Double flower domestication is of great value in ornamental plants and presents an excellent system to study the mechanism of morphological alterations by human selection. The classic ABC model provides a genetic framework underlying the control of floral organ identity and organogenesis from which key regulators have been identified and evaluated in many plant species. Recent molecular studies have underscored the importance of C-class homeotic genes, whose functional attenuation contributed to the floral diversity in various species. Cultivated Camellia japonica L. possesses several types of double flowers, however the molecular mechanism underlying their floral morphological diversification remains unclear. In this study, we cloned the C-class orthologous gene CjAG in C. japonica. We analyzed the expression patterns of CjAG in wild C. japonica, and performed ectopic expression in Arabidopsis. These results revealed that CjAG shared conserved C-class function that controls stamen and carpel development. Further we analyzed the expression pattern of CjAG in two different C. japonica double-flower varieties, `Shibaxueshi’ and `Jinpanlizhi’, and showed that expression of CjAG was highly contracted in `Shibaxueshi’ but expanded in inner petals of `Jinpanlizhi’. Moreover, detailed expression analyses of B- and C-class genes have uncovered differential patterns of B-class genes in the inner organs of `Jinpanlizhi’. These results demonstrated that the contraction and expansion of CjAG expression were associated with the formation of different types of double flowers. Our studies have manifested two different trajectories of double flower domestication regarding the C-class gene expression in C. japonica.

Construction of small town plays an important role in the progress of the urbanization in China. And better planning of small town is very important on promoting economic development and the construction of spiritual civilization of town and city. The current planning situations of 16 small towns which had powerful economy in Shandong province were investigated by surveying weather and natural environment factors, the economy and population status and land arrangement, measuring land area and taking relative photos. The results were as follows. Firstly, small town usually had small population density and land area. A dop tendency of economic degree was demonstrated from east to west. Besides, there were wide differences of natural conditions in these towns. Secondly, most land arrangements were unreasonable, the land proportions were imbalance. Generally there was a lack of completed transportation land and green space.