The comprehensive carrying capacity of urban land can reflect the re- source level, economic scale, social development and environmental pressure of ur- ban land carrying. The assessment indicator system of urban land...The comprehensive carrying capacity of urban land can reflect the re- source level, economic scale, social development and environmental pressure of ur- ban land carrying. The assessment indicator system of urban land comprehensive carrying capacity was constructed from the 4 aspects of resource, economy, society, environment, and principal component analysis and cluster analysis were used to evaluate the urban land comprehensive carrying capacity of Guangxi and the 14 cities in 2005-2014, and analyzed its spatial and temporal characteristics as well as the driving forces, with the aim to provide references for improving the urban land comprehensive carrying capacity. The results showed that, the overall urban land comprehensive carrying capacity in Guangxi increased in 2005-2014, and there were significant differences in the land comprehensive carrying capacities among the cities in Guangxi in 2005-2014, in which Liuzhou, Guilin, Nanning belonged to the regions with the highest carrying capacity, while Beihai, Yulin, Wutong belonged to the regions with high carrying capacity, and the carrying capacities of the other cities changed with the changes of time. The economic development degree was an important factor influencing urban land comprehensive carrying capacity, but could not directly represent the urban land comprehensive carrying capacity level.展开更多
为了利用叶绿体基因工程技术改良普通油茶的重要经济性状,该研究以普通油茶叶绿体全基因组序列为材料,从中筛选出51条长度大于300 bp且以ATG起始的非重复CDS(Coding DNA Sequence)为对象,利用CodonW软件分析其密码子偏好性。结果表明:...为了利用叶绿体基因工程技术改良普通油茶的重要经济性状,该研究以普通油茶叶绿体全基因组序列为材料,从中筛选出51条长度大于300 bp且以ATG起始的非重复CDS(Coding DNA Sequence)为对象,利用CodonW软件分析其密码子偏好性。结果表明:密码子第三位GC含量为27.55%,ENC范围在35.23~56.67之间,平均值为46.09;RSCU值大于1.00的密码子数目为30个,其中29个第三位碱基以U或A结尾;中性绘图表明GC12与GC3的相关系数为0.143,相关性不显著,回归系数为0.0573;频数分布显示,55%基因的ENC比值集中分布在0~0.1,25%基因的ENC比值分布在0.1~0.2之间;对应分析结果表明,第一向量轴占10.12%的差异,第二向量轴占9.36%的差异,其余两轴分别占7.97%和7.46%,前4轴累计差异为34.91%。中性绘图、ENC-plot和对应性分析均表明普通油茶叶绿体基因密码子偏好受突变作用,更多受选择的影响。最终取高表达优越密码子和高频密码子共有的CUU、AUU、GUU、GUA、UAA、CAA、AAA、GAC、GAA、CCU、ACU、GCU、GCA、UGU、CGU、AGU、UUG、GGU等18个密码子作为最优密码子。该研究结果为利用叶绿体基因工程技术改良普通油茶重要经济性状奠定了基础。展开更多
基金Supported by the Open Bidding Projects of the Office of Land and Resources of the Guangxi Zhuang Autonomous Region(GXZC2015-G3-0575-GTZB)~~
文摘The comprehensive carrying capacity of urban land can reflect the re- source level, economic scale, social development and environmental pressure of ur- ban land carrying. The assessment indicator system of urban land comprehensive carrying capacity was constructed from the 4 aspects of resource, economy, society, environment, and principal component analysis and cluster analysis were used to evaluate the urban land comprehensive carrying capacity of Guangxi and the 14 cities in 2005-2014, and analyzed its spatial and temporal characteristics as well as the driving forces, with the aim to provide references for improving the urban land comprehensive carrying capacity. The results showed that, the overall urban land comprehensive carrying capacity in Guangxi increased in 2005-2014, and there were significant differences in the land comprehensive carrying capacities among the cities in Guangxi in 2005-2014, in which Liuzhou, Guilin, Nanning belonged to the regions with the highest carrying capacity, while Beihai, Yulin, Wutong belonged to the regions with high carrying capacity, and the carrying capacities of the other cities changed with the changes of time. The economic development degree was an important factor influencing urban land comprehensive carrying capacity, but could not directly represent the urban land comprehensive carrying capacity level.
文摘为了利用叶绿体基因工程技术改良普通油茶的重要经济性状,该研究以普通油茶叶绿体全基因组序列为材料,从中筛选出51条长度大于300 bp且以ATG起始的非重复CDS(Coding DNA Sequence)为对象,利用CodonW软件分析其密码子偏好性。结果表明:密码子第三位GC含量为27.55%,ENC范围在35.23~56.67之间,平均值为46.09;RSCU值大于1.00的密码子数目为30个,其中29个第三位碱基以U或A结尾;中性绘图表明GC12与GC3的相关系数为0.143,相关性不显著,回归系数为0.0573;频数分布显示,55%基因的ENC比值集中分布在0~0.1,25%基因的ENC比值分布在0.1~0.2之间;对应分析结果表明,第一向量轴占10.12%的差异,第二向量轴占9.36%的差异,其余两轴分别占7.97%和7.46%,前4轴累计差异为34.91%。中性绘图、ENC-plot和对应性分析均表明普通油茶叶绿体基因密码子偏好受突变作用,更多受选择的影响。最终取高表达优越密码子和高频密码子共有的CUU、AUU、GUU、GUA、UAA、CAA、AAA、GAC、GAA、CCU、ACU、GCU、GCA、UGU、CGU、AGU、UUG、GGU等18个密码子作为最优密码子。该研究结果为利用叶绿体基因工程技术改良普通油茶重要经济性状奠定了基础。
