About Lesson
Terminologies
a) Seed inoculation: refers to the practice of applying artificially prepared cultures of Rhizobia to leguminous seed before sowing.
A. Inoculation of Rhizobium:
- To establish a symbiosis, the bacterial microsymbionts gain access to single plant cells and install themselves in compartments surrounded by a plant membrane.
- In legumes, gram-negative soil bacteria belonging to the family Rhizobiaceae (here collectively called Rhizobium) infect root tissue and induce the formation of nitrogen-fixing nodules.
- Some specific Rhizobium nodulate only specific legumes while others nodulate in several species.
|
Rhizobium Species |
Crops |
|
R. leguminosarum |
Pisum sp (Peas), Lathyrus sp, Vicia sp, Lens sp (Lentil) |
|
R. tripoli |
Trifolium (Berseem) |
|
R. phaseoli |
Phaseolus (Kidney bean) |
|
R. meliloti |
Melilotus, Medicago (Leucern), Trigonella (Fenugreek) |
|
Bradyrhizobium japonicum |
Glycine (Soybean) |
|
Bradyrhizobium sp |
Arachis (Ground nut), Cajanus (Pigeon pea), Cicer (Chick pea), Sesbania |
- Efficacy of Rhizobium in N fixation depends on various internal and external factors as;
a) Soil pH (Alkaline is favorable)
b) Availability of Ca and P
c) Temperature (>140C)
d) Soil aeration
e) Optimum moisture level (40-80% of FC)
f) Specificity of rhizobia strains to specific species.
