Effect of temperature on sex expression in onion (Allium cepa L.).

At the onset of bolting, eleven populations of the variety Wolska were placed in the greenhouse at constant temperatures of 14, 17, 20 or 23 deg C. The percentage of male-fertile plants increased with increasing temperature, the critical temperature appearing to be 17 deg C. The transference of plants from outside to a constant temperature of 14 deg C, three or six weeks after the initiation of bolting, showed the effect of temperature to decrease with time, suggesting that induction of male sterility occurs in the early stages of bolting. Observations on an unspecified number of A and B lines of the variety Rijnsburg at 14, 20 and 23 deg C indicated that instability of sex expression occurs only in B lines. (Abstract retrieved from CAB Abstracts by CABI’s permission