针垫花开花授粉生物学特性

【目的】深入了解针垫花（Leucospermum cordifolium）的开花结实特性，探求其结实率低的原因，推动其种子生产、杂交育种、花期调控以及新品种培育工作。【方法】本文以针垫花(Leucospermum cordifolium)为主要材料，对其开花物候、花部特征、花粉活力、柱头可授性、杂交指数、授粉结实特性进行研究。【结果】1）针垫花的花期一般在冬末、早春至夏季；2）最适合测定其花粉活力的离体萌发培养基为30g/L蔗糖+150mg/L硼酸+50mg/L氯化钙，花粉活力为67.47%；3）在开花第1-7d柱头可授性逐渐加强，第5-7d的时最为强烈；杂交指数估算结果表明针垫花部分自交亲和，异交，需要传粉者；4）田间观测发现其在自然状态下结实率较低，但可以自发完成授粉，不存在无融合生殖现象；5）人工授粉试验发现针垫花异株异花授粉的结实率最高，为17.14%，而自花授粉的结实率最低，为4.94%。【结论】针垫花的雌雄蕊异熟是导致其自然结实率低的原因之一，而雌蕊花柱中及子房部位的胼胝质、花粉萌发后花粉管顶端膨大畸形是造成其结实率低的重要原因。

Biological Characteristics of Flowering and Pollination in Leucospermum cordifolium

【Objective】To gain a deeper understanding of the flowering and fruiting characteristics of Leucospermum cordifolium, explore the reasons for its low fruiting rate, and promote its seed production, hybrid breeding, flowering period regulation, and new variety cultivation.【Methods】This article uses Leucospermum cordifolium as the main material to study its flowering phenology, floral characteristics, pollen vitality, stigma acceptability, hybridization index, and pollination and fruiting characteristics.【Results】1) The flowering period of Leucospermum cordifolium is generally in late winter, early spring to summer; 2) The most suitable in vitro germination medium for measuring its pollen vitality is 30g/L sucrose+150mg/L boric acid+50mg/L calcium chloride, with a pollen vitality of 67.47%; 3) The receptivity of the stigma gradually increases from day 1 to day 7 of flowering, and is strongest from day 5 to day 7; The estimation results of hybridization index indicate that Leucospermum cordifolium is partially self compatible, cross compatible, and requires pollination; 4) Field observations have shown that its fruiting rate is relatively low in its natural state, but it can spontaneously complete pollination and there is no phenomenon of apomixis; 5) The artificial pollination experiment found that Leucospermum cordifolium had the highest seed setting rate during cross pollination, at 17.14%, while self pollination had the lowest seed setting rate, at 4.94%.【Conclusion】One of the reasons for the low natural fruiting rate of Leucospermum cordifolium is due to the different ripening of its stamens, while the callus in the pistil style and ovary, as well as the abnormal enlargement of the pollen tube tip after pollen germination, are important reasons for its low fruiting rate.