1. This work aims to analyze the existence of both partner choice and plant sanctions in Medicago truncatula- Sinorhizobium meliloti symbiosis by performing split-root experiments with natural strains (Gubry-Rangin et al. 2010). Noë & Hammerstein (1994) described symbiosis as ‘biological market’ since the plants are able to exchange the nutrients with different species which will create the conflict. The strains with different fixation level in natural rhizobia populations were described by Miller & Sirois (1982) and Rangin et al. (2008). Bull & Rice (1991) and Simms & Taylor (2002) suggested that rhizobia symbiosis is likely explained by the partner choice model as the bacteria are not transmitted vertically between plant generations. In …show more content…
The bacterial fitness was then measured using different parameters including the number of nodules, biomass per nodule, and the number of rhizobia per nodule.
Figure Number What method(s) gave these data? What do these data show?
1(a) split-root experiment Measurements of aerial biomass obtained in the split-root experiment:
- The N2-fixing strain appears efficient in nitrogen fixation than non-fixing strain
1(b) split-root experiment Measurements of nodule number obtained in the split-root experiment:
- The nodule number was significantly higher in roots inoculated with the non-fixing strain than the N2-fixing strain. This supports the pre-infection partner selection.
- There are restrictions of nodule formation in the non-limiting side of the plant when one side of the plant is nitrogen deficient in order to maintain the optimal nitrogen content.
1(c) split-root experiment Measurements of nodule biomass per nodule obtained in the split-root experiment:
- The biomass per nodule significantly higher for the N2-fixing strain compared with the non-fixing strain
- The mean biomass per nodule was higher in the N2-fixing strain which indicates that M. truncatula plants might be able to limit the nodule development of inefficient strain in order to avoid wasting resources.
- In the mixed treatment, a significantly higher biomass per nodule was measured for the N2-fixing strain than the
might affect the fitness of each variant. In other words which factors might increase plant growth, survival,
Nitrate reduction was tested for by inoculating a nitrate broth with the unknown gram (-) culture, and allowing growth to take place. Adding 2 drops of both sulfanilic acid and α-napththylamine to the medium if the first test to see if nitrite is present. If nitrite is present, the medium turns red, indicating a positive test. However, if the medium does not change, a second test is performed to see if nitrite was further reduced. In this second test, zinc powder is added to the broth to catalyze the reduction of any nitrate present to nitrite. If nitrate is present when the zinc is added the reduction of this compound will cause the medium to turn red, from the previously added reagents. Red medium on the second addition indicates nitrate was not reduced and a negative test result. However, if the medium does not change after the addition of the zinc, the unknown is positive for nitrate reduction, as the nitrite has just been further reduced, preventing its detection. The result that yielded was positive on the first step.
Abstract: Many people use enrichment to grow cultures for mutant colonies. In this specific experiment we selected to kill the non-auxotrophic cells and find any auxotrophs that did not die during an enrichment process. We
This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate student’s writing of lab reports by providing this information in an editable file which can be sent to an instructor.
By using three different treatments, a full complement of nutrient, a full complement without the most important nutrient, Nitrogen and a full complement of Phosphorus, the length of the root and shoot and the biomass are observed and analyzed. If nitrogen was deprived from the rye seedlings growth process then the biomass, shoot length and root length will be affected more than depriving the rye seedlings from phosphorus. The null hypothesis would be, if rye was deprived the nutrient phosphorus, then it would have a larger effect on the rye seedlings shoot length, root length, and biomass than depriving the plant from nitrogen.
Table 1 shows the results of our measurements for each of the three weeks. As seen in the table, the shortest plant measured for the control grew a total of 7.5 cm over the course of seven weeks. Meanwhile, the shortest plant measured for the SUPERthrive grew a total of 6.85 cm. The tallest plant measured for the control group grew 10.5 cm, while the tallest plant measured for the SUPERthrive group grew 8.5 cm. Figure 1 shows each of the heights for all three weeks. There is little change between each group. Figure 2 shows the average change in height for each group. The SUPERthrive group had an average of 4.5 cm change in growth while the control group had an average change of 3.83 cm over the seven weeks. Figure 2 was taken
Parasitic or Mutual Symbiotic Relationship? Author: Natasha Patel. Lab Partner: Ariana Crolene. Mira Costa College 3333 Manchester Ave Cardiff, CA 92007.
The effect of Gibberellins on dwarf and normal peas was studied under laboratory conditions in order to gain a better understanding of plant hormones. Problem: determine how the plant hormone Gibberellins affects on steam elongation and to measure the effect of this hormone on growth.
According to a study, an experiment was done over the course of six years on the growth, needle, carbon, and nitrogen, chlorophyll, and
All the graphs inform shows how long does the bacteria takes to grow.The best time to induce the bacteria is in Log phases since in this phrase the bacteria is growing and reproducing the stronger, as a result, the O.D will be 0.6 at time point six which is shown at the time point and light coming through the (o.d) graph. The plates chart indicates how many colonies of bacteria are in the triplicate plates of 10^-4, 10^-5, 10^-6, and
The results showed There was a preference in treatment on the species Trifulium spp. (χ2 = 205.20; p = 2.19x10-42; df = 2). The same result was observed for the species Raphanus spp. (X2=497.80;p=4.50x10-139;df=2) An analysis of variances was performed on the data in order to identify where was the significant variation on the respective shoot lengths of both species. Results showed that there was no significant variance in neither of the species between the shoot’s length and the treatments used. (Table 2) The same analysis was also done for the root’s length of both species. Results demonstrated that there was at least one significant difference between the three treatments and root’s length in both types of plants. It was found in clover root’s length that a comparison of the control group and Rhizobium treatment on clover root’s length were no significant different from each other (Tukey HSD: p>0.05). There was a significant difference when comparing all other types of techniques used (Tukey HSD: p<0.05). In radish root’s lengths the results showed that there was a significant difference when comparing the Urea technique against the Control group (Tukey HSD: p<0.05). There was no significant difference on the other two comparisons (Tukey HSD:
From the SBA plate, get a well formed isolated colony in order to perform gram stain technique for it. After gram staining observe and jot down
There are many phases in the nitrogen cycle where bacteria is helpful to move along a phase or process that takes place. Like Rhizobium is a bacterium that helps in aid the nitrogen fixation phase. Rhizobium is a small heterotrophic soil bacteria capable of forming symbiotic nodules on the roots of leguminous (seeds of plants or fruits) plants and become bacteria that fixes atmospheric nitrogen (Merriam Webster). It has rod shape (bacillus) bacteria that forms staph colonies. They are motile, so they can move. Rhizobium, is an aerobic bacterium, therefore it must have oxygen to grow into colonies. It grows best at 25 degrees Celsius or 77 degrees F. Basically, rhizobium turns the free nitrogen air into ammonia and nitrate for plant assimilation.
Unknown 52 was initially grown in a Tryptic Soy Agar (TSA) plate, which is an undefined medium where the exact composition of the nutrient was not known. TSA plate was incubated for 24 hours at 35 oC which showed isolated colonies that were small, white, flat smooth margins, round, shiny colonies on the medium (1).
is a risk of dehydration. Isolation of nitrogen entails the loss of water. It is assumed that the loss of