GENETICAL AND PHYSIOLOGICAL ANALYSIS OF PSEUDO- SELF-COMPATIBILITY IN PETUNIA HYBRIDA

Abstract

The genes participating in true or pseudo-self-compatibility of Petunia hybrida were analyzed. It was found that pseudo-compatibility is probably caused by polygenic system rather than S alleles, and that true self-compatibility is due to the change in S gene to S_f. Furthermore, the time needed for pollen-tube growth from stigma to ovary was examined in the plants showing various grades of compatibility. The result was that the lower the grade of compatibility, the slower was the growth rate.
It is supposed that in the style of self-incompatible plant exists certain substance named as S substance which suppresses pollen-tube growth of own pollen grains. The specificity of this S substance depends on S allele and its activity is probably controlled by polygene. Pseudo-compatibility may be brought about by lowered activity of the S substance and by increased vitality of pollen.