Study of the combination ability of variety populations of variegated alfalfa (Medicago varia l.) for successful selection in the conditions of the Middle Volga
The article presents results of the research work on assessment of the total combining ability of 14 varieties of variegated alfalfa (Medicago varia L.) of various ecological and geographical origin for identifying the best ones in terms of productivity in order to include them in the breeding process in the Middle Volga region. The study of the original varieties and their hybrid forms was carried out in a field experiment of 2012 sowing year with a three-year usage of the herbage (2013-2015). The characteristics of the varieties are given according to the main morpho-biological characteristics (the intensity of early spring growth, the height of plants at cutting ripeness stage) and economically significant parameters (content of green phytomass, leafiness, seed yield) in comparison with the traditional zoned variety Kuibyshevskaya. According to the green mass yield, the following were identified: KSI24, Population 8, KSI Super, KSI13, characterized by an average value of total combining ability (104.2 -101.9%); Population 4, Izumruda and KSI T /Z provided reliably high productivity for 3 years of grass stand usage (14.0 -16.0 kg / m2), with a high total combining ability effect (108.0-123.5%). According to the seed yield, the most productive varieties with a high total combining ability were identified: Population 2 (113.5%), Population 7 (111.8%), Gyuzel SP 03 (110.8%), Population 4 (109.8%), KSI T/Z (107.3%), KSI 24 (105.6%), KM population (105.1%). According to the results of the study, such varieties of variegated alfalfa as KSI T/Z, KSI 24, KSI 13, Gyuzel SP 03 were included as components of new polycross populations for further breeding work. Currently, these populations are undergoing selection formation in plots of biotypic selection on a field provocative background.