野生麻花秦艽中化感活性物质对牧草萌发及生理特性的影响

采用超声提取法从野生麻花秦艽中提取龙胆苦苷(gentiopicroside)和黄酮(flavonoids),用不同浓度龙胆苦苷和黄酮提取液处理受试植物紫花苜蓿、红三叶和白三叶,通过对受试植物种子萌发和幼苗生理特性苗高、根长、鲜重以及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)3种抗氧化酶活性]的研究,探讨了野生麻花秦艽的化感作用及抗氧化性。研究表明,野生麻花秦艽中龙胆苦苷和黄酮提取液对受体植物的种子萌发和幼苗生长大多表现出化感抑制作用,仅龙胆苦苷浓度为2.52 mg/mL时,对白三叶的苗高表现出促进生长的作用;随龙胆苦苷和黄酮提取液浓度增大,对3种抗氧化酶活性影响程度不同:3种受体植物幼苗体内的POD和CAT的活性分别在6.30和1.95 mg/mL时达到最大值,紫花苜蓿幼苗体内SOD活性在浓度分别为12.60和3.90 mg/mL时活性最大,分别为22.971和25.013 U/g,红三叶和白三叶幼苗体内的SOD活性在6.30和1.95 mg/mL时达到最大值,说明不同植物对化感胁迫的耐受能力不同,紫花苜蓿对化感胁迫的耐受能力强于红三叶和白三叶。

Effects of active allelochemicals from feral Gentiana straminea on the seed germination and seedling physiological properties of forages

Gentiopicroside and flavonoids were extracted from feral Gentiana stram inea using ultrasonic extraction methods and then the extracts were applied at different concentrations to three forages,Medicago sativa,Trifolium pratense and T.repens.The forages' seed germination and seedling physiological properties (seedling height,root length,fresh weight and the activities of SOD,POD and CAT) were measured to analyze the allelopathy and antioxidation effects of feral G.straminea.In general,the gentiopicroside and flavonoid extracts showed allelopathic inhibitory effects on seed germination and seedling growth in the selected forages.The exception was gentiopicroside at 2.52 mg/mL,which increased seedling height in T.repens.The effects of gentiopicroside and flavonoid extracts on the activity of anti-oxidative enzymes varied with extract concentration.Specifically,both POD and CAT activities in seedlings of the three forages peaked when the concentrations of gentiopicroside and flavonoid extracts were 6.30 and 1.95 mg/mL respectively.When the concentrations of gentiopicroside and flavonoid extracts were 12.60 and 3.90 mg/mL respectively,SOD activity in M.sativa seedlings reached their maximums (22.971 and 25.013 U/g respectively),while in T.pretense and T.repens these activities peaked when the concentrations of gentiopicroside and flavonoid extracts were 6.30 and 1.95 mg/mL respectively.In conclusion,the sampled plants differ in their tolerance to allelopathic stress and M.sativa shows a greater tolerance than either T.pretense and T.repens.