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Silicon promotes nodule formation and nodule function in symbiotic cowpea ( Vigna unguiculata )
Author(s) -
NELWAMONDO A.,
DAKORA F. D.
Publication year - 1999
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.1469-8137.1999.00409.x
Subject(s) - silicic acid , vigna , nodule (geology) , symbiosis , nitrogen fixation , silicon , dry matter , biology , bradyrhizobium , nutrient , agronomy , bradyrhizobium japonicum , botany , rhizobium , horticulture , chemistry , inoculation , rhizobiaceae , bacteria , ecology , paleontology , genetics , organic chemistry
Applying silicon in the form of metasilicic acid (H 4 SiO 3 ) or silicic acid (H 4 SiO 3 ) to Bradyrhizobium ‐infected, hydroponically grown cowpea seedlings resulted in a significant ( P ⩽0.05) increase in the number of nodules, nodule dry matter, and nitrogen fixed on a per plant basis. Total dry matter of plants increased with silicon supply, and the differences were significant ( P ⩽0.05) at the higher silicon concentrations. Cowpea plants cultured in sand were also assessed for their response to silicic acid. Nodule number and nodule mass increased with silicon supply to sand cultured plants, though nitrogen fixation was unaltered. Although silicon is not essential for growth of cowpea, it is important for nodule formation and nodule functioning in hydroponically grown plants. Consequently, data collected and conclusions drawn from earlier glasshouse experiments, which have excluded silicon from nutrient solutions, may be flawed. Future studies on nodulation and nitrogen fixation using legumes in liquid culture must therefore include silicon as a nutrient element.