Selection in tetraploid rye

Abstract

A population of tetraploid spring rye was selected for high seed‐set and regular meiosis on the one hand, and for low seed‐set and irregular meiosis on the other. After four generations the euploid plants in the “high” and the “low” selection lines were compared with the euploid plants in the unselected population belonging to the same C‐generation. A significant positive correlation between meiotic regularity and seed‐set was found in the “high” population while in the “low” population the correlation was negative. In the unselected population none of the cytological features gave a significant correlation with seed‐set. Plant vigour, representing possible physiological factors, was demonstrated to interact in a supplementary manner with cytological factors in determining the level of seed‐set in plants of the unselected population. The relative importance of cytological factors and plant vigour in determining seed‐set was found to vary depending on the type of selection applied. This led to the conclusion that the genetical control of the cytological factors is independent from that of plant vigour.