Inheritance of powdery mildew resistance in Aurotica’s introgressive lines

Abstract

Aim. Frequency of alien chromatin inheritance in hybrids from crosses of common wheat and introgressive lines determines whether transfer of alien chromatin controlling desirable trait into common wheat genome would be successful. The paper presents results of introgressive lines assessment for frequency of transfer of alien dominant trait of powdery mildew resistance to their progeny in the crossing with recurrent genotype Aurora, which was a recipient cultivar in the development of these lines. Methods. Artificial hybridization of introgressive lines with common wheat, visual assessment of cross components and hybrids F1 and F2 for powdery mildew resistance. Determination of chromosome numbers and chromosome configurations in meiosis M1 of F1 plants. Results. Among F2 plants, from the crossing of resistant to powdery mildew introgressive lines of Aurotica and susceptible cultivar Aurora excess of susceptible plants was observed. In order to explain distortion of ratio susceptible : resistant plants in comparison with expected for monogenic segregation, we propose the determined fact of absence in meiosis M1 of MPC of bivalent chromosome conjugation, which results in formation of aneuploid gametes and zygotes with reduced viability. As the third parameter, the one that can influence the mentioned ratio, we propose d parameter, which quantitatively expresses excess of gametes without alien chromatin controlling resistance to powdery mildew. Conclusion. Model of inheritance, which best explains experimental data of F2 plants segregation for resistant and susceptible if the trait is controlled by one dominant gene, takes into account the following conditions for calculation of probabilities of resistant or susceptible plant formation: all female and only euploid male gametes function, nullisomic zygotes are not viable, during meiosis elimination of meiosis products with alien chromatin occurs with parameter d = 0,11–0,12.Received 11.06.2018