Plant Soil Environ., 2007, 53(2):65-71 | DOI: 10.17221/2301-PSE

Seedling treatments and phosphorus solution concentrations affect nodulation and nodule functions in soybean (Glycine max L.)

S.J. Miao^1,2,3, X.Z. Han¹, X.B. Liu¹, Y.F. Qiao¹

¹ Northeast Institute of Geography and Agrio-Ecology, CAS, Harbin, China

² Collegeof Resource and Environment, Northeast Agricultural University, Harbin Heilongjiang, China

³ Graduate School, CAS, Beijing, China

The effect of three seedling treatments: T₀, normal germination; T₁, cotyledons removed; T₂, cotyledons removed 5 days earlier than in T₁; and two phosphorus levels (P₀ and P₃₀) on nodulation and nodule function in soybean [Glycine max (L.) Merr.] were investigated in nutrient solution culture. The number of nodules formed at P₀ was in the order T₂ > T₀ > T₁, but it was T₀ > T₂ > T₁ at P₃₀. Nodule dry weight per plant had the same tendency as the nodule number. Nodule size (dry weight per nodule) in seedlings ranged from 0.601 to 1.089 mg in the order T₀ > T₁ > T₂, regardless of P level. For example, nodule size in T₀ was larger by 86% and 52% than T₂ at P₀ and P₃₀, respectively. Furthermore, regardless of P level, a specific acetylene reduction activity (ARA, µM C₂H₄/h/g nodule) increased with P content in seedlings, but no significant difference was found (P < 0.05). Leghemoglobin (Lb) content was not significantly affected by P level; however, seedlings (T₀ and T₁) significantly affected the Lb content per unit plant biomass (P < 0.05). All these results suggest that seedling P content plays a key role in nodulation and nodule function of soybean.

Keywords: soybean [Glycine max (L.) Merr. ]; seedling; phosphorus nutrition; nitrogenase activity; leghemoglobin concentration

Published: February 28, 2007  Show citation