生长延缓剂对华北边坡绿化3种草本植物种子发芽的影响

草本植物可以稳定公路、铁路和矿山等工程建设遗留的大量裸露边坡,并改善其生态环境,而以灌草型植物为目标群落的边坡绿化中,草本种子比灌木种子萌发和生长快、竞争性强,开展植物生长延缓剂的研究,以抑制草本种子萌发和生长.以华北地区的常用的沙打旺、紫花苜蓿和高羊茅为试材,探索不同浓度的矮壮素、多效唑和烯效唑溶液,单独浸种处理对3种草本植物发芽势及胚根和胚芽生长的影响.结果表明:矮壮素和烯效唑溶液降低了沙打旺和紫花苜蓿的胚芽长度比,提高了胚根长度比;300～400 mg/L的多效唑溶液对3种草本种子的发芽势均具有抑制效果,500 mg/L的烯效唑溶液对紫花苜蓿和高羊茅的发芽势都具有抑制效果.该研究可为植物生长延缓剂处理边坡绿化草本种子提供参考指标.

Effects of plant growth retardants on the germination of 3 herbaceous seeds in slope greening in North China

[Background] Herbs can reinforce a large number of exposed slopes left by construction work of roads,railways and mines and other projects.It also improves their ecological environment.In comparison of the shrub seeds,the herbaceous seeds germinate and grow more rapidly.Moreover,the herbaceous seeds are more competitive than shrub seeds in herb-shrub mixed type,which is the target community in the slopes greening.The application of plant growth retardants in lawn conservation is more extensive.However,there are few studies on the soaking treatment of herbaceous plants in slope greening.Therefore,it is necessary to develop the study of plant growth retardants to inhibit the germination of herbaceous seeds.[Methods] In this paper,Astragalus adsurgens,Medicago sativa and Festuca arundinacea,that are widely used in slopes greening in North China,were selected as the test materials.Chlormequat,uniconazole and paclobutrazol were chosen as test retardant reagent.A seed soaking experiment was carried out by using different density and kind of above three plant growth retardants.Firstly,three herbs seeds were soaked in different concentrations of chlormequat,paclobutrazol and uniconazole solution.Then three seeds were taken out,washed and placed in a constant temperature incubator within 15 days.Finally,the germination energies of three herbs and their effects of radicle and embryo growth were analyzed.[Results] For A.adsurgens,the optimal paclobutrazol soaking concentration were 300-500 mg/L,and optimal chlormequat soaking concentration was 100 mg/L.For M.sativa,the optimal paclobutrazol soaking concentration was 480 mg/L,and optimal uniconazole soaking concentration was 320 mg/L.For F.arundinacea,the optimal chlormequat soaking concentration was 520 mg/L,and optimal paclobutrazol soaking concentration was 420 mg/L.Chlormequat and uniconazole solution reduced the ratio of germ length of A.adsurgens and M.sativa,and increased the ratio of radicle length.The germination energies of the three herbaceous seeds were inhibited by the 300-400 mg/L paclobutrazol solution.The germination energies of A.adsurgens and F.arundinacea were inhibited by 500 mg/L uniconazole solution.The inhibitory effect of chlormequat solution on the germination energy of M.sativa and F.arundinacea was significant.And the higher the concentration of chlormequat solution,the stronger the inhibitory effect on the length of their embryo.[Conculsions] The inhibitory effect of paclobutrazol on the germination energy of A.adsurgens,M.sativa and F.arundinacea was significant,and also inhibited the germ length of A.adsurgens and M.sativa.Uniconazole had a significant inhibitory effect on A.adsurgens and F.arundinacea.Therefore,three plant growth retardants inhibited the germination of three herbaceous seeds,which provides reference index for plant growth retardants to treat herbaceous seeds in slopes greening.