Page 2 Plant-Bacteria Interactions Edited by Iqbal Ahmad, John ...

94j 5 Diversity and Potential of Nonsymbiotic Diazotrophic Bacteria in Promoting Plant Growth
Figure 5.2 Factors of root colonization. Main steps of root colonization.
Factors involved in every step of root colonization by
bacteria. Plant, biotic factors and abiotic factors.
involved and its competitiveness for nodulation against indigenous rhizobia. Symbiotic
nitrogen fixation is also influenced by environmental factors. Increasing
symbiotic nitrogen fixation is rational, since leguminous crops are an important
source of protein and environmentally safe, avoiding the use of nitrogen fertilizers.
Rhizobial strain selection and legume breeding are conventional approaches to
improve this process and, more recently, molecular approaches have demonstrated