Assessment of the nature of inheritance of quantitative traits by F1 hybrids of soft spring wheat in the conditions of the CRNZ

Relevance. The selection of pairs for crossing is the main task of studying a collection of any crop. It is important to know which parental forms have high variety-forming ability. Therefore, the aim of our study was to study the nature of the inheritance of quantitative productivity traits by F1 hybrids of soft spring wheat and to identify the most promising combinations for further breeding work. Material and Methods. Intraspecific F1 hybrids and their parental forms of soft spring wheat were used as the material for the study. The original forms were comprehensively studied (including the index method) in collection nurseries in 2019-2021, differing in meteorological conditions. The most productive varieties were used as maternal forms, and forms with high resistance to diseases, lodging, and high grain quality were used as paternal forms. Based on each maternal form, a series of F1 hybrids of the topcross type were obtained. In F1 hybrids, the inheritance pattern of quantitative traits of the ear of soft spring wheat related to yield (number and weight of grains per ear, number of grains per ear, weight of 1000 grains) was analyzed and phenotypic dominance indices were calculated (according to Griffing), where depression corresponds to the value D < -1; recessive inheritance – at - 1 < D < -0.5; additive effect of genes – at -0.5 < D < 0.5; dominance – at 0.5 < D < 1; heterosis is observed at D - 1. The coefficient of true heterosis was calculated according to Omarov D.S. Results. It was found that approximately half of the studied hybrid combinations exhibit heterosis in the number of grains in the main spike (about 60%), about 30% of combinations exhibit heterosis in the number of grains in a spikelet, over 60 % – in the weight of grains from the main spike and about 80 % - in the weight of 1000 grains. This serves as indirect evidence of the effectiveness of the index method for selecting pairs for crossing. Promising combinations with a forecast of selection in subsequent generations of transgressive yield lines of spring wheat for CRHZ were identified. For the maternal form Zlata, the best combinations were obtained with pollinators MK No. 41, Sudarynya, Simbirtsit and MK No. 153; for Ekada 66 – Simbirtsit, Zlata; for Granni – Liza, Lada; for KVS Aquilon – AC Taber, Agata, AC Karma; for Ivolga - Granni.