Overcoming Self-Incompatibility of Brassica napus by Salt (NaC1) Spray

The results of studies from 1982 to 1989 confirm that self-incompatibility (SI) of B. napus can be effectively overcome by spraying solutions of 2 — 10 % table salt (NaCl) during the flowering period. The optimum salt concentration was found to be 5 %. Spraying onto both stigma and stamen is better than onto only one of them, in particular better than spraying only onto the stamen. When self-pollination occurred at intervals of 1 to 32 hours after spraying 5 % NaCl solution upon stigma and stamen, the compatibility indexes fall slightly; they decrease considerably after 72 and 120 hours, but still then they stay higher than without spraying. After spraying 5 % NaCl solution at intervals of 4, 5, 8 and 24 hours, respectively, the compatibility indexes after self-pollination are almost equal to that of bud-pollination; this treatment is effective even at intervals of 48 or 72 hours after selfing. In practice, spraying 5 % NaCl solution every 3 to 5 days during the flowering period is enough for satisfying seed set of SI lines under field conditions.