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1350~1640年英国农民经济的分化 被引量:2
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作者 黄春高 《首都师范大学学报(社会科学版)》 2004年第1期18-25,共8页
本文讨论 1 350~ 1 640年英国农民分化问题 ,对传统的商品化导致两极分化理论模式提出质疑 ,认为该模式不足以解释英国农民分化的复杂性 ;同时论证英国农民分化乃是多种因素共同作用的结果 ,而且呈现出不同的类型。作者认为 ,只有结合... 本文讨论 1 350~ 1 640年英国农民分化问题 ,对传统的商品化导致两极分化理论模式提出质疑 ,认为该模式不足以解释英国农民分化的复杂性 ;同时论证英国农民分化乃是多种因素共同作用的结果 ,而且呈现出不同的类型。作者认为 ,只有结合长期的人口变化趋势和家庭人口周期以及商品化来考察 。 展开更多
关键词 英国 农民经济 两极分化 人口分化 新马尔萨斯主义 继承制度
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Population genetic variation and historical dynamics of the natural enemy insect Propylea japonica(Coleoptera: Coccinellidae) in China 被引量:1
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作者 WANG Meng-qi ZHAGN Hong-rui +4 位作者 XI Yu-qiang WANG Gao-ping ZHAO Man ZHANG Li-juan GUO Xian-ru 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第8期2456-2469,共14页
Propylea japonica(Coleoptera:Coccinellidae)is a natural enemy insect with a wide range of predation in Chinese mainland and is commonly used in pest management.However,its genetic pattern(i.e.,genetic variation,geneti... Propylea japonica(Coleoptera:Coccinellidae)is a natural enemy insect with a wide range of predation in Chinese mainland and is commonly used in pest management.However,its genetic pattern(i.e.,genetic variation,genetic structure,and historical population dynamics)is still unclear,impeding the development of biological control of insect pests.Population genetic research has the potential to optimize strategies at different stages of the biological control processes.This study used 23 nuclear microsatellite sites and mitochondrial COI genes to investigate the population genetics of Propylea japonica based on 462 specimens collected from 30 sampling sites in China.The microsatellite dataset showed a moderate level of genetic diversity,but the mitochondrial genes showed a high level of genetic diversity.Populations from the Yellow River basin were more genetically diverse than those in the Yangtze River basin.Propylea japonica has not yet formed a significant genealogical structure in China,but there was a population structure signal to some extent,which may be caused by frequent gene flow between populations.The species has experienced population expansion after a bottleneck,potentially thanks to the tri-trophic plant–insect–natural enemy relationship.Knowledge of population genetics is of importance in using predators to control pests.Our study complements existing knowledge of an important natural predator in agroecosystems through estimating its genetic diversity and population differentiation and speculating about historical dynamics. 展开更多
关键词 demographic history genetic differentiation genetic diversity population expansion MICROSATELLITE mitochondrial Col
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