Pa-1)略低于湿季(0.019 g m-2 s-1 M Pa-1),但差异并不明显.样树土壤/叶片水势差与平均液流密度显著相关(P<0.0 01),而样树树形特征和水力导度之间关系表现为水力导度与树高呈现明显相关性(P=0.016),与胸径、冠幅相关性均不显著.上述结果表明,荷木水力导度表现出明显的日变化,其大小在一定程度上受到树形指标的影响.展开更多
基金supported by the 38th and 39th CHINAREs and all members of the two Antarctic cruisessupported by Ministry of Natural Resources of the People’s Republic of China and the Chinese Arctic and Antarctic Administration。
文摘This paper was based on data collected during the 38th and 39th Chinese National Antarctic Research Expeditions in the Amundsen Sea. The spatiotemporal distribution patterns of length(total length, AT) and sexual maturity stages of Antarctic krill(Euphausia superba) were examined. The age structure and geographic distribution of cluster groups also were studied. The results reveal significant diurnal variations in the length and maturity stages of Antarctic krill during the morning(MRN) to morning twilight(MTW) period, with mean lengths ranging from 28.92 to 45.87 mm. Two cyclical patterns were observed.Regarding maturity stages, the krill were composed of juveniles, adult males, and adult females in increasing order of proportion,with a notably higher proportion of non-gravid females compared to gravid females, and mainly distributed in evening twilight(ETW) to dawn(DWN), MTW to day(DAY), MRN to MTW, MRN to MTW and night(NIT) to DAY periods, respectively.Significant spatial variations in krill length and maturity stages occur, with a marked regional boundary around 130°W. K-means clustering analysis of krill length identified Group Ⅰ, Group Ⅱ, and Group Ⅲ, with dominant age classes of 3+, 0 and 3+, and 3+to 4+, respectively. Group Ⅱ was widely distributed in the surveyed waters, whereas Group Ⅰ and Group Ⅲ were distributed only in waters west of 130°W. The study area features a significant continental slope, where adults and gravid females were primarily distributed on its slopes and to the south. This spatial pattern also profoundly influenced the distribution of different cluster groups.
文摘为科学评价南极磷虾这一新兴资源,同时为小型虾的高值化加工利用提供参考,选取体型上相近的南极磷虾与脊尾白虾作为研究对象,通过测定基本营养成分、氨基酸组成和脂肪酸组成分析2种虾的营养学特征,通过测定游离氨基酸与呈味核苷酸,进而计算滋味活性值与味精当量(equivalent umami concentration,EUC)评价其鲜度。结果表明,南极磷虾和脊尾白虾的粗蛋白质量分数具有显著性差异(P<0.05),分别为13.25%和16.41%,粗脂肪质量分数同样差异显著(P<0.05),分别为3.12%和1.10%。2种虾的脂肪酸组成有明显不同,南极磷虾的不饱和脂肪酸含量相对更高。南极磷虾的水解氨基酸总量低于脊尾白虾(P<0.05),但必需氨基酸所占比例更高,更加符合FAO/WHO推荐的蛋白质营养的理想模式。南极磷虾和脊尾白虾均是次黄嘌呤核苷酸和游离谷氨酸对鲜味起主要贡献作用,其EUC分别为11.01 g MSG/100 g和12.98 g MSG/100 g。南极磷虾与脊尾白虾都具有较高的营养价值,且具备理想的鲜味特征,在普通食品、调味品开发方面具有广阔的市场前景。
基金TheNationalNaturalScienceFoundationofChina (No .39670 1 36) PhDFund (No .980 5580 8)ofMinistryofEducationP .R .China Center
文摘Amplified fragment length polymorphism(AFLP)was used to analyze 2 populations: Schima superba Gardn. et Champ. and Castanopsis chinensis Hance. across three different communities representing three succession stages, in Dinghu Mountain, China. These two were middle succession species in the lower subtropical broad_leaved forest. Four AFLP primer combinations using total 48 individuals of S. superba provided 24, 40, 27 and 27 reliable bands, of which 15, 23, 23 and 16 were polymorphic, respectively. Similarly, total 48 individuals of C. chinensis provided 27, 20, 33 and 39 reliable bands, of which 12, 5, 15 and 13 were polymorphic respectively. These bands were used as presence/absence data to assess the levels of genetic variation and population structure of those species. From average heterozygosity, S. superba possessed higher molecular variation than C. chinensis . Analysis of molecular variance(AMOVA)indicated that most of the genetic variation of S. superba was due to the differences within population(95.99%, P <0.001), with 4.01% ( P <0.001)genetic variation among population. Similarly, AMOVA indicated the most of the genetic variation of C. chinensis was due to the differences within population(75.36%, P <0.001), with 24.64%( P <0.001)genetic variation among communities(24.64%). DCA(Detrended Correspondence Analysis) analysis showed that the individuals of S. superba from the same community did not cluster together, while the individuals of C. chinensis from the same community roughly cluster together. The above results reflected the biological characteristics of the two different species suggesting the significant effect of microenvironment of different community on population differentiation and its relationship of which to forest succession resulted in genetic divergence.
文摘通过对不同个体水力导度(KL)的研究,揭示水力导度在树木水分利用中的关键作用,可为深入研究森林水分循环提供理论依据.采用热消散探针液流测定系统连续监测广州地区6棵不同大小荷木(Schima superba)样树的液流密度(JS),结合树木的叶片水势(ΨL)、土壤湿度、树高、边材面积(AS)、冠幅等参数,分析整树水力导度的日变化和干湿季变化,揭示不同大小样树水力导度的变化规律.结果显示:不同胸径大小的6棵样树液流密度差别明显,液流密度最大值未出现在胸径最大的样树中,而是在胸径略小的树木中.通过测定6棵样树的液流密度值可以进一步求算出样树的整树水力导度,总体上讲,6棵树的日均水力导度表现出明显的起伏波动;其中干季水力导度(0.017 g m-2s-1 M Pa-1)略低于湿季(0.019 g m-2 s-1 M Pa-1),但差异并不明显.样树土壤/叶片水势差与平均液流密度显著相关(P<0.0 01),而样树树形特征和水力导度之间关系表现为水力导度与树高呈现明显相关性(P=0.016),与胸径、冠幅相关性均不显著.上述结果表明,荷木水力导度表现出明显的日变化,其大小在一定程度上受到树形指标的影响.
