苜蓿沙土盆栽试验的水分生态适应性

Ecological Adaptability of Alfalfa Varieties Investigated by Pot Experiment with Sandy Soil under Different Moisture Conditions

在温室进行沙土盆栽试验,研究WL-323、Siriver和固原苜蓿在不同土壤水分条件下的耗水特征、生理指标、生物学性状、产草量和水分利用效率的变化。结果表明:苜蓿在生育期的耗水特征因水分条件和品种而异;水分胁迫值(PMS)与土壤含水量呈显著负相关;供试苜蓿叶绿素含量与土壤含水量相关不显著;株高、分枝数、分枝总长、叶片数、根数、主根长、根颈粗和干根重等性状均随着土壤水分的增加呈上升趋势,而根冠比则呈下降趋势;WL-323的根系发达、植株发育良好,产草量和水分利用效率高,对沙土的适应性最优;Siriver的干根重和根冠比高,抗旱性能较好,产草量和水分利用效率居中;固原苜蓿对沙土的生态适应性最差;研究结果对沙化土地区苜蓿品种的合理布局与水分调控具有科学指导价值。

In order to discover the ecological adaptability of different varieties in sand land areas, the pot experiment was conducted in greenhouse to investigate the water consumption features, plant physiological indexes, biological characters, output and water use efficiency （WUE） of three alfalfa varieties （WL-323, Siriver and Guyuan） under different soil moisture conditions. The results showed that the water consumption features of alfalfa at various growing stages changed along with the differences of moisture conditions and varieties; there was a remarkable negative correlativity between plant moisture stress （PMS） and soil moisture content, but the change of chlorophyll content in leaves among different moisture conditions and varieties was not remarkable~ the plant height, branch number per plant, total branch length per plant, leaf number per plant, root number per plant, root depth, root collar diameter and dry weight of root of alfalfa tended to increase, but the ratio of root/canopy tended to decrease, along with the rise of soil moisture. Among the tested varieties, WL-323 was characterized with large root system, well- developed canopy, high forage output and high WUE, so its ecological adaptability to sandy soil was optimal; Siriver was characterized with high dry weight of root and high ratio of root/canopy, so its drought-resistance was relatively strong and its output and WUE was moderate; Guyuan was a variety with the lowest ecological adaptability to sandy soil. The results may be helpful to the rational distribution of alfalfa varieties and soil moisture adjustment on sandy land.