Morphological responses of wheat (Triticum aestivum L.) roots to phosphorus supply in two contrasting soils

作者：Yuan, H. M.; Blackwell, M.; Mcgrath, S.; George, T. S.; Granger, S. J.; Hawkins, J. M. B.; Dunham, S.; Shen, J. B.^*

来源：Journal of Agricultural Science, 2016, 154(1): 98-108.

DOI：10.1017/S0021859615000702

• HAIR LENGTH
• USE EFFICIENCY
• OLSEN P
• BARLEY
• ACQUISITION
• GROWTH
• DEFICIENCY
• FIELD
• TOLERANCE
• CULTIVARS

To cope with phosphorus (P) deficiency, plants adapt root morphology to enhance inorganic P (Pi) acquisition from soil by allocating more biomass to roots, but whether the responses can be modified across gradients of P supply is not fully understood. The present study examined changes in root-length density (RLD), root-hair density (RHD) and root-hair length (RHL) of wheat (Triticum aestivum L.) in two contrasting soils, the Rough and Barnfield soils. Wheat plants were grown for 3 weeks in thin-plate rhizotrons in two soils with additions of 0, 10, 25, 50, 100 and 200 mg P/kg soil. Contrary to published literature, as P additions increased it was observed that a concomitant increase in RHL (250 to 1054 mu M in the Rough soil and 303-1075 mu M in the Barnfield soil) and RHD (57 to 122/mm in the Rough soil and 56-120/mm in the Barnfield soil), while RLD generally decreased (2480-1130 cm/cm(3) in the Rough soil and 1716-865 cm/cm(3) in the Barnfield soil). The levels of added P that resulted in critical P concentrations in the soils enabling maximum shoot biomass production were 50 mg/kg P in the Rough soil and 100 mg/kg P in the Barnfield soil, and these additions influenced root morphological changes. Under severe P deficiency, P supply increased RHL and RHD, but RLD was decreased. Improvement in lateral root and root-hair responses in wheat at extreme P deficiency may be a worthy target for breeding more sustainable genotypes for future agroecosystems.

• 出版日期2016-1
• 单位中国农业大学