白花桔梗与紫花桔梗传粉生物学特性比较研究

本试验对白花桔梗和紫花桔梗传粉生物学特性进行了比较研究。结果表明,白花桔梗与紫花桔梗只有花冠宽具有显著性差异,花冠长、子房宽、裂片长、裂片宽、裂深、雄蕊长和雌蕊长均无显著性差异;白花桔梗、紫花桔梗的平均单株花粉数分别为5.86×105个和5.05×105个,花粉/胚珠比值分别为2 282.3和2 195.1,两者均属于兼性异交;白花桔梗与紫花桔梗开花当天花粉活力均达到最大值,开花后第2天柱头可受性均达到最高,两者在花粉活力和柱头可受性上无明显差异;白花桔梗和紫花桔梗在风媒的作用下,传播花粉的距离分别为1.5m和0.8m;昆虫传粉最远距离分别为9.8m和6.5m。本试验通过研究白花桔梗和紫花桔梗传粉生物学差异比较,为今后桔梗育种工作提供理论依据。

Comparative Study on Pollination Biology between White Flower Platycodon grandiflorum and Purple Flower Platycodon grandiflorum

Through the comparative study between white flower Platycodon grand/florum and purple flower P. grand/florum on pollination biolo- gy, tile results showed that white flower P. grandiflorum and purple flower P. grandiflorum had significant difference in the width of corolla, in addition to the length of corolla, ovary width, flower lobes long, lobes broadly, the length of stamens and the length of pistil; The average pollen number of white flower P. grand/florum and purple flower P. grandiflorum was 5.86 x lOs and 5.05 x l0s respectively,pollen ovule ratio was 2 282.3 and 2 195.1 respectively, both of white flower P. grand/florum and purple flower P. grandiflorum all belonged to facuhative xenogamy. White flower P. grand/florum and purple flower P. grandiflorum had no significant difference in pollen vitality and stigma receptivi- ty, the pollen viability was highest on the first day and the stigma receptivity was the highest on the 2nd day after flowering. In terms of pollina- tion distance,the white flower P. grandiflorum and the purple flower P. grand/florum Pollen dispersal could reach 1.5m and 0.8m by wind, 9.8m and 6.5m by insect. By comparative study on pollination biology between white flower P. grand/florum and purple flower P. grandiflorum can provide theoretical basis for future breeding of platycodon.