the effects of rhizobium on soybean growth
THE EFFECTS OF RHIZOBIUM ON SOYBEAN GROWTH,The meaning of this experiment was to test the three hypotheses, when planted in a nitrogen poor soil, soybeans will grow larger if their roots are infected with the nitrogen fixing bacteria, Rhizobium. Also if planted in a nitrogen rich soil, soybeans will resist becoming infected by Rhizobium. Lastly, if planted in a nitrogen rich soil, than soybeans that do become infected by Rhizobium will grow less than those that are not infected. The most widespread of symbiotic relationships are those between the plant family Fabaceae and the bacterial genus Rhizobium. Rhizobium bacteria enter roots through the root hairs. The first nodules are formed on the primary root. The invading bacterium induces the formation known as an infection thread. The infection thread grows through the root hair cell, and into the cells root cortex. When the thread grows through the root cortex, bacteria are released, the bacteria are then enclosed by a portion of the plasma membrane surrounding the thread. The root nodules then begin to form. Root nodules are necessary for nitrogen fixation, without them nitrogen fixation cannot occur.
Finally the hypothesis, if planted in a nitrogen rich soil, soybeans that do become infected by Rhizobium will grow less than those that are not. The individual shoot weight of the plant planted in high nitrogen soil that was not treated with Rhizobium weighed 1. 2 the individual nodule number in the high nitrogen soil was 0 in the -H treatment, and 0 in the +H treatment. The class data did support the hypothesis. This is accomplished by the protein leghemoglobin, which has a high affinity for oxygen. Of the 27 plants 10 had grown nodules. This allows the anaerobic conditions to be maintained while the roots can still receive a supply of oxygen. Also four seeds were kept free of Rhizobium inoculation, these were carefully kept away from any contact with the dried Rhizobium. g nodule development, Rhizobium bacteria undergo morphological and physiological changes. After harvesting the shoots, the root nodules were harvested. From there they were taken down to the greenhouse, and were maintained by greenhouse staff for the following four weeks. 1, and a plant biology 102 assistant recorded the class data. Next the four uninfected seeds were planted, two in a high nitrogen soil without Rhizobium, these were labeled -H.
Common topics in this essay:
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Rhizobium Rhizobium,
Rhizobium Finally,
SOIL INTRODUCTION,
Rhizobium Lastly,
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People Environment,
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CITED Introduction,
Wi98 Plants,
Andrea Wi98,
Wolfe Andrea,
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