Microorganisms

Introduction

Cytokinins are evident products of when bacteria are prevalent in inoculated lettuce plants with formation of Zea tin riboside as the most abundant cytokinins. Consequently, cytokinins are derived for plant use through symbiotic factors with the rhizosphere microorganisms. This implies that plants are not automated to manufacture their own cytokinins putting the requirement for derivation from the soil. Although the re is still some discrepancy on the ability of plants to produce their own cytokinins, there is believe that they manufacture part of these elements in automated systems from physiological processes (Royle, D. J., and C. J. Hickman,1963).

This implies that a plant cultured in a soil would lead to increased cytokinins from the interactions of the rhizosphere priming effect, while the conditions that determine prevalence of working of enzymes also affect the rate of this process (Chee & Newhook, I960). Depiction of this could be through growing lettuce plants in solutions cultured with the rhizosphere micro-organisms and a control experiment without these conditions. It is evident that the rhizosphere micro-organisms’ act as growth regulators since the hormonal influence is also a growth regulator. Moreover, treatment of seeds of these lettuce plants is essential to avoid suppressed growth due to pathogenic fungal attack. Comparison between the cultured solution and the control solution could give lead to ascertaining the role of bacteria in abundance of hormones and their consequent antifungal activity. In real essence, a culture solution containing Bacillus sp. in a fungal medium is essential in ascertaining inhibition of the pathogen causing micro-organisms, which in turn influence plant growth.

In this experiment, the lettuce seeds were used since they bear dicotyledons whose roots are capable of giving support to the nitrogen fixating bacteria. During germination of the lettuce seeds, there is formation of the root and the shoot. The root is made up of root nodules that give support to the nitrogen fixing bacteria. The essence of PGPR screening on the lettuce seeds in the experiment is to view existence of the nitrogen fixing bacteria and relate it to positive plant growth. Putting the seeds in a culture solution reduces the chances of infection by the culture solution having the phytophthora species, while the control experiment does not involve use of antifungal bacteria, which is expected to show a retard in plant growth (Chen & Zentmyer, 1969).

OBJECTIVES: To perform PGPR screening on lettuce and to characterize the list of beneficial isolated soil bacteria with antifungal activity.

SIGNIFICANCE: To identify microbes with bio-control properties in order to provide an alternative agricultural solution for the widespread use of pesticides in crops. Moreover, the research has emphasis on identification of microbes with effects on the direct growth lettuce as significance.