七叶树花粉活力和柱头可授性变化的研究

采用花粉离体萌发法研究不同蔗糖浓度、硼酸浓度和不同温度对七叶树花粉萌发的影响及花粉活力测定,用联苯胺-过氧化氢法测定柱头可授性.结果表明:七叶树花粉萌发的最佳培养基是12％蔗糖+30 mg/L硼酸,花粉萌发的最适温度为25℃.雄花在开花当天花粉活力最高达75.69％,并在开花当天的上午10:00时,花粉活力最强,10:00～16:00花粉活力保持较高活力,是最佳授粉时段.两性花的柱头可授期持续时间较长,为8～9 d,开花3d达到最强,开花1～4 d柱头可授性保持较高水平,为授粉的最佳时间段.因此,从七叶树的花部特征、花粉活力与柱头可授性及花粉萌发的条件看,在长期的自然选择下七叶树在花部结构和开花生理上都是相配合的,以保障生殖成功.

Pollen viability and stigma receptivity of Aesculus chinensis

In vitro pollen-germinating method was used to study the effects of different sucrose and boric acid concentrations,and temperatures on pollen germination and vitality of Aesculus chinese.Benzidine-hydrogen peroxide method was used to assay stigma receptive.The results showed that the best sucrose and boric acid concentration for pollen germination was 12% and 30mg/L,respectively,and the optimized temperature was 25℃.The pollen viability of male flowers maintained at higher levels from 10:00 to 16:00 and the highest(75.69%) at 10:00 during the flowering day.As a result,the best time for pollination was at 10:00.The stigma receptivity of perfect flowers lasted about 8-9d,the stigma receptivity maintained at high levels 1-4d after flowering and was the strongest 3 after flowering.As a result,the best time for pollination was at 1-4d after flowering.According to the floral character,pollen viability,stigma receptivity and pollen germination of A.chinensis,during long terms of natural selection,the floral structure was matched with flowering physiology of A.chinensis in order to guarantee successful reproduction.