I did a lab biology project on seed germination and the results weren't as expected. pH 5 worked better than pH 6 or 7 which seemed weird because surely it would be too acidic. I've been trying to find an explanation as to why I got these results and I think, possibly, it's to do with the buffer solutions I used. What could be in the buffer solution which might give these results.
Also, a jelly-like layer became visible when water was added. I thought maybe it was from the absorption of water. But that's just a guess
Thanks in advance for any help!
To understand why pH 5 worked better for seed germination than pH 6 or 7, it's indeed important to consider the buffer solutions you used. Buffer solutions are used to maintain a stable pH, preventing significant changes in acidity or alkalinity. Typically, these solutions contain a weak acid and its conjugate base (or a weak base and its conjugate acid).
One possible explanation for pH 5 working better could be that the buffer solution at pH 5 effectively maintained a slightly acidic environment, which promotes seed germination for some species. Some seeds have specific pH requirements for optimal germination because their enzymes and biochemical processes function best under certain pH conditions.
On the other hand, the buffer solutions at pH 6 and 7 might have caused the environment to become too alkaline for the seeds. This alkaline condition could have limited the activity of enzymes necessary for seed germination, thereby reducing the germination rate compared to the slightly acidic pH 5.
It's important to note that different plant species have specific pH preferences for germination. Therefore, the optimal pH for seed germination can vary from species to species. Understanding the pH requirements of the species you were working with can help explain the results you obtained.
Regarding the jelly-like layer that became visible when water was added, your guess about it being related to water absorption is likely correct. Seeds have protective coverings such as seed coats that can absorb water and swell. This swelling often softens the seed coat, allowing the seed to germinate and the emerging root or shoot to break through. The jelly-like layer you observed could be a result of this swelling and softening process.
To further investigate the reasons for pH-related differences in your results and confirm the assumptions made about the buffer solutions and water absorption, it would be beneficial to review the literature on seed germination of the specific plant species you worked with. Additionally, conducting further experiments with different pH levels and buffer solutions would provide a more comprehensive understanding of the effects of pH on seed germination.