喀斯特生境下AMF侵染对任豆生长的影响

喀斯特地区土壤退化,植被定植更新困难,丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)具有增强植物养分吸收能力和抵抗逆境胁迫能力。研究喀斯特生境下植物与AMF共生效果,选择优势菌种促进喀斯特植被恢复,对于提高植物定植成活率具有重要作用。以豆科植物任豆(Zenia insignis)幼苗为试验材料,盆栽条件下,选取喀斯特优势菌种-摩西球囊霉(Funneliformis mosseae)、根内球囊霉(Rhizophagus intraradices),2种菌根真菌混合菌剂进行接种,培养180 d,研究贫瘠喀斯特土壤生境和养分较高的滇柏林下土壤生境下AMF对任豆生长影响。结果表明:摩西球囊霉、根内球囊霉和混合接种均能侵染任豆根系,幼嫩根系更易侵染,木质化根系侵染率下降。接种摩西球囊霉,贫瘠喀斯特土壤生境下,株高、地径、地上生物量、地下生物量和总生物量分别提高68.92%、56.18%、83.90%、42.20%和67.34%;养分较高的滇柏林下喀斯特土壤生境下,株高、地上生物量、地下生物量和总生物量分别提高48.05%、6.77%、7.92%和8.89%;根内球囊霉处理接种效应低于摩西球囊霉和混合接种处理,对生物量增长为负效应,混合接种处理接种效应介于单接种之间,摩西球囊霉接种效果优于根内球囊霉和混合接种。摩西球囊霉在贫瘠喀斯特土壤生境下发挥的促生效应优于养分较高的喀斯特土壤,可作为喀斯特侵蚀区植被恢复菌根真菌干扰途径的优势菌种,混合接种作为接种剂具有单接种兼容效应。

Effects of Arbuscular Mycorrhizal Fungi(AMF) on the Growth of Zenia insignis in Karst Habitats

It is difficult for plants to survive and grow under the Karst erosion regions. Arbuscular mycorrhizal fungi(AMF) have positive effects on plant growth and increase resistance of plants to environmental stresses. It is important to study the symbiotic effect of plants and AMF in Karst habitats, and to select dominant species to promote Karst vegetation recovery and improve plant survival. In this study, we took Zenia insignis, an important native species in the Karst regions of southwestern China, as our experimental material. We used two arbuscular mycorrhizal fungi specie Funneliformis mosseae(Fm), Rhizophagus intraradices(Ri) and mixed mycorrhizal fungi to inoculate Zenia insignis seedlings. The soil mediums were low nutrient Karst soil and cupressus duclouxiana soil. The results showed that AMF inoculation could infected of the Zenia insignis. Fresh Zenia insignis roots were easy to be infected, Colonization percentage was falling when the Zenia insignis roots become woodenized. Plants inoculated with Fm had the highest plant height, basal diameter, aboveground biomass, underground biomass and total biomass compared to other AMF species under low nutrient Karst soil, Growth parameters were increased by 68.92%, 56.18%, 83.90%, 42.20% and 67.34%. Plants inoculated with Fm had the highest plant height, aboveground biomass,underground biomass and total biomass compared to other AMF species under higher nutrient karst soil(Cupressus duclouxiana soil), Growth parameters were increased by 48.05%, 6.77%, 7.92%, and 8.89%. Ri inoculation treatment effect was lower than Fm and Mi treatment, the growth parameters were negative effect. Mi inoculation treatment effect was between single inoculation. Fm inoculation treatment effect was higher than Ri and Mi, among which the Fm has the best performance under low nutrient karst soil. It is conculuded that Funneliformis mosseae show application potential for vegetation restoration under the low nutrient Karst soil.