Chin J Plant Ecol ›› 2006, Vol. 30 ›› Issue (6): 991-997.DOI: 10.17521/cjpe.2006.0127

• Research Articles • Previous Articles     Next Articles

EFFECTS OF NITROGEN FORMS ON ENDOGENOUS PLANT HORMONES CONTENT IN DIFFERENT ORGANS OF WHEAT AFTER ANTHESIS

MA Zong-Bin1, WANG Xiao-Chun2, HE Jian-Guo1, MA Xin-Ming1,*()   

  1. 1 College of Agriculture, Henan Agricultural University, Zhengzhou 450002, China
    2 College of Life Sciences, Henan Agricultural University, Zhengzhou 450002, China
  • Received:2006-02-17 Accepted:2006-05-31 Online:2006-02-17 Published:2006-11-30
  • Contact: MA Xin-Ming

Abstract:

Background and Aims Applying different forms of nitrogen is an important method to regulate nitrogen metabolism of wheat. Endogenous plant hormones play an important role in grain filling of wheat. The objectives of this study were to 1) elucidate the effects of nitrogen forms on endogenous hormones content in roots, flag leaves and grains of wheat after anthesis, and 2) find nitrogen application methods for the wheat cultivar `Yumai 49'.

Methods Pot experiments utilizing a sandy loam soil and wheat cultivar 'Yumai 49' were completed during 2003-2005. Nitrogen forms were CONH4-N (urea), NH4-N(NH4HCO3) and NO3-N(NaNO3), and nitrification inhibitor dicyandiamide (DCD) was applied in CONH4-N and NH4-N treatments. Spikes of wheat which flowered on same day were marked and roots, flag leaves and grains were sampled at fixed dates. Each sample weighed 0.5 g FW and was stored at -40 ℃. The enzyme-linked immunosorbent assay (ELISA) method was used to determine the content of IAA, GA3, ABA and ZR.

Key Results Compared with NO3-N treatment, GA3 content in CONH4-N treated flag leaves and IAA and ABA content in grains were higher 5-15 days after anthesis, and the grain-filling rate (GFR) was higher in this period. GA3 content in CONH4-N treated roots, IAA and GA3 content in flag leaves, and ABA content in grains were higher, IAA content in grains was lower 15-25 days after anthesis, and the GFR was lower in this period. Compared with NO3-N treatment, ZR content in grains was higher 5 days after anthesis in all NH4-N treatments. IAA and ABA content in grains was lower about 15 days after anthesis, and the GFR was lower in this period. ZR and GA3 content in roots, IAA and GA3 content in flag leaves, and ABA and GA3 content in grains were lower, ABA content in flag leaves and IAA content in grains were higher 15-25 days after anthesis and the GFR was higher in this period. Compared with NO3-N treatment, the grain weight of wheat was significantly greater in NH4-N treatment, and grain yield was increased significantly either in NH4-N or CONH4-N treatments.

Conclusions This study showed that endogenous hormones in wheat responded differently to nitrogen forms after anthesis. The GFR of wheat regulated by nitrogen forms was realized through the balance of endogenous hormones in roots, flag leaves and grains. We recommend that CONH4-N or NH4-N mixed with DCD be applied to wheat cultivar `Yumai 49'.

Key words: Nitrogen forms, Wheat, Root, Flag leaf, Grain, Endogenous plant hormones content