The growth and element nutrition of soybean inoculated with Bradyrhizobium diazoefficiens and two arbuscular mycorrhizas (AM) (Claroideoglomus etunicatum and Rhizophagus sp. R10) were evaluated in potted soils with moderately elevated cadmium (Cd). Each independent experiment was setup as a randomized 3×4 factorial with soil Cd (0, 3, and 6 mg Cd kg-1 soil) and inoculation (rhizobium, AM fungi, rhizobium + AM fungi, uninoculated control) treatments. Elevated soil Cd decreased root colonization by C. etunicatum, but the reverse was the case with Rhizophagus sp. R10. In both experiments, dual inoculation had the best growth while Cd at 6 mg kg-1 soil lowered plant performance and effectiveness of B. diazoefficiens single inoculation. The Cd toxicity to nodules observed in single rhizobium treatment was minimized in dual inoculation, and nodule resilience against Cd was better when Rhizophagus sp. R10 was the co-inoculant. Compared to control, Rhizophagus sp. R10 decreased the Cd and Mn concentrations in the root, stem, and leaf; while C. etunicatum supported greater Cd phytoaccumulation but minimized Cd-induced fluctuations in root Mn and modulated Mn concentration in the leaf via increases in available soil Mn. Arbuscular mycorrhizas variably modulate Mn with Cd for improved performance of soybean in soils with moderately elevated Cd.
We compared the sugar, dry matter, and effective ingredient levels of the dried corms of the medicinal plant Pinellia ternata Breit. obtained by two drying methods: natural and freeze drying. The sucrose, glucose, and fructose levels were significantly higher in the naturally dried corm than those in the freeze-dried corm. Dry matter content was also significantly higher in naturally dried corm than in freeze-dried corm. There was no significant difference between the levels of the effective ingredients in the corms obtained using the different drying methods. The two drying methods, natural and freeze drying, affected the sugar content of P. ternata corm.
Leptochloa chinensis (L.) Nees, is known as a noxious weed species in upland and lowland crop cultivation, and has naturalized in many countries as an invasive plant species. In this study, the allelopathic characteristic of L. chinensis was evaluated to understand its invasiveness. An aqueous methanol extract of the above-grand parts of L. chinensis suppressed the growth of weed species; Echinochloa crus-galli (L.) Beauv., Vulpia myuros (L.) C. C. Gmel. and Lolium multiflorum Lam., and crop plants; cress (Lepidum sativum L.), lettuce (Lactuca sativa L.) and alfalfa (Medicago sativa L.). Significant reductions in the growth were observed as the extract concentration was increased. The effectiveness of the extract varied with the test plant species. The present research suggests that L. chinensis may have allelopathic characteristic and the characteristic of L. chinensis may contribute its invasiveness.