[Greenhouse with a convex spherical planting surface as a prototype of space greenhouse and an instrument for studying the plant gravitropism].

IBMP has developed a technology and unit for cultivating self-opening crops on a convex planting surface illuminated by light-emitting diodes mounted on an external concentric panel ("Hemisphere"). The unit has a structure of two-member clinostat with semispherical plant growth chamber with a 600-mm diameter and a speed of from 1 to 10 revo about each axis; water potential in the root supply system is maintained at 1.0 +/- 0.45 KPa. Having the data of 1200 measurements in the growth chamber, PAR latitude and meridian gradients were determined which did not exceed 0.7 micromol/(m2 x s x cm) in the work area and differed from the radial gradient by order and, therefore, had a negligible contribution to the axial organs' deviation from the radial directions during laboratory tests. Maximal centrifugal acceleration was equal to 10(-10) of the acceleration of gravity and did not impact the gravitropic crop reactions in the growth chamber. Five 5-day tests with semidwarf wheat Triticum aestivum L., cult. Lada were performed in the "Hemisphere" growth chamber turned at different angles relative to the gravity vector. In immobile growth chamber plants inclination from the vertical was a function of the angle between the PAR gradient and vector and the gravity vector at the site of each seed. Crop rotation at 3 revo about the horizontal axis did not produce noteworthy plant inclination suggesting neutralization of the plant geotropic reactions. In all tests about 80% of the plants formed the first leaf and about 20% reached the coleoptiles phase. Morphometric differences in the tests were insignificant. On a balance, the tests showed that prototype of space greenhouse "Hemisphere" is fit to run laboratory investigations of the plant gravitropic reactions in both static and dynamic conditions.