Inheritance of Productive Tillering by Spring Barley Hybrids
The purpose of the research was to establish the nature of the inheritance of productive spring barley hybrids tillering in the system of diallel crosses. The experiments were conducted in the Krasnoyarsk forest-steppe of Eastern Siberia in 2015-2017. The soil was ordinary low-thick chernozem; the content of humus (by Tyurin) was 6.00%; of N-NO3 (by ionometric express method) - 31.3 mg/ kg of soil; P2O5 and K2O (by Machigin) - 5.00 mg/100 g of soil and 21.9 mg/100 g of soil, respectively; the reaction of the soil solution was neutral (pH 6.2). The forecrop was bare fallow. The agrometeorological conditions during vegetation periods in the years of the study were contrasting: 2015 was dry (the hydrothermal coefficient was 0.95); 2016 and 2017 were wet (the hydrothermal coefficient varied from 1.47 to 1.59). The experiment involved four parental components. The crossings were carried out according to the diallelic 4 x 4 scheme. The first generation (F1) had all the types of productive tillering inheritance - from depression to overdominance; half of the combinations showed true heterosis (Hp = -5.00 - 4.80). The feature under study was controlled by additively dominant genetic system with a predominance of recessive gene effects (F=-0.4 and -0.01 was less than 0). When Musson and Nutans 302 were included in crossings, the additive effects of genes played a predominant role in the inheritance pattern (sigma2gi was more than sigma2si). At the same time, hybrids of the first and second generations, created with the participation of the selection sample U-30-3624 and Malva variety, were noted the influence of dominant and possibly epistatic effects of genes (sigma2gi was less than sigma2si). Malva x Nuttans 302 and Malva x U-30-3624 hybrid combinations turned to be promising in breeding for the increase of productive tillering under the conditions of the Krasnoyarsk forest-steppe. Nutans 302 (Preria x Tan 1) variety was recommended as a donor to increase the productive tillering of barley (gi = 0.5256 and 0.2169).