The genetic diversity of pepper resources is rich and the potential of breeding is great. Therefore, the objectives of the study were to determine the genetic diversity and population structure of 32 accessions of Capsicum germplasm resources and contribute to breeding of pepper. In this study, the genetic diversity of different species of pepper germplasm was studied from the molecular level, which provided reference for the collection, research and rational utilization of pepper germplasm resources. 80 pairs of SSR primers were designed based on the whole genome coding region sequence of pepper. The 32 accessions of Capsicum germplasm resources of 12 species (subspecies) with different geographical origin and different traits were selected to screen 80 pairs of primers, which was to obtain clear bands, good stability of 40 SSR polymorphic primers. DPS, MEGA7 and POPGENE32 software were used to analyze the genetic diversity of 32 pepper germplasm resources. The results showed that 40 pairs of primers amplified 122 polymorphic bands, with an average of 3.05 loci amplified by each pair of primers, which showed that the SSR primers had high practicability in the genetic analysis of pepper. The mean value of effective allele number (Ne), observed heterozygosity (Ho), expected heterozygosity (He), shannon-weaver index (I), polymorphism information content (PIC) were showed that pepper genetic information is rich. Based on cluster analysis of UPGMA method and principal component analysis were basically consistent with the source of Capsicum were divided into 10 clusters.

In this article, the socioeconomic determinants on urban population in China are empirically investigated with a theoretical equilibrium model for city size. While much of the research on urban size focuses on the impact of agglomeration economies based on “optimal city size” theory, this model is eschewed in our research due to its theoretical paradox in the real world, and we turn instead toward an intermediate solution proposed by Camagni, Capello, and Caragliu. This equilibrium model is estimated on a sample of 111 prefectural cities in China with multiple regression and artificial neural networks. Empirical results have shown that the model explains the variance in the data very well, and all the determinants have significant impacts on Chinese city sizes. Although sample cities have reached their equilibrium sizes as a whole, there is substantially unbalanced distribution of population within the urban system, with a strong contingent of cities that are either squarely too large or too small.

Abstract:The issue uses ecological footprint method to research 7 target counties of Beijing and gains the per capita ecological deficit after 12 percent areas deduction for biological diversification. We found that target region has a magnified trend of ecological deficit and then, we try to offer some proposals about how to develop the mountainous counties.

A theoretical framework of the match between industries and cities is first established based on agglomeration economies. Building on this framework, we use 3‐digit manufacturing industries of 335 cities in China during 2003–2007 and establish a quantitative relationship between manufacturing and cities through analysing their threshold effects. We find that more innovative industries, with orders of rates of new products' value (RNPV) mean less than 30, share localization economies, while less innovative industries, with orders of RNPV mean more than 30, are not significantly subject to agglomeration economies. Cities with orders of size less than 30 do not share agglomeration economies significantly, those with orders of size between 30 and 230 are subject to urbanization economies, and those with orders of size more than 230 are subject to localization economies. We propose a path to match industries with cities: producer services should be developed in cities with orders of size less than 30; industries with orders of RNPV mean less than 30 are matched with cities with orders of size between 30 and 230; and other manufacturing is matched with cities with orders of size more than 230.

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