seed growth in given conditions.

"A horizontal mud shaft rotating at certain speed (say 60RPM) and a seed planted on its axis."

The plant would tend to stay on the axis of rotation.

"Or a mud sphere having universal motion and seed planted on its CG."

The C.G. of a sphere is at it's center. It will be confused and not know which way to turn!

If the conditions of your experiment are such that germination cannot occur, then your result might turn out inconclusive for any event. For one, the mention of "mud" muddies the experiment's design.

Plants can sense their environment.

A sunflower follows the sun. (a researcher said it senses the side of the heat on the stem)

It can sense temperatures.

A tree (like a pine) senses gravity. If it is forced out of balance there must be an imbalance of tension and the growth would be stimulated to correct the imbalance.

Roots can be trained to go to a specific depth by forcing the water table down.

Seeds like beans always direct the roots down and the plant up. Since there don't seem to be any other stimulus it must rely on gravity.

The capillary action of water in soils or in the plant may be a clue.

An experiment in space should be interesting. (Sphere with a blob of soil suspended at the centre)

Plants grown on a rotating turn table lean to the center as they grow. Seeds planted sideways, upside down or way too deep, still grow up. Plants must sense gravity It's their only way out of the dark soil.

Plants germinate and use gravity to position the root down and the cotyledon up. This is done by hormones in the tip of the root and the base of the cotyledon. Once light starts activating the chlorophyll certain hormones are trigger by different colors of light. This also can be a clock for flowering.

Some of the best manuals in common terms is Marijuana growers handbooks (I was surprised) Just don't leave them sitting out or someone may get the wrong idea about your interests.

here is a website that might help http://plantsinmotion.bio.indiana.edu/plantmotion/movements/tropism/tropisms.html

Brad

Well, I have placed tomato seeds in potting mix in my homebrew enclosure(an old fridge)- in all cases the the seeds grow towards the light(plants!)- the rate of growth is phenomenal- ie from seeds to 1" plant in 3 days- etc- the light/heat source is an incandescent bulb, thermostatically controlled to 25'C- with lag of 3'C- the bulb holder can be placed anywhere I desire- I find with several fermenters in place the best pos is at their base- thus the plants grow sideways towards the light- so I turn the plants every day - next day the plant is leaning the other way towards the light- this said, the plants do not have a high survival rate when planted in an outdoor garden- obviously, too conditioned to the fridge temp/light on /off rate- probably need hardening gradually- however gravity must be involved somehow- or could it be difference of voltage potential between base(soil/potting mix) & light energy?.

Plant seedlings have been grown in orbit by NASA (and presumably the Russians did likewise) for several decades. Suggest you do an online search for the results.

Hello friends thanks to all for your valuable inputs,

The experimental conditions I suggested are not the simulation of low gravity or no gravity likewise in the space, in the suggested conditions gravity and sunlight is very much there but it is rotating around the seed at a given speed, in a way we are trying to fool the seed.

I think germination will take place at a very low speed (say one revolution in 6hrs) that can be increased slowly to certain level once germination takes place, exact values can be different for different for different seeds,

fresh inputs are welocme.