The Effect of Dye Tetrazolium in Predicting Seed Viability, Lab Report Example

Introduction

Agriculture is a major industry and it is important for farmers to ensure they can obtain the largest yield from their crops. One method, the use of dye tetrazolium, is widely used to determine whether the seed’s electron transport system is working, thereby indicating that the seed is viable. When tetrazolium is added to a seed, it will turn red or pink if it is able to accept hydrogen electrons; if the seed is dead, this process will not occur. We hypothesize that seeds that are boiled will be inactive and therefore not be dyed by tetrazolium. Proof of this concept is beneficial to farmers because they will not waste valuable time planting seeds that will not grow.

Materials and Methods

Seed viability was determined amongst groups of bean and corn seeds. Three seeds from each group were cut in half along their axis with a sharp razor blade. The embryo, endosperm, and seed coat of each seed was located and recorded. Several drops of TTC were placed into two petri dishes; corn seeds were placed into dish “A” and bean seeds were placed into dish “B”. The seed halves were then placed face down and immersed in TTC. After approximately 30 minutes, the seeds were removed from the petri dishes using forceps and observed for color. Color changes and lack thereof were recorded for each seed.

Data and Results

All of three out of three seeds in group A (corn seeds)turned a red color, while all three out of three of the seeds in group B (bean seeds) remained colorless.

Discussion and Conclusions

Since all three out of three seeds in group A, the corn seeds, turned red as a consequence of dye tetrazolium staining, we can conclude that these seeds are active because their electron transport system is working. Likewise, all three out of three seeds in group B, the bean seeds, remained colorless because they had been boiled. Therefore, the proteins required for enzymatic activity and electron transport were inactive.

This principle could be supported by repeating the experiment using cyanide. Cyanide blocks the electron transport chain, thereby inactivating the seed. It does so by using up all of the electrons. If cyanide is added to the corn seeds in group A, it is expected that they will remain colorless. If these same seeds were treated with dye tetrazolium after treatment with cyanide, it is also expected that they will remain colorless.

Originally, I believed that only the embryo would turn red after exposure to TTC. However, after completing this experiment I recognized that any area of the seed that requires the electron transport chain would be stained. No staining at all is seen in the boiled seeds because this process is deactivated.

This experiment is useful to determine which seeds are active and which are not, but it would be beneficial to repeat the experiment with additional seed types to confirm that this observation is true for every seed. Furthermore, a greater sample size should be used to ensure that all seeds, rather than just most, follow this trend. It is important to account for outliers in the data, and using a larger sample size will help determine whether this is the case. Ultimately, this additional application would be useful for farmers because it will prove that the use of dye tetrazolium staining is effective to determine the viability of seeds.

Works Cited

Activity 3: Respiration in Plant Embryos. N.D. Web. 30 June 2014.

How to Write an Informal Lab Report. N.D. Web. 30 June 2014.