Breeding value of drought-resistant sterile sorghum lines

Abstract

Currently, breeders often use multidimensional statistics methods to process a large set of experimental data. To characterize the breeding value of 20 sorghum lines with cytoplasmic male sterility (CMS lines) under arid cultivation conditions, during the research there was applied a cluster analysis, allowing to group the lines into clusters according to similar indicators from 15 analyzed agronomic and physiological characteristics. The studies were carried out during 2019-2021, various in meteorological conditions: the hydrothermal coefficient was 0.59-0.84 during the vegetation period of plants. Cytoplasmic male sterility lines were sown at a density of 100 thousand plants per 1 hectare. Breeding and physiological traits were evaluated according to generally accepted methods. The assessment of agronomic and physiological characteristics was carried out according to generally accepted methods. For further practical work, based on the results of the conducted studies, four CMS lines of grain sorghum (clusters 2, 3, 5) were identified according to a complex of physiological and breeding characteristics. Sterile lines (A2 Vostorg, M35-1А Pischevoe 614, A3 Feterita 14 and A2 KVV 114) were distinguished by the highest seed yield of 3.02-3.50 t/ha, high water content (72.7-73.7 %) and water retention capacity of leaves (72.2-84.3 %), low water deficiency (6.5-8.7 %). The study of moisture loss during the natural wilting of leaves confirmed the high resistance to drought in the flowering phase of the sterile A2 KVV 114 line, in which the intensity of moisture loss after 1 hour was only 9.9 %, 1.5 h – 15.8 % and 24 h – 68.6 %. In breeding for increasing drought resistance the CMS-line A1 Efremovskoe 2 (the sixth cluster) should be noted, as it was inferior to the above-described lines only in terms of low water deficiency (16.5 %), indicating average drought resistance. The line is the tallest with large leaves (length – 46.7 cm, area – 163.8 cm2) and form 3.21 t/ha of seeds on average for the period presented. The use of the obtained data provides the increasing of the breeding process for the creation of productive drought-resistant F1 sorghum hybrids.