Analysis of Japonica Rice Breeding Lines under Diverse Elevation in Yunnan Province

The Yunnan-Guizhou Platue is one of the most specific japonica rice plant areares in the world. Breeding new varieties wih high yield, cold tolerance, diseases resistance and good qulity is an important measure for food and social security in this area.In our research, fourteen pre-comparative experiment varieties bred in 2009 were successional planted for 2 years in the following three different altitude locations, Aziying village which altitude is 2140m, Kunming city which altitude is 1916m, and Yiliang village which altitude is 1530m. The agronomic performances, harvest yielding, exterior qualities, cold tolerance, rice blast resistance, also and the adaption of these varieties were preliminary analyzed. The results showed that the plant height (PH), the productive panicles numbers (PPN), and the 1000-grain weight decreased accompany with the altitude grow higher. In which among different altitude locations the PH varied about 10cm, the PPN alteration little, while the 1000-grain weight varied 1 gram which reached to a significant differentiation. The highest output per mu was in Yiliang village, and then following Kunming’s which got 4.3% decrease, the lowest output turned up in Aziying village which was 42.5% remarkably lower than Kunming’s. The weakest brown rice qualities appeared in Aziying’s materials where the number of dark color of rice was increased. In this research, Aziying village is proved to be an ideal place to test the cold tolerance of breeding materials. All the 14 varieties’seed setting ration were between 51.4% and 79.7%, and above 70% were deduced to the strong range against cold. The rice blast resistance analysis results were affected by temperature and humidity in different years which should be tested seriously. In addition, the adoption analysis should be combined the former three characters and also the comprehensive elite performances. At last 4 varieties, with preferable comprehensive performances and more widen adaptations, were chosen out to expanding across both north and middle-north japonica rice plant areas of Yunnan province.Through our research a practical rule and also a theoretical foundation for Yunnan japonica rice breeding was revealed. It proved that it’s benefit for selecting excellent rice varieties under multi-locations plant test and with the four characters synchronizing identifications.