Combining ability of soft winter wheat varieties by plant traits in F1 hybrids in topcross system

Abstract

Combining ability of soft winter wheat varieties by quantitative features of plants in F₁ hybrids in the TopCross system was determined in the Laboratory of Winter Wheat Breeding and Physiology of the Plant Production Institute nd. a V.Ya. Yuryev of NAAS.

Purpose. To estimate the total (TCA) and specific (SCA) combining ability, the ratio of their variances in F₁ and, on this basis,  exceedence of additive or non-additive gene effects and prediction of selection efficiency by quantitative features of soft winter wheat varieties .

Material and Methods. The source material used in full topcrosses were 10 maternal varieties of different geographical origin (Zemlyachka, Melodiya, Bogemiya, Bunchuk, Analog, Yubilyar Mironovskiy, Yunona, Bogatka, Torrild, Zarnitsa) and four paternal varieties- testers of national breeding by the Plant Production Institute nd. a V.Ya. Yuryev of NAAS (Gordovyta, Doridna, Kharus, Alyans). Crossings were carried out in 2011 and 2012. F₁ was grown in 2012 and 2013. Plant productivity (grain weight) and its structural elements as well as other quantitative traits were analyzed in 50 plants. TCA, SCA and the ratio of variance on the grounds of traits in F₁ plants were determined by dispersion and genetic analyses, and, on this basis, the ratio of additive and non-additive gene effects for prediction of selection efficiency by plant traits was calculated.

Conclusions. Within two years (2012 and 2013) strong  effects of TCA by certain traits were found: in the variety Zarnitsa - by four traits; in Yunona - by three traits; in the varieties Melodiya, Analog, Bunchuk, Torrild - by one trait. These traits are determined by a large number of genes defining the level of their indices. Exceedence of the TCA variance values over the SCA variances was registered in the variety Zarnitsa - by three traits; in the varieties Yunona, Yubilyar Mironovskiy – by two traits; in the varieties Melodiya, Analog, Bogemiya, Bunchuk – by one trait. This means exceedence of  additive gene effects with greater efficiency of selection for them in these varieties. Strong and weak effects of SCA and accordingly more or less deviations of a trait value from the mean effect of TCA in parents were assessed.