Direct and indirect effects of glomalin, mycorrhizal hyphae, and roots on aggregate stabiliLEty in rhizosphere of trifoliate orange

作者：Wu Qiang Sheng^*; Cao Ming Qin; Zou Ying Ning; He Xin hua

来源：Scientific Reports, 2014, 4(1): 5823.

DOI：10.1038/srep05823

To test direct and indirect effects of glomalin, mycorrhizal hyphae, and roots on aggregate stability, perspex pots separated by 37-mu m nylon mesh in the middle were used to form root-free hyphae and root/hyphae chambers, where trifoliate orange (Poncirus trifoliata) seedlings were colonized by Funneliformis mosseae orParaglomus occultum in the root/hyphae chamber. Both fungal species induced significantly higher plant growth, root total length, easily-extractable glomalin-related soil protein (EE-GRSP) and total GRSP (T-GRSP), and mean weight diameter (an aggregate stability indicator). The Pearson correlation showed that root colonization or soil hyphal length significantly positively correlated with EE-GRSP, difficultly-extractable GRSP (DE-GRSP), T-GRSP, and water-stable aggregates in 2.00-4.00, 0.50-1.00, and 0.25-0.50 mm size fractions. The path analysis indicated that in the root/hyphae chamber, aggregate stability derived from a direct effect of root colonization, EE-GRSP or DE-GRSP. Meanwhile, the direct effect was stronger by EE-GRSP or DE-GRSP than by mycorrhizal colonization. In the root-free hyphae chamber, mycorrhizal-mediated aggregate stability was due to total effect but not direct effect of soil hyphal length, EE-GRSP and T-GRSP. Our results suggest that GRSP among these tested factors may be the primary contributor to aggregate stability in the citrus rhizosphere.

• 出版日期2014-7-25
• 单位长江大学; 中国农业科学院农业资源与农业区划研究所