Response to Selection for Winter Survival and Yield in Different Populations of Synthetic Hexaploid Wheats (Triticum dicoccum/Aegilops tauschii)

Pureline selection was applied in Synthetic Hexaploid Wheat populations (SHW), obtained from irradiated seeds with ۱۵۰ Gy gamma rays and compared with their corresponding controls. The selection was performed in progenies of ۲۰ initial plants from three amphiploids (۸ from SHW۳۲, ۴ - SHW۱۰۶ and ۸ - SHW۱۰۷) generating ۱۹ M۱-۳ and ۱۹ C۲-۵ lines. Two families did not survive winter in the first year. All selected lines expressed high germination, intermediate type of growth in winter and good seed set in the field conditions. The irradiation of seeds did not influence the germination and winter survival of the SHW plants. The response to direct selection was based on the mean performance of progenies for grain number and kernel weight per main spike and the selected elite plants in M۳ and C۴-۵ generations. The coefficient of heritability and genetic advance for these traits were highest in SHW۱۰۶, followed by SHW۳۲. SHW۱۰۷ displayed the largest morphological variability and sterility during the investigated period. All synthetics formed long, but sparse ears with seed fertility being lower than their tetraploid parents, but elite plants of SHW۳۲ and ۱۰۶ were equaled to tetraploid parent No ۴۵۴۳۲ on grain weight per major spike in ۲۰۱۳. Seed irradiation with ۱۵۰ Gy gamma rays did not cause any effects on the two investigated traits. The selected subset of ۱۰ lines from the three amphiploids represents a source of spike productivity for use in wheat breeding programs to enhance yield potential.

Keywords:

Field emergence , Genetic parameters , Irradiation , Synthetic hexaploid wheat , Winter survival