Autor(es): Ge, Y. ; Hawkesford, M. J. ; Rosolem, C. A. [UNESP] ; Mooney, S. J. ; Ashton, R. W. ; Evans, J. ; Whalley, W. R.
Data: 2020
Identificador Persistente: http://hdl.handle.net/11449/194859
Origem: Oasisbr
Assunto(s): Leaf stunting; Root impedance; Nutrient stress
Made available in DSpace on 2020-12-10T16:56:48Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-08-01
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
FAPEG-Goias Research Foundation
FAPEMA-Maranhao Research Foundation
Biotechnology and Biological Sciences Research Council
Designing Future Wheat Programme by the UK Biotechnology and Biological Sciences Research Council
In the field, wheat experiences a combination of physical and nutrient stresses. There has been a tendency to study root impedance and water stress in separation and less is known about how they might interact. In this study, we investigated the effect of root impedance on the growth of three wheat varieties (Cadenza, Xi19 and Battalion) at different levels of nitrate availability, from 0-20 mM nitrate, in sand culture. This model system allows soil strength to be increased while maintaining adequate water availability. In a separate pot experiment, we grew the same wheat varieties in a loamy sand where soil was allowed to dry sufficiently to both reduce water potential and increase root impedance. This pot experiment also had a range of nitrate availabilities 0-20 mM nitrate. Once the seedlings were established we limited water supply to apply a matric potential of approximately - 200 kPa to the roots. Soil drying increased the penetrometer resistance from approximately 300 kPa to more than 1 MPa. There were differences between the two experimental systems; growth was smaller in the soil-based experiment compared to the sand culture. However, the effects of the experimental treatment, root impedance or water withholding, relative to the control were comparable. Our data confirmed that leaf elongation in Cadenza (carrying the tall Rht allele) was the most sensitive to root impedance. Leaf stunting occurred irrespective of nitrate availability. Leaf elongation in the Xi19 and Battalion (carrying the semi-dwarf Rht allele) was less sensitive to root impedance and drought than Candenza. We suggest that the critical stress in a pot experiment where the soil was allowed to dry to approximately - 200 kPa was root impedance and not water availability.
Rothamsted Res, Harpenden AL5 2JQ, Herts, England
Sao Paulo State Univ, Botucatu, SP, Brazil
Univ Nottingham, Sch Biosci, Loughborough, Leics, England
Sao Paulo State Univ, Botucatu, SP, Brazil
FAPESP: 2015/50305-8
FAPEG-Goias Research Foundation: 2015-10267001479
FAPEMA-Maranhao Research Foundation: RCUK-02771/16
Biotechnology and Biological Sciences Research Council: BB/N013201/1
Designing Future Wheat Programme by the UK Biotechnology and Biological Sciences Research Council: BB/P016855/1
