低磷和干旱胁迫条件下接种摩西球囊霉对白花草木犀营养吸收和生长的影响

 利用盆栽试验研究了低磷和干旱胁迫条件下接种摩西球囊霉(Glomus mosseae)对白花草木犀营养吸收和生长的影响.设置土壤相对含水量65%和35%两个处理,并设置磷营养0、25、50mg·kg^-13个水平(P₀,P₂₅,P₅₀),在上述两个因素的基础上分别进行接种和不接种摩西球囊霉处理.结果表明,干旱胁迫对白花草木犀根系菌根侵染率的影响不明显,但高磷水平(50mg·kg^-1)和干旱胁迫显著抑制了白花草木犀根系AM真菌的侵染(P<0.01).接种AM真菌不仅能够显著促进白花草木犀对N、P营养元素的吸收,还能够减弱干旱逆境对白花草木犀生长的影响.此外,无论是正常供水或者是干旱胁迫,接种AM真菌均显著增加了白花草木犀水分利用效率.在室内温室条件下,初步发现接种菌根能够促进干旱区、半干旱区牧草生长,恢复退化草原.

Effects of Inoculation of Glomus mosseae on the Growth and Nutrition Uptake of Melilotus albus Desr. Under Water Stress and Phosphorus Deficiency Conditions

A pot experiment was conducted to investigate the effects of inoculation of Glomus mosseae on the growth and nutrition uptake of Melilotus albus Desr. under water stress and/or phosphorus deficiency conditions. The pot trials include two levels of soil relative water contents (35% and 65%) and three levels of phosphorus (0, 25, 50mg·kg^-1), either with inoculation of Glomus mosseae or without inoculation. The results show that the water stress does not inhibit the mycorrhizal infection of Melilotus albus. However, a high level of P in soils (50mg·kg^-1) under water stress would significantly inhibit the mycorrhizal colonization. The inoculation of Glomus mosseae significantly increases the uptake of N and P in Melilotus albus and consequently alleviates the negative effects of Melilotus albus under water stress. The highest biomass of the shoot and the root of Melilotus albus is recorded in the treatments of inoculation in 50mg P·kg^-1 soils. In addition, the inoculation of Glomus mosseae significantly enhances the coefficient of the water use of Melilotus albus under water stress or not. The results suggest that the inoculation of arbuscular mycorrhizal (AM) fungus may be a promising approach for increasing the growth of grass and enhancing the revegetation of the degraded grassland in arid and semi-arid regions.