Abstract:

For clarifying the effects of fertilizer on the root growth of alfalfa(Medicago sativa) seedling in southern China, a pot trial was carried out to study root system growth with 4 cultivars(Icon, WL-525HQ, Supersonic and WL-903)treated by five concentrations of nutrient solution(0.1, 0.2, 0.3, 0.4 and 0.5 times Hoagland solution). The results indicated that the average root length, root number, root volume and root surface area of plant treated by 0.1 and 0.2 times Hoagland solution were greater than those treated by 0.4 and 0.5 times Hoagland solution. But average root diameter, root dry weight, plant height and stem dry weight increased significantly(P<0.05) with the concentration of Hoagland solution increasing. The effect of nutrient solution concentration on root-shoot ratio was no significant difference among treatments suggesting that the ability of lateral root growth in alfalfa seedling stage was stronger at the lower concentration of nutrient solution, and the high level of nutrition promoted the growth of aboveground and root dry matter accumulation significantly.

Key words: Lateral root, Dry matter accumulation, Root system, Nutrition level, Alfalfa

摘要：

为明确施肥对紫花苜蓿(Medicago sativa)根系生长的影响,采用盆栽试验方法,分析了5种营养浓度(0.1,0.2,0.3,0.4和0.5倍Hoagland营养液)水平对紫花苜蓿(品种:标杆、WL-525HQ、超音速和WL-903)苗期根系生长的影响。结果表明:0.1和0.2倍Hoagland营养液处理的平均根长、根尖数、根体积和根表面积均大于0.4和0.5倍营养液浓度处理;但是平均根直径、根干重,及株高和茎叶干重均随营养液浓度的提高而显著增加(P<0.05);根冠比受营养水平差异的影响较小。分析结果说明,高营养水平虽不利于紫花苜蓿苗期侧根的发生和生长,但显著促进紫花苜蓿小苗地上部的生长,并增加了根系的干物质积累。

关键词: 侧根, 干物质积累, 根系, 营养水平, 紫花苜蓿