| Rice is China’s first major grain crop, research and development application of rice super high yield cultivation technology is of great strategic significance to improve the comprehensive production capacity of rice in our country and ensure food supply safely. The study established months daily average temperature prediction model of Yongzhou area based on historical climate data; And according to the requirement of the super hybrid rice safe breeding to meteorological conditions, we carried on fine grid calculation of super hybrid rice breeding climate risk in Yongzhou area, then ensured the safe areas of breeding; then combining with the demand of flowering stage safe period, ensured optimum period of breeding. The main research conclusion is as follows:(1) Established months daily average temperature prediction model of Yongzhou area based on geographical elements, and ensured monthly temperature lapse rate from June to September were0.54,0.66,0.65, and0.53℃/100m respectively.(2) According to hybrid rice breeding climate risk level indicators, we carried on fine grid calculation of super hybrid rice breeding climate risk in Yongzhou area by using1:250000terrain data and historical climate data, then ensured the safe areas of super hybrid rice breeding in each unit of the county level. Results show that the risk free seed production areas were mainly distributed in low altitude areas like river valleys and hilly terrain, high-risk seed production areas were mainly distributed in high altitude mountain areas.(3) The higher stagnation temperature of sterility, the higher appeared chances of fertility sensitive period in low temperature. The appeared chances of fertility sensitive period in low temperature in early June was the highest, then gradually reduced with time delay, the lowest showed in July and August, and increased with time delay. According to the appeared chances of fertility sensitive period in low temperature, we ensured the super hybrid rice safe breeding fertility sensitive period time arrangement of sterility critical temperature23.5℃:it was in the middle ten days of July to the middle ten days of August in Yongzhou city and Dongan, Qiyang, Shuangpai, Dao county; and Ningyuan, and from July to August in Xintian and Jiangyong county; Lanshan county was in the first and middle ten days of August, Jianghua county was in the middle ten days of July to the first ten days of August.(4) Before the middle ten days of September, the flowering stage weather comprehensive hazard index was below4.0in Jiangyong and Jianghua county. Flowering stage start date before September15could obtain high seed production yield. The flowering stage weather comprehensive hazard index was above8in the middle ten days of July in Dongan, Shuangpai, Ningyuan, Xintian, Lanshan and Dao county, so in the production we should avoid to arrange flowering stage start and end dates in July, then the breeding production of super hybrid rice can be guaranteed. The flowering stage weather comprehensive hazard index in Yongzhou city, Qiyang county was higher than other areas apparently, it was above8in July, the highest was more than12. So in the production we should avoid to arrange flowering stage start and end dates from the third ten days of June to the first ten days of August, then the breeding production of super hybrid rice can be guaranteed.(5) Found the optimum allocation according to the length of comprehensive fertility safety period and flowering stage safety period. Finally ensured the optimal sterile line fertility transform sensitive period and parent flowering stage pollination and seeding time in the common sterility stagnation temperature of23.0and23.5℃. |
