Abstract:
In vitro pollen germination provides a novel approach and strategy to accelerate genetic
improvement of tree breeding. Studies about pollen germination and tube growth of Chinese fir are
limited. Therefore, this study aimed to investigate the effects of sucrose, boric acid, pH, and time
of incubation on pollen germination and tube growth. Pollen from 9 clones were selected. In vitro
germination was performed in basic media as control, and in different concentrations of sucrose
(0, 10 and 15%), boric acid (0.01, 0.1 and 0.2%), and pH levels (4.5, 5 and 7). Pollen germination
rates and tube growth were recorded periodically at 1, 12, 24, and 48 h. The results showed that
sucrose imposes significant effects on pollen germination and tube growth. The effects are most
obvious at concentration of 15%. Boric acid significantly promoted germination and tube growth.
The promotion was most notable in lower concentration of 0.01%. The media adjusted to pH 7.0
boosted the germination and pollen tube growth. The optimum time of incubation was 24 and
48 h for pollen germination and tube growth, respectively. Sucrose, pH, and time of incubation
were positively correlated, whereas boric acid negatively correlated with pollen germination and
tube growth. This study provided experimental evidences for selecting viable pollens for Chinese
fir breeding.
