不同浸种方法对北京工程边坡喷播常用灌木种子发芽的影响

Effects of varied immersing methods on the germination of tree seeds for the engineering slope greening in Beijing

为促进北京工程边坡喷播常用的灌木种子发芽,提高灌木种子相对草本的竞争力,尝试采用植物生长促进剂浸种、热水浸种等生产上常用的浸种方法,确定最佳浸种时长、最佳热水浸种初始温度及最优植物生长促进剂种类和浓度等,促进灌木种子发芽成活。结果表明：1）在植物生长促进剂浸种的情况下,最佳浸种时长为12 h;2）对3种灌木种子发芽均有促进作用的低浓度促进剂为赤霉素100 mg/L和萘乙酸10-8mg/L,发芽势综合约在30%;3）适宜紫穗槐、胡枝子发芽的热水浸种初始温度,分别在60～70和60～80℃,热水浸泡对荆条发芽有抑制作用。综合3个试验,发现针对具有硬实性质的种子,可先用初始温度为60～70℃的热水浸种2 h,后用赤霉素100 mg/L或萘乙酸10-8mg/L溶液浸种10 h的方法,促进灌木种子发芽;对非硬实性质的种子,直接用赤霉素100 mg/L或萘乙酸10-8mg/L溶液浸种12 h。综合试验结果可用于生产,具有一定的创新性和可行性。

[Background] The most frequently used seeds in slope spraying in Beijing are the combination of shrub and herbal seeds. The combination of two kinds of seeds has better effect for the conservation of soil and water in Beijing highways＇ slope. However,the problem of competition between shrub and herbal often appears after spraying seeds and as a matter of fact,the goal to form the shrubbased phytocenosis cannot be achieved. Therefore,promoting shrub seeds ＇ relative competitiveness should be concerned. There are two ways： one way is waking the seeds and promoting their germination and shorten the germinating time; the other way is strengthening the shrub seedlings. [Methods] In order to promote shrub seeds＇ germination and relative competitiveness with herbal seeds,two immersing methods of using plant growth accelerators and hot water were applied to stimulate germination of shrub seeds. Three experiments were conducted to obtain the optimal soaking time, the optimal initial temperature of hot water and optimal concentration of plant growth accelerators. The first experiment wasto soak shrub seeds for different time periods. The second experiment was to use different initial temperatures of hot water to soak shrub seeds. The third experiment was to soak shrub seeds using different concentrations of plant growth accelerators. At last,combining all the results and a final method was summarized. [Results] 1） The optimal soaking time was 12 h in the case of immersing in plant growth accelerators. 2） The optimal concentration for Amorpha fruticosa L. was NAA-10- 8mg / L. The optimal concentration for Lespedeza bicolor was gibberellin-160 mg / L. The optimal concentration for Vitex negundo var. heterophylla was NAA-10- 6mg / L. The optimal concentration of plant growth accelerator was gibberellin-100 mg / L or NAA-10- 8mg / L,which had promoting effect to all three kinds of shrub seeds. The average germination potential was about 30%. 3） The suitable initial temperature of hot water for Amorpha fruticosa L. was 60- 70 ℃ and 60- 80 ℃ for Lespedeza bicolor. And hot water had inhibiting effect to Vitex negundo var. heterophylla,thus other soaking methods for Vitex negundo var.heterophylla could be researched to promote germination,for example,reserving the seeds in sand at low temperature. [Conclusions] The combining result of three experiments showed that seeds with hard nature could be soaked in 60- 70 ℃ of hot water for 2 h and then soaked in plant growth accelerators（ gibberellin-100 mg /L or NAA-10- 8mg / L） for 10 h,which would stimulate the germination of shrub seeds. The seeds without hard nature could be directly soaked in plant growth accelerators（ gibberellin-100 mg / L or NAA-10- 8mg / L） for 12 h. The combined soaking methods of seeds are innovative and feasible,and could be used in practice.