| By using pipe cultivation experiment, eight ecotypes of Eruca Sativa Mill from different regions (high drought-resistant types: Huining, Longxi; medium drought-resistant types: Xinghe, Zhangbei, Hetian, Varomin; low drought-resistant types: Sichuan, Xiliang) were selected to study their characters of root growth and distribution. The results indicated that the vertical distribution of root biomass was simulated by the equation of y=a+bx+cx2+dx3. All equation parameters (a, b, c and d) of Huining, Longxi, Xinghe and Xiliang were clearly different with Zhangbei, Hetian, Varomin and Sichuan, and the root system biomass and root/shoot ratio of the former types were lower than the latter ones. The vertical distribution of root system biomass in various layers show different diversification rules. The materials of high drought resistance had a medial root system biomass; the materials of medium drought resistance had a large or small root system biomass; and the materials of low drought resistance had a large root system biomass than others. |