成熟度对5个常规粳稻种子质量的影响

  目的   探讨成熟度对常规粳稻Oryza sativa种子质量的影响。  方法   以‘春江糯6号’‘Chunjiangnuo 6’、‘绍糯9714’ ‘Shaonuo 9714’、‘秀水121’‘Xiushui 121’、‘秀水14’‘Xiushui 14’和‘浙粳70’‘Zhejing 70’等5个常规粳稻品种为材料，比较并分析成熟度对鲜种子含水量、千粒重及发芽率的影响。  结果   鲜种子含水量随成熟度增加不断降低。与正常收获时期（‘绍糯9714’在盛花期后68 d，其他品种在盛花期后73 d）的种子相比，5个粳稻品种的干千粒重于盛花期后50~55 d达最大值，增加了0.9%~2.6%，以‘春江糯6号’和‘绍糯9714’增长最为明显。5个粳稻品种种子的发芽率随收获期延长先增加后降低，发芽率均于盛花期后50 d达到最大，与正常收获时期的种子相比发芽率增加了1.0%~7.1%，以‘秀水121’增长最为明显。相关分析表明:鲜种子含水量和千粒重均与发芽率显著或极显著相关。对不同粳稻品种鲜种子含水量与发芽率进行二次项建模可较好地预测种子发芽率，回归方程为:y=-0.099 6x2+5.739 5x+15.883 0。  结论   随成熟度增加，粳稻不同品种种子质量逐渐升高，千粒重和发芽率在达到最大值后趋于平稳，如收获过迟则会引起种子质量下降。

Effects of maturity on seed quality of five conventional japonica rice cultivars

  Objective   The aim is to explore the effect of maturity on seed quality of conventional japonica rice.  Method  Five conventional japonica rice cultivars of 'Chunjiangnuo 6', 'Shaonuo 9714', 'Xiushui 121', 'Xiushui 14' and 'Zhejing 70' were used as materials, and the effects of maturity on moisture content of fresh rice seeds, 1 000-grain weight and germination rate were compared and analyzed.  Result   The moisture content of fresh seeds decreased with the increase of maturity. Compared with the seeds in the normal harvest period(68 DAF for 'Shaonuo 9714', 73 DAF for other four cultivars), the 1000-grain weight of dry seeds of the five rice cultivars reached the maximum value at 50-55 days after flowering, which increased by 0.9%-2.6%, especially for 'Chunjiangnuo 6' and 'Shaonuo 9714'. The germination rate of five rice cultivars increased first and then decreased with the extension of the harvest period, and reached the maximum at 50 days after flowering, increasing by 1.0%-7.1% compared with the seeds in the normal harvest period, especially for 'Xiushui 121'. The results of correlation analysis also showed that the moisture content of fresh seeds and 1000-grain weight had significant or extremely significant correlations with germination rate. The germination rate of seeds could be well predicted by establishing a quadratic equation model between moisture content of fresh seeds and germination rate of different rice cultivars, and the regression equation was:y=-0.099 6x2+5.739 5x+15.883 0.  Conclusion  The seed quality of the five rice cultivars was improving as the seed maturity increasing, and reached the maximum then did not improve. So harvesting on time is necessary.