Studies On The Characteristics Of Japonica Rice Varieties Which Are The Most Widely Cultivated In Zhejiang Province

Rice growth environment for example soil, atmospheric etc, becomes increasingly serious. Strong radiation, low temperature, high temperature and the low effectively of nitrogen, phosphorus and potassium in soil content will affecte the normal growth and development of rice. First we need to have a comprehensive understanding on these rice variety characteristics in order to obtaining the rice of high and stable productive, good quality. The materials japonica rice varieties for example Zhejing 22 are the most widely cultivated in province Zhejiang. We provide a reference for the production and application through dealing these materials with low nitrogen, low phosphorus, low potassium, radiation, low temperature, flooding, etc. The main results showed that:1. The plant's root length, seedling height, root weight, seedling weight and the nitrogen content of root and seeding had no significant differences between low nitrogen (10 mg/L) stress and normal nitrogen (40 mg/L). This result showed that these japonica rice varieties had better resistance to 10 mg/L of low nitrogen environment.2. The plant's root length, root weight, shoot ratio and phosphorus utilization efficiency etc. have significant differences between low phosphorus (0.5 mg/L) stress and normal phosphorus (10 mg/L). This result explaineded that these japonica rice varieties showed different resistant abilities to 0.5 mg/L low phosphorus. Zhejing 22 and Xiushui 63 displayed more strong resistance ability to low phosphorus, and Xiushui 128 displayed more weak resistance ability to low phosphorus.3. The plant's root length, seedling height, the root weight, seedling weight, the potassium content of root and seeding had no significant differences between low potassium (3 mg/L) stress and normal potassium (40 mg/L). This paper explained these japonica rice varieties represented different resistant abilities to 3 mg/L low potassium. Jia 991 and Zhejing 30 represented more strong resistance ability to low potassium.4. The germinated seeds of these japonica rice dry seeds which done with the treatment by 300 gray 60Co-γray, the results showed that there were some differences in the sensitivity among japonica varieties. Zhejing 22, Zhejing 27 and Xiushui 110 had more susceptible, while Zhejing 30, Jia 991 and Xiushui 63 had more resistance to 60Co-y ray radiation.5. By flooding rice germinating seed in 2-10cm soil, we judged the tolerance for the earth stress through observing seeds sprout rate. The results of the study indicated that we can be turns the soil 6cm as an observation critical point for rice seed resistance soil submergence. Zhejing 30 and Xiushui 134 had stronger tolerance for soil submergence.6. By flooding rice germinating seed in 2-10cm water, we judged the tolerance for the flooded stress through observing seeds sprout rate. The results of the study showed that Zhejing 27, Zhejing 22 and Xiushui 63 had better properties in water-resistant flooded.7. Rice seed which treated with cold and wet at the low temperature, did not reduce the rice seed germination, even a short time improved germination rate, which did not exist significant differences. Rice seed sprout rates were not reduced under 4℃low-temperature processing seed germination 7d. But Rice seed sprout rates were significantly reduced at 4℃low-temperature for 10-15d. Zhejing 22 and Xiushui 114 were more sensitive to chilling injury sensitivity, while Zhejing 22 and Zhejing 30 were poorer on chilling injury sensitivity.8. These japonica rice varieties which had strong photosensitive, were not significant influenced by short illumination. Zhejing 22 and Xiushui 110 were more sensitivity, while Zhejing 30 and Xiushui 114 were less sensitivity to short illumination.