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Maize (Zea mays L.) populations are potential sources of favorable alleles absent in parental inbred lines to improve elite hybrids. The maize hybrid Zhengdan 958 has been hampered by the lack of favorable new alleles for improving yield and commodity quality. In the present study, 16 testcrosses made by using eight synthetic populations as the donors and the two parental lines of Zhengdan 958 as the receptors were evaluated in 2009 and 2010 at Shunyi, Beijing and Xinxiang, Henan Province for grain yield and test weight. Four genetic parameters were used to determine the breeding potential of eight synthetic populations as the donors to improve the target hybrid. Several synthetic populations were identified as the potential sources of favorable alleles absent in the target hybrid for each trait evaluated. The two most promising germplasms, WBMC-4 and Shanxi Syn3, had the potential for simultaneously improving grain yield and test weight of the target hybrid, which could be used to improve the parental lines Zheng 58 and Chang 7-2, respectively, and further broaden the germplasm base of Chinese heterotic groups PA and Sipingtou.

Introgression of exotic maize (Zea mays L.) germplasm is an effective approach to broadening the genetic base of Chinese germplasm. America is the center of maize origin and germplasm diversity. By analyzing general combining ability effects and heterosis responses among maize populations from the U.S., International Maize and Wheat Improvement Center (CIMMYT), and Brazil studied by different authors, 24 elite maize populations from America region, including eight U.S. populations, eight CIMMYT populations, and eight Brazilian populations, were identified as having high potential in China. Based on adaptation improvement, we suggest to introgress BSSS(R)C10, BS10(FR)C14, BS13(S)C9, BSK(HI)C8 Syn 3, BR106, Pop44(C8), and Pop45(C3) into Chinese heterotic group A, and introgress BS11(FR)C14, BS16(S)C3 Syn 2, BS29(R)C3, BSCB1(R)C14, BR105, and Pop42(C4) into Chinese heterotic group B by forming semi-exotic populations or pools, respectively, in order to broaden the Chinese germplasm base.

Purpose: This article describes the design and restoration for 180 cases diagnosed with dentition defect accompanied with medium to severe abrasion and attrition. The purpose of this study is to discuss the rehabilitation of vertical dimension, the balance of occlusion and the whole occlusion system., Methods: Before clinical preparation of the 180 clinical cases, diagnostic casts were made. Entire restoration treatment plan was adopted to make removable partial dentures with full crown restorations along with occlusion splints. The clinical effect were evaluated at 2nd week, 4th week and 9th week., Results: Of the 180 cases, 148 patients (82.2%) adapted to the denture in 2-3 weeks, 24 patients (13.3%) in 4-5 weeks, 8 patients (14.5%) in 5-6 weeks. The further observation were evaluated over 10-15 years with clinical satisfaction., Conclusion: This method not only reserves the tooth structure, but also restores configuration and function of the lost tissues. It's really a constantly effective remedy.