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为揭示黄土丘陵区天然草地群落优势种达乌里胡枝子(Lespedeza davurica L.)根系生长与土壤水分供应条件间的关系,采用盆栽控制试验,设置高水(土壤田间持水量80%)、中水(土壤田间持水量60%)和低水(土壤田间持水量40%)3个处理后,在现蕾期、开花期和结实期进行阶段改善水分供应条件,生育期末测定和计算了不同土壤水分处理下达乌里胡枝子根系生物量和形态特征.结果表明:达乌里胡枝子根系生长与水分供应条件密切相关,充分的水分供应有利于促进其根系生物量增大和根系长度的生长,但适度水分胁迫有利于增强其根系的吸收能力.其根系生物量和总根长在高水处理下显著最高(P<0.05);根表面积、比根长和比根面积以中水处理下显著最高(P<0.05);不同水分处理下,其根系平均直径为0.76-0.94 mm,根系生物量、根表面积和总根长间存在显著的正相关关系(P<0.05).综上,充足的水分供应有利于促进达乌里胡枝子根系生物量积累和根系形态建成,其根系生物量及其形态特征对水分阶段改变的响应不仅取决于水分供应条件改善的幅度,也与其生育期密切相关.
In order to reveal the relationship between root growth and soil water supply of the dominant species of natural grassland community in the hilly Loess Plateau, pot experiment was conducted to set high water (80% field capacity) After three treatments, water (soil field water content 60%) and low water (soil field water content 40%), water supply conditions were improved during the budding, flowering and fruiting phases, and different soil The root biomass and morphological characteristics of Lespedeza obliquus were studied under the condition of water treatment.The results showed that the root growth of Lespedeza davurica was closely related to the water supply condition and adequate water supply could promote the growth of root biomass and root length, Moderate water stress was beneficial to enhance the absorption capacity of its root system, and its root biomass and total root length were significantly higher under high water treatment (P <0.05). Root surface area, specific root length and specific root area were significantly higher under water treatment (P <0.05). Under different water treatments, the root mean diameter was 0.76-0.94 mm, there was a significant positive correlation between root biomass, root surface area and total root length (P <0.05) Sub-suppliers and promoting LDF root biomass accumulation and root morphogenesis, their root biomass and morphology in response to changes in the water phase of the water supply depends not only on improved conditions magnitude, is also closely related to its growth period.