Abstract:
Cryopreservation of pollen offers a simple and effective method of
long-term pollen storage. Pollen may be stored in liquid nitrogen (LN)
for many years without loss of its essential capabilities to pollinate,
fertilize, and set normal fruit and seed when used in plant breeding,
for controlled pollinations, or for the conservation of plant genetic
resources. Pollen of Corylus, Fragaria, Pyrus, Rubus and Vaccinium was
frozen in LN either freshly collected, air dried, or after equilibration
with atmospheres of 0, 20, 40, 60, 80, 90, or 100% relative humidity.
Survival was assayed by in vitro germination on a sucrose-agar medium
and by controlled pollinations (in Corylus only). All pollen survived
freezing in LN provided the pollen moisture content was adjusted properly.
Pollen of the wind-pollinated genus Corylus was not tolerant of
desiccation and survived freezing at very high moisture content levels
relative to the insect-pollinated Rosaceae pollens which survived freezing
only when dried prior to their immersion in LN.
Guidelines are presented for the establishment of a pollen bank at
the National Clonal Germplasm Repository (NCGR) in Corvallis, using
cryopreservation for the long-term conservation of plant genetic resources.
