Study On Maize (Zea Mays. L) Varieties Evolvement Regularity Since 1982 And Future Breeding Strategy In China

Maize (Zea mays. L) Cultivars evolution regularity form 1982 in China was summed up from maize breeding and production, ecological conditions and breeding objectives through investigating and statistic, comparison analysis, logical deducing. The current of corn breeding and production was revealed. The effect of genetic improvement in maize cultivars evolution was evaluated. The change of each breeding method and strategy was detailed. The historical character and value in use of the cultivar recourse were clarified. And the strategy for future breeding and further development route were brought out, which will provide scientific foundation for exploring maize germplasm resources, improving the maize breeding and production level, and promoting the sustain development of maize production in China.The main conclusions are as follows:1. The general situation of maize cultivars'evolution in China:The planting area and the quantity of corn cultivars are increasing steadily. From 1982 to 2005, maize planting area had increased from 278.1450 million mu to 395.3715 million mu. Along with the plant area increased, the total planting area of maize cultivars which planted more than 0.1 million mu per year increased, too. From 1982 to 2005, it had been increased by more than 150 million mu. The quantity of maize cultivars was rising from 146 cultivars per year in 1980s to 205 cultivars per year in 1990s and in the recent 5 years 304 cultivars per year on average, the number of cultivars of maize has doubled in the last 24 years.2 The genetic constitute, pattern of heterosis and the character of germplasm evolution of major cultivars in China.The cultivar of the biggest popularization accumulative total area is Zhongdan 2 from 1982 to 1987, Danyu 13 from 1988-1994, Yedan 13 from 1995 to 2000, Nongda 108 form 2001 to 2005, and all of them were in the first place during that time. It is noticable that after only 5 years, the popularization accumulative total area of Zhengdan 958 has come up to 132.71 million mu, and the popularization still increased, while other maize cultivars'are decline. The regularity of major maize cultivar genetic composing transformation: The typical cultivar in the first stage (from 1982 to 1987) was Zhongdan 2, and the distinct character of this stage was that the hybrids were made by the typical inbred line Mo17. Danyu 13 was the typical cultivar in the second stage (from 1988 to 1994), the major parents were Mo17 and Huangzao 4. Yedan 13 was the typical hybrid in the third stage (from 1995 to 2000), and the parent was changed from Mo17 and Huangzao 4 to Ye 478. During the forth stage (from 1995 to 2000), Nongda 108 was the typical hybrid, and P-group inbred lines, which line was selected from 78599, were the character of this stage. Along with the widespread of Zhengdan 958 (Zheng 58×Chang 7-2) from 2006, the main character of today will be drought tolerance, lodging and disease resistance, high and stable yield, high hybrid seed yield.3 The problem of maize breeding in China: The breeding units are chaotic; ordinary maize still plays the major role in breeding; germplasm resource is limited, the research work is lagged; and the system innovation is absence.4 The demand of future development of maize cultivars in China: high yield, multi-resistance, characteristic maize, high efficiency of resource utilization and be suitable for mechanization.5 The strategy for the development of maize breeding in China: First, enhancing bringing in, researching and utilizing foreign germplasm, especially tropic and sub- tropic maize germplasm; domesticating wild type maize; and creating new type germplasm by bio- technology. Second, combination of germplasm researching and breeding should be used. Third, the nation should give support to germplasm research. At last, adjust the breeding objects according to the sustainable development strategy.6 Development thinking of maize breeding research in the main production area of ChinaPreponderant Area of maize in China should focus on the selection and spreading of feeding maize with mid-early maturity, density tolerance, feeding (or grain using), silage, high oil content and quality protein character, and processing maize of high starch content or sweet-waxy corn.