EFFECT OF ROOT EXOMETABOLITES OF WHEAT WITH DIFFERENT GENOME PLOIDY ON GROWTH OF AZOSPIRILLUM-BRASILENSE

The growth of Azospirillum brasilense Cd on root exometabolites of dip loid and hexaploid wheats was studied under model conditions in liquid culture. Quantitative and qualitative composition of the root exudate s was determined. Growth of azospirilla was shown to be more intense i n the rhizosphere of diploid wheats. However, the proportion of azospi rilla adsorbed on the root surface was found to be greater in hexaploi d varieties. The total number of bacteria calculated per the amount of carbon in the exometabolites was greater for diploid than for hexaplo id wheats. This was probably due to an increased content of organic ac ids and low concentrations of amino acids and carbohydrates in the exu dates of diploid wheat.