一品红雌花发育特性及柱头可授性

Pistillate Flower Development and Stigma Receptivity of Euphorbia pulcherrima

[目的]该研究指在探究一品红雌花柱头发育形态与柱头可授性的关系。[方法]以一年生一品红‘千禧’为材料，对其雌花发育进行了宏观及扫描电镜（SEM）观察，并采用联苯胺-过氧化氢法和活体花粉萌发法检测柱头可授性。[结果]一品红雌花发育进程可分为显花期、初开期、Y字期、八字期和翻卷期5个时期。雌花发育与柱头可授性具有相关性：柱头可授期在柱头裂片微张（初开期）和柱头开始翻卷（八字期）之间，最佳授粉期为八字期，持续时间3~5 d，柱头倒八状， SEM观察柱头表面可见大量渗出物；采用联苯胺-过氧化氢法检测柱头不同形态时期的可授性结果与活体花粉萌发法基本吻合。[结论]该研究表明在育种实践中，可根据雌花柱头发育形态来判别一品红最佳授粉时期。

Objective] This study aimed to investigate the relationship between pistil-late flower developmental morphology and stigma receptivity in Euphorbia pulcherri-ma. [Method] One-year-old adult plants of E. pulcherrima cultivar ‘Mil enium’ were used as experimental materials to analyze pistil ate flower development process by macroscopic and scanning electron microscope （SEM） observation. Stigma receptivity was detected with benzidine-hydrogen peroxide method and in vivo pol en germina-tion method. [Result] The pistil ate flower development process of E. pulcherrima was consisted of columnar stigma phase, stigma lobe slightly opening phase, Y-shape stigma lobe phase, inverse V-shaped stigma lobe phase and stigma curling phase. Pistil ate flower development and stigma receptivity of E. pulcherrima exhibit-ed certain correlation. The stigma receptive period lasted from stigma lobe slightly opening phase to inverse V-shaped stigma lobe phase; inverse V-shaped stigma lobe phase was appropriate for pol ination, lasting for 3-5 d, with V-shaped stigma lobe and a large amount of exudates on stigma surface according to SEM obser-vation. Stigma receptivity of E. pulcherrima detected with benzidine-hydrogen perox-ide method was consistent with that detected in vivo pol en germination method. [Conclusion] ln breeding practice, the optimal pol ination period of E. pulcherrima can be determined based on the developmental morphology of pistil ate flower.