ON THE VARIATION OF FERTILITY IN THE INBRED STRAINS OF RADISH (RAPHANUS SATIVUS VAR. RADICOLA)

Abstract

The article comprises the description of the results of four years studies of fertility (measured by the per cent setting of siliques and the number of seeds per silique) of inbred plants of five varieties of radish (Raphanus sativus var. radicola) and of cross-pollinated controls. It has been shown that the varieties studied are heterogeneous with respect to self-compatibility. The fertility of inbred plants differs from that of cross-pollinated plants of the same variety. In the inbred plants the fertility is much more variable. Al l the degrees of fertility from complete self-incompatibility to high fertility appear in the course of segregation. A correlation has been established between the fertility of the inbred and of the cross-pollinated plants of the same variety. Thus "Ledianaya sosulka" ("Icicle") and "Saxa", the most fertile varieties under the conditions of free cross-pollination proved to be the most self-compatible. "Virovsky beliy" (All-Union Institute of Plant Industry White), a less fertile variety, exhibited a considerable self-incompatibility. A general reduction of fertility was observed as the result of inbreeding common to all the varieties studied. A dependence of the results of inbreeding on the time of isolation has been demonstrated.