Effect Of Glucose-containing Monosaccharides On The Symbiotic Properties Of Soybean Nodule Bacteria And Plant Crop Formation
O.V. Kyrychenko, Yu.O. Khomenko, S.Ya. Kots
The symbiotic properties of soybean nodule bacteria, root nodules forming (nodulation ability), nitrogen-fixing activity and efficiency under the influence of monosaccharides (0.01 M glucose and N-acetyl-D-glucosamine) on rhizobium culture were investigated in greenhouse with sandy soils. Nodulation activity and efficiency was estimated by the number and weight of the nodules formed on the roots of plants; by the formation of vegetative mass and by the yield of soybean seeds. Nitrogenase activity was determined by acetylene-reductase method. The control variant was inoculated by monoculture of soybean rhizobium. A significant increase in the degree of realization of the nodulation ability of rhizobium has been established under the influence of glucose-containing monosaccharides on the culture of microorganisms. Adding glucose to bacteria led to increase the average number of nodules per plant by 1.6, 2.2, and 1.7 times respectively in the phase of development of two true leaves, flowering and active bean formation in soybean. At the same time the weight of the root nodules was increased by 1.4, 2.3, and 1.4 times respectively as compared to control. The number of root nodules was increased by 2.2, 2.3, and 1.4 times as compared to the control while of glucosamine was used; while the weight of these nodules were 2.1 and 1.9 times higher than control in the phase of development of two true leaves and flowering, while in the phase of active beans formation it did not differ from control.The functional activityof the soybean symbiotic system that was formed by rhizobial culture and modified by glucose, had the highest positive effect, since the nitrogen-fixing activity remained stable and was 2.1 and 1.7 times higher than control.Rhizobia, to suspension of which we added glucosamine, formed a symbiosis with activity that was 1.7 times higher than monoculture in the flowering phase, but later it was at the control level. We registered that inoculants on the basis of bacteria and glucose-containing monosaccharides activated seeds germination. The first true leaf of plants (up to 3.5 times higher than control), their above green mass (25-27% higher) and root system (10-16% higher) were actively formed while we used inoculant with rhizobia and glucose. Plants in the variant with the pre-sowing inoculation of seeds by bacteria and glucosamine almost did not differ from the control.The yield of soybean seeds significantly exceeded (up to 14%) the crop, produced by plants with inoculation by monoculture of rhizobia under the influence of glucose-containing monosaccharides. We indicated high efficiency of soybean-rhizobium symbiosis formed by nodule bacteria modified of glucose-containing monosaccharides. Thus, the use of glucose-containing monosaccherides as additional “green” and safe natural agents in complex inoculants with nodule soybean bacteria promotes a more complete implementation of the symbiotic and productive potential of soybean-rhizobial symbiosis compared with the use for seeds pre-sowing treatment only of rhizobia monoculture in greenhouse with sandy culture.