Flowering time in oil flax can be influenced by microgametophytic selection

The effect of selection for pollen competitive ability in F₁hybrids on days to flowering and some other morphological traits was studied in oil flax. Various intensity of selection on the rate of pollen tube growth was ensured by the change of the time intervals from pollination to the deletion of a part of the style. In the experimental variants the upper half of the style of F₁hybrids was cut off at 40, 60, and 120 minutes, in the control styles being native. It was shown that F₂ population structure essentialy changed for some morphological traits independence of competition intensity between the microgametophytes. The percentage of early flowering genotypes increased with shortening the period from pollination till style excision. In the treatment where styles were cut off 40 min after pollination the frequency of early flowering plants was highest while the frequency of those plants in 120 min treatment approached the control. Moreover, some treatments considerably influenced the phenotypic ratio in the F₂ population for such traits as petal colour and number of side shoots. It is concluded that a positive relationship exists between pollen competitive ability and early flowering in oil flax. The approach based on selection of fast growing pollen tubes that increases the frequency of early flowering plants could be used in oil flax breeding for early ripeness. This revised version was published online in July 2006 with corrections to the Cover Date.