Variation of Pollen Viability and Storability in Asparagus (Asparagus officinalis L.) Cultivars

The optimal culture condition for evaluating pollen viability of asparagus was studied. Sucrose was an effective constituent of the media for raising pollen germination rate. The medium containing 30% sucrose, 0.01% borate and 3% agar was found to be optimum for assessing pollen viability. Effects of temperature and light conditions during in vitro culture on pollen germination rate were not recognized in the range of 20-30 °C in this investigation. Varietal difference of pollen viability and storability was also investigated. Pollen germination rate was varied individually within each diploid cultivar, whereas it was uniformly low in triploid cultivar 'Hiroshima Green'. Average percentage of pollen germination in each diploid cultivar was approximately the same, and it was higher than in triploid 'Hiroshima Green'. Pollen viability declined to 0% after storage for three months at 25 °C. Optimum storage temperature, at which pollen viability could be maintained after 12 months storage, was either -20 or -40 °C.