Sporogenesis in F1 hybrids from the crosses between common wheat and lines with introgressions from Amblyopyrum muticum

Abstract

Hybridization of wheat lines comprising fragments of alien genetic material (introgression) with common wheat cultivars is effective and widespread means of transferring alien genes into genomes of modern wheat cultivars, and remains the main method of expending genetic pool of common wheat using genes of wild relatives. Success of such transfer depends on the processes of sporo- and gametogenesis in F1 hybrids, therefore cytological assessment of this processes is obligatory. Stages of meiosis and microgametogenesis were studied on cytological preparations of spikes of F1 hybrids from reciprocal crosses of common wheat cultivars and wheat lines of introgression origin with alien genetic material from wheat wild relative Amblyopyrum muticum. Sporogenesis in F1 hybrids occurs with disorders in both male and female sexual areas. Instead of 21 closed bivalents chromosome configurations in maximal association of chromosomes in M1 PMC could contain up to 8 open bivalents, up to 12 univalents, including three- and quadrivalents. In A1 lagging chromatids were observed, and up to 5 micronuclei per cell were registered in tetrads. Quantitative characteristics of chromosome associations in M1 PMC did not differ for hybrids obtained using introgression lines as female (direct crossing) and male (reverse crossing) cross components. The difference between reciprocal crosses was detected only for the quantity of cells in tetrads with different quantity of micronuclei. F1 hybrids from direct crosses had smaller portion of cells without micronuclei, and more cells with 1-3 micronuclei compared to hybrids of reverse crosses.