Submitted to: Southern Nursery Association Research Conference
Publication Type: Proceedings
Publication Acceptance Date: January 19, 2009
Publication Date: May 8, 2009
Citation: Sakhanokho, H.F. 2009. Storage and Viability of Hedychium Pollen. Southern Nursery Association Research Conference, 54:361-364. Interpretive Summary: Hedychium (ornamental gingers) species generally flower in the summer and fall, but some bloom in winter and spring times. Since the flowering times of these plants are not synchronized, there is a need to find a way for storing and conserving viable pollen that can be later used for hybridization. The maintenance of pollen viability depends on several factors, including variety, temperature and storage duration. In vitro germination is a quick and dependable method used for testing the viability of stored pollen. An in vitro pollen germination method was developed using the “hanging drop technique”. Overall, this method was very effective in germinating Hedychium pollens, but the germination rate varied depending on the variety used. The effect of storage temperature (4 0C or 39.2 F and -20 0C or -4 0F) and duration (0, 1, and 3 months) on pollen germination was also evaluated for Hedychium forrestii. The results showed that Hedychium forrestii pollen grains can remain viable for at least three months when stored at -20 0C (-4 0F).
Technical Abstract: Hedychium species generally flower in the summer and fall, but some bloom in winter and spring times. The different flowering times of the species implies that there is a need to find a way for storing and conserving viable pollen. The maintenance of pollen viability depends on several factors, including genotype, temperature and storage duration. In vitro germination is a quick and dependable method used for testing pollen viability. The hanging drop technique was employed following using a liquid medium containing 1.2 M sucrose, 0.42 g/l calcium nitrate, 0.20 g/l boric acid, 0.1 g/l potassium nitrate, and 0.22 g/l magnesium sulfate. The effect of storage temperature (4 0C and -20 0C) and duration (0, 1, and 3 months) on pollen germination was evaluated for H. forrestii. The effect of genotype on in vitro pollen germination was also assessed for 9 Hedychium species and cultivars. For H. forrestii pollen grains germination rate was highest (88.5%) for freshly processed pollen and lowest (1.2%) for pollen grains stored for three months at 4 0C. Both storage temperature and duration affected germination rate. Compared to that of the control (88.5%), viability of pollen grains stored at 4 0C for one and three months decreased about 82 and 87 percentage points, respectively. On the other hand, a high germination rate (74.8%) was obtained when pollen grains were stored at -20 0C for one month. This viability dropped about 59 percentage points (74.8 to 16.2%) when pollen grains were stored at the same temperature for two additional months. These results show that Hedychium pollen grains can remain viable for at least three months when stored at -20 0C. Overall, the pollen germination medium used with the hanging drop technique was effective, but germination was sensitive to genotype, with rates ranging from 88.5% to only 11.2%.