Analysis About The Information Of Hunan Releasing Test In Hybrid Rice 1976-2000 Year

It has been 25 years since the first hybrid rice combination entered the Hunan rice regional triad in 1976. Since then already 289 hybrid rice combination has entered Hunan regional trials. Some were early rice and some were late rice, some were Japonica, the majority were indica. The progress in indica hybrid rice was significantFrom 1976 to 1985 was the starting stage of hybrid rice's going into regional trial with less combinations which entered the trial. From 1986 to 1995 was the development stage when the number of entries of hybrid rice combination which entered the trial was increasing.From 1996 to 2000 was the stage when hybrid rice was progress very fast. Half of the entry which entered the regional trials were hybrid rice, and more and more stable CMS line were frequently used to develop hybrid rice combination.Hybrid rice yield was somewhat higher the 1990s than those in the 70-80s. In the 1990s hybrid rice yield became stable. At present the Hybrid rice appearance quality and milling quality was much better than in the 1970s. More and more hybrid rice combinations has been evaluated as high-grain-quality rice. But there are more works to do on hybrid rice quality in improvement.In the ninth 5 year plan stage, hybrid rice combinations were susceptible to rice blast and bacterial leaf bright. But early rice were more resistant to blb.Analysis on the main traits of hybrid rice indicates: Early hybrid rice yield correlates positively to effective panicle number and seed set rate, negatively to spikelet number per panicle. Late hybrid rice yield correlates positively with yield per-day and plant height significantly middle hybrid rice correlates positively with the yield per-day significantly and positively with the spikelet number per panicle and filled grain number significantly...