Badhepuri Mahesh Kumar, Generally the PGRs present in the medium are used to decide the height of the plants in vitro. More amount of cytokinins in the medium cause stunted growth while low concentrations can help to elongate the shoots.

Even the intensity of light also have effect on the growth of the shoots in vitro.

Badhepuri Mahesh Kumar, Growth regulators, light (wave length, intensity and photoperiod), temperature and the gas phase which develops above the culture system are responsible for it.

Thank You Mahipal Shekhawat Sir & M. Manokari madam for sharing valuable information

I will try to consider your suggestions and will design new strategy

Dear Badhepuri Mahesh Kumar,

On which plant species you are facing this problem? And also you have not mentioned the PGRs of the optimised media.

The PGRs effect on length of in vitro shoots varies from plant to plant but generally combination of cytokinins and auxins are reported to increase the length of internodal region and in turn shoot length.

Addition of GA3 (1-10micromolar), alone or in combination with optimised media, facilitates increase in shoot length.

Supplementing optimised media with AdSO4 has been reported in many species for elongation of shoots.

Another factor we have observed is-at the time of subcultured, if shoots are too small and separated from explant, it affects overall length of shoot. Similarly sometimes removal of explant and subculturing of shoots only will be beneficial, again depending on plant species but you can try if you have not done yet.

All the best.

Thank you Ashutosh Pathak Sir for sharing your valuable experience.

Plants name Alternanthera sps, Ctroton Sps, and Aristolochia were there.

I agree with you different plants will respond differently to the different combinations of hormones.

We do use AdSo4 in the medium.

Actually, I would like to know the generalized concept behind the invitro shoot length effect.

In fact, I have once tried GA3 medium also the results were not that much satisfying. I have to optimize that.

I would like to hear experts like you for better growth and development of the establishment of cultures

Thank you So much for your suggestions.

I think there is not generalized concept as I have also faced same problem where GA3 had not given effective results and AdSO4 did.

One more thing you can try is liquid cultures as it minimises the apical dominance and helps in elongation as well as multiplication of shoots.

Badhepuri Mahesh Kumar Add low amount of auxin (IBA or NAA) (0.01 to 0.2 mg/l) to the medium while you have a high amount of cytokinin.

Thank You Ashutosh Pathak Sir

I will try both AdSO4 and Liquide culture

Thank you

Thank you Sir Kourosh Vahdati

I am using both Cytokinins and Auxins in a low conc. the ratio 5/1 or 2.5/1