QTL mapping in hexaploid soft wheat (Triticum aestivum L.) in West-Siberian plain

Mapping of quantitative traits loci (QTL) is a modern approach to studying their genetic variability. In this, mapping QTL which determine the economically valuable traits and their effective use in the marker assisted selection are of practical interest. Here, we report evaluation of a set of 114 recombinant inbred lines of spring wheat ( Triticum aestivum L.) mapping population ITMI (International Triticeae Mapping Initiative) in the conditions of West-Siberian plain, Russia. The ITMI mapping population was obtained by crossing spring wheat Triticum aestivum L. cultivar Opata 85 with a synthetic hexaploid W7984, the amphidiploid which was produced by crossing Aegilops tauschii Coss. (DD) sample CIGM86.940 and tetraploid wheat T. turgidum var. durum cultivar Altar 84 (AABB). In total, 42 different economically valuable traits were evaluation during the vegetation period, and 55 quantitative trait loci were identified. The dependence fidelity between the identified loci and trait polymorphism was estimated based on the threshold of the likelihood ratio of LOD-score (logarithm of odds). For 35 identified QTL, LOD _ 3.0 was found. Identified QTL were dispersed on 19 linkage groups different chromosomes and expressed in environment conditions of southern forest-steppe zone of West-Siberian plain with varying certainty. It was shown that the manifestation of the identified QTL may be environmentally dependent or independent, and the investigated quantitative traits correlated and were interrelated. To determine the nature of the relationship between the evaluated traits, the correlation coefficients rxy were calculated. We revealed different correlations between expression of the evaluated economically valuable traits studied which stresses on the complex nature of their manifestation. It is established that the genetic variability of most of the traits evaluated is usually controlled by several QTL with broad effects which correlate with one another or by a large number of QTL with small effects. The detected QTL and linked molecular markers may be of interest for further study of the genetic control of economically valuable traits determined by identified QTL and for implementing marker-assisted selection in bread wheat.