INFLUENCE OF A MUTANT PLASTOM ON THE EXPR ESSION OF MORPHOLOGICAL ANDPHYSIOLOGICAL TRAITS OF SUNFLOWER HYBRIDS

The role of the plastom, the nuclear genome, and their interaction in genetic control of morphological and physiological traits was studied in F1 hybrids produced by crossing several mutant plastom sunflower li nes. Traits related to seed productivity were controlled more effectiv ely by the plastom. The common habitus of the plants was mainly contro lled by the nuclear genome. The specific effects of mutant plastogenes on morphological and physiological traits were determined in differen t crossing combinations. Hybrids with identical nuclei exhibiting hete rosis caused by mutation differences in plastoms were selected. A modi fying effect of mutant plastom on the expression of nuclear genes is h ypothesited.