Methodological aspects of analysis of new background traits in soybean

Two new methods of selection of highly productive soybean forms protected with patents of the Russian Federation were developed using new background traits diameter of a main stem and weight of a main stem piece which usage for soybean breeding was theoretically proved. These selection methods are based on a relation between breeding trait (weight of seeds from a plant) and background one. Plant traits vary under environmental impacts, so dependence of background traits estimations on environmental factors (especially of moistening and plant height) was studied. Results showed plants analysis under new background traits immediately after selection in field is inadmissible due to different water content of seeds and stem; this does not prove objectivity of estimations of these plant organs weights. Equation of all plant organs moistening can be reach after keeping the plants in bundles in dry heated rooms within two months. Therefore, after that objective estimation of background traits is possible. The research results refused a hypothesis that length of a main stem influence on estimations of diameter and piece weight of a low part of a stem. The new background traits diameter of a main stem and weight of a main stem piece can be used effectively at selection of potential productive soybean plants independently of their height being within limits of created cultivar models.