Effects of incubation temperature on asparagus bud sprouting, abscisic acid content and sex
Dormancy in asparagus (Asparagus officinalis) spears depends on the growing temperature. It is crucial to understand the mechanism of the induction and break of dormancy related with bud sprouting of asparagus. During periods with low temperatures, the contents of several components; e.g. plant hormones in asparagus buds change and the plants acquire dormancy. Similarly, higher temperatures suppress sprouting. In this study, we investigated the effects of incubation temperatures on the sprouting rate of buds, growth of spears, ABA concentration and sex. During 22 days of low-temperature incubation, sprouting was not inhibited at 25°C, but it was almost inhibited at 16°C. The ABA concentrations of white bud clusters were higher at 16°C than at 25°C at the end of the incubation period, but they were not significantly different between male and female plants. The ABA concentrations were higher in brown than in white bud clusters, and they were similar among brown bud clusters at both 25 and 16°C. In the high-temperature incubation experiment, sprouting was slightly suppressed and growth rate of spears was significantly decreased at 38°C compared to those at 25°C. The ABA concentration of white bud clusters decreased gradually during the incubation at both 38 and 25°C, but that of brown bud clusters increased at both temperatures. Moreover, the ABA levels in both white and brown bud clusters from male plants fluctuated and they were higher compared to their levels in bud clusters from female plants. These results suggest that sprouting varied with the incubation temperature and may or may not be regulated by ABA.
Fukuda, M., Matsuo, S., Watanabe, S. and Uragami, A. (2018). Effects of incubation temperature on asparagus bud sprouting, abscisic acid content and sex. Acta Hortic. 1223, 151-158
dormancy, bud clusters, endogenous ABA concentrations, male and female plants