INFLUENCE OF BIOLOGICAL ACTIVE SUBSTANCES ON THE PROLINE CONTENT OF SOYBEAN SORTS WITH VARIOUS RESISTANCES TO DROUGHT

Abstract

This paper examines the influence of two types of biologically active substances:
humate (LG) and salicylic acid (SA) on soybean cultivars with different response to the action of pedological
drought: Licurici, Colina, Horboveanca – sorts with medium resistant to drought, and Zodiac and S-4-04 – sorts
with increased resistant to drought. The SBA influence on soybean plantlets was studied at two moisture levels:
1) optimum – 70 % TCW (total capacity of water in soil) and 2) hydric stress – 35 % TCW. Under optimum condition
of cultivation the treatment with salicylic acid and humate determined the proline increased content in sorts more
sensitive to drought, while resistant sorts reduce its content in comparison with the witness cultivated in the
same conditions. On the hydric deficit background proline content increased significantly in the leaves of all sorts
studied, and administration of humate and salicylic acid led to an increase even more accentuated of osmoprotective
content compared to plants treated exogenously, but assured with water. Under stress conditions, sorts with higher
sensitivity to hydric deficit showed superior values of the parameter investigated, while resistant sorts had lower
values in comparison with the witness cultivated on the stress background and higher compared to the witness cultivated
under optimal moisture conditions. The most pronounced reductions attest for the sorts with high resistance to drought,
suggesting possible implications of the substances investigated in modulating cellular metabolism.