Responses of root system of Lespedeza davurica L. to soil water change

Abstract

This study aimed to clarify the relationship between root morphological characteristics of Lespedeza davurica L. under different soil water conditions. One pot experiment was conducted to investigate the root biomass, total root length, root surface area, root average diameter, specific root length and specific root area under three soil water regimes, i.e. sufficient water supply (HW, 80% FC), moderate water stress (MW, 60% FC) and severe water stress (LW, 40% FC). Besides, at the three main growth periods (budding, flowering and grain filling stage), soil water contents were improved separately from MW to HW, LW to HW and MW, respectively. Root biomass and morphological characteristics under different soil moisture treatments at the end of growth period were measured and calculated. Results showed that root biomass and total root length were significantly higher in the HW than other regimes (P < 0.05), and root surface area, specific root length and specific root area significantly higher in the MW regime than others (P < 0.05). The root average diameter was 0.76-0.94 mm under different water regimes. Positive linear relationships existed between total root length and root biomass as well as root surface area. In summary, sufficient water supply is favorable to root biomass accumulation and morphology formation of L. davurica, and their responses to soil water change are related to the degree of water condition improvement and its growing stage.