[Epigenetic variability induced by nicotinic acid in Triticum aestivum L]

The effect of nicotinic acid (NA) on hereditary traits of spring common wheat cultivar Kazakhstanskaya 126 (K.126) were studied under the laboratory and field conditions. Treatment of seeds and vegetating plants with 0.01-0.1% NA (aqueous solution) induced heritable epigenetic changes in wheat. As a result, strong tall plants with the long productive spike, large seeds, and several quantitative and qualitative characters other than in the original cultivar were obtained in the second and further generations after treatment. Crosses of changed plants with each other did not result in segregation with respect to leaf downiness or anthocyan stem color in F2-F4, suggesting the same epigenetic state of genes responsible for changed characters. In crosses with the original cultivar, characters of the changed plants always dominated in F1. Basing on the current views, the changes were attributed to a transition of the hl1 and pc recessive marker genes into new, dominant epiallelic states Hl1 and Pc, which respectively determine downy leaves and the colored stem. The NA effect was specific, since only one type of the variation was observed. The changed characters were stable, and no reversion to the original phenotype was detected in 57 generations.