Effect of environmental temperatures on flower morphology and fertility alternation of male sterile line 160S of Brassica napus
Comparison on the flower morphologic and pollen fertility alteration of male sterile line 160S in Brassica napus under natural temperature conditions were conducted. The results showed that the temperature was the main factors to flower morphologic and pollen fertility alteration. Under male sterile conditions, the anthers of 160S were all smaller than the normal ones and the pollens were completely male sterile, the ratio of pollen stained with TTC solution were nearly 0 and the self-pollenated pod-setting ratio was only 1.2%. The anthers of 160S were all normal, and there were no difference with the anthers of those two normal lines under fertile condition. The percentage of fertile pollen stained with TTC solution and the self-pollenated pod-setting ratio were all above 80%. The percentage of pollen fertility and the self-pollenated pod-setting ratio of 160S decreased along with temperature rising, and the fertility transformation direction was fertile, part fertile and then complete sterile. The study showed that 160S showed complete male sterility above 25°C while it showed complete normal fertility below 18°C.