Selection of Rhizobium strains as inoculants
The first characteristic of importance in choosing strains of Rhizobium is their capacity to fix nitrogen, and selection for this trait is widespread. Also well known is the need to have isolates that compete with other strains of the same species, and such selections are routinely made in research or commercial practices. Not well recognized is the need for obtaining root-nodule bacteria that are able to overcome ecological constraints that limit their survival on seeds or their survival and growth in soil and the root zone. A major stress is drying, and strains can be selected that are resistant to water loss both in soil and on seeds. Acid and temperature extremes may also be of significance, and methods are available to screen and often to select strains resistant to these two abiotic stresses. In some soils salinity and alkalinity may be major stresses, but often these stresses are exerted more on the plant than on the bacteria; nevertheless, rhizobia can be selected that withstand these deleterious factors. In many farming systems, fungicides are applied to seeds for control of plant pathogens, and strains can be selected or techniques can be devised to protect the rhizobia from the deleterious effects of these chemicals. In addition, rhizobia are often susceptible to predation by protozoa in the rhizosphere and they are poor competitors with the more fast growing bacteria in this zone, and techniques will be suggested by which these significant biological stresses may be minimized
| Main Authors: | , , , , |
|---|---|
| Format: | biblioteca |
| Published: |
San José (Costa Rica)
1985
|
| Subjects: | RHIZOBIUM, FIJACION DEL NITROGENO, SELECCION, INOCULACION, |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|