Analysis of F_3 and F_4 hybrids of the crosses 6x triticale x 6x tritordeum with primary tetraploids

摘要

F_3 plants of the combinations 111, 112 and 113 as well as F_4 plants of 111 and 113 were estimated. The F_3 hybrids yielded spikes of three types: spindle-shaped, shorter and wider, subcompactoid. In the next generation such diversity occurred only in combination 111. The F_3 plants with spindle-shaped spikes had long spike of high number of spikelets and florets and very low grain number. The subcompactoid spikes were of middle length (7-8 cm) with 28-30 spikelets most of the latter being highly sterile. The hybrids of shorter and wider spike were of good fertility. Considerable increase in grain mean number was recorded in F_4 plants with spindle-shaped spikes. The hybrids in that generation manifested high cytological stability. The sterility of the plants with shorter and wider and subcompactoid spikes is probably due to the small number of dividing pollen mother cells and limited production of pollen grains, as well as to the influence of high temperature on pollination and fertilization. The percentage of cells with 14 bivalents in the metaphase first in the spindle shaped spikes reached 76%, whilst in the F_4 spikes of the other types it was about 55%