大丽花花粉活力及离体萌发研究

为筛选大丽花花粉活力有效的测定方法,了解大丽花不同品种的花粉活力,以大丽花栽培品种为试验材料,采用4种方法检测大丽花花粉活力,在此基础上,采用单因素试验和正交设计试验分别对大丽花花粉的离体萌发培养条件及培养基组分进行优化,得到最优方案后进一步检测、比较不同品种之间的花粉活力。研究结果显示,TTC染色法不能使花粉着色,I₂-KI和孢粉染色法不能有效区分有活力和无活力花粉,离体萌发法效果良好,可准确直观地反映大丽花花粉活力状况, 是测定大丽花花粉活力的有效方法。当培养条件为pH 6.0、温度25℃、培养时间2.5 h时,花粉萌发率最高。培养基组分对大丽花花粉萌发的影响程度依次为PEG>蔗糖>硼酸,实际最佳处理组合为A₃B₄C₂,即PEG4000 25 g/L、蔗糖60 g/L、硼酸50 mg/L的处理组合下,大丽花花粉萌发率最高达62.1%。采用上述获得的最优方案检测22个大丽花品种的花粉活力,花粉萌发率为11.75%~78.72%,不同品种的花粉萌发率差异大,其中,‘兰花公主’的花粉萌发率最低,‘波彻儿’最高。大丽花品种的花粉活力多样性丰富,所测定的22个大丽花品种有14个品种正常可育,杂交时可用作父本;8个品种为半不育或低不育,杂交时更适合作母本。

Pollen Viability and in Vitro Germination of Dahlia Cultivars

To screen out the effective method and the optimal scheme for determining pollen viability of Dahlia, as well as to understand the pollen viability of Dahlia cultivars, four methods were used to detect the pollen viability of Dahlia cultivars. On this basis, single factor experiment and orthogonal design experiment were adopted to optimize the culture conditions and medium components of Dahlia pollen germination in vitro, and then the pollen viability of different cultivars was further detected and compared. The results show that TTC staining method could not make pollen coloration, I₂-KI staining and sporopollen staining could not effectively distinguish the active and inactive pollen, while in vitro germination culture method is an effective method to determine the pollen viability of Dahlia, which could accurately and intuitively reflect the test results. The pollen germination rate is the highest when the pH is 6.0, the cultivation temperature is 25℃ and the cultivation time is 2.5 h. The effects of medium components on the pollen germination in vitro for Dahlia are as following: PEG> sucrose> boric acid. The best combination is A₃B₄C₂ formulated with 25 g/L PEG 4000, 60 g/L sucrose and 50 mg/L boric acid, and the highest pollen germination rate is up to 62.1%. The pollen viability of 22 Dahlia cultivars is detected using the optimal scheme obtained above, the pollen germination rate is 11.75%-78.72%, and the pollen germination rate of different cultivars varies greatly. The pollen germination rate of ‘Orchid Princess’ is the lowest while that of ‘Pocher’ is the highest. The pollen viability of Dahlia cultivars is rich in diversity. Among the 22 Dahlia cultivars tested in this study, 14 cultivars are fertile and could be used as male parent when crossing, and eight cultivars are semi-sterile or low sterile, which are more suitable for female parent.