桔梗种子灌浆特性研究

Studies on Grain Filling Characteristics of Platycodon grandiflorum

以2a生桔梗栽培群体为材料,对桔梗籽粒灌浆特性进行研究。结果表明,开花后10～19d,桔梗籽粒鲜质量迅速下降,花后19d降到最低,之后开始上升,花后46d达到最大后又开始下降;籽粒干质量的增加趋势呈"S"型曲线,符合Logistic方程,桔梗籽粒灌浆经历渐增期(花后14d内)、快增期(花后15～31d)和缓增期(花后32～51d),最大灌浆速率出现在花后22d,开花49～51d后籽粒干质量达到最大,籽粒灌浆也基本结束,此时籽粒含水量降到36.1%以下,为种子最佳采收期。籽粒干质量与灌浆持续时间呈极显著正相关,与籽粒含水量呈极显著负相关,而与灌浆速率无显著相关性。

The grain filling characteristics were studied during blossom in two-years-cultivated Platycodon grandiflorum plants in order to provide theoretic basis for its seed standard production.The results showed that the 1 000-grain fresh mass decreased sharply during 10-19 days after blossom,then started to increase from the trough on 19 days after blossom and reached peak on 46 days after blossom.The change of grain dry mass was characteristic of the ＂S＂ curve with the start-filling duration（14 days after blossom）,the fast-filling duration（from 15 day to 31 days after blossom） and the slow-filling duration（from 32 days to 51 days after blossom）,which fitted to Logistic equation.The maximum point for the grain filling rate was appeared on 22 days after blossom.The grain dry mass was reached peak and the grain filling was finished correspondingly during 49-51 days after blossom,water content of grain was be lower than 36.1%,this period was the best harvesting time.The seed dry mass were positively and significantly related with the filling duration while negatively and significantly related with water concentration,but unrelated with the grain filling rate.