Quantitative assessment of oil palm pollen after 23 years of cryobanking

Cryopreservation of pollen grains is an effective means of conserving desired germplasm of crop plants. Cryoconserved pollen are expected to be long-lived and thus can be suitably retrieved to overcome hybridization constraints imposed by a variety of reasons. We ascertained the performance of oil palm pollen grains (Tenera hybrids) that were cryobanked 23 years ago using liquid nitrogen (-196 degrees C). Cryostored pollen were assessed for viability, in-vitro germinability and vigour. Our analysis showed a marginal decline in viability, assessed through fluorochromatic reaction test, of cryopreserved pollen as compared to fresh ones (pre-storage assessment); however, the viability did not decline in the cryostate since it was last tested 15 years back. On the other hand, germinability and vigour of cryopreserved pollen were maintained to the levels of fresh pollen. Our study, for the first time, demonstrates the amenability of pollen grains for cryopreservation of any plant species beyond a period of two decades in general, and that for oil palm in particular.