Dear Apoorva .. pH's of culture media are usually adjusted in a range between 5.4 and 5.8, as you have mentioned. In this range, most of plants and protocols are developed quite well. Nutrition of explants, as well as in vitro outputs, depends on the pH of culture media. pH is an important and variable chemical property of culture media. Besides nutritional aspects, you must also to consider that regardless in vitro culture is a potential stressful condition, in vitro cultured explants could reach an homeostatic equilibrium. If this equilibrium is altered, several disorder might arise, as endophytic "releasing". However, why not use pHs out of this range? You can try, and assess the results. Good luck!!!!!

The pH of the medium is adjusted/suggested in between 5.5–6.0.

The uptake of nutrients is good at that particular pH.

It may differ also. For e.g. apple tissue culture a range of medium pH (5.5–7.5) also works. Studies shown it is not necessary to adjust pH for apple.

Medium pH between 5.5 and 7.5 has Minimal Effects on Tissue Culture of Apple.

Xiaoxin Shi and Lili Yang.

HORTSCIENCE 52(3):475–478. 2017. doi: 10.21273/HORTSCI11443-16

If the ph is lower than 5, proper gelling of the medium will not take place, while u will have hard medium when ph is more than 6.For proper gelling of the agar solified medium , ph range of the medium should be kept at the mentioned range.

Hope this may help you.

As it has been mentioned the pH is adjusted to 5.8 to optimize nutrient absorption, since optimum level of most of the nutrients are available to the plants at this pH. In addition, at low and high pH the consistency of the medium is affected. The attachment is a summary and can be found in many plant physiology or soil books.

Dear Apoorva:

Optimized environment for minor and major minerals and also agar activity is PH= 5.8.

So, if you set another you will have new treatment in your job.

Best wishes

As mentioned already by the RG members following this thread, pH influences the availability and uptake of nutrients and plant roots' growth.

I actually experimented on this. I left the pH unadjusted. I just prepared the media and without adjusting it to 5.8 I tried to grow Arabidopsis. The seeds didnt grow at all they became white and died. The media was far too acidic for growth. The agar seemed pale and it did solidify, there was no issue with the consistency of the media, but your plant won't grow. I had taken a pic too, if you want I can find the picture and send it to you for reference.

Basically, when your pH is more than 6, the nutrients that are in the solution will precipitate, and their will be lost from plants reach. When the solution pH is lower/acidic, basically the plant roots will not grow. At the same time, at a lower pH, the nutrients will not remain in the solution but concentrate at the base of the vessel, making the concentration armful to the plants.

We also use gelrite. And there the proper pH is essential.

Hi Folks,

< pH's of culture media are usually adjusted in a range between 5.4 and 5.8, as you have mentioned. >; < pH is adjusted to 5.8 to optimize nutrient absorption...>;

5.4-5.8 is the adjusted pH value *before autoclaving*. The pH value change after autoclaving. Have you ever measured the pH value after autoclaving? You should do that for your future reference. The pH value changed significantly after autoclaving.

See this paper:

Stability of tissue culture medium pH as a function of autoclaving, time, and cultured plant materialArticle Stability of tissue culture medium pH as a function of autoc...