Variability of the main breeding traits of sorgo CMS lines depending on the weather conditions of the Saratov region

Abstract

Determining the nature of the interaction between the genotype and the environment is one of the critical stages of breeding practice for selecting effective parental forms of hybrids of the first generation of sorghum and their stable seed reproduction in the arid conditions of the Saratov region. The contribution of regulated and unregulated factors to the overall variability of a trait can be determined using a two-factor analysis of variance used in this work. The research objects were 11 sterile lines of grain sorghum grown on the experimental field of the Federal State Budgetary Research Institution RosRISM (Russian Research Institute of Sorghum and Maize) “Rossorgo” during 2009–2018. The meteorological conditions of plant cultivation varied significantly: in 2013 and 2017, they were characterised as sufficiently humid (Hydrothermal coefficient - HTC = 0.98–1.01), 2011 – acutely dry (HTC = 0.26), other years – dry (HTC = 0.45–0.68). As a result of the tests, it was found that the CMS lines differed in economically valuable traits. The sterile line A1 Efremovskoe 2 should be classified as tall (131.2 cm) and more productive (4.41 t/ha of seeds) with a well-developed leaf apparatus (the area of the giant leaf is 238.0 cm2). Low-growing CMS lines M35 and 9E Pishchevoe 614 (94.9–98.5 cm) were distinguished by the protrusion of the inflorescence stem - 21.6 cm, and A3, A4 and 9E Zheltozernoe 10 (109.8–110.2 cm) - with a long leaf (50.7–51.5 cm). Medium-sized lines A2 Vostorga and A4 KP 70 had a long inflorescence (23.0–24.5 cm), while A3 Feterita 14 had a short inflorescence (13.7 cm). It was found that the genotype (41.4–61.6%) had a more substantial effect on the overall variability of plant height, length and protrusion of the stem of the inflorescence, and leaf length, while the environmental factor had a more substantial effect on seed yield (55.3%).