Studies On Characteristics Of Stress Tolerance Of Early Hybrid Rice Seeds

With the development of early super hybrid rice, the quality of seed has been attracting more and more attention of research and application institutions. New seeds'germination started, germination rate and vigor of germination are more quickly than conventional rice. Stages in seed germination, it has stronger metabolism advantage and higher viability, but the seed dormancy, storage and stress tolerance is not very good. The stress tolerance of seeds is easy to deteriorate in the process of development and storage. It has caused tremendous economic losses on agricultural production. Revealing the seed's stress tolerance, and improving the seed's vitality and resistant storage, has great significance on promotion and application of super hybrid rice. The research takes the super hybrid rice zhuliangyou02 seed as material and conventional rice seed as contrast, and it researches how to improve seed vitality and quality in production in order to offer academic guidance.Ⅰ.A comparison of the stress tolerance of different maturity seed's on the super hybrid rice zhuliangyou02.With the development of super hybrid rice zhuliangyou02 seed, the water content of seed is reducing and the germination rate is growing. The seed is Pollinated 9d has germination capacity, pollinated 17-21d's has highest germination rate, but the germination rate of overripe seed is declined.Low Temperature Storage capacity of seed is related to maturity, water content, storage temperature and time. The higher maturity and water content within safety limits of the seed have stronger low Temperature storage capacity. In the storage conditions between 5℃and-5℃, the germination rate of the seed with more water content is decreasing; particularly the seed with low-maturity is the most sensitive.The super hybrid rice zhuliangyou02 seed has the artificial aging of no-high temperature and humidity, and with the aging time, the germination rate of the super hybrid rice zhuliangyou02 seed is decreasing. Between the seed have different maturity; it grown by 15-17d has the strongest ability in high temperature and humidity.Ⅱ.A comparison of stress tolerance between hybrid rice seeds and conventional rice seeds.The germination rate of rice seed with different water contents in different storage temperatures has significant impact. The hybrid rice seed with more water contents have more sensitive than conventional rice seed. The rice seed has 30% water content is stored in-20℃, has the particularly low temperature harm, and all seeds haven't germination capacity was stored 30d. And the super hybrid rice zhuliangyou02 seed is more obvious than others. The 5℃temperature is the helpful temperature for stored lower water content of rice seed. The rice seed have the highest germination rate stored by drying silica gel. Research results Show: reducing the rice seed's water content and improving the storage capacity of seed are the most effective measures.With the immersion in cold water, the germination rate of the rice seed has decreased, and the margin of the super hybrid rice zhuliangyou02 seed is more than conventional rice seed'. With the immersion in cold water between 5℃and 10℃and 15℃, the greatest harm is the immersion in 15℃water, and the second harm is the immersion in 5℃water. And the seed has a bad breath in higher temperature, and has the harm in lower temperature.Being rehydrated treatment in 8h and 16h and 24h, the seed has the largest harm in 24h, the second harm in 16h, and the third harm in 8h. Rehydration capacity of resistance of the super hybrid rice zhuliangyou02 seed is worse than conventional rice seed'. The seed of IndicaPSB RC82 is from the Philippines and Japonica is from Japan both have stronger rehydration capacity of resistances.The germination capacity of the rice seed decreases when temperature decreases, and the seed have different germination capacities in different variety. Under the 25℃and 20℃, the speed of the seed germinating is slowly, and the germination vigor has an obviously decreasing. Have an affected in 15℃, the germination rate has an obviously decreasing, and the seed haven't germinating in 10℃. And Indica germination capacity in low temperature is higher than Japonica.There are significant differences in the harvest sprouting feature of different rice variety. Easy to harvest sprouting of seed has no dormancy and weekly ability in high temperature and humidity, and than difficult to harvest sprouting of seed.