Evaluation of genetic components and combining ability for spike length in winter six-rowed barley under conditions of Forest-Steppe of Ukraine

Abstract

Purpose. To reveal plant breeding and genetic characte­ristics of winter six-row barley varieties by spike length and to identify effective sources of high combining ability under conditions of the Forest-Steppe of Ukraine. Methods. The research was carried out at the V. M. Remeslo Myronivka Institute of Wheat of NAAS in 2012/13–2014/15 on winter six-rowed barley varieties ‘Paladin Myronivskyi’, ‘Zherar’, ‘Selena Star’, ‘Strimkyi’, ‘Cartel’, ‘Existens’, ‘Cinderella’ as well as on F 1 derived from crossing them at complete diallel scheme (7´7). Analysis of variance, combining ability and genetic parameters were calculated in accordance to conventional methods (B. A. Dospekhov, 1985; M. A. Fedin et al., 1980). Results. The significant differences in spike length were revealed, which allowed to estimate combining ability and to calculate parameters of genetic variation. The high effects of general combining ability (GCA) were peculiar to the ‘Strimkyi’ (g i = 0.64–0.76) and ‘Paladin Myronivskyi’ (g i = 0.34–0.53) varieties along the years. Positive GCA effects of middle and of high levels were marked for the variety ‘Existens’ (g i = 0.07–0.23). Graphical analysis and parameters of genetic variation showed the presence of intra-locus overdominance in 2012/13 ( = 1.16) and partial dominance in 2013/14 ( = 0.69) and in 2014/15 ( = 0.82). Significant expression of epistasis was not detected. During the years, dominance was directed on external traits increasing and was under control of dominant alleles (effects). Conclusions. Breeding and genetic traits of spike length of winter barley varieties in scheme of complete diallel crosses were revealed for the first time under the conditions of the Forest-Steppe zone of Ukraine. The variations in genetic control of the trait from overdominance in dry 2012/13 to the partial dominance in wet 2013/14 and 2014/15 were revealed. ‘Strimkyi’, ‘Paladin Myronivskyi’, ‘Existens’ varieties were identified with increased GCA for spike length. These varieties have high value in breeding.