GA3浸种处理对五种晚花杜鹃种子萌发的影响

晚花杜鹃(late flower Rhododendron)是一类花期较晚的杜鹃品种,具有较高的观赏价值,被广泛应用于庭院种植和园林绿化。随着旅游以及经济发展的需要,开发和利用晚花杜鹃资源显得非常迫切。自然条件下晚花杜鹃萌发率相对较低,因此为提高晚花杜鹃萌发率,探究不同浓度赤霉素(GA_3)处理对五种杜鹃种子萌发的影响,该文以五种晚花杜鹃(小白杜鹃、大白杜鹃、桃叶杜鹃、长蕊杜鹃和九龙山杜鹃)为实验材料,通过不同浓度(0、300、400、500、600、700 mg·L~(-1))的GA_3对五种晚花杜鹃种子进行24 h浸种处理,测定其发芽指数、发芽势、发芽率以及成苗率等指标,分别确定五种杜鹃种子萌发的最适GA_3浓度,并对相同处理下五种杜鹃种子的萌发率和成苗率进行比较。结果表明:(1) GA_3浸种对五种晚花杜鹃种子萌发具有促进作用,在适当GA_3浓度下五种杜鹃种子的发芽指数、发芽势和发芽率均显著高于对照组,萌发时滞、萌发高峰期和持续萌发时间均较对照组浓度相对缩短。(2)大白杜鹃、桃叶杜鹃和九龙山杜鹃种子在GA_3浓度为600 mg·L~(-1)处理时各项萌发指标相对较好;长蕊杜鹃以GA_3浓度为700 mg·L~(-1)浸种处理萌发效果相对较好;小白杜鹃以GA_3浓度为400和700 mg·L~(-1)处理最好。因此,在杜鹃的栽培中,可以采用赤霉素GA_3处理法提高种子发芽率,缩短萌发时间。

Effects of GA3 on seeds germination of five species of late flower Rhododendron

The flowering time of late flower Rhododendron is later than common species, and it has high ornamental and research values. Therefore, it has been widely used in garden planting and landscaping as a horticultural variety. With the increasing requirement of tourism and rapid economic development, it is extremely urgent to develop and utilize the resources of late flower Rhododendron. Germination rate of late flowering Rhododendron is relatively low under natural conditions. Therefore, in order to improve the germination rate of late flower Rhododendron and explore the effects of different concentrations of GA₃ on the germination of five species of late flower Rhododendron, we took the seeds of five species late flower Rhododendron(R. maculatum, R. decorum, R. annae, R. stamineum and R. jiulongshanense)as experimental materials, and soaked the five species seeds of late flower Rhododendron in GA₃ with different concentrations(0, 300, 400, 500, 600, 700 mg·L^-1 )for 24 h, furthermore, germination index, germination potential, germination rate and seedling percentage of them have been determined. Meanwhile, the optimum concentration of GA₃ for germination of five species of Rhododendron seeds was determined, and we also compared the germination rates of five species of late flower Rhododendron seeds. The results were as follows:(1)A certain concentration of GA₃ promoted the germination of five species seeds of late flower Rhododendron. In addition, the germination indexes, germination potentials, germination rates and seedling rates of five species seeds of Rhododendron at a certain concentration of GA₃ were significantly higher than those of the control, and the germination time lag, germination peak period and sustained germination lasting time were relatively shorter than those of the control.(2)Germination indicators of the seeds of R. stamineum, R. annae and R. jiulongshanense were relatively higher when treated with 600 mg·L^-1; and the germination rate of R. stamineum seeds was relatively higher when soaked with 700 mg·L^-1 GA₃; The germination rate of R. maculatum was higher when treated with 400 and 700 mg·L^-1 GA₃. To sum up, the GA₃ treatment can be extensively used to improve seed germination rate and shorten the germination time in the cultivation of late flower Rhododendron.