不同花柱类型连翘的花粉形态和生活力比较

为找出连翘(Forsythia suspensa)结实率低的原因,采用电镜扫描、TTC染色、离体培养等技术,对连翘花粉的大小、形态、外壁纹饰、生活力和发芽率进行了观察和测定。结果表明:连翘花粉均为长椭圆形,沟状萌发孔、三沟、长达两极,花粉外壁纹饰为典型的网状雕纹,其中短花柱型连翘花粉的极轴长平均为36.47μm,赤道轴长平均为29.09μm,长花柱型连翘的极轴长平均为37.55μm,赤道轴长平均为23.1μm。短花柱型花粉的生活力为82.5%,长花柱的为69.3%,差异达到极显著水平。2种花粉均在400 mg/L硼酸培养基上萌发率最高,且短花柱花粉萌发率明显高于长花柱花粉的萌发率。因此,连翘结实率低的原因可能与花粉的发芽率及花粉形态有关。

Comparison of pollen morphology and viability between two types of Forsythia suspensa

To identify the reasons for low seed setting in Forsythia suspensa,the pollen size,shape,surface sculpture,viability and germination rate were examined using Scanning Electron Microscope,TTC staining,and culture in vitro.The results showed that: the pollen shape was oblong oval with three germinal furrows which extended to the two poles;the exine ornamentation was of typical network sculpture;the polar axis and equatorial axis length were 36.47 μm and 29.09 μm respectively for short style type Forsythia suspense and 37.55 μm and 23.1 μm for long style type Forsythia suspensa;the pollen viability was 76.6% for short style type Forsythia suspense and 51.6% for long style type of Forsythia suspensa,with statistically significant differences.The pollen in long and short style type of Forsythia suspensa was of highest germination rate on the medium with 400 mg/L boric acid,and that in latter was significantly higher than in the former.Therefore,the reason for low seed setting in Forsythia suspensa may be related to the pollen germination rate and pollen grain type.