Effect of Cu toxicity on growth of cowpea (Vigna unguiculata)

Accurate determination of the rhizotoxicity of Cu in dilute nutrient solutions is hindered by the difficulty of maintaining constant, pre-determined concentrations of Cu (micromolar) in solution. The critical Cu²⁺ activity associated with a reduction in the growth of solution-grown cowpea (Vigna ung...

Full description

Saved in:
Bibliographic Details
Published in:Plant and soil 2006-01, Vol.279 (1-2), p.287-296
Main Authors: Kopittke, P.M, Menzies, N.W
Format: Article
Language:English
Subjects:
Acid soils
Agronomy. Soil science and plant productions
Biological and medical sciences
calcium
Cation exchange
copper
cowpeas
Deficiencies. Phytotoxicity of elements. Salinity
Epidermis
Fundamental and applied biological sciences. Psychology
General agronomy. Plant production
iron
Legumes
magnesium
Nutrient concentrations
Nutrient solutions
phytotoxicity
Plant growth
plant micronutrients
Plant nutrition
Plant roots
Plants
potassium
Resins
root growth
Root tips
Roots
soil nutrients
Soil toxicity
soil-plant interactions
Soil-plant relationships. Soil fertility. Fertilization. Amendments
Toxicity
Vigna unguiculata
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Accurate determination of the rhizotoxicity of Cu in dilute nutrient solutions is hindered by the difficulty of maintaining constant, pre-determined concentrations of Cu (micromolar) in solution. The critical Cu²⁺ activity associated with a reduction in the growth of solution-grown cowpea (Vigna unguiculata (L.) Walp. cv. Caloona) was determined in a system in which Cu was maintained constant through the use of a cation exchange resin. The growth of roots and shoots was found to be reduced at solution Cu²⁺ activities >=1.7 μM (corresponding to 90% maximum growth). Although root growth was most likely reduced due to a direct Cu²⁺ toxicity, it is considered that the shoot growth reduction is attributable to a decrease in tissue concentrations of K, Ca, Mg, and Fe and the formation of interveinal chlorosis. At high Cu²⁺ activities, roots were brown in color, short and thick, had bent root tips with cracking of the epidermis and outer cortex, and had local swellings behind the roots tips due to a reduction in cell elongation. Root hair growth was reduced at concentrations lower than that which caused a significant reduction in overall root fresh weight.
ISSN:0032-079X
1573-5036
DOI:10.1007/s11104-005-1578-z