柳枝稷根际土化感潜势的环境异质性表达

Allelopathic Potential Expression of the Environmental Heterogeneity in Switchgrass Rhizosphere Soil

以不同生长环境(宁夏固原、陕西杨凌)条件下的4个柳枝稷品种(‘Pathfinder’、‘Foresberg’、‘Nebraska 28’、‘Dakota’)为试材,以生菜、苜蓿和多花黑麦草为受体,采用室内皿培发芽测试法,研究了柳枝稷根际土浸提液对受体种子的影响。结果表明:柳枝稷根际土对3种受体的化感潜势是由品种和环境效应共同作用的结果。‘Dakota’根际土浸提液对生菜的化感作用环境效应最为强烈,在相同环境(杨凌)条件下,对生菜的化感促进作用最强;‘Forestberg’和‘Dakota’对苜蓿幼苗生长的结果表明,2种柳枝稷根际土的化感表达对生长环境的响应不敏感,而‘Pathfinder’表现较为强烈。‘Nebraska 28’对苜蓿幼苗生长的化感作用在品种间表现突出;多花黑麦草幼苗生长对柳枝稷根际土的化感响应表现出环境异质性;种植在杨凌和固原的‘Pathfinder’、‘Forestberg’和‘Dakota’分别对生菜及苜蓿种子萌发均有显著的抑制作用。该研究可为柳枝稷作为牧草引种及其与其它牧草间套作、混播等提供科学依据。

Taking four eultivars of switchgrass （ ‘ Pathfinder＇, ‘ Forestberg ＇, ‘ Nebraska 28 ＇, ‘ Dakota＇ ） from different growth conditions （Guyuan,Yangling） as materials,and lettuce, alfalfa and annual ryegrass seeds as recipients. Effect of the extract of rhizosphere soil of switchgrass on the seed of recipients was studied by biological test methods. The results showed that the rhizosphere soil allelopathic potential of switchgrass on three recipients was the result of both variety and environmental. Effect of the extract of ‘ Dakota ’ rhizosphere soil on lettuce was the most intense between the two environments,and the strongest promotion was preformed in lettuce seedling growth at same condition （Yangling） among the cultivars. Allelopathic effect of ‘Forestberg＇ and ‘Dakota＇ to alfalfa seedling growth showed that the two switchgrass rhizosphere were not sensitive to the environment, while the performance ＇Pathfinder＇ was stronger. The allelopathic effect of ‘Nebraska 28＇ on alfalfa seedling growth was outstanding among the tested varieties. Ryegrass seedling growth showed allelopathic response to environmental heterogeneity; Lettuce seed germination were inhibited by ‘Pathfinder＇, ‘Forestberg＇ and ‘Dakota＇ in Yangling and the alfalfa seed germination were significantly inhibited by the same three varieties in Guyuan. The research could provide the scientific basis for using switchgrass as forage introduction, intercropping and mixed seeding with other forage.