Plant and Soil

, Volume 232, Issue 1, pp 69–79

Effect of phosphorus availability on basal root shallowness in common bean

  • Hong Liao
  • Gerardo Rubio
  • Xiaolong Yan
  • Aiqin Cao
  • Kathleen M. Brown
  • Jonathan P. Lynch
Article

DOI: 10.1023/A:1010381919003

Cite this article as:
Liao, H., Rubio, G., Yan, X. et al. Plant and Soil (2001) 232: 69. doi:10.1023/A:1010381919003

Abstract

Root gravitropism may be an important element of plant response to phosphorus availability because it determines root foraging in fertile topsoil horizons, and thereby phosphorus acquisition. In this study we seek to test this hypothesis in both two dimensional paper growth pouch and three-dimensional solid media of sand and soil cultures. Five common bean (Phaseolus vulgaris L.) genotypes with contrasting adaptation to low phosphorus availability were evaluated in growth pouches over 6 days of growth, and in sand culture and soil culture over 4 weeks of growth. In all three media, phosphorus availability regulated the gravitropic response of basal roots in a genotype-dependent manner. In pouches, sand, and soil, the phosphorus-inefficient genotype DOR 364 had deeper roots with phosphorus stress, whereas the phosphorus-efficient genotype G19833 responded to phosphorus stress by producing shallower roots. Genotypes were most responsive to phosphorus stress in sand culture, where relative root allocation to the 0–3- and 3–6-cm horizons increased 50% with phosphorus stress, and varied 300% (3–6 cm) to 500% (0–3 cm) among genotypes. Our results indicate that (1) phosphorus availability regulates root gravitropic growth in both paper and solid media, (2) responses observed in young seedlings continue throughout vegetative growth, (3) the response of root gravitropism to phosphorus availability varies among genotypes, and (4) genotypic adaptation to low phosphorus availability is correlated with the ability to allocate roots to shallow soil horizons under phosphorus stress.

common beanphosphorus availabilitybasal root gravitropism

Copyright information

© Kluwer Academic Publishers 2001

Authors and Affiliations

  • Hong Liao
    • 1
    • 2
  • Gerardo Rubio
    • 2
    • 3
  • Xiaolong Yan
    • 1
  • Aiqin Cao
    • 1
  • Kathleen M. Brown
    • 2
  • Jonathan P. Lynch
    • 2
  1. 1.Laboratory of Plant Nutritional Genetics and Root Biology CenterSouth China Agricultural UniversityGuangzhouChina
  2. 2.Department of HorticultureThe Pennsylvania State UniversityUniversity ParkUSA
  3. 3.Faculty of AgronomyUniversity of Buenos AiresBuenos AiresArgentina