【摘要】 植物根系是沙化地中植物固沙的重要基础,为明确不同治沙草本植物根系形态格局特征,本研究在青藏高原东南缘比较了资源圃和沙化地中一年生燕麦(Avena sativa)、多年生垂穗披碱草(Elymus nutans)和以礼草(Kengyilia hirsuta)地下根系根尖数、分枝数、平均直径、根长、根表面积、根体积的形态特征,分析了3种草本根尖比、根长比、根表面积比、根体积比的形态格局特征,探讨3种草本根系对沙化环境的适应能力。结果表明,一年生燕麦根系表面积和根体积在资源圃中显著高于沙地(P <0.05);垂穗披碱草根系形态在资源圃和沙地中没有明显差异(P> 0.05);以礼草根系根尖数、根分枝数、根长、根表面积在资源圃中明显低于沙地,但是以礼草根系平均直径在资源圃中明显高于沙地(P <0.05)。一年生燕麦根系体积在沙地中大量减少,增加0.2～0.4 mm各径级下的根尖比、根长比、表面积比、体积比用于适应沙化环境;多年生的垂穗披碱草并未显著调整自身根系结构用于适应沙化环境;多年生以礼草通过减少了较大径级(0.7～0.8 mm)的根长和表面积来增加了小径级(0.1～0.2 mm)的根长、表面积和体积的格局,来增加对沙化环境的适应性;垂穗披碱草和以礼草根系形态格局比燕麦根系形态格局更加适应沙化环境。更多还原

【Abstract】 The roots of plants are an important component in desert restoration. To understand the root morphology patterns of grasses being used to recover deserts, we studied grass roots in the Southeast Tibetan Plateau. Roots of the annual grass Avena sativa and the perennial grasses Elymus nutans and Roegneria hirsuta were collected from a field gene bank and sandy land. The tips, forks, average diameter, length, surface, and volume of the grass roots were compared and the ratios of the root tips, length, surface, and volume were analyzed. We discussed the suitability of different root morphologies to desert environments. The results show that the root surface and volume of A. sativa in the field gene bank were significantly higher than those in the sandy land. The root morphology of E. nutans had no significant differences between the field gene bank and sandy land. Additionally, the root tips, forks, length, and surface of R. hirsuta in the field gene bank were significantly lower than those from the sandy land; however, the average root diameter of R. hirsuta was significantly higher. There was a significant decrease in the root volume of A. sativa in the sandy land compared with the field gene bank. However, A. sativa increased the ratios of the root tips, length, surface, and volume, under a diameter of 0.2～ 0.4 mm, to suit desert environments. E. nutans did not significantly change its root morphology to suit desert environments. R. hirsuta increased the root length, surface, and volume patterns, under a diameter of 0.1～0.2 mm, to suit desert environments by decreasing the root length and surface between 0.7 and 0.8 mm. The root morphology patterns of E. nutans and R. hirsuta are more suitable to desert environments than those of A. sativa.更多还原