关键词: 大豆, 根际土壤, 油菜, 根肿病

Abstract: The population of Schizothorax irregularis Ddy, an endemic species in Xinjiang, has declined rapidly due to hydroelectricity construction. Investigation of their swimming capability will provide the basis required for fishery passage facilities design. The induction velocity, critical swimming speed and burst swimming speed were measured by increasing velocity tests. The swimming endurance of S. irregularis was measured by fixed velocity tests. Induction velocity (1.41±0.28 BL·s^-1 or 24.50±4.13 cm·s^-1, BL: body length), critical swimming speed (6.04±1.21 BL·s^-1 or 117.61±12.34 cm·s^-1) and burst swimming speed (11.41±2.79 BL·s^-1 or 210.24±39.56 cm·s^-1) declined with the increases of body length. Results from swimming endurance tests showed that  the swimming time or swimming endurance significantly decreased with the increases of flow rate (80-135 cm·s^-1) and that swimming endurance was negatively related to swimming velocity. Eighty percent of fishes could pass the fishway when maximum velocity was less than 1.9 m·s^-1. Therefore, we suggest that when the target fish of fishway is S. irregularis, the minimum velocity in fishway should exceed 0.3 m·s^-1, the flow rate at entrance and vertical slot could range from 1.2 to 1.9 m·s^-1, and the main flow rate in the rest pool ranges from 0.3 to 1 m·s^-1.

Key words: rhizosphere soil., clubroot, oilseed rape, soybean